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HomeMy WebLinkAboutSupporting Documentation - Response to Comments - 06/19/2024 FINAL DRAINAGE REPORT FOR POLESTAR VILLAGE Prepared For: POLESTAR GARDEN, INC PO BOX 211582 FORT COLLINS, COLORADO 80521 Michael Gornik (808) 443-9956 June 19`h 2024 Project No. 39797.01 Prepared By: JR Engineering, LLC 2900 South College Avenue, Suite I A Fort Collins, CO 80525 i ii TABLE OF CONTENTS TABLEOF CONTENTS..............................................................................................................................ii APPENDIX ..........................................................................................................................................iii Engineer's Certification Block................................................................................................................ iii GENERAL DESCRIPTION AND LOCATION................................................................................................1 LOCATION...........................................................................................................................................1 DESCRIPTION OF PROPERTY...............................................................................................................1 MASTER DRAINAGE BASIN DESCRIPTION...........................................................................................1 FLOODPLAIN SUBMITTAL REQUIREMENTS........................................................................................2 DRAINAGE BASINS AND SUB-BASINS .....................................................................................................2 MAJOR BASINS AND SUB-BASINS.......................................................................................................2 EXISTING SUB-BASIN DESCRIPTION....................................................................................................2 EXISTING OFFSITE DRAINAGE BASINS................................................................................................3 EXISTING OFFSITE DRAINAGE DESCRIPTIONS ....................................................................................3 PROPOSED SUB-BASINS DESCRIPTIONS.............................................................................................4 PROJECT DESCRIPTION...........................................................................................................................9 PROJECTDESCRIPTION.......................................................................................................................9 PROPOSED DRAINAGE FACILITIES..........................................................................................................9 GENERAL CONCEPT............................................................................................................................9 WATER QUALITY/DETENTION FACILITIES..........................................................................................9 LOW IMPACT DEVELOPMENT...........................................................................................................10 DRAINAGE DESIGN CRITERIA................................................................................................................10 REGULATIONS...................................................................................................................................10 FOUR STEP PROCESS TO PROTECT RECEIVING WATERS..................................................................10 DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS..............................................................11 HYDROLOGIC CRITERIA.....................................................................................................................13 HYDRAULIC CRITERIA........................................................................................................................14 FLOODPLAIN REGULATIONS COMPLIANCE......................................................................................15 MODIFICATIONS OF CRITERIA..........................................................................................................15 EROSION CONTROL..........................................................................................................................15 CONCLUSIONS......................................................................................................................................16 COMPLIANCE WITH STANDARDS .....................................................................................................16 DRAINAGE CONCEPT........................................................................................................................16 REFERENCES .........................................................................................................................................17 ii Ili APPENDIX Appendix A—Figures Appendix B—Hydrologic Calculations Appendix C—Hydraulic Calculations Appendix D—Water Quality Calculations Appendix E—Reference Appendix F—Maps Appendix G—LID Exhibit Engineer's Certification Block I hereby attest that this report for the final drainage design for the Polestar Village was prepared by me or under my direct supervision, in accordance with the provisions of the Fort Collins Stormwater Criteria Manual. I understand that the City of Fort Collins does not and will not assume liability for drainage facilities designed by others. Joseph Martin Frank, PE Registered Professional Engineer State of Colorado No. 53399 iii 1 GENERAL DESCRIPTION AND LOCATION LOCATION The site is located in The Northwest Quarter of Section 16, Township 7 North, Range 69 West of the 6th P.M. in the City of Fort Collins, Larimer County, Colorado. More specifically, the site is a 20.78-acre property that is currently undeveloped. The site borders Mountaire Subdivision to the east, and to the south, the site borders the back of single-family residential lots facing West Elizabeth Ave. To the west, the site borders the Scenic Views retention pond and the Scenic Views Subdivision. To the north, the site borders single-family residential subdivisions, Locust Grove Filing No. 3, Locust Grove Filing No. 2, and the street Orchard Place. For additional information, refer to the site vicinity map within Appendix A of this report. DESCRIPTION OF PROPERTY The site generally drains west to east at a 2.5% to I% slope. The site is located in the Canal Importation Basin, specifically north of West Elizabeth Street, east of South Overland Trail, and directly East of the Scenic Views Subdivision. The existing streets Orchard Place and West Plum Street dead end within the site. The Natural Resources Conservation Service (NRCS) soil survey shows that the majority are type C soils, which are characterized by a lower infiltration rate and corresponding higher runoff rates. The remaining soil on site are made up of Type B soils, which are characterized by a moderate infiltration rate and lower runoff rates. For additional information, refer to the NRCS soil map within Appendix A of this report.The existing site is currently used for Agricultural purposes and has an existing house,greenhouse, and field purposed for crops and areas with native grass. The existing irrigation ditch; i.e. the Pleasant Valley and Lake Canal is within the site, it borders the western boundary.The existing groundwater depths and boring locations are shown in Appendix E of this report. The depth from the bottom of the proposed pond to groundwater is approximately 6 feet, as shown in the Polestar Groundwater measurements spreadsheet in Appendix E of this report. MASTER DRAINAGE BASIN DESCRIPTION The site is located in the Canal Importation basin. The 2022 Canal Importation Basin — Selected Plan Update by Jacobs Engineering report specifies that the site is to have a regional detention facility. For additional information on the drainage patterns and characteristics of the site, refer to the Drainage Basins and Sub-Basins section of this report. 2 FLOODPLAIN SUBMITTAL REQUIREMENTS The site is on FEMA FIRM panel 08069C0960F, dated 12/19/2006, as shown in Appendix A. The site lies within FEMA Zone X, areas which are determined to be outside the 0.2% annual chance floodplain. The site is not located within a FEMA regulated floodplain, as shown in Appendix A in the FEMA attachments. The site is located in the City of Fort Collins Canal Importation floodway and floodplain, as shown in Appendix A in the City of Fort Collins Flood map.JR Engineering has prepared a CLOMR for the Polestar site.Once the grading on the site is completed,a LOMR will be submitted to verify the site is in compliance with the CLOMR. No building permits for the residential structures in the existing effective floodway will be issued until the LOMR is approved. The finished floor elevations near the Sand Filter and Scenic Views Pond are currently 1.5 feet above the base floodplain elevation,while the finished floor elevations for the homes and lots adjacent to the Polestar Detention Facility are I foot above the base floodplain elevation. These elevations comply with Chapter 10 of the City Code, ensuring adherence to floodplain regulations such as flood proofing, floodway regulation, erosion buffer zone regulation, and no-rise certification. Additionally, the Conditional Letter of Map Revision (CLOMR) has been submitted, and the floodplain use permit will be submitted prior to the overlot grading, further securing compliance and safety against potential flood events. DRAINAGE BASINS AND SUB-BASINS MAJOR BASINS AND SUB-BASINS The Polestar Village site is 20.78 Acres; the site will be developed into a single-family, multi-family residential community with a community center and other amenities. The site will include future regional onsite and offsite detention. The site is located in the Canal Importation basin. EXISTING SUB-BASIN DESCRIPTION There are offsite areas that flow across the proposed development site.The existing drainage basins within the site flow from west to east. The existing corrected effective basin map is shown in Appendix E of this report. Basin EP 21.5, acres and 3.1% impervious. This basin is composed of native grassland and an existing shed and includes a small portion of residential lots from Locust Grove that drains directly onto the site and drains to a swale towards West Plum Street. 3 EXISTING OFFSITE DRAINAGE BASINS Currently, the site collects offsite runoff at two different locations. The site is currently in the overflow path of the Scenic Views retention pond and receives direct runoff from Locust Grove Filing No. 3;which enters the site via curb and gutter from Locust Grove Drive. The Scenic Views retention facility receives overflow runoff from the Pleasant Valley and Lake Canal, runoff from the Scenic Views multi-family Subdivision, the Colorado State Equine Horse Center, and the Center of Disease Control facility. For additional information, refer to the existing drainage basin SWMM map done in the hydrology portion of the CLOMR in Appendix E of this report. EXISTING OFFSITE DRAINAGE DESCRIPTIONS The offsite flows are currently routed through the site. The existing offsite basins have been modeled in the Canal Importation Basin Selected Plan Update Conceptual Design Report—Plum Channel Flow Path by Jacobs Engineering Group; Dated June, 2022 and within the Canal Importation Basin Hydrologic Conversion from MODSWMM to EPA SWMM 5.1 Anderson Consulting Engineers, Inc., December 6, 2013, (Revised July 3rd 2014).JR Engineering has revised some of the basins in section 5.0 of the CLOMR to account for Polestar site. The basin map for the offsite areas is shown within the corrected effective SWMM drainage map within Appendix E for the revised hydrology update within the CLOMR. Basin 13 is 2.9 acres and 10% impervious. This basin is directly tributary to the privately owned Scenic Views retention facility. The Scenic Views Pond was designed by JR Engineering, LTD to be a temporary retention facility in 1998 as shown in Appendix E of this report. The temporary retention facility has not yet been converted into a detention facility. The retention pond is pumped into the Pleasant Valley and Lake Canal via the existing submersible sumps pump, as shown in Appendix E of this report. The main pump has to be manually started, so the pond was modeled as a complete retention pond with no outflow, just an overflow path within the existing SWMM model. From the 1998 Scenic Views report,the manually operated pump system is designed to evacuate the pond within 24 hours after a large rainstorm event. Since this pond is a retention pond, without a gravity outfall the City does not model any volume below the spillway (the gravity outfall). This offsite basin is shown in the existing SWMM map shown within Appendix E of this report. 17W is 10.2 Acres and 45% impervious. This offsite basin is shown in the existing SWMM map, as shown within Appendix F of this report. For SWMM master planning purposes, Anderson used 45% impervious for single-family detached residential homes. This basin drains from Locust Grove Drive onto the Polestar site. 4 Basin 10, 64.4 Acres, and 20% impervious. This basin is tributary to the Colorado State University Equine Reproduction Laboratory, located west of the site directly west of South Overland Trail. Runoff from this basin is released from the Equine Center pond and is then piped to the Scenic Views pond. This offsite basin is shown in the existing SWMM map shown within Appendix F of this report. Basin 11, 23.1 Acres and 70% impervious. This basin is tributary to the Scenic View's subdivision. Runoff from this basin is detained in the Scenic Views pond. This offsite basin is shown in the existing SWMM map shown within Appendix E of this report. PROPOSED SUB-BASINS DESCRIPTIONS To model the proposed runoff going into the on-site detention facility the pond was modeled as a composite 21.5-acre basin in SWMM a with 50%impervious value.The Polestar SWMM model was slightly more conservative than the basin area and impervious values to account for potential site changes and design variations through the CLOMR process, and the basin was delineated over a small portion of the Locust Grove subdivision that accounts for additional area. The proposed net area of the site is 20.78 acres at 47.5% impervious. The following is a description of the individual sub-basins for the onsite composite basin. The drainage sub-basin basins have been broken up and delineated, the onsite runoff is being routed with the rational method. The proposed site and pond drainage was modeled in a composite basin within SWMM, as part of the revised hydrology section of the CLOMR. Basin A1, 1.02 acres and 15.8% impervious this basin is composed of open space a proposed walk and a sand-filer and an overflow structure that treats runoff and water quality from the Polestar Village site. Basin A2, 0.60 acres and 50.1% impervious this basin is composed of multi-family residential units, a 24' wide private alley- Hoku Lane, and onsite parking.The runoff from this basin will be conveyed via a paned alley to the curb and gutter on West Plum Street. Basin A3, 0.78 acres and 25.3% impervious this basin is composed of multi-family residential units, duplex units, a private walk and a Swale. The runoff from this basin will be conveyed via a swale and chase to West Plum Street at dp 3a. 5 Basin A4, 1.23 acres and 65.0% impervious this basin is composed of multi-family residential units, paved walk and paved driveways, paved parking spaces, a portion of the mitigated wetland and a 24' wide private alley Ohana Circle . The runoff from this basin goes to design point 4a and drains to W. Plum Street. Basin A5, 0.42 acres and 56.5% impervious this basin is composed of a courtyard, paved walks, duplex and multi-family units. The runoff drains to multiple area inlets. The runoff is then piped within the proposed storm sewer system in West Plum Street. Basin A6, 1.03 acres and 56.5% impervious this basin is composed of a local street West Plum Street, paved walk and front-facing multi-family units. The runoff from this basin goes to a sump inlet at design point 6a. Basin AT 0.85 acres and 60.5% impervious this basin is composed of a local Street West Plum, paved walk. The runoff from this basin goes to a sump inlet at design point 7a. Basin A8,0.58 acres and 83.8%impervious, composed of the mixed-used community building,the northern portion of the temple, community, bed and breakfast building, the wellness center, a duplex, multi-family units, pedestrian walks, and a 24' wide private alley Ohana Circle. Runoff from this basin drains to W. Plum Street at dp 5d. Basin A9.1, 0.16 acres and 84.4%impervious,this basin is composed of the mixed used community building and a multi-family unit. Runoff from this basin will be captured via a series of on-grade inlets at dp 9a and piped to the proposed storm sewer in W. Plum St. Basin A9.2, 0.03 acres and 54.5% impervious, this basin is composed of open space, pedestrian walks and parts of the multi-family units drain to this basin. This basin drains to an area inlet at dp 9.2a, where runoff is then piped to the storm sewer in W. Plum St. Basin A 10,0.09 acres and 84.7%impervious, is composed of the eastern portion of the temple,community, bed and breakfast building. Runoff from this building will drain into an area inlet at dp I Oa, where it will then be piped to the proposed storm sewer system in W. Plum St. 6 Basin AI I, 0.13 acres and 68.8% impervious, this basin is composed of pedestrian walks, a portion of a multi-family unit, a gazebo. Runoff from this basin makes its way to an area inlet at dp I I a, where it is then piped to the proposed storm sewer system in W. Plum St. Basin Al2, 0.26 acres and 33.7% impervious this basin is composed of pedestrian walks a portion of the onsite playground and picnic area. Runoff from this basin makes its way to an area inlet where it is then piped to the proposed storm sewer system in W. Plum St. Basin A13, 0.40 acres and 61.0% impervious, this basin is made up a portion of the eastern half of the group home/ wellness center and the western portion of the temple, community, bed and breakfast building. Basin A15, 0.49 acres and 23.5% impervious, this basin is made up of pedestrian walks and a portion of the mitigated wetland. Runoff from this basin overtops the wetland and drains to an area inlet a dp 15a, where it is then piped to the proposed storm sewer system in W. Plum St. Basin A16, 0.13 acres and 46.1% impervious, this basin is made up of pedestrian walks, the pickle ball court, and drains to an area inlet at dp 16a. The runoff is then piped to the proposed storm sewer system in W. Plum St. Basin A 17, 0.43 acres and 29.6% impervious, is made up of pedestrian walks, the community garden, and multi-family units. Runoff from this basin drains to a series of on-grade area inlets at dp 17a. The runoff from this basin is then piped to the proposed storm sewer system in W. Plum Street. Basin A 18, 0.70 acres and 46.6% impervious, is made up of pedestrian walks, the community garden, the agriculture building, and multi-family units. Runoff from this basin is pipe via a series of on-grade inlets and a pipe with a trench drain at dp 18a due to the shallow slope of the swale. The runoff from this basin is then piped to the proposed storm system within W. Plum St. Basin A 19, 0.35 acres and 52.4% impervious is made up of pedestrian walks, the agriculture building, and a portion of the pickleball court. Runoff from this basin drains to a series of on-grade area inlets at dp 19a where it is then piped to the proposed storm sewer system in W. Plum St, 7 Basin BI, 1.23 acres and 49.8% impervious, is made up of pedestrian walks, multi-family units, duplex units, a rain garden, and a 24' wide private alley - Mele Lane. Runoff of from this basin drains via a chase drain to a rain garden where it is treated for water quality. This the runoff from this basin goes to the onsite Polestar detention pond. Basin B2, 0.33 acres and 74.9% impervious, is made up of pedestrian walks, multi-family units, and a 24' wide private alley- Koku Lane. Runoff of from this basin drains via a chase drain to a rain garden where it is treated for water quality. This the runoff from this basin goes to the onsite Polestar detention Pond. Basin C1, 0.28 acres and 47.5 % impervious this basin is composed of residential multi family units, paved walk, and a rain-garden.The runoff from this basin drains into a rain garden, where it is then released into the Polestar detention facility. Basin C2, 0.32 acres, and 30.5% impervious this basin is composed of paved walk, grass and the multi- family units. The runoff from this basin drains into an area inlet a design point 2C. Basin D I, 0.35 acres and 64.1% impervious this basin is composed a 24' wide paved private alley— Happy Heart Way, a duplex unit and paved walk. The runoff from this basin drains via the alley to a curb cut at 2d where it confluences with the runoff from Basin D2 and is treated for water quality. Basin D2, 0.22 acres and 62.9% impervious basin, is composed of a 24' wide paved private alley— Happy Heart Way, a duplex unit, and a paved walk. The runoff from this basin drains via the alley to a curb cut at 2d. Basin D3, 0.16 acres and 69.8% impervious this basin is this basin is composed a 24' wide paved private alley— Happy Heart Way, a duplex unit and paved walk. The runoff from this basin drains via the alley to a curb cut at 3d. From then the runoff is treated for water quality in a rain garden where it is then piped to the Polestar detention facility. Basin D4, 0.25 acres and 60.9% impervious this basin is this basin is composed a 24' wide paved private alley— Happy Heart Way, a duplex unit and paved walk. The runoff from this basin drains via the alley to a curb cut at 4d. From then the runoff is treated for water quality in a rain garden where it is then piped to the Polestar detention facility. 8 Basin D5, 0.29 acres and 67.3% impervious this basin is this basin is composed W. Plum Street, pedestrian walks and a portion of some multi-family units. The runoff from this basin drains to the rain garden via a chase a 5d. From then the runoff is treated for water quality in a rain garden where it is then piped to the Polestar detention facility. Basin D6, 0.28 acres and 68.2% impervious this basin is this basin is composed W. Plum Street. Runoff from this basin drain to a rain garden via a chase at dp 6d. From there on the runoff is then piped to the onsite Polestar detention pond. Basin D7, 0.15 acres and 64.4% impervious this basin is this basin is composed of a 24' wide private alley - Pono Way, and a duplex unit. Runoff from this basin drain to a rain garden via a curb cut at dp 7d. From there on the runoff is then treated within a rain garden and then it is pipe to the onsite Polestar detention pond. Basin D8, 0.18 acres, and 91.8% impervious this basin is composed of a 24' wide private— Pono Way, and pedestrian walks. Runoff from this basins drains via a curb cut at dp 8d. Basin E I is 2.24 acres and 4 1.1% impervious. This basin consists of West Orchard Place and single-family residential units. The runoff from this basin will drain via a mid-block pan at dp I e. Basin E2, 0.54 acres and 54.2% impervious this basin consists of a local residential road West Orchard Place, single family units and drains via curb and gutter to an on grade a mid block pan at dp 2e. Basin E3, 0.31 acres and 59.0% impervious this basin consists of a local residential road West Orchard Place, single family units and drains via curb and gutter to an on grade inlet a design point 3e. Basin F1, which is 3.9 acres and 31.6% impervious, is composed of the onsite detention facility. OS1, 0.61 acres and 15.2% impervious this basin drains onto West Orchard Place, this basin is part of the back of lots of the Locust Grove subdivision. The runoff from this basin drains in the mid-block pan in West Orchard St and is released into the interim detention facility. OS2, 0.09 acres and 50.8% impervious, part of the Locust Grove Subdivision, this basin drains onto West Orchard Place and drains into the detention facility. 9 PROJECT DESCRIPTION PROJECT DESCRIPTION Polestar Village is a residential multi-family development that will consist of a community center, wellness center, alleys, and local and collector roadways. The Polestar Village site will hold regional detention and water quality for the site. In the future, after the site is fully developed,the Canal Importation basin offsite improvements will be built with additional volume from the Jacobs Canal Importation basin Selected Plan updated June 2022.JR Engineering has designated approximately 3 acres of the site for regional detention. The proposed and future detention facility volume requirements were done by modeling the site in EPA SWMM as part of the revised hydrology portion of the CLOMR, as shown within Appendix E. The future onsite regional detention facility is shown in Appendix F of this report. PROPOSED DRAINAGE FACILITIES GENERAL CONCEPT The proposed improvements to the Polestar Village site will result in the developed condition being treated and detained for water quality. Low-impact development best management practices are proposed to improve the quality of runoff and aid in reducing peak flows. Specifically, rain gardens are proposed near the central portion of the site to treat and provide water quality for the majority of the development. Runoff from the site is captured in inlets located in the alleys and grate inlet along the curb and gutter. Runoff is conveyed in storm sewers, along curb and gutter, and via surface flow to rain gardens. Secondly, surface overflow paths will be provided, such that the 100-year storm flows remain at least 1.0 to 1.5 feet below the finished floor elevation. WATER QUALITY/ DETENTION FACILITIES The majority of the water quality is treated within the onsite rain gardens and sand filter. The remaining water quality within the site will be treated in the water quality and detention facility. A small portion of the site of a type A lot, will be left untreated due to the lot draining to the existing West Orchard R.O.W and pavement adjacent to the lot frontage. Additionally, a portion of the berm and access road to the detention pond will drain off-site and into the Plum Channel drainage way. This is not anticipated to have any negative impact on downstream drainage infrastructure, and the total water quality is being treated for 99% of the Polestar site's modified impervious area. For additional information, the LID water quality treatment exhibit is shown in Appendix G of this report. 10 LOW IMPACT DEVELOPMENT A minimum of 75 percent of new impervious surface area is treated by a Low-Impact Development (LID) best management practice (BMP) in accordance with City criteria. An illustrative LID/ Surface Map is provided in Appendix G, and the sizing of the LID methods is provided in Appendix D. DRAINAGE DESIGN CRITERIA REGULATIONS This report was prepared to meet or exceed the City of Fort Collins stormwater criteria. The City of Fort Collins Stormwater Criteria Manual (dated 2018)(FCSCM) and the Urban Drainage Flood Control District's (UDFCD) Drainage Criteria Manual (USDCM)Volumes 1,2 and 3 were referenced as guidelines for this design. FOUR STEP PROCESS TO PROTECT RECEIVING WATERS The City of Fort Collins requires the Four Step Process to protect receiving waters.The four-step process incorporates reducing runoff volume, treating water quality capture volume, stabilizing streams, and implementing long-term source controls.Volume reduction is an important part of the Four Step Process and is fundamental to effective stormwater management. Per City Criteria, a minimum of 75 percent of new impervious surface area must be treated by a Low-Impact Development (LID) best management practice (BMP). The site incorporates rain gardens to provide water quality. The rain gardens will need to be cleaned and maintained to allow for long-term protection of the receiving waters. The proposed LID BMPs will have the effect of slowing runoff through the site lot and increasing infiltration and rainfall interception by encouraging infiltration and careful selection of vegetative cover. The improvements will decrease the runoff coefficient from the site and are expected to have no adverse impact on the timing, quantity, or quality of stormwater runoff. Overall, water quality will be improved by the development. The majority of the new impervious area is treated by the proposed raingarden in the northwestern portion of the site as illustrated in the LID/Surface Map is provided in Appendix G. Refer to Appendix G for additional information on water quality treatment methods throughout the site. Step 1—Employ Runoff Reduction Practices All of the developed runoff through the site will be routed through the onsite interim Polestar detention pond. Step 2—Implement BMPS that Provide a Water Quality Capture Volume 11 The Polestar site BMP treatment methods include bioretention basins (rain gardens), a sand filter, and WQCV provided within the interim Polestar detention pond. Step 3—Stabilize Drainageways The Interim Polestar detention facility provides flood control for the site. The runoff leaving the site will be channelized via a Swale reinforced wall and a concrete pan with an energy dissipation forebay. In addition, a headwall is being built for the existing twin 24" RCP conduits to provide further stabilization to the existing drainage way. Step 4— Implement site-specific and other source-control BMPs To further enhance the stormwater management practices at the Polestar site, a dog waste station will be installed near the detention pond. This station will include waste bags and a disposal waste station, encouraging pet owners to clean up after their pets. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS The site is part of the Canal Importation - Basin Selected Plan Updates Alternatives Analysis Report, by Jacobs Engineering Group and is currently in the process of conceptual design. The site was previously analyzed in the Canal Importation Basin Hydrologic Conversion from MODSWMM to EPA SWMM 5.1; Anderson Consulting Engineers, Inc, December 6, 2013, (Revised July 3rd 2014).Jacobs Engineering group is currently modifying the Anderson model for the City of Fort Collins Capital Improvement plan for the Canal Importation basin. JR Engineering has evaluated the floodplain for the site, and JR Engineering has prepared a CLOMR to show that the improvements to the site are not within the floodplain.The CLOMR shows to the newly mapped floodway and floodplain, ultimately a LOMR will need to be approved to ensure the site complies with the CLOMR. The improvements for the planned regional Happy Hearts detention facility will take place in the future after the site is developed into Polestar Village. The Polestar Community will not impact the downstream development, and onsite detention will be provided within the site, but the homes downstream of the site will remain within the floodplain until the improvements to the offsite and onsite facilities are put in place as recommended in the Canal Importation - Basin Selected Plan Updates, by Jacobs. The following items are a list of the subject improvements. • Conversion of Scenic Views retention pond to a detention pond. • Addition of a pipe outfall from the Scenic Views detention pond to the Happy Heart Farms, i.e., Polestar detention pond. • The volume of the onsite detention pond should be increased per the proposed outfall. 12 • Construction of the planned outfall from the regional detention facility Currently, in the 100-year event, the Pleasant Valley and Lake Canal overflows and spills into the Scenic Views pond. The Scenic Views pond has a manually operated pumped outfall to the Pleasant Valley and Lake Canal. In the 100-year event, water overtops the Scenic Views pond and goes on the Polestar site, creating a floodplain as shown in the existing drainage map within Appendix F. In the proposed condition, the floodplain will go onto the onsite rain garden, overtop W. Plum Street and then the floodplain will be contained within the proposed detention facility. However, due to the shallow gravity outfall and limited volume the ultimate detention facility, as shown in Appendix E. - cannot be built due to the lack of a deep gravity outfall.The interim condition provides a drainage easement, an energy dissipation structure, and a concrete pan and will convey runoff, as shown in the Drainage Map in Appendix F. The onsite detention requirement for the site is the runoff difference between the 100-year developed inflow rate and the 2-year historic runoff is 4.88 Acre-ft. For additional information on the detention pond volume calculation, please refer to the referenced CLOMR provided hydrology portion provided in Appendix E. Jacobs calculated the ultimate volume (Happy Heart Detention Pond)within the Canal Importation - Basin Selected Plan Updates dated June 2022 as 8.3 Acre-ft. The total ultimate detention volume was calculated by adding the Happy Heart Detention pond of volume 8.3 Acre-ft with the required interim (onsite) detention volume 4.88 Acre-ft for the Polestar site for a total volume of 13.18 Acre-ft.JR Engineering has verified that the proposed pond layout can be graded in the future to detain over 13.18 Acre-ft as shown in the Future regional detention map provided in Appendix F. JR Engineering has prepared three SWMM models for the Polestar site within the City of Fort Collins Canal Importation Basin: the Corrected Effective Model, the Proposed Model, and the Ultimate Model. The City of Fort Collins has requested that JR Engineering incorporate the Polestar Drainage model into the City master Canal Importation Drainage Plan SWMM mode. This was completed within the revised hydrology portion of the CLOMR, as shown within Appendix E. The groundwater for the site is greater than two feet below the Polestar detention pond invert, as noted in the CTL groundwater exhibit in Appendix E. 13 HYDROLOGIC CRITERIA Weighted percent imperviousness were calculated for each basin using the Fort Collins Stormwater Criteria Manual Table 3.2-2 for each basin. EPA SWMM was used to model the runoff for the site and size the Polestar detention facility since the corresponding tributary area of the site is over 20 acres, and there are multiple detention basins upstream of the site that are in series with one another. The City of Fort Collins area has rainfall depths associated with the table below, as shown in Chapter 5 of the Fort Collins Stormwater Criteria Manual (FCSCM). Table 4.1-4. IDF Table for SWIIMM Intensity Intensity Intensity Intensity Intensity Intensity Duration 2tyear 5-year 10-year 25-year 50-year 100-year min Inlhr inlhr infhr inlhr inlhr infhr 5 0.29 0.40 0.49 0.63 0.79 1.00 10 0.33 0.45 0.56 0.72 0.90 1.14 15 0.38 0.53 0_65 0.84 1.05 1.33 20 0.64 0.89 1.09 1.41 1.77 2.23 25 0.81 1.13 1.39 1.80 2.25 2.84 30 1.57 2.19 2.69 3.48 4.36 5.49 35 2.85 3.97 4.87 6.30 7.40 9.95 40 1.18 1.64 2.02 2.61 3.27 4.12 45 0.71 0.99 1.21 1.57 1.97 2.48 50 0.42 0.58 0.71 0.92 1.16 1.45 55 0.35 0.49 0.60 0.77 0.97 1.22 60 0.30 0.42 0.52 0.67 0.84 1.06 65 0.20 0.28 0.39 0.62 0.79 1.00 70 0.19 0.27 0.37 0.59 0.75 0.95 75 0.18 0.25 0.35 0.56 0.72 0.91 80 0.17 0.24 0.34 0.54 0.69 0.67 85 0.17 0.23 0.32 0.52 0.66 0.84 90 0.16 0.22 0.31 0.50 0.64 0.81 95 0.15 0.21 0.30 0.48 0.62 0.78 100 0.15 0.20 0.29 0.47 0.60 0.75 105 0.14 0.19 0.28 0.45 0.58 0.73 110 0.14 0.19 0.27 0.44 0-56 0.71 115 0.13 0.18 0.26 0.42 0.54 0_69 120 0.13 0.18 0.25 0.41 0.53 0.67 The rational method was used to size the onsite storm sewer drainage facilities. Runoff coefficients from the FCSCM Table 3.2-1. Zoning Classification - Runoff Coefficients and Table 3.2-2. Surface Type - Runoff Coefficients were utilized to calculate the composite C values. Rainfall intensities for the 2 year minor storm and 100 year major storm were taken from table 3.4-1. 1DF Table for Rational Method. 14 HYDRAULIC CRITERIA StormCAD was utilized to determine the hydraulic capacity of the storm sewer system on site. Headloss coefficients were input as recommended by AMEC. "Modeling Hydraulic and Energy Sewer Gradients in Storm Sewers: A Comparison of Computational Methods." UDFCD, 6 Oct. 2009. The stormCAD V8i input/results are shown in Appendix C. A tailwater condition was used in the stormCAD model. The tailwater entered into the StormCAD model for the storm outfalls corresponds to the peak inflow within the pond for the 100-year event. This occurs 40 minutes into the model, and the depth of the pond is at 5105.98. No tail water was used for the 2-year model. For the sand filter, the water WQCV depth was used as the tailwater condition in the 100-year event. This corresponds to an elevation of 5107.55. For the outfall, a 100-year tailwater condition of 5106.23 was used to model the outfall into the floodplain located within the energy dissipation forebay. 5106.23 is the water surface elevation in the CLOMR at section 4673.7—which is within in the energy dissipation directly downstream of the pipe. There is a mid-block pan that bi-sects West Orchard Place,that accepts runoff from Locust Grove. Runoff from the midblock pan drains into a chase drains and is then conveyed via a swale into a type C let. The overflow from the swale in the 100 year event drains directly into the Polestar detention facility. The hydraulics of the mid-block plan and the Swale were modeled within Flow Master as shown in Appendix C of this report. The 100-year spillway from the Scenic Views Pond and the Polestar Pond were sized during the CLOMR process in Flow Master. For additional information on the Spillway sizing, refer to the attached variance letter for the CLOMR in Appendix E of this Report. The inlets for the site were sized using parameters from the Fort Collins Stormwater Criteria Manual (FCSCM). The UD Inlet MHFD-Inlet, Version 5.03 (August, 2023) spreadsheet was utilized for the design and sizing of these inlets, as shown in Appendix C of this Report. 15 FLOODPLAIN REGULATIONS COMPLIANCE As previously stated, the site lies within FEMA Zone X, areas which are determined to be outside the 0.2% annual chance floodplain. The site is not located within a FEMA-regulated floodplain, as shown in Appendix A in the FEMA attachments. The site is located in the City of Fort Collins Floodplain and there is a floodway within the site, as shown in Appendix A in the City of Fort Collins Flood map. All development is within in compliance with Chapter 10 of the City of Fort Collins Code. MODIFICATIONS OF CRITERIA JR Engineering is proposing modifications for the spillway in Scenic Views Pond to increase emergency overflow capacity, decrease the overall breadth of the floodplain, and reduce the emergency overflow depth from 1.9 ft to 1.75 ft, as shown in the attached variance letter from the CLOMR in Appendix E. The proposed improvement will stop the spillway from overflowing by making it longer. In addition, the new proposed configuration will provide 6" of freeboard for the Scenic Views Spillway. The proposed Polestar/Happy Heart Farms Spillway is intended to prevent the flow from the emergency spillway from being directed towards existing structures and homes downstream. Both proposed spillways exceed the required depth of six inches, but the variance is necessary to achieve the desired outcomes. For additional information, refer to Appendix E for the variance letter is being review which was done with the CLOMR. EROSION CONTROL The Polestar Utility Plans are in compliance with the Erosion Control Criteria established by the City of Fort Collins. The erosion control measures have been designed to minimize soil erosion and sediment transport off-site, ensuring compliance with local, state, and federal water quality regulations. All control measures will be maintained and inspected regularly to ensure their effectiveness throughout the construction process until final stabilization is achieved. All Erosion Control Materials and measures detailed in the Utility Plans adhere to the standards and specifications set forth by the City of Fort Collins within the Stormwater Criteria Manual. Erosion Control Plans, as referenced in the Polestar Utility Plans, are living documents that can be subject to change under the direction of the Engineer of Record and/or the City of Fort Collins Engineering Department. 16 CONCLUSIONS COMPLIANCE WITH STANDARDS The hydrologic and water quality calculations were performed using the required methods as outlined in the City of Fort Collins Stormwater Criteria Manual. The drainage plan and Stormwater management measures proposed within the Polestar site are complaint with all applicable State and Federal regulations governing Stormwater discharge. The drainage design conforms to the Jacobs' Master Canal Importation Basin plan by providing an area designed for detention in the ultimate gravity pond outfall configuration. The site conforms to the revised Hydrology of documented Polestar Floodplain Modeling Report by JR Engineering dated June of 2023. The floodplain compliance requirements for the site have been detailed in the CLOMR (Conditional Letter of Map Revision) for various parameters, including elevation, flood proofing, critical facilities, tie-in of upstream and downstream WSEL (Water Surface Elevation), and structures. DRAINAGE CONCEPT The proposed concept for the Polestar Village Development involves surface flows and piping of developed conditions and offsite flow through the interim detention facility. The site includes LID water quality facilities with rain gardens. Runoff for the site will be treated in an interim detention facility onsite. The proposed development will affect the drainageway termed "Plum Street Flow Path" which is located in the northwestern portion of the Canal Importation Basin. Onsite detention is provided for the Polestar site, but the homes downstream of the site will remain with the floodplain until the improvements to the offsite and onsite facilities are put in place as recommended in the Canal importation—Basin Selected Plan Updates Analysis Report, by Jacobs dated June 2022. 17 REFERENCES Fort Collins Stormwater Criteria Manual; City of Fort Collins, Colorado, December 2018. Urban Storm Drainage Criteria Manual (Volumes I, 2,and 3); Urban Drainage and Flood Control District, June 2001. Canal Importation Basin Hydrologic Conversion from MODSWMM to EPA SWMM 5.1 Anderson Consulting Engineers, Inc, December 6, 20213, (Revised July 3rd 2014) Canal Importation basin Selected Plan Update,Jacobs Engineering Group, Dated June 2023 Preliminary Geotechnical Investigation Polestar Village; CTL Thompson, Dated November 2021 Floodplain Modeling Report for Polestar Village;JR Engineering, Dated June 2022 18 APPENDIX A - FIGURES W MULBERRY ST 1 � o I J I = I I H uiQ a > v ORCHARD PL co Z cl) W J J J > °' m O co Y W ELIZABETH ST I I I I ------- _-- \1 I I J i i I I 1 1 � I I W PROSPECT RD \ VICINITY MAP SCALE: 1"=1000' VICINITY MAP 1000 500 0 1000 2000 POLESTAR VILLAGE JOB NO. 3979701 ORIGINAL SCALE: 1" = 1000' 6-5-2022 SHEET 1 OF 1 A Westrian Company Centennial%3-740-M•Colorado�ft 719-593-M Fat Com 97&491-90•www7 ineeri Can 3 Hydrologic Soil Group—Larimer County Area,Colorado (V N m - O O 488700 48W 48W 489000 489100 489200 489300 489400 40°34'59"N 40°34'59"N m I - g i g �I 4' - 1 14N. fir• - `-? m� j �Y,Soil Map m"y not be vald'at this scare. m— ,� 40°34'23"N � � � T...na� � � _' 401 34'23"N 488700 488800 488900 489000 489100 489200 489300 489400 3 3 iv h Map Scale:1:5,390 fi printed on A portrait(8.5"x 11")sheet. o Meters N ° 0 50 100 200 300 Feet 0 250 500 1000 1500 Map projection:Web Mercator Comer coordinates:WGS84 Edge tics:UTM Zone 13N WGS84 USDA Natural Resources Web Soil Survey 5/17/2022 Conservation Service National Cooperative Soil Survey Page 1 of 4 Hydrologic Soil Group—Larimer County Area,Colorado MAP LEGEND MAP INFORMATION Area of Interest(AOI) 0 C The soil surveys that comprise your AOI were mapped at Area of Interest(AOI) 0 CID 1:24,000. Soils © D Warning:Soil Map may not be valid at this scale. Soil Rating Polygons A Not rated or not available Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil F—] AID Water Features line placement.The maps do not show the small areas of Streams and Canals contrasting soils that could have been shown at a more detailed 0 B scale. Transportation B/D *.. Rails Please rely on the bar scale on each map sheet for map 0 C measurements. � Interstate Highways 0 C/D US Routes Source of Map: Natural Resources Conservation Service Web Soil Survey URL: 0 D Major Roads Coordinate System: Web Mercator(EPSG:3857) 0 Not rated or not available Local Roads Maps from the Web Soil Survey are based on the Web Mercator Soil Rating Lines Background projection,which preserves direction and shape but distorts q distance and area.A projection that preserves area,such as the Aerial Photography Albers equal-area conic projection,should be used if more .-.. AID accurate calculations of distance or area are required. ++� B This product is generated from the USDA-NRCS certified data as ti B/D of the version date(s)listed below. C Soil Survey Area: Larimer County Area,Colorado Survey Area Data: Version 16,Sep 2,2021 r.i CID Soil map units are labeled(as space allows)for map scales ... D 1:50,000 or larger. Not rated or not available Date(s)aerial images were photographed: Aug 11,2018—Aug Soil Rating Points 12,2018 p A The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background E3 AID imagery displayed on these maps.As a result,some minor B shifting of map unit boundaries may be evident. B/D USDA Natural Resources Web Soil Survey 5/17/2022 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group—Larimer County Area,Colorado Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 3 Altvan-Satanta loams,0 B 68.4 43.1% to 3 percent slopes 4 Altvan-Satanta loams,3 B 38.2 24.1% to 9 percent slopes 37 Fort Collins loam,5 to 9 C 0.0 0.0% percent slopes 48 Heldt clay loam,0 to 3 C 9.2 5.8% percent slopes 64 Loveland clay loam,0 to C 15.9 10.0% 1 percent slopes 74 Nunn clay loam, 1 to 3 C 2.2 1.4% percent slopes 76 Nunn clay loam,wet, 1 C 11.8 7.5% to 3 percent slopes 95 Satanta loam, 1 to 3 C 12.9 8.1% percent slopes Totals for Area of Interest 158.5 100.0% USDA Natural Resources Web Soil Survey 5/17/2022 Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group—Larimer County Area,Colorado Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D)and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential)when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential)when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher USDA Natural Resources Web Soil Survey 5/17/2022 Conservation Service National Cooperative Soil Survey Page 4 of 4 'fir Al 4 lollRJL -?R MA pp F.�N �ARIlLllA; a , *�It -�HAD P — A tl f 41 mot lip 771 '* PLUM.ST p -V4j. , AL-1 1- 0 j VY EUIV ST - —. +W z i , AWANC '" �, ." ; i H k 61 City Flood Risk Map High Risk This information is based on the Federal Emergency Management City Floodway-Area of 100-year floodplain with greatest depths and Agency(FEMA)Flood Insurance Rate Map(FIRM)and the City of fastest velocities. Fort Collins Master Drainageway Plans. This letter does not imply that the referenced property will or will not be free from flooding or City Flood Fringe-May Include: damage. A property not in the Special Flood Hazard Area or in a Areas of FEMA 100-year floodplain(FEMA Zones A,AE,AO,and AH) City Designated Floodplain may be damaged by a flood greater Areas of City 100-year floodplain including ponding areas and sheet than that predicted on the map or from a local drainage problem flow areas with average depths of 1-3 feet. not shown on the map. This map does not create liability on the part of the City,or any officer or employee thereof,for any damage There is a 1%annual chance that these areas will be flooded. that results from reliance on this information. Moderate Risk All floodplain boundaries May include: are approximate. Areas of FEMA 500-year floodplain(FEMA Zone X-shaded). City of Areas of FEMA or City 100-year floodplain(sheet flow)with Fort Collins average depths of less than 1 foot. N `- Areas protected by levees from the 100-year flood. GIs Low Risk W Feet E 0 70 140 280 420 560 = Areas outside of FEMA and City mapped 100-year and 500-year floodplains.Local drainage problems may still exist. S Printed:07/14/2021 NOTES TO USERS 309000OFT FLOODING EFFECTS FROM 3095000FT ZONE AE 3100000 FT LEGEND ZONE AE CACHE LA POUDRE RIVER 1 50 11, 1-" JOINS PANEL 0743 (E c ° , (EL 5090) JOINS PANEL 0744 1050 0T 30" �, ,, INS map is for use in administering the National Flood insurance Program. it does 0 5 _ _ 0 8, ° �rECIAL FLOOD HAZARD AREAS(SFHAs)SUBJECT T O 1NUNDA—HON not necessarily identify all areas subject to flooding, particularly from local drainage 400 37'30" BY THE 1%ANNUAL CHANCE FLOOD sources of small size. The community map repository should be consulted for ZONE AE The 1%annual chance flood(100-year flood),also known as the base flood,is the flood that has a possible updated or additional flood hazard information. ZONE AE ZONE X (EL 5096) 4497000m N 1% chance of being equaled or exceeded in any given year. The Special Flood Hazard Area is the (EL 5098) area subject to flooding by the 1%annual chance flood. Areas of Special Flood Hazard include To obtain more detailed information in areas where Base Flood Elevations(BEES) 1470000FT Zones A,AE, AH,AO,AR,A99,V,and VE. The Base Flood Elevation is the water-surface elevation + N + of the 1%annual chance flood. and/or floodways have been determined,users are encouraged to consult the Flood a B� FLOODING EFFECTS FROM Profiles and FloodwayData and/or Summary of Stillwater Elevations tables contained p ZONE A No Base Flood Elevations determined. ry C CACHE LA POUDRE RIVER within the Flood Insurance Study(FIS) Report that accompanies this FIRM. Users ZONE X y92� ZONE AE Base Flood Elevations determined. should be aware that BFEs shown on the FIRM represent rounded whole-foot y� ZONE AH Flood depths of 1 to 3 feet(usually areas of ponding); Base Flood Elevations elevations. These BFEs are intended for flood insurance rating purposes only and o <<Q determined. should not be used as the sole source of flood elevation information. Accordingly, 0 09 ZONE AO Flood depths of 1 to 3 feet (usually sheet flow on sloping terrain); average flood elevation data presented in the FIS Report should be utilized in conjunction with depths determined.For areas of alluvial fan flooding,velocities also determined. the FIRM for purposes of construction and/or floodplain management. ZONE AR Special Flood Hazard Areas formerly protected from the 1%annual chance flood by a flood control system that was subsequently decertified. Zone AR indicates that the former flood control system is being restored to provide Boundaries of the floodwa s were comp uted at cross sections and inte olated y p rp 36 o rn protection from the 1%annual chance or greater flood. between cross sections. The floodways were based on hydraulic considerations with r` 31 ° regard to requirements of the National Flood Insurance Program. Floodway widths IY � ZONE A99 Area be protected from 1/°annual chance flood by a Federal flood protection and other pertinent floodway data are provided in the Floodway Data table shown on systemm under construction;no Base Flood Elevations determined. this FIRM. FLOODWAY AREAS IN ZONE AE The floodway is the channel of a stream plus any adjacent floodplain areas that must be kept free of Certain areas not in Special Flood Hazard Areas may be protected by flood control encroachment so that the 1%annual chance flood can be carried without substantial increases in structures. Refer to Section 2.4"Flood Protection Measures"of the Flood Insurance flood heights. Study Report for information on flood control structures for this jurisdiction. OTHER FLOOD AREAS Cm _4496000m N FEMA recommends that a Flood Insurance Policy be purchased for structures in z ZONE x Areas of 0.2%annual chance flood; areas of 1%annual chance flood with areas where levees are shown as providing protection from the 1% annual chance average depths of less than 1 foot or with drainage areas less than 1 square flood. Flooding is not covered by standard properly/fire/dwelling insurance policies nor 0 mile; and areas protected by levees from 1% annual chance flood. is it covered by Homeowners Insurance, Renters Insurance, Condominium Owners o Larimer County OTHER AREAS Insurance,or Commercial Property Insurance. Contact your insurance agent and local rN InUnincor Unincorporated Areas THIS AREA SHOWN AT A floodplain administrator for further information. p ZONE x Areas determined to be outside the 0.2%annual chance floodplain. 080101 m ZONE D Areas in which flood hazards are undetermined,but possible. Visit http://www.fema.gov/i)df/fhm/frm gsah.pdf for information on levees and the risk COUNTY ROAD 50 of flooding in areas shown as being protected by levees. T.8 N. SCALE OF 1 " — 500' o Floodplain boundary T.7 N. W Floodway boundary ON MAP NUMBER t) Z Zone D boundary The projection used in the preparation of this map was State Plane Colorado North ( a (feet). The horizontal datum was NAD 83,GRS80 spheroid.Differences in datum, spheroid, projection or UTM zones used in the production of FIRMS for adjacent 1465000FT + + 08069CO957 Z Boundary dividing Special Flood Hazard Area zones and jurisdictions may result in slight positional differences in map features across jurisdiction 0 f boundary dividing Special Flood Hazard Areas of different Base boundaries. These differences do not affect the accuracy of this FIRM. Flood Elevations,flood depths or flood velocities. —513 Base Flood Elevation line and value;elevation in feet* Flood elevations on this map are referenced to the North American Vertical Datum of Base Flood Elevation value where uniform within zone; 1988. These flood elevations must be compared to structure and ground elevations COUNTY ROAD 25G EL 987 elevation in feet* referenced to the same vertical datum. For information regarding conversion between the National Geodetic Vertical Datum of 1929 and the North American ALPACA TRAIL / *Referenced to the North American Vertical Datum of 1988 Vertical Datum of 1988, visit the National Geodetic Survey website at .449500 0m N A A Goss section line hftp://www.ngs.noaa.gov or contact the National Geodetic Survey at the following address: 104-50'37.5",39-30'00" Geographic coordinates referenced to the North American Spatial Reference System Division U, Datum of 1983(NAD 83),Western Hemisphere National Geodetic Survey,NOAA 3180000 FT 5000-foot ticks: Colorado State Plane coordinate Silver Spring Metro Center y system,North zone,Lambert Conformal 1315 East-West Highway RED RIDGE TRAIL 6 Conic projection Silver Spring,Maryland 20910 7 4276000'N 1000-meter Universal Transverse Mercator grid ticks,zone 13 (301)713-3191 1 v O KK6400 X National Geodetic Survey bench mark(see explanation in To obtain current elevation,description,and/or location information for bench marks Notes to Users section of this FIRM panel) shown on this map, please contact the Information Services Branch of the National Geodetic Survey at(301)713-3242,or visit its website at hftp://www.ngs.noaa.gov. COUNTY BIRCH DRIVE FLOOD INSURANCE RATE MAP LODGEPOLE PLACE ROAD 48C Base map information shown on this FIRM was provided by the Larimer County GIS MAP REPOSITORY and Mapping Department.Additional input was provided by the City of Fort Collins REDWOOD COURT Refer to listing of Map Repositories on Map Index Geographic Information Service Division.These data are current as of 2005. N o EFFECTIVE DATE OF COUNTYWIDE O The profile baselines depicted on this map represent the hydraulic modeling baselines DECEMBER E AT that match the flood profiles in the Flood Insurance Study report.As a result of improved 006 z ZONE A topographic data,the profile baseline, in some cases, may deviate significantly from D the channel centerline or appear outside the Special Flood Hazard Area. PECAN DRIVE �94000m N EFFECTIVE DATE(S)OF REVISION(S)TO THIS PANEL Corporate limits shown on this map are based on the best data available at the time of publication. Because changes due to annexations or de-annexations may have 146000OFT + occurred after this map was published, map users should contact appropriate BLUE SPRUCE DRIVE- community officials to verify current corporate limit locations. Please refer to the separately printed Map Index for an overview map of the s county showing the layout of map panels; community map repository addresses; RED CEDAR DRIVE x and a Listing of Communities table containing National Flood Insurance Program > q dates for each community as well as a listing of the panels on which each community �� fl is located. LO O lO W Contact the FEMA Map Service Center at 1-800-358-9616 for information W ..% O OC1 rn �:;, Q D on available products associated with this FIRM. Available products may include zr previously issued Letters of Map Change, a Flood Insurance Study Report, and/or d digital versions of this map. The FEMA Map Service Center may also be reached by n City of Fort Collins Fax at 1-800-358-9620 and its website at hftp://www.msc.fema.aov. z LAPORTE AVENUE O �' o COUNTY ROAD 46E QSQl Q2 For community map revision history prior to countywide mapping,refer to the Community ` G X w Map History table located in the Flood Insurance Study report for this jurisdiction. If you have questions about this map or questions concerning the National Flood r LL0512 J Lu Insurance Program in general, please call 1-877-FEMA MAP(1-877-336 2627)or 1 a 3 ;+ ¢ 9 To determine if flood insurance is available in this community,contact your insurance agent or call visit the FEMA website at hftp://www.fema.gov. 0 9 4493000m N the National Flood Insurance Program at 1-800-638-6620. 7 8 0 0 . z o G) £ > O Larimer County Vertical Datum Offset Table �" r`` 7 o = /`o�ll{yIutullV{lllr'�\' Vertical Datum Vertical Datum o Larimer County Flooding Source Offset(ft) Flooding Source Offset(ft) °° Unincorporated Areas City of Fort Collins Cache La Poudre River 3.0 ' + 4 Q$Q1Q1 ' MAP SCALE 1"=1000' �' 080102 Larimer County Soo o 1000 2000FEET jt p MULBERRY STREET(L _ Unincorporated Areas METERS 1455000FT + x1 �� + 080101 300 0 300 600 � � Example: To convert Cache La Poudre River elevations to NAVD 88,3.0 feet were added to the I NGVD 29 elevations. RAMPART ROAD PANEL 0960E Panel Location Map '' I �,, 4492000m N FIRM FLOOD INSURANCE RATE MAP LARIMER COUNTY, I7orsetdnth Reservoir 16 ark ELIZABETH STREET o ® COLORADO / _ 17 W AND INCORPORATED AREAS — z CATALPA PLACE Q 13 _ a 18 s J i _ CORN FLOWER DRIVE Z PANEL 960 OF 1420 ^y o t Z JO PLEASANT VALLEY ROAD Larimer Count O BLUE FLAX COURT BANYAN DRIVE (SEE MAP INDEX FOR FIRM PANEL LAYOUT) y ? O CONTAINS: lag CATALPA DRIVE r� Unincorporated Areas w ,� _ U 080101 ey :E u- C, a m COMMUNITY NUMBER PANEL SUFFIX x, Q } 4491 OOOm FORT COLLINS,CITY OF 080102 0960 F N 3x s � U City of Fort Collins v�oG LARIMER COUNTY 080101 0960 F 080102 �� PROSPECT ROAD + 1450000FT— ZONE X + 1 i§c DEN GOL CURRANT BOULEVARD Lu L SPRUCE DRIVE w C) 0 1 X ZONE A ' a ZONE X 120 1 Notice to User: The Map Number shown below should be used when placing map orders; the 24 19 Larimer County` _ — _ Community Number shown above should be This Digital Flood Insurance Rate Map(DFIRM)was produced ' used on insurance a lications for the subject through a Cooperating Technical Partner (CTP)agreement Unincorporated Areas a pp ) between the State of Colorado Water Conservation Board and 080101 community. the Federal Emergency Management Agency (FEMA). 400 33'45" 400 33'45" R coxs 1050 11' 15" JOINS PANEL 0970 JOINS PANEL 0967 105°07' 30" oti4Ai--�F� MAP NUMBER � 4 OOOm 4 OOOm 4 OOOm 4 OOOm 4 OOOm 1' � a 85 E 86 E 87 E 88 E 89 E ® o aP r� Additional Flood Hazard Information and � ��"' 08069C0960F Z. resources are available from local communities /t"w� and the Colorado water conservation Board. NOTE: MAP AREA SHOWN ON THIS PANEL IS LOCATED WITHIN TOWNSHIP 7 NORTH, RANGE 69 WEST,AND TOWNSHIP 8 NORTH, RANGE 70 WEST AND TOWNSHIP 7 NORTH, RANGE 70 WEST,TOWNSHIP 8 NORTH, RANGE 69 WEST. `~ 4` EFFECTIVE DATE ADD IS; DECEMBER 19, 2006 Federal Emergency Management Agency City of Fort Collins Utilities Fit Collins Floodplain Administration (970)416-2632 City of Fort Collins Floodplain Review Checklist Development Review Submittals Instructions: Complete this checklist by marking all boxes that have been adequately completed. Put an"NA"next to any items that are not applicable to this particular submittal. Any boxes that are left blank and do not have an"NA"marked next to them are considered incomplete. Date of Review: Reviewer's Name: Plat Man The following required items are on the plat: ❑ 100-year floodplain boundary ❑ City ❑ FEMA ❑ Floodway boundary ❑ City ❑ FEMA ❑ These items match the FIRM. (FEMA Basin) ❑ These items match the Master Plan. (City Basin) Site Plan The following required items are on the site plan: ❑ 100-year floodplain boundary- FEMA and City ❑ 500-year floodplain boundary(ifproposed structure is a"critical facility" and a 500-year floodplain is mapped) ❑ Floodway boundary ❑ Erosion buffer zones ❑ Restrictions related to use (ie. critical facility or no residential use of lower floor if floodproofed mixed use structure) Drainage and/or Grading Plan (or a separate Floodplain Sheet if it is too cluttered on Drainage and Grading Plan) The following required items are on the drainage and/or grading plan: ❑ 100-year floodplain boundary- FEMA and City ❑ 500-year floodplain boundary(ifproposed structure is a"critical facility" and a 500-year floodplain is mapped) ❑ Floodway boundary Page 1 of 7 City of Fort Collins Utilities Fit Collins Floodplain Administration (970)416-2632 ❑ Erosion buffer zones ❑ Cross-section locations ❑ BFE lines ❑ Lowest floor elevation of structures(bottom of basement or crawl space is considered the lowest floor) ❑ The floodplain and floodway boundaries are in the correct location and labeled properly. ❑ The cross-section and BFE lines are in the correct location and labeled properly. ❑ Elevations are referenced to the 1988 datum: ❑ Floodway regulations have been met. ❑ No fill in the floodway unless a hydraulic analysis shows "no-rise". ❑ No manufactured homes,except in an existing park,can be placed in the floodway. ❑ No changing a nonconforming non-residential or mixed use structure to a residential structure. ❑ Landscaping meets requirements for no encroachment in the floodway without a hydraulic analysis to show"no-rise". ❑ No storage of materials or equipment. ❑ A note is on the plans about the above floodway restrictions. ❑ Critical facilities regulations have been met: ❑ 100 year—no at-risk population, essential service, government service or hazardous material critical facilities ❑ 500 year Poudm—no at-risk population or essential service, critical facilities ❑ Any pedestrian bridges in the floodway that are not able to pass the 100-year flow are designed to be"break-away". ❑ Fences in the floodway will not block conveyance. Example: split-rail fence cabled together to not float, flap at bottom of privacy fence to allow water through (flap at BFE or above). ❑ Any items in the floodway that can float(Example: picnic tables,bike racks, etc.) are noted as being anchored. ❑ Erosion Buffer Zone requirements have been met: ❑ Design of any allowed development minimizes disturbance to channel bed and banks. Page 2 of 7 City of Fort Collins Utilities Fit Collins Floodplain Administration (970)416-2632 ❑ No structures allowed. ❑ No additions to existing structures allowed. ❑ Any fencing is split-rail design and break-away,but cabled.Must be oriented parallel to general flow direction. ❑ No detention or water quality ponds. ❑ No bike or pedestrian paths or trails except as required to cross streams or waterways. ❑ Road, bicycle and pedestrian bridges must span erosion buffer zone. ❑ No fill. ❑ No outdoor storage of non-residential materials or equipment. ❑ No driveways or parking areas. ❑ No irrigated vegetation and non-native trees, grasses, or shrubs. ❑ No utilities except as necessary to cross streams or waterways. ❑ No grading or excavation except as required for permitted activities in erosion buffer zone. ❑ No construction traffic except as required for permitted activities in erosion buffer zone. ❑ Any construction in the erosion buffer zone shows that it will not impact the channel stability. ❑ A note is on the plans about the above erosion buffer zone restrictions. ❑ Any necessary floodplain modeling has been submitted and approved. All modeling must follow the City's floodplain modeling guidelines. Special Poudre River Regulations ❑ Poudre River Floodway Regulations have been met. ❑ No construction ofnew residential,non-residential or mixed- use structures. ❑ No redevelopment of residential, non-residential or mixed-use structures. ❑ No additions to residential, non-residential or mixed-use structures. ❑ No fill unless hydraulic analysis shows "no-rise". ❑ Poudre River floodplain regulations have been met ❑ No construction of new residential or mixed-use structures ❑ No additions to residential structures ❑ No additions to mixed-use structures if there is an expansion in the residential-use area of the structure. ❑ No floatable materials on non-residential sites ❑ Emergency Response and Preparedness Plan(ERPP) draft has been prepared. Page 3 of 7 City of Fort Collins Utilities Fit Collins Floodplain Administration (970)416-2632 Information Related to Structures in the Floodplain ❑ For structures in the floodplain, a table is shown that lists the following: ❑ City BFE at upstream end of structure ❑ FEMA BFE at upstream end of structure (if different than City BFE) ❑ Regulatory flood protection elevation ❑ Lowest floor elevation(bottom ofbasement or crawl space is considered lowest floor) ❑ Floodproofing elevation for non-residential structures (if applicable) ❑ Garage slab elevation ❑ HVAC elevation ❑ The BFE at upstream end of structures are correct based on interpolation between the cross-sections. ❑ The regulatory flood protection elevation is correct. ❑ The lowest floor and HVAC are at or above the regulatory flood protection elevation. ❑ Elevations are referenced to the 1988 datum. ❑ A typical drawing detail is included for each foundation type proposed(slab-on- grade, basement, crawl space) showing the elevation of the HVAC and lowest floor elevation (which includes bottom of the basement or crawl space)relative to the BFE. ❑ If garage is not elevated to the regulatory flood protection elevation, then a drawing detail is included showing vent placement, size, and number. ❑ There is 1 square inch of venting for every 1 square foot of enclosed area. ❑ The bottom of the venting is not higher than 1 foot above grade. ❑ The venting is on at least two sides,preferably on upstream and downstream sides. (Does not have to be divided equally). ❑ If a non-residential structure is to be floodproofed, one of these conditions is met: ❑ All requirements on separate sheet titled"Floodproofing Guidelines" have been met. ❑ If floodproofing information is not submitted as part of the plans, then a note is on the plans stating that floodproofing information will be submitted at the time of the building permit application. ❑ For manufactured homes, all submittal requirements on separate sheet titled "Installation of a Mobile Home Located in a Floodplain: Submittal Requirements" have been met. Page 4 of 7 City of Fort Collins Utilities Fit Collins Floodplain Administration (970)416-2632 ❑ If the floodplain use permit is not going to be submitted until the building permit is applied for, then a note is on the plans stating that the floodplain use permit will be submitted at the time of building permit application. ❑ A note is on the plans stating that a FEMA elevation or floodproofing certificate will be completed and approved before the CO is issued. This is required even if property is only in a City floodplain. Drainage Report ❑ The site is described as being in the floodplain. Floodplain name and if the floodplain is a FEMA or City-designated is described. Any floodway or erosion buffer zones on the site are described. ❑ The FEMA FIRM panel # and date and/or the Master Plan information is cited. ❑ A copy of the FIRM panel with the site location marked is included in the report. ❑ If a floodplain modeling report has been submitted, that report is referenced. The reason for the floodplain modeling report is described. ❑ If a FEMA CLOMR or LOMR has been approved for the site, the case number is referenced. The reason for the CLOMR or LOMR is described. ❑ If a FEMA LOMR is required after construction, this is stated in the report. ❑ The location of the structures relative to the floodplain is described. If there is both a FEMA and a City floodplain on the site, the location of the structures relative to both is described. ❑ The use of the structures is described. This is to determine if the structure is residential, non-residential, or mixed-use. Also, structures in all 100-year and Poudre River 500-year floodplains cannot be used as a critical facility. (See Chapter 10 of City Code for definitions.) ❑ If in the Poudre River 100-year floodplain, the requirement to complete an Emergency Response and Preparedness Plan(ERPP) is discussed and the requirement for annual training drills and an annual update in the first quarter of every year is discussed. ❑ The report describes how the development is in compliance with the applicable floodplain regulation(Chapter 10 of City Code). (Examples: elevation of lowest floor above regulatory flood protection elevation, floodproofing, floodway regulation, erosion buffer zone regulation, no-rise, etc.) Page 5 of 7 City of Fort Collins Utilities Fit Collins Floodplain Administration (970)416-2632 ❑ The type of foundation construction for the structures (i.e. slab-on-grade, crawl space, basement, etc.) is discussed in the report. ❑ The type of foundation matches with the lowest floor elevations and grading plan. ❑ If any of the garages are not going to be elevated above the regulatory flood protection elevation, the hydraulic venting requirements are discussed. ❑ For structures in the floodplain, a table is included(same table as on the Drainage/Grading Plan)that lists the following: ❑ City BFE at upstream end of structure ❑ FEMA BFE at upstream end of structure (if different than City BFE) ❑ Regulatory flood protection elevation ❑ Lowest floor elevation(bottom ofbasement or crawl space is considered lowest floor) ❑ F000dproofing elevation for non-residential structures (if applicable) ❑ Garage slab elevation ❑ HVAC elevation ❑ Elevations are referenced to the NAVD 1988 datum. ❑ If the floodplain use permit is not going to be submitted until the building permit is applied for, then a note must be included in the report that states the permit will be submitted at the time of building permit application. ❑ If floodproofing information is not submitted as part of the plans, then a note must be in the report stating that floodproofing information will be submitted at the time of the building permit application. ❑ A note is in the report stating that a FEMA elevation or floodproofmg certificate will be completed and approved before the CO is issued. ❑ In the compliance section, Chapter 10 of City Code is listed. Floodplain Use Permit ❑ Floodplain Use Permit has been submitted for each structure. ❑ Permit fee has been submitted. ❑ All information on permit matches the plans. ❑ All information on permit meets floodplain regulations. Page 6 of 7 City of Fort Collins Utilities Fit Collins Floodplain Administration (970)416-2632 FEMA CLOMR AUproval ❑ FEMA has approved any necessary CLOMRs. ❑ The City has received copies of all updates to the FEMA submittal. Additional Comments: Floodplain terminology is defined in Chapter 10 of City Code. NOTE: Issues specific to individual sites may arise that result in additional requirements. These will be discussed during initial meetings with the applicant. Please refer to Chapter 10 of City Code for specific floodplain regulations. Page 7 of 7 19 APPENDIX B - HYDROLOGIC CALCULATIONS COMPOSITE%IMPERVIOUS CALCULATIONS Subdivision:Polestar Project Name: Polestar Location:Fort Collins Project No.:39797.01 Calculated By: ARJ Checked By: Date: 5/17/24 Paved Roads and Walks Single Family Lots Roofs Landscaping/Lawns Weighted Weighted Weighted Basins Total Weighted%Imp. Basin ID Total Area(ac) %Imp. Area(ac) %Im %Imp. Area(ac) %Im %Imp. Area(ac) %it %Imp. Area(ac) Weighted%Imp. P p p• Al 1.02 100% 0.03 2.9% 45% 0.12 5.4% 90% 0.07 6.0% 2% 0.80 1.6% 15.8% A2 0.60 100% 0.19 31.5% 45% 0.00 0.0% 90% 0.12 17.6% 2% 0.29 1.0% 50.1% A3 0.78 100% 0.08 10.0% 45% 0.00 0.0% 90% 0.12 13.9% 2% 0.58 1.5% 25.3% A4 1.23 100% 0.58 47.6% 45% 0.00 0.0% 90% 0.23 16.7% 2% 0.42 0.7% 65.0% A5 0.42 100% 0.06 14.7% 45% 0.00 0.0% 90% 0.19 41.1% 2% 0.17 0.8% 56.5% A6 1.03 100% 0.61 59.7% 45% 0.09 4.1% 90% 0.05 4.4% 2% 0.27 0.5% 68.7% A7 0.85 100% 0.48 57.2% 45% 0.01 0.5% 90% 0.05 4.9% 2% 0.31 0.7% 63.3% A8 0.58 100% 0.39 66.7% 45% 0.00 0.0% 90% 0.11 16.8% 2% 0.09 0.3% 83.8% A9.1 0.16 100% 0.05 32.2% 45% 0.00 0.0% 90% 0.09 52.0% 2% 0.02 0.2% 84.4% A9.2 0.03 100% 0.01 37.2% 45% 0.00 0.0% 90% 0.01 16.4% 2% 0.01 0.9% 54.5% A10 0.09 100% 0.02 25.8% 45% 0.00 0.0% 90% 0.06 58.7% 2% 0.01 0.2% 84.7% All 0.13 100% 0.04 34.7% 45% 0.00 0.0% 90% 0.05 33.6% 2% 0.04 0.6% 68.8% Al2 0.26 100% 0.06 21.7% 45% 0.00 0.0% 90% 0.03 10.7% 2% 0.17 1.3% 33.7% A13 0.40 100% 0.03 7.2% 45% 0.00 0.0% 90% 0.23 53.1% 2% 0.13 0.7% 61.0% A14 0.09 100% 0.00 0.0% 45% 0.00 0.0% 90% 0.02 19.6% 2% 0.07 1.6% 21.1% A15 0.49 100% 0.06 11.6% 45% 0.00 0.0% 90% 0.06 10.3% 2% 0.38 1.5% 23.5% A16 0.13 100% 0.06 45.0% 45% 0.00 0.0% 90% 0.00 0.0% 2% 0.07 1.1% 46.1% A17 0.43 100% 0.04 9.0% 45% 0.00 0.0% 90% 0.09 19.1% 2% 0.30 1.4% 29.6% A18 0.70 100% 0.17 24.8% 45% 0.00 0.0% 90% 0.16 20.8% 2% 0.37 1.0% 46.6% A19 0.31 100% 0.13 42.8% 45% 0.00 0.0% 90% 0.05 13.4% 2% 0.13 0.8% 57.0% Bl 1.23 100% 0.32 25.6% 45% 0.00 0.0% 90% 0.32 23.3% 2% 0.60 1.0% 49.8% B2 0.31 100% 0.18 58.1% 45% 0.00 0.0% 90% 0.07 19.2% 2% 0.06 0.4% 77.7% Cl 0.28 100% 0.00 1.2% 45% 0.00 0.0% 90% 0.14 44.8% 2% 0.14 1.0% 47.0% C2 0.32 100% 0.02 6.2% 45% 0.00 0.0% 90% 0.08 23.0% 2% 0.22 1.4% 30.5% Dl 0.35 100% 0.20 55.9% 45% 0.00 0.0% 90% 0.03 7.5% 2% 0.13 0.7% 64.1% D2 0.22 100% 0.11 50.1% 45% 0.00 0.0% 90% 0.03 12.0% 2% 0.08 0.7% 62.9% D3 0.16 100% 0.09 53.2% 45% 0.00 0.0% 90% 0.03 16.1% 2% 0.05 0.6% 69.8% D4 0.25 100% 0.14 54.9% 45% 0.00 0.0% 90% 0.01 5.2% 2% 0.10 0.8% 60.9% D5 0.29 100% 0.15 51.3% 45% 0.00 0.0% 90% 0.05 15.3% 2% 0.09 0.6% 67.3% D6 0.28 100% 0.16 57.3% 45% 0.00 0.0% 90% 0.00 0.0% 2% 0.12 0.9% 58.2% D7 0.11 100% 0.07 66.1% 45% 0.00 0.0% 90% 0.02 19.1% 2% 0.01 0.3% 85.5% D8 0.19 100% 0.15 78.9% 45% 0.00 0.0% 90% 0.02 11.4% 2% 0.02 0.2% 90.5% El 2.24 100% 0.41 18.3% 45% 1.10 22.1% 90% 0.00 0.0% 2% 0.73 0.6% 41.1% E2 0.54 100% 0.19 34.6% 45% 0.23 19.1% 90% 0.00 0.0% 2% 0.12 0.5% 54.2% E3 0.31 100% 0.11 35.0% 45% 0.17 23.7% 90% 0.00 0.0% 2% 0.04 0.2% 59.0% Fl 3.92 100% 0.04 1.0% 45% 0.53 6.0% 90% 1.00 22.9% 2% 2.36 1.2% 31.2% Onsite Basins 20.75 47.5% 17W 10.20 45.0% OSl 0.61 100% 0.00 0.0% 45% 0.00 0.0% 90% 0.09 13.5% 2% 0.52 1.7% 15.2% OS2 0.09 100% 0.03 36.0% 45% 0.0% 90% 0.01 13.8% 2% 0.04 1.0% 50.8% X:V970000.e109N701\E.e10.v geV979701 D.i-W Calcs_Templat Q.07A. Pegs I oft 5/17/2024 Table 4.1-3.Surface Type-Percent Impervious Percent Impervious Surface Type 11%) Hardscape or Hard Surface As halt,Concrete ion Rooftop 90 Recycled Asphalt so Gravel 40 Pavers 40 Landscape or Pervious Surface Playgrounds 25 Lawns,Sandy soil 2 Lawns,Clayey soil 2 X:V970000.e11\39N701\E.e10.regrV979701 D.i-W Calcs_Template_v2.07A. Prgr2of2 5/17/2024 COMPOSITE RUNOFF COEFFICIENT CALCULATIONS Subdivision:Polestar Project Name:POlestar Location:Fort Collins Project No.:39797.01 Calculated By:AM Checked Ry: Date:5/17/24 Paved Roads/Ashphak Single Family tots Roofs Lawns Total Area(x) Xydrologic Runoff Runoff Razim Total Weighted Rasim Total Weighted B-10 Area lx) 2-RC 100-YEARC Runoff Coefficient Area(ac) 2-YEARC 100-YEARC Area lac) -.RC 100-YEARC RurwlFCcefliiien[ Arealx) 2-YEARC 300-YEARC 2YEARC 100 YEAR SoilsGmup [oelficlent Coefficient Al 1.02 C 0.95 0.03 a.03 0.03 0.55 0.12 0.0) 0.08 0.95 0.0) 0- 0.08 0.20 D.05 0.01 - 0.17 D.21 A2 O.fia C 0.95 0.19 0.30 0.37 0.55 0.00 a.00 0.00 0.95 0.12 0.19 0.23 0.2a U. OAa OA0 0.49 0.61 A3 O.JB C 0.95 0.08 0.09 a.12 a 55 0.00 0.00 0.00 0.95 0.12 0.15 0.18 0.20 0.00 0.00 0.00 0.24 0.30 A4 1.23 C 0.95 0.58 0.45 0.56 0.55 O.o0 0.00 O.o0 0.95 0.23 0.18 0.22 0.2o a.Da a.00 0.00 0.63 0.)9 A5 OA2 C a- 0.06 0.14 017 0.55 0.00 0.00 0.00 0.95 0.19 0.43 0.54 0.20 0.00 0.00 0.00 0.57 0.72 Afi 1.03 C 0.95 0.61 0.5) 0.)1 0.55 O.a9 - O.a6 0.95 0.a5 O.Os 0.a6 0.2a 0.a4 0.01 OAl 0.6) 0.84 A] 0.65 C 0.95 0A8 0.54 a.fi8 0.55 0.01 0.01 0.01 0.95 0.05 0.05 O.Ofi 0.20 0.01 0.00 0.00 O.fiO O.JS A8 0.58 C 0.95 0.39 0.63 a.]9 a.55 O.o0 a.00 O.o0 0.95 0.11 0.18 0.22 0.2o o.Da a.a0 0.00 0.81 1.00 A9.1 0.16 C 0.95 0.05 0.31 0.38 0.55 0.00 0.00 0.00 0.95 0.09 0.15 0.69 0.20 0.00 0.00 0.00 0.85 1.00 A9.2 0.03 C 1.95 - O.)3 0.9] 1.55 0.00 a.00 0.00 1.95 0.a1 0.3fi 0.44 1.2a U. OAa 0.00 1.08 1.00 A10 0.09 C 0.95 0.02 0.25 a.31 a 55 0.00 0.00 0.00 0.95 0.06 0.62 0.77 0.20 0.00 0.00 0.00 0.8fi 1.00 All 0.13 C 0.95 0.04 0.33 0.41 0.51 O.o0 a.00 O.o0 0.95 0.05 0.35 0.44 0.20 0.Oa a.00 O.a0 0.68 Us A32 0.26 C 0.95 0.06 0.21 0.26 0.55 0.00 0.00 0.00 0.95 0.03 0.11 0.14 0.20 0.00 0.00 0.00 0.32 0A0 A33 0.40 C 0.95 O.a3 OA) O.a9 0.55 0.00 a.00 0.00 0.95 0.23 0.Sfi U. a.2a U. OAa 0.00 0.63 0.79 A14 0.09 B 0.95 0.00 0.00 a.00 0.55 0.00 0.00 0.00 0.95 0.02 0.21 0.26 0.15 0.00 0.00 0.00 0.21 - A15 0.49 B 0.95 0.06 0.11 0.14 0.55 O.o0 a.00 O.o0 0.95 0.a6 0.11 0.14 0.15 a.Da a.00 0.00 0.22 0.27 Alb 0.13 B 0.95 0.06 OA3 0.53 0.55 0.00 0.00 0.00 0.95 0.00 0.0a 0.00 0.15 0.00 0.00 0.00 OA3 0.53 Al) 0.43 C 0.95 O.a4 OA9 0.11 0.55 0.00 - 0.00 0.95 0.a9 a.20 0.25 0.2a U. O.Oa 0.00 0.29 0.36 A18 O.JO B/C 0.95 0.1) 0.24 0.29 a 55 0.00 0.00 0.00 0.95 0.16 0.22 0.27 0.15 0.00 0.00 0.00 0.45 O.SJ A19 0.31 C 0.95 0.13 - 0.51 1.55 O.o0 a.00 O.o0 0.95 0.05 0.14 a.18 0.2o a.Da a.00 0.00 0.55 0.68 B] 1.23 C 0.95 0.32 0.24 0.30 0.55 0.00 0.00 0.00 0.95 0.32 D.25 0.31 0.20 D.00 0.00 0.00 0A9 o- B2 0.31 C 0.95 U. 0.55 0.69 0.55 0.00 a.00 0.00 0.95 0.a7 a.20 0.25 0.2a U. O.Oa 0.00 0.75 0.94 C3 0.28 C 0.95 0.00 - 0.01 a 55 0.00 0.00 0.00 0.95 0.14 0.4) 0.59 0.20 0.00 0.00 0.00 0.48 0.61 C2 0.32 C 0.95 0.a2 O.afi O.a7 0.55 O.o0 a.00 O.o0 0.95 o.a8 0.24 0.30 0.2o a.aa a.00 0.00 U. 0.38 Dl 0.35 B 0.95 0.20 a.53 0.66 0.55 0.00 0.00 0.00 0.95 0.03 0.08 0.10 0.15 0.00 0.00 0.00 0.61 0.76 D2 0.22 C 0.95 0.11 0.48 U. 0.55 0.00 - 0.00 0.95 0.a3 0.13 0.16 0.2a U. O.Oa 0.00 0.60 0.75 D3 0.16 C 0.95 0.09 0.51 0.63 0.55 0.00 0.00 moo 0.95 0.03 0.1J a.tl 0.20 0.00 0.00 0.00 O.fiJ 0.84 D4 0.25 C 0.95 0.14 0.52 a.65 0.55 O.o0 a.00 O.o0 0.95 0.01 0.05 D.a) 0.2o a.aa a.00 OAO 0.58 0.)2 DS 0.29 C 0.95 0.15 - 0.61 1.55 0.00 0.00 0.00 0.95 0.05 0.16 0.20 0.20 a.00 0.00 0.00 0.65 0.81 D6 0.28 C 0.95 OJ6 0.54 U. 2.55 0.00 M 0.00 0.95 0.a0 0.00 0.a0 0.2a U. O.Oa 0.00 0.54 0.68 D) 0.11 C 0.95 O.OJ 0.63 0.78 3.55 0.00 0.00 0.00 0.95 0.02 0.20 0.25 0.20 0.00 0.00 0.00 0.83 1.00 D8 0.19 C 0.95 0.15 O.JS 0.94 4.55 O.A. a.00 O.o0 0.95 - 0.12 0.15 0.2o a.Da a.00 OAO 0.8) 1.00 El 2.24 C 1.95 - a.36 0.41 0.55 1.10 0.2) 0.34 0.95 0.00 D.00 0.00 0.20 D.22 0.02 OA2 0.65 0.81 E2 0.54 N/ 0.95 0.19 0.33 OAI 0.55 0.23 a.23 0.29 0.95 0.a0 O.a0 0.a0 a.15 0.19 0.05 0.0) 0.62 0.77 E3 0.31 B/C 0.95 0.11 0.33 OA2 a 55 0.17 0.29 0.36 0.95 0.00 0.00 0.00 0.15 0.24 0.11 0.14 0.)4 0A9 F3 3.92 C 0.95 0.04 0.01 - a.55 0.53 - 0.09 0.95 1.0a 0.24 0.3a 0.2o a.a6 a.00 O.a0 0.33 0A1 051 0.61 C a- 0.00 a.00 0.00 0.55 0.00 0.00 0.00 0.95 D.09 0.14 0.18 0.20 O.Oa a.00 0.00 0.14 0.18 052 OA9 C 0.95 O.a3 0.34 0.43 0.55 0.00 - 0.00 0.95 0.a1 0.15 J. a.2a O.Oa O.Oa 0.00 0.49 0.61 1aal!-4.ianlnP ClasslRsadpn-PunoP CoeRldanls Lard lxa nlrranmamd.t c Pwd.mld urean estate G.9p Iaw oen: o.ss Metllum Dense G.69 M19h D—v D.PS canln.rcw eommer�al o.Ps Intlustr6al 0.99 una.9elPPPe o a tunas rranslrmn o.xn Gmeneelts, alcultwe G.9G - su SuAxee oaa[ceLRoenea artlscape9r Hard Sudxce eryded Asphalt D.00 D.sO D.sO landsgpoeor PervinuP9urface santly Soil,Fla[Slope<2% 0.10 sanay son.As smppz-> G.ss eep Sbpe> G20 Lawns,Clayey soil,Ftlat Slope<P D.20 y y oll,Ste pl9bpe> 035 xvvl0.wWM1s.Ymos�pmwwmg. mol mmaw_ _mp _E.o,+km veip2.usE 5il'lMaa STANDARD FORM SF-2 TIME OF CONCENTRATION Subdivision:Palestar Project Name:Polestar Location:Fort Collins Project No.:39797.01 Calculated By:ARJ Checked By: Date:5/17/24 SUB-BASIN INITIAL/OVERLAND TBAVELTIME Time at Concentration-tlleck DATA IT) (TJ IT0 FMAL BASIN D.A. Hydrologic ImpeMous Cz. C. L S. ta,zrmr tl,zmvee, Lr Sr X VEL. tz COMP.t,..z re., COMP.tezm,nar TOTAL Urbanized t, t,.zmo, tezm n.. ID I-) SoilsGroup I%) (min) (Mn) (ft) I%) (ft/s) (min) (min) (min) LENGTH(R) (min) Al 1.02 C 16% 0.17 0.21 15 2.0% 24.6 23.5 104 8.8% 5.0 1.5 1.2 25.7 24.6 118.9 10.7 11.0 11.0 A2 0.60 C. 50% 0.49 0.61 42.5 2.D% 27.3 21.9 105 2.1% 20.0 2.9 0.6 27.9 22.5 147.2 10A 11.0 11.0 A3 0.78 C 25% 0.24 0.30 50 4.0% 33.0 30.7 151 2.2% 15.0 2.2 1.1 34.1 31.9 200.7 11.1 11.0 11.0 A4 1.23 C 65% 0.63 0.79 12 3.0% 9.7 6.5 449 1.0% 20.0 2.0 3.8 13.5 10.3 461.1 12.6 13.0 10.0 AS 0.42 C 57% 0.57 0.72 5 2:0% 8.0 5.8 55 1.1% 15.0 1.5 0.6 8.6 6.4 60.0 10.3 9.0 6.0 A6 1.03 C 69% 0.67 0.84 13 2.0% 10.5 6.4 643 0.8% 20.0 1.8 6.0 16.5 12.4 655.5 13.6 14.0 110 A7 0.85 C 63% 0.60 0.75 13 2.0% 12.2 8.5 595 0.9% 20.0 1.9 5.2 17.4 13.7 607.8 13.4 13.0 13.0 A8 0.58 C 84% 0.81 1.00 1 12 1 3,0%1 5.9 2.1 n1l 1.3%1 20.01 2.3 1.6 7.6 3.71 233.4 11.31 8.0 5.0 A9.1 0.16 C 84% 0.0 1.00 5 2.0% 3.7 1.5 67 0.6% 20.2 1 .6 0.7 4.4 2.2 72.0 10.4 5.0 5.0 AU 0.03 C 54% 1.08 1.00 5 2.0% 0.3 1.5 5 10.0% 20.0 6.3 6.0 0.3 1.5 10.0 10.1 5.0 5.0 AID 0.D9 C 85% 0.86 1.00 5 2.0% 3.6 1.5 30 3.4% 15.0 2.8 0.2 3.8 1.7 35.0 10.2 5.0 5.0 All 0.13 C 69% 0.0 0.85 5 2.0% 6.3 3.7 60 2.0% 15.0 2.1 0.5 6.8 4.2 65.0 10A 7.0 5.0 Al2 0.26 C 34% 0.32 0.40 5 2.0% 11.9 10.7 102 0.7% 15.0 1.3 1.3 13.2 12.0 107.3 10.6 11.0 11.0 A13 0.40 B 61% 0.63 0.79 5 2.0% 7.2 4.9 50 1.0% 1SD 1.5 0.6 7.7 S.3 55.0 10.3 8.0 5.0 A14 0.09 B 21% 0.21 0.26 5 2.0% 13.6 12.8 20 2.4% 15.0 2.3 0.1 13.7 12.9 25.0 10.1 10.0 10.0 A15 OA9 a 24% 0.22 0.27 5 2.0% 13.4 12.6 119 1.4% 15.0 118 1.1 14S 133 123.5 10.7 11.0 11.0 A16 0.13 C 46% 0.43 0.53 5 2.0%1 10.21 8.6 54 0.716 15.0 1.3 0.71 10.9 9.31 59.1 10.31 10.0 9.0 A17 0.43 B/C 30% 1 0.29 0.36 5 2.0% 12.4 11.3 113 1.8% 20.0 2.7 0.7 13.1 12.0 118.0 10.7 11.0 11.0 A18 0.70 C 47% OAS OS7 30 3.4% 20.2 16.6 ISO 0.6% 15.0 1.1 2.2 22.4 18.8 180.0 11.0 11.0 11.0 A19 0.31 C 5]% 0.55 0.68 5 3.4% 7.1 5.3 30 3.9% 15.0 3.0 0.2 7.2 5.5 35.0 10.2 7.0 5.0 BS 1.23 C SD% 0.49 0.61 24 2.0% 20A 16.3 175 0.5% 20.0 1.4 2.1 22.4 18.4 199.0 11.1 I1.0 11.0 B2 0.31 C 78% 0.75 0.94 24 2.0% 11.5 5.2 204 1.8% 20.0 2.7 1.3 12.8 6.5 228.0 11.3 11.0 5.0 C1 0.28 C 47% O:48 0.61 3 25.0% 3.1 2.5 54 5.9% 20.0 4.9 0.2 3.3 17 STO 10.3 SD 5.0 C2 0.32 B 31% 0.30 0.38 5 10% 12.1 11.0 62 2.0% 15.0 2.1 0.5 12.6 11.5 67.0 10.4 10.0 10.0 DI 0.35 C 64% 0.61 0.76 24 2.0% 16.3 11.3 54 0.8% 20.0 1.7 0.5 16.9 11.8 78.1 10.4 10.0 100 D2 0.22 C 63% 0.60 0.75 24 2.0% 16.51 11.5 87 0.8%1 20.0 1.7 0.8 17.4 12.4 111.0 10.6 11.0 11.0 D3 0.16 C 70% 0.0 0." 24 2.0% 14.2 8.5 60 0.9% 20.0 1.7 0.6. 14.7 9.1 84.0 10.5 10.0 9.0 D4 0.25 C 61% 0.58 0.72 24 2.0% 17.4 12.6 65 0.8% 20.0 1.7 0.6 18.1 13.3 99.0 10.5 10.0 10.0 D5 0.29 C 67% 0,65 0.81 13 2.0% 11.0 7.1 231 2.0% 20.0 2.9 1.4 12.4 8.4 244.0 11A 11.0 8.0 D5 0.28 C 58% 0.54. 0.68 13 2.0% 13.6 10.3 264 2.0% 20.0 2.8 1.6 15.2 11.9 277.0 11.5 12.0 12.0 D7 0.11 C 85% 0.83 1.00 24 10% 9.0 3.3 60 0A% 20.0 1.7 0.6 9.6 3.9 84.0 10.5 10.0 5.0 OS 0.19 C 90% 0.97 1.00 24 .2.096 7.7 3.3 83 0.8% 20.0 1.7 0.8 8.5 4.1 107.0 10.6 8.0 5.0 El 2.24 C 1 41% 0.02 0.65 130 4.0% 66.3 27.9 505 1.0% 20.0 2.0 4.11 70.5 32.01 635.3 13.51 4.0 14.0 E2 0.54 B/C 54% 0.07 0.62 501 2.0%1 49.71 23.31 2701 I.mI 20.01 2.0 2.3 52.0 25.6 320.0 11.8 12.0 12.0 E3 0.31 B/C 59% 0.14 0.74 50 2.0% 46.1 17.5 143 1.1% 20.0 2.1 1.2 47.2 18.6 193.0 11.1 11.0 11.0 F1 3.92 C 31% O.00 0.33 50 1.0% 66.3 46.6 475 0.5% 20.0 1.4 5.6 71.9 52.2 525.0 12.9 13.0 13.0 051 0.61 C 15% 0.00 0.14 46 1.]% 53.8 46:9 66 1.4% 5.0 0.6 1.9 55.7 48.7 112.0 10.6 11.0 11.0 OS2 0.09 C 51% 0.00 0.49 50 I.Q% 66.51 37.0 MI 3.0%1 20,01 1S 1.0 67S 38.0 265.0 11.5 11,0 ILO NOTES: T=T.+Tr Velocity V=I!*SMo.S Tya.Esma e}smrr. rez� yo r.ncx VMere-T,=T°Gl Time of Cnncentation,minutes T vm t�wade T,=Initialer Overland Flow Time of Concentration,minutes xo.y b.vv�d T,=Channelizetl Flaw In Swale,Gutter or Pipe,minutes T_ :� oe.u�e re ralwrevvwrw,.. Iwmn vem'etm,4lmemlontss VAe,e:G-F.e9rerrcy.4l�mme°t Ext°r.4imewaMess -L.INener°.emm rlo..lm �„m.e+re.. *.•T.e<.M n,,..m X:J91aMPxl1�]9!9]0I�Eacel�OnmegV9l%01 Omim�Cvke Tmrylou vE.0ti6m ego 1 of l 511t2Pt4 STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN (RATIONAL METHOD PROCEDURE) Project Name: Polestar Subdivision:Polestar Project No.:39797.01 Location:Fort Collins Calculated By: AM Design Storm:2-Year Checked By: Date:5 17 24 DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVELTIME STREET - - - - - - e .K REMARKS rp -- ou El 2.24 0.02 14.0 0.06 1.92 0.1 Flow from SWMM 17W 11.7 OSl 0.61 0.00 11.0 0.00 2.13 0.0 OS2 0.09 0.00 11.0 0.00 2.13 0.0 Flow into Pan le 11.8 Flow into Pan 2e E2 O.S4 0.07 12.0 0.04 2.05 0.1 11.9 Flow into.pan and then swale 5.1 11.9 Runoff Drains Into type C-all runoff captured for 2-year event 5.2 11.9 Total runoff into overflow Swale piped flow into the pond Ongrade Inlet-Drains to Pond 3e E3 0.31 0.14 11.0 0.04 2.13� 0.1 Runoff Collected Via Nyloplastic and ADS pipe 19a A19 0.31 0.55 7.0 0.17 2.52'. 0.4 7.00 0.17 2.52 0.4 0.4 0.2 0.5% 12 194 lA 2.3 Drains-Basin A19 Runoff Collected Via Trench Drain and ADS pipe 18a A18 0.70 0.45 11.0 0.32 2.13 0.7 11.0 0.49 2.13 1.01 1.0 0.5 0.5% 18 139 1.4 1.6 Drains-Basin A19 and A18 Runoff Collected Via Nyloplastic and ADS pipe 17. A17 0.43 0.29 11.0 0.12 2.13 0.3 12.6 0.61 2.01 1.2 1.2 0.6 0.3% 38 90 1.2 1.3 Drains-Basin A19,.A78,and A17 Runoff Collected Via Nyloplastic and ADS pipe 13a A13 0.40 0.63. 8.0 0.25 2.40. 0.6 0.6 0.3 0.9% 12 50 1.9 0.4 Drains Basin A13 Runoff Collected Via Nyloplastic and ADS pipe 15a A15 0.49 0.22 11.0 0.11 2.13 0.2 11.0 0.36 2.13 0.8 1 0.1 0.8% 18 90 1.8 0.8 Drains Basin A13,and A15 Runoff Collected Via Nyloplastic and ADS pipe 14a A14 0.09 0.21 10.0 0.02 2.21. 0.0 11.8 0.38 2.07 0.8 0.8 0.02 0.8% 18 70 1.8 0.7 Drains Basin A33,A15,A14 Runoff Collected Via Nyloplastic and ADS pipe 16. A16 0.13 0.43' 10.0 0.06 7.21. 0.1 12.5 0.44 2.02 0.9 0.9 0.1 0.8% 18 140 1.8 1.0 Drains Basin A13,A35,A14 and A16 X:a070000,-979701\Exc-­-9701 Dviw Calyx.Tempi v].07.xL.m Ni I of4 5120/1034 STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN (RATIONAL METHOD PROCEDURE) Project Name: Polestar Subdivision:Polestar Project No.:39797.01 Location:Fort Collins Calculated By: AM Design Storm:2-Year Checked By: Date:S 17 24 DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVELTIME STREET - - - - - - - REMARKS rp ¢ .E o _ Za _ _ l0a A10 0.09 0.86 5.0 0.08 2.85 0.2 0.2 0.1 4.8% 6 60 4.4 0.2 Runoff Collected Via Nyloplastic and ADS pipe 1.1 13.5 0.53 1.95 1.0 1.0 0.5 0.5% 18 30I 1A 0.4 A13,A15,A14,A16+A10 Runoff Collected Via Nyloplastic and ADS pipe 12a Al2 0.26 0.32 11.0 0.08 2.13 0.2 13.9 0.61 1.93 1.2 1.2 0.1 0.5% 18 15 1.4 0.2 A13,A15,A14,A16+A10 and Al2 Runoff Collected Via Nyloplastic and ADS pipe lla All 0.13 0.68 7.0 0.09 2.52 0.2 0.2 0.1 5.0% 6 9 4.5 0.0 A13,A15,A14,A16+A10 and Al2,All 1.2 14.1 1.31 1.92 2.5 2.5 1.3 0.5% 24 90 1.4 1.1 Collected Runoff Basins All-A19 9.1A A9.1 0.16 0.85 5.0 0.14 2.85 0.4 0.4 0.1 2.5% 8 20 3.2 0.1 9.2a A9.2 0.03 1.08 5.0 0.03 2.85, 0.1 1"2 14' . 1*'6 2.7 2.7 1.5 0.5% 24 230 1.4 2.7 Total Runoff Basins 9.1a-19a Court-yard Sa AS 0.42 0.57 9.0 1 2.30 0.6 Drains to nyloplatic and type C inlets 1.3 . 2.9 2.9 1.7 1 24 400 LA 4.7 Runoff drains to sump inlet at Dp 7a 7a A7 0.85 0.60 13.0 0.51 1.98 1.0 1.4 22.6 2.23 1.51 3.4 3.4 22 0.5% 24 22 1.4 0.3 Runoff From alley and temple frontage 8. A8 0.58 0.81 8.0 0.47 2.40 1.1 1.1 0.47. 0.87% 217 1.9 1.9 Drains to Plum Street Basin AB Runoff From alleys and temple frontage 4a A4 1.23 0.63 23.0 0.77 1.98' 1.5 13.0 1.24 1.98 2.5 2.5 0.77 1 83 1.9 0.7 Basins A8 and A4 Runoff From alleys,open space and temple frontage 3a A3 0.78 0.24 11.0 0.19 2.13 0.4 13.7I 1.43 1.94 2.8 2.8 0.19 0.87% 74 1.9 0.7 Basins A8,A4,and A3 Runoff From alleys,open space and temple frontage 2a A2 0.60 0.49 11.0 0.29 2.13 0.6 14.4 1.72 1.90 3.3 3.3 0.29 0.70% 118 1.7 1.2 Basins A8,A4,and A3,A2 Total infow to sump inlet at DP 6a 6a A6 1.03 0.67 14.0 0.69 1.92 1.3 15.6 2.41 1.83 4.4 Basins A6,A8,A4,and A3,A2 Toatl runoff into Sand Filter Forehay-Basin A2-All 1.5 22.9 4.64 1.49 6.9 6.9 4.6 0.5% 30 X:V070000,a 979a31E,elln,ai­ 970I Dviw Calyx.Tempi v].07.xL.m Ni pf4 5120/1034 STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN (RATIONAL METHOD PROCEDURE) Project Name: Polestar Subdivision:Polestar Project No.:39797.01 Location:Fort Collins Calculated By: AM Design Storm:2-Year Checked By: Date:S 17 24 DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVELTIME STREET - - - -c - - e .K REMARKS o. ca a arp -, _ _ _ _ 2 m '-° � _ -- £ a a a a o ou Al 1.02 0.17 11.0 0.17 2.13 0.4 Overflow into the Polestar Detention Pond 1.6 22.9 4.81 1.49 7.2 7.2 0.5% 30 Overflows and is then Piped in Type D inlet 16 81 1.23 0.49 11.0 0.60 2.13 1.3 26 B2 0.31 0.75 11.0 0.24 2.13 0.5 Run-off into rain garden 2.1 K0.252.21 1.8 6.S%, 12 Overflow into pond Runoff into RG lc C1 0.28 0.48 5.0 0.14 2.85 0.4 Runoff Into RG 2c C2 0.32 0.30 10.0 0.10 2.21. 0.2 0.2 0.43% 10 7d D7 0.11 0.83' 10.0 0.09 2.21 0.2 Rd DS 0.19 0.87, 8.0 0.16 2.40 0.410.0 Runoff into rain garden 3.1 10.0 OAS 2.21 1.1 1.1 4.4% 12 Overflow Into pond piped In ADS Pipe X:1i070000-979701\Exc-­-970I rivi g Calyx.Te IiMe v2.07.xism Ni 5120/2024 STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN (RATIONAL METHOD PROCEDURE) Project Name: Polestar Subdivision:Polestar Project No.:39797.01 Location:Fort Collins Calculated By: ARJ Design Storm:2-Year Checked By: Date:5 17 24 DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVELTIME STREET - - - - - - e .K REMARKS m '-° � _ -- a a Vw ou oCir Basin D1 ld Dl 0.35 0.61 10.0 0.21 2.21 0.5 Drains via curb cut to RG 2d D2 0.22 0.60 11.0 0.13 2.13 0.3 11.0 0.34 2.13 0.7 Basins DS and 02 Drains via curb cut to RG 3d D3 0.16 0.67 10.0 0.11 2.21 0.2 11.0 0.45 2.13 1.0 Basins 1 and D3 Runoff into rain garden 4.1 11.0 OAS 2.13 1.0 1.0 0.5% 18 60 LA 0.7 Overflow Into pond Runoff into RG Sd DS 0.29 0.65 11.0 0.19 2.13 0.4 Total Runoff into RG 4d D4 0.25 0.58 10.0 0.14 2.21 0.3 11.0 0.33 2.13 0.7 Piped runoff into type C inlet 4.2 11.7 0.78 2.01 1.6 1.6 0.5% 18 173 1.4 2.0 Runoff Drains into RG Drains via Curb Cut 6d D6 0.28 0.54 12.0 OAS 2.05 0.3 Runoff Drains into Polestar Detention Pond 4.3 13.1 0A3 1.94 1.8 1.8 0.8% 18 Piped Basin D6-01 Notes: Street and Pipe C•A values are determined by O/i using the catchment's intensity value. X:1i970000,all\3979701\Fscelln��a 97970IDdw Calyx.Tempii Pa9e41r4 5120/1034 STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN (RATIONAL METHOD PROCEDURE) Proj-N-:Polestar Subdivision:Polestar PrpjeR No.:39797.01 Incation:Fort Collins Calculated By:AM Design Stwm:100-Year Checked By: Date:5 1]24 DIRECT RUNOFF TOTALRUNOFF STREET PIPE TRAYELTIME STREET - o _ .. REMARKS O O O" - - E1 2.24 0.65 14.0 1.45 6.71 9.7 Flow from SW MM 17W 59.9 O51 0.61 0.14 11.0 0.091 7.421 0.7 OS2 0.09 0.49 11.0 004 7.42 0.3 Flow.into Pan le 70.6 Flow into Pan 2e E2 0:54 0.62 12.0 0.33 7.L6 2.4 73.0 Flow into pao.and then swage 5.1 3113 Runoff Drains into type C-with 11 of head inlet-42.]ds Grains id[o Swale 5.2 73.0 Total runoff Into overflow swage piped flow into the pond Degrade inlet-Dains[o Pond 3e E3 0.31 0.74 11A 0:23 7.42 1.7 Runoff Collected Via Nytopl-1 and ADS pipe 19. A19 0.31 0.68 5.0 0.21 9.95 2.1 5.001 0.21 9.951 2.1 2A 0.2 0.5% 121 L941 1.41 2.3 Drains-Basin A39 Runoff Colleded Via Trench Drain and ADS pipe Me A18 0.70 0.57 11.o 0.40 7.42 3.0 I1.0 D.61 7.42 4.5 4.5 0.6 0.5% 18 139 1.4 l.fi Drains-Basin A39 and A18 Runoff Collected Via Nyloplastic and ADS pipe 17a Al] 0.43 0.35 11.0 0-16 7.42 1.2 12.6 0.77 7.02 5.4 5.4 0.8 0.3% 18 90 1.2 1.30rains-Basin A39,AS8,and All Runoff Collected We Nyloplastic and ADS pipe. 13, A13 0.40 0.79 5.0 0.31 9.95 3.1 3.1 0.3 0.9% 12 50 1.9 0.4 Drains Basin Ala Runoff Colleded Via NylopiasdC and ADS pipe 15a A DA9 0.27 11.0 0.34 7.42 1.0 11A 0,45 7.42 3:3 3.3 0A 0.8% 18 90 1.8 0.8 Drains Basin All,and A15 Runoff Colleded Via Nyloplastic and ADS pipe 14a A14 0.09 0.26 10.0 VI2 7.72 0.2 11.8 0,47 7.21 :14 3.4 0.02 0.8% 18 70 1.8 0.7 Drans-n A13,A15,A14 Runoff Colleded Via NylopJ-1 and ADS pipe 16. AI6 GAS 0.53 9.0 0.07 8.03 0.6 12.5 054 T 3.8 18 0.1 0.9% 18 140 1.8 10 Grans Basin All,A35,A14 and A16 10. A10 0.09 1.00 5.0 0.09 9.95 0.9 0.9 0.1 4.8% 61 60111 4.4111 0.2 ��FIBaIIII�� Runoff Colleded Via Nyloplastic and ADS pipe 1.1 4,31 0.61 0.5% 18 30 1.4 0AW3,AIS;A34,A16♦A10 Runoff Colleded Vla Nyloplasic and ADS pipe 12. Al2 0,26 0.40 11.0 0.10 7.42 0.7 13.9 0.73 6.73 .4.9 4.9 0.1 0.5% 18 15 1.4 0.2 A13,A15,A34,A36+Al0and Al2 Runoff ColleRed Vla Nyloplastic and ADS pipe lla All 0.13 0.85 5.0 0.11 9.95 1.1 1.1 0.1 5.0% 6 9 4.5 0.0 A13,All,A34,A16t A10 a nd Al2,All 1.2 1 1 1 1 14.1 1.61 6.69 10.8 10.8 1.6 0.5% 24 90 1.4 1.1 Collected Runoff Basins All-A19 9.1A A9.1 0.16 1.W 5.0 0.16 9.95 1.6 1.6 0.2 2.5% 8 20 3.2 0.1 9.2a A9.2 0.03 1.W 5.0 0.03 9.95 0.3 15.2 1.80 6.48 11.7 11.7 1.9 0.5% 24 230 1.4 2.7 Total Runoff Basins 9.1a-19a Court-yard 5. AS 0.42 0.72 6.0 0.30 9.31 2.8 Drainsto nytoptatic and type Cinlets 1.3 37.9 2XlQ. $ �L23 32.5 2.1 0.5% 24 400 1.4 4.7 x.Vs'iowp.aWSlYmncweAO�emaaevVzafii p,ameb�cola rzmphR vz.ptabm v.iael�I-uzlrp.a STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN (RATIONAL METHOD PROCEDURE( Proj-Name:Polestar Subdivision:Polestar Project No.:39797.01 Location:Fort Collins Calculated By:AM Design Storm:100-Year Checked By: Date:5 1]24 DIRECT RUNOFF TOTALRUNOFF STRE]..,7 PIPE TRAYELTIME STREET S _ _ ,r REMARKS ra E O d oT' tosump i11111Dp7a ]a A] D.BS 0.75 13.0 0.64 fi.92 4.41.4 22 6: 2.74 5.25 14.4 14.4 27 g59F 24 R 1A p:3Runoff From alley and templefrontageRa AB: 0.58 1.00 5.0 0.58 9.95 SS 5.8 0.58 217 TA 19 Drains to Plum Street Basin A8Runoff From alleys and temple frontage 4a M 1.23 0.79 10.0 0.97 7.72 7.5 10.0 L55 7.72 12.0 12.0 0.97 83 11 1.7 Basins AeandA4 Runoff From alleys,open space and temple frontge3a A3 0.73 0.30 11.0 D24 7A2 1.8 11A. L79 7.42 13.3 13A 0.24 74 1.9 0.7 Basins A8,A4,and A3 Runoff From alleys,open space and temple frontage 2a A2 0.60 0.61 1L0 036 7.42 2.7 11.7 2.15 7.24 15.6 15,6 0.36 0.70% lib 1.7 1.2 Basins A8,A4,and A3,A2 Total infow to sump inlet at DP fia E. Ab 1.03 0." 12.0 0.86 7.16 6.2 12.9 3.01 6.94 20.9 Basins A6,AS,A4 and A3,A2 Toa l runoff Into Sand Filter Forebay-Basin A2-A19 LS 22.9 5.75 5.21 30.0 30.0 5.7 0.5% 30 Al 1.02 0.21 I1.0 0.21 7.42 LIS Overflow Into the Polestar Detention Pond L6 22.9: 5.95 5.21 31.1 311 0.5% 30 MS ff od is then Piped In Type D inlet Ib BI 1.23 D.61 11.0 0.75 7.42 5.6 lb B2 0.31 0.94 5.0 0.30 9.31 2.8 Run-off Into rain garden L 2 A no 1.05 7A2 7:8 7.8 6.5% 12 Overflow into pond Runoff Into RG Ls CI 0.29 0.61 5.0 0.17 9.95 1.7 Runoff Into RG 2:c C2 0,32 0.38 10.0 0.12 7.72 0.9 0.9 0.43% 10 update to SD inches in dh 7d D7 0.11 1.00 5.0 0.11 9.95 1.1 Rd DR 0.19 LOG 5.0 0.19 S.95 1.9 5.0 0.30 9.95 3.0 Ronpff Into rain garden 3.1 10.0 0.59 7.72 4.6 4.6 4.4%. 12 Overfl[.nt' ondplpedin ADSplpe Basin D1 Id 01 0.35 0.75 10.0 0:27 7.72 2.1 Drains via curb­RG RG 2d D2 0.22 0.75 11.0 0Ab 7.42 1.2 11.0 0.43 7.42 3.2 1 1 Basins D3 and D2 Drains via curb cut.RG 3d D3 D.16 3.84 9.0 0.. 8.03 1.1 11.0 0.57 7.42 4.2 Baatns D1,O2 and D3 Runoff Into rain gaMen 4.1 11A 0.57 7.42 42 4.2 0.5% 18 60 1.4 0.70verFlow Into pbnd Runoff Into RG Sd D5 0.29 0.81 8.0 0.24 8.38 2.0 Total Runoff Into RG 4d D4 0.25 0.72 To.0 0.18 7.72 1.4 10.0 0.42 7.72 3.2 Piped runoff into 1ypeC i01et 4.2 117 0.99 7.24 72 1.2 O, 18 M 1.4 "4 Runoff Drains into RG Dame via Curb Cu, Ed Dfi 0.28 0.68 12.0 0.19 7.1b 1.4 R ffOrainsimo Poleafar0-ibn For 4.3 13.7 1.18 6.77 8:0 B.0 0.8%. 18 Pipetl Basin D6-01 Notes: Street and Pipe.C-A values are determined by q]i using the catchment's intens'dy valu, x.uvrmm.aWSlYmncwenD�emaaevVrifii o.awy�cola rzmphR vz.orabm ease-or..!rzVzury PIPE OUTFALL RIPRAP SIZING CALCULATIONS subdivision:Polestar Project Name:Polestar Location:Fort Collins ProJect No.:39797.01 Calculated By:ARJ Checked By: Date:5 17 24 STORM DRAIN SYSTEM DESIGN POINT-2.1 DESIGN POINT-3.1 DESIGN POINT-4.3 Design Point SA Design Point-3e DESIGN POINT-1.S Notes Quo(cfs): 7.8 4.6 8.0 30.3 1.7 30.0 Conduit Pipe Pipe Pipe Pipe pipe Pipe D„Pipe Diameter(in): 12 12 18 30 15 30 W,Box Width(ft): N/A N/A N/A N/A N/A N/A H,Box Height(it): N/A N/A N/A N/A N/A N/A Y„Tailwater Depth(ft): 0.40 0.40 0.40 1.88 0.40 1.88 If unknown,use Y,ID,Im-H)=0.4 Yr/Bc or Y,1H 0.40 0.40 0.27 0.75 0.32 0.75 Pond Tw assumed to be at.75 Yt/H for DP 1.5 Q/D2.1 or Q/(WH") 7.79 4.55 1 2.90 3.07 0.98 3.03 Supercritical? Yes Yes Yes Yes Yes Yes Yn,Normal Depth(ft)[Supercritical]: 0.72 0.58 0.63 0.87 0.53 2.50 D a,H.(in)[Superentical]: 0.86 0.79 1.07 1.68 0.89 2.50 Riprap dso(in)(Supercritical]: 6.76 4.05 6.50 3.36 1.46 2.95 Riprap dso(in)(Subcritical]: N/A. N/A N/A N/A N/A. NIA Required Riprap Size: L L L L L L Fig.9-38 a!Fig.9-36 of o(1.); 9 9 9 9 9 9 Expansion Factor,1/12 tan0): 3,00 3.00 3.00 3100 3.00 3.00 Read from Fig.9-35 or 9-36 0: 0.17 0.17 0.17 0.17 0.17 0.17 Erosive Sails? No. No No No Yes No Area of Flow,A,(ft'): 1.11 0.65 1.14 4.33 0.34 4.28 A,Q/V Length of Protection,L,(it): 5.3 1.9 4.1 -0.6 -1.2 -0.7 L=(1/(2 tan 0))(At/Yt-D) Min Length(ft) 3,0 3.0 4.5 7.5 3.8 7.5 Min L=3D or 3H Max Length(ft) 10.0 10.0 15.0 25.0 12.5 25.0 Max L=10D or 10H Min Bottom Width,T(ft): 2-8 1.6 2.8 2.3 0.9 2.3 T=2-(L,-tan0)+W Design Length(ft) 6.0 3.0 4.5 7.5 3.8 7.5 Design Wldth(ft) 2.8 1.6 2.8 2.3 0.9 2.3 Riprap Depth(in) 18 18 18 18 18 18 Depth=2(dsa) Type It Bedding Depth(in)' 6 6 6 6 6 6 "Not used if Soil Riprap Cutoff Wall No No, No: Yes No Yes Cutoff Wall Depth(ft) 2.0 10 Depth of Riprap and Base Cutoff Wall Width(ft) 8.3 8.3 Note:No Type It Base to be used if Soil Riprap is specified within the plans .For use when the flaw in the culvert is supercritical(and less than full). x-xw-979mr-D a 70i �_cda.._'re pl. ,z0'i.xum Pen,r 1 srnn0zs 6+Eap.mla ANIM a r - fIH 5 B ga o a o b 6 / I- TAILWATER DEPTH/CONDUIT HEIGHT.Yr/D f liu'n v-}<,Fipxr•In.lunar l.r rllrulxr rns•tu P• 9•E.Pa.lw Ami. 7 6 a 3 I/e b' z 0 0 .1 2 .S • 3 .6 .r e 9 10 TAILWATER DEPTH/CONDUIT HEIGHT-YI/H Tits.9-36.E.P..W./.nor 1'.r feclnd.l.r—d.11. x--979Ml—o.a-701—W cuG._ plat.z.oT.k. N 2—s;i�noza OVERFLOW CHANNEL CC - RIPRAP CALCULATIONS Subdivision: Polestar Village Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Calculated By: ARJ Checked By: Overflow at DP 5.1 Date: 5/21/24 RIP-RAP METHOD-ISBASH Method D50=stone size(ft) — a" V a=average channel velocity(ft/s) G s=specific gravity of stone G " — 1 G=gravitational constant(ft/s A2) �j J C=0.86 for high turbulence zones 1.20 for low turbulence b zones Pay Item Percent of Material Typical Typical Stone Stone Stone Size Smaller Than rLSU� Dimensions' 3V'0gheiRhl'' Value Units Typical(Tnehes) Slone (Inches} (1'omtds) Va 8.5 ft/s 70-100 12 95 Gs 2.5 50-�o U 35 �PTa1' 35-50 6 10 Gs 32.2 (ft/s A2) 2-10 2 a.a C 1 70-100 15 160 Rtprip g 50-70 l2 85 35-50 9 35 2-10 3 1.3 70-100 21 440 D(50) 0.75 feet aturap 12 50-70 is 275 35-50 12 85 D(50) 1 91 inches 1 2-10 4 3 100 30 0280 lvpnp 1a 50-70 24 650 35-50 LS 275 *using type L riprap-9" 2-10 6 10 100 42 3500 Riluap 24 50-70 33 1700 35-50 24 fi50 2-10 9 3S 'd-50=nominal stnne size based©n typical rack mass 'e<ryivalent7 eaical diameter •bated t l 111eific g—i,ty-2 5 Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Calculated By: ARJ Checked By: Date: 5/17/24 Private Drains v t v CL G1 v H *' 0 N !Z o a ° c '^ 00 - a a a° 0 v c o C a` 19a 2.1 0.50% 0.93 12 18a 4.5 0.50% 1.25 18 17a 5.4 0.34% 1.43 18 13a 3.1 0.90% 0.97 12 15a 3.3 0.78% 1.02 18 14a 3.4 0.78% 1.03 18 16a 3.8 0.78% 1.07 18 10a 0.9 4.75% 0.44 6 1.1 4.3 0.50% 1.22 18 12a 4.9 0.50% 1.28 18 11a 1.1 5.00% 0.48 6 1.2 10.8 0.50% 1.72 24 9.1A 1.6 2.50% 0.62 8 9.2a 11.7 0.50% 1.78 24 4.1 4.2 0.47% 1.23 18 4.2 7.2 0.50% 1.48 18 3.1 1 4.6 1 4.40% 0.83 12 2.1 1 7.8 1 6.54% 0.941 12 2c 1 0.9 1 0.43% 0.711 10 n=0.013 See Equation Below: Minimum Diameter Gf Circular Pipe Under Fall Flaw Conditions Coo' 5 a I ,� I inhere Depth y is constant. D =diameter of pipe(ft) CO =2.16 fvr USCS units 0 =flow(ft i sec) n =Marmirug's roughness coefficient S =slope(fun) X:\3970000.all\3979701\Excel\Drainage\3979701 Drainage_Calcs_Template_v2.07.xlsm Page 1 of 1 5/17/2024 20 APPENDIX C - HYDRAULIC CALCULATIONS Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate 12"Pedestrian Nyloplast Head(ft) 0.2 Properties Orifice Flow Area(in) 50.6 Orifice Flow Area(ft) 0.35 Weir Flow Perimeter(in) 43.25 Weir Flow Perimeter(ft) 3.60 Solution Capacity(cfs) 0.75 Capacity(gpm) 337.28 Design Point 100 YR(cfs) 9.1a 1.6 No of inlets 3 Total Cap.(cfs) 2.25 FS 1.42 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 g=Gravitational Constant(32.2sf2� `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate IType C Head(ft) 0.1 Properties Orifice Flow Area(in) 907.2 Orifice Flow Area(ft) 6.30 Weir Flow Perimeter(in) 144.00 Weir Flow Perimeter(ft) 12.00 Solution Capacity(cfs) 1.26 Capacity(gpm) 567.12 Design Point 100 YR(cfs) 9.2a 0.3 No of inlets 1 Total Cap.(cfs) 1.26 FS 4.23 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient Note:using CDOT Type C Inlet L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 t ns \f g=Gravitational Cotant(32.252 `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input //AM Type of Grate 15"Pedestrian Nyloplast Head(ft) 0.17 Properties Orifice Flow Area(in) 81.25 Orifice Flow Area(ft) 0.56 Weir Flow Perimeter(in) 54.25 Weir Flow Perimeter(ft) 4.52 Solution Capacity(cfs) 1.06 Capacity(gpm) 473.58 Design Point 100 YR(cfs) 10a 0.9 No of inlets 1 Total Cap.(cfs) 1.06 FS 1.18 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 g=Gravitational Constant(32.2sf2� `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate 18"Drop In Nyloplast Head(ft) 0.6 Properties Orifice Flow Area(in) 84.61 Orifice Flow Area(ft) 0.58 Weir Flow Perimeter(in) 48.00 Weir Flow Perimeter(ft) 4.00 Solution Capacity(cfs) 2.18 Capacity(gpm) 976.83 Design Point 100 YR(cfs) 11a 1.1 No of inlets 1 Total Cap.(cfs) 2.18 FS 1.99 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 g=Gravitational Constant(32.2sf2� `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate 24"Drop In Nyloplast Head(ft) 0.4 Properties Orifice Flow Area(in) 164.94 Orifice Flow Area(ft) 1.14 Weir Flow Perimeter(in) 66.28 Weir Flow Perimeter(ft) 5.52 Solution Capacity(cfs) 3.46 Capacity(gpm) 1554.81 Design Point 100 YR(cfs) 12a 0.7 No of inlets 1 Total Cap.(cfs) 3.46 FS 4.67 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient Note:Additional inlets one 12" -Drop in inlet and one 18"drop in inlet L=Perimeter of Grate Opening(ft)H=Flow Height of Water SurfaceAbove Weir(ft) have been added to capture flow along this run associated with DP 12a along the swale and at Tee's CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 t ns \f g=Gravitational Cotant(32.252 `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate 18"Drop In Nyloplast Head(ft) 0.55 Properties Orifice Flow Area(in) 84.61 Orifice Flow Area(ft) 0.58 Weir Flow Perimeter(in) 48.00 Weir Flow Perimeter(ft) 4.00 Solution Capacity(cfs) 2.08 Capacity(gpm) 935.24 Design Point 100 YR(cfs) 13a 3.1 No of inlets 3 Total Cap.(cfs) 6.25 FS 2.03 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 t ns \f g=Gravitational Cotant(32.252 `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input //RYA Type of Grate 12"Drop In Nyloplast Head(ft) 0.3 Properties Orifice Flow Area(in) 39.75 Orifice Flow Area(ft) 0.27 Weir Flow Perimeter(in) 33.31 Weir Flow Perimeter(ft) 2.78 Solution Capacity(cfs) 0.72 Capacity(gpm) 324.50 Design Point 100 YR(cfs) 14a 0.2 No of inlets 1 Total Cap.(cfs) 0.72 FS 4.68 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 t ns \f g=Gravitational Cotant(32.252 `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input //t= Type of Grate 18"Drop In Nyloplast Head(ft) 0.2 Properties Orifice Flow Area(in) 84.61 Orifice Flow Area(ft) 0.58 Weir Flow Perimeter(in) 48.00 Weir Flow Perimeter(ft) 4.00 Solution Capacity(cfs) 1.19 Capacity(gpm) 534.73 Design Point 100 YR(cfs) 15a 1.0 No of inlets 2 Total Cap.(cfs) 2.38 FS 2.29 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 g=Gravitational Constant(32.2sf2� `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate 12"Drop In Nyloplast Head(ft) 0.2 Properties Orifice Flow Area(in) 39.75 Orifice Flow Area(ft) 0.27 Weir Flow Perimeter(in) 33.31 Weir Flow Perimeter(ft) 2.78 Solution Capacity(cfs) 0.59 Capacity(gpm) 264.96 Design Point 100 YR(cfs) 16a 0.6 No of inlets 2 Total Cap.(cfs) 1.18 FS 2.10 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 g=Gravitational Constant(32.2sf2� `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate 18"Drop In Nyloplast Head(ft) 0.1 Properties Orifice Flow Area(in) 84.61 Orifice Flow Area(ft) 0.58 Weir Flow Perimeter(in) 48.00 Weir Flow Perimeter(ft) 4.00 Solution Capacity(cfs) 0.42 Capacity(gpm) 189.06 Design Point 100 YR(cfs) 17a 1.2 No of inlets 6 Total Cap.(cfs) 2.53 FS 2.13 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient Note:6 inlets along shallow swale designed to capture flow L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 t ns \f g=Gravitational Cotant(32.252 `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input AAAType of Grate 18"Drop In and Trench drain Nyloplast Head(ft) 0.1 Trench Drain Properties Inlet Length (ft) 133 Orifice Flow Area(in) 84.61 Opening(in) 5 Orifice Flow Area(ft) 0.58 Area-(ft) 55.42 Weir Flow Perimeter(in) 48.00 Perimeter(ft) 266.83 Weir Flow Perimeter(ft) 4.00 Capacity 28.10 Solution Capacity(cfs) 0.42 Capacity(gpm) 189.06 Design Point 100 YR(cfs) 18a 3.0 No of inlets+Trench Drain 2 Inlets and 1 Trench drain Total Cap.(cfs) 28.94 FS 9.75 Qweir=CLH3/2 C=3.33 Weir Discharge Coefficient Note:Trench drain along shallow swale designed to capture flow t=Perimeterof Grate opening(ft)H=Flow Height o f Water Surface Above Weir(ft) Swale is at 0.5%One Small 8"inlet to capture nuisance flows in this basin Ql.fKa=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice Utz g=Gravitation¢!Constant�32.2fftt///I s� H=Depth a f Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate 12"Pedestrian Nyloplast Head(ft) 0.15 Properties Orifice Flow Area(in) 50.6 Orifice Flow Area(ft) 0.35 Weir Flow Perimeter(in) 43.25 Weir Flow Perimeter(ft) 3.60 Solution Capacity(cfs) 0.65 Capacity(gpm) 292.09 Design Point 100 YR(cfs) 19a 2.0 No of inlets 4 Total Cap.(cfs) 2.60 FS 1.27 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 t ns \f g=Gravitational Cotant(32.252 `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate 24"Dome Nyloplast Head(ft) 0.375 Properties Orifice Flow Area(in) 265.19 Orifice Flow Area(ft) 1.83 Weir Flow Perimeter(in) 71.47 Weir Flow Perimeter(ft) 5.96 Solution Capacity(cfs) 4.55 Capacity(gpm) 2044.06 Design Point 100 YR(cfs) 2.1 7.8 No of inlets 2 Total Cap.(cfs) 9.11 FS 1.17 Qwnr=CLHa!'- C=3.33 Weir Discharge Coefficient L=Perimeter of Grate Opening(ft) H=Flow Height of Water Surface Above Weir(ft) Qo,j,=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(ftz g=Gravitational Constant l(32.2 f) H=Depth of WaterA bone Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate 18"Dome Nyloplast Head(ft) 0.33 Properties Orifice Flow Area(in) 170.74 Orifice Flow Area(ft) 1.18 Weir Flow Perimeter(in) 53.85 Weir Flow Perimeter(ft) 4.49 Solution Capacity(cfs) 2.88 Capacity(gpm) 1290.68 Design Point 100 YR(cfs) 3.1 4.6 No of inlets 2 Total Cap.(cfs) 5.75 FS 1.25 Qwnr=CLHa!'- C=3.33 Weir Discharge Coefficient L=Perimeter of Grate Opening(ft) H=Flow Height of Water Surface Above Weir(ft) Qo,j,=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(ftz g=Gravitational Constant l(32.2 f) H=Depth of WaterA bone Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate IType C Head(ft) 0.20 Properties Orifice Flow Area(in) 907.2 Orifice Flow Area(ft) 6.30 Weir Flow Perimeter(in) 144.00 Weir Flow Perimeter(ft) 12.00 Solution Capacity(cfs) 3.57 Capacity(gpm) 1604.07 Design Point 100 YR(cfs) 6d 1.4 No of inlets 1 Total Cap.(cfs) 3.57 FS 2.55 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient Note:using CDOT Type C Inlet L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 t ns \f g=Gravitational Cotant(32.252 `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input //AM Type of Grate 18"Dome Nyloplast Head(ft) 0.25 Properties Orifice Flow Area(in) 170.74 Orifice Flow Area(ft) 1.18 Weir Flow Perimeter(in) 53.85 Weir Flow Perimeter(ft) 4.49 Solution Capacity(cfs) 1.87 Capacity(gpm) 838.32 Design Point 100 YR(cfs) 4.1 4.2 No of inlets 4 Total Cap.(cfs) 7.47 FS 1.78 Qwnr=CLHa!'- C=3.33 Weir Discharge Coefficient L=Perimeter of Grate Opening(ft) H=Flow Height of Water Surface Above Weir(ft) Qo,j,=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(ftz g=Gravitational Constant l(32.2 f) H=Depth of WaterA bone Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate IType C Head(ft) 0.6 Properties Orifice Flow Area(in) 907.2 Orifice Flow Area(ft) 6.30 Weir Flow Perimeter(in) 144.00 Weir Flow Perimeter(ft) 12.00 Solution Capacity(cfs) 14.13 Capacity(gpm) 6340.64 Design Point 100 YR(cfs) 4d 3.2 No of inlets 1 Total Cap.(cfs) 14.13 FS 4.41 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient Note:using CDOT Type C Inlet L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 t ns \f g=Gravitational Cotant(32.252 `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Design Storm: 100-Year Calculated By: ARJ Checked By: Date: May-24 Input Type of Grate IType C Head(ft) 1 Properties Orifice Flow Area(in) 907.2 Orifice Flow Area(ft) 6.30 Weir Flow Perimeter(in) 144.00 Weir Flow Perimeter(ft) 12.00 Solution Capacity(cfs) 30.32 Capacity(gpm) 13608.56 Design Point 100 YR(cfs) 5.1 30.3 No of inlets 1 Total Cap.(cfs) 30.32 FS 1.00 Q,,.,;r=CLH31= C=3.33 Weir Discharge Coefficient Note:using CDOT Type C Inlet L=Perimeter of Grate Opening(ft) H=Flow Height of Water SurfaceAbove Weir(ft) Q,rtfic.=CA 2gh C=0.60 Orifice Discharge Coefficient A=Area of the Orifice(,ft2 t ns \f g=Gravitational Cotant(32.252 `` H=Depth of Water Above Center of Orifice(ft) uses the lesser of these two equations DISCLAIMER:SAFETY FACTORS ARE NOT INCLUDED IN THESE CALCULATIONS.ACTUAL CALCULATIONS SHOULD BE CARRIED OUT AND VERIFIED BY THE DESIGN ENGINEER TAKING INTO ACCOUNT ALL LOCAL CONDITIONS.NYLOPLAST RECOMMENDS USING A REV 2.1.21 MINIMUM SAFETY FACTOR OF 1.25 FOR PAVED AREAS AND 2.0 FOR TURF AREAS.ADS/NYLOPLAST IS NOT RESPONSIBLE FOR MISUSE OF THIS TOOL. MHFD-Inlet Version 5.03(August 2023 • � C � ' � • ' • • ' • • • (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Project:Polestar Inlet ID:Inlet DP 6a T r,ye,, T. STREET � p CROWN 3 � e Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK= 13.0 ft Side Slope Behind Curb(leave blank for no conveyance credit behind curb) SBACK= 0.020 ft/ft Manning's Roughness Behind Curb(typically between 0.012 and 0.020) nBACK= 0.016 Height of Curb at Gutter Flow Line HCURB= 6.00 inches Distance from Curb Face to Street Crown TCRowN= 16.0 ft Gutter Width W= 2.00 ft Street Transverse Slope Sx= 0.020 ft/ft Gutter Cross Slope(typically 2 inches over 24 inches or 0.083 ft/ft) SW= 0.083 ft/ft Street Longitudinal Slope-Enter 0 for sump condition So= 0.000 ft/ft Manning's Roughness for Street Section(typically between 0.012 and 0.020) nHBEET= 0.016 Minor Storm Major Storm Max.Allowable Spread for Minor&Major Storm TMAx= 5.0 16.0 ft Max.Allowable Depth at Gutter Flowline for Minor&Major Storm dMAx= 6.0 12.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Ma or Storm MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallm= SUMP SUMP cfS MHFD-Inlet v5.03.xlsm,Inlet DP 6a 5/21/2024,3:03 PM MHFD-Inlet, Version 5.03(August 2023) Lo(C) H-Curb H-Vert W WP\ = `Lo(G) Design Information(Input) MINOR MAJOR FC unit length 3 Type of Inlet User-Defined Combination Type= User-Defined Combination Local Depression(additional to continuous gutter depression'a'from above) aio.i= 2.00 inches Number of Unit Inlets(Grate or Curb Opening) No= 6 Water Depth at Flowline(outside of local depression) Pending Depth= 6.0 7.2 inches Grate Information MINOR MAJOR i✓override Depths Length of a Unit Grate L.(G)= 3.00 3.00 feet Width of a Unit Grate W,= 2.00 00 feet Open Area Ratio for a Grate(typical values 0.15-0.90) A ate= 0.60 Clogging Factor for a Single Grate(typical value 0.50-0.70) Ct(G)= 0.50 0.50 Grate Weir Coefficient(typical value 2.15-3.60) Cw (G)= 3.00 -00 Grate Orifice Coefficient(typical value 0.60-0.80) C,(G)= 0.67 0.67 Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening L.(C)= 3.00 00 feet Height of Vertical Curb Opening in Inches Hen= 6.00 00 inches Height of Curb Orifice Throat in Inches Hthm t= 6.00 00 inches Angle of Throat Theta= 0.00 0.00 degrees Side Width for Depression Pan(typically the gutter width of 2 feet) WP= 2.00 2.00 feet Clogging Factor for a Single Curb Opening(typical value 0.10) Q(C)= 0.10 0.10 Curb Opening Weir Coefficient(typical value 2.3-3.7) C (C)= 3.00 Curb Opening Orifice Coefficient(typical value 0.60-0.70) Co(C)= 0.67 Low Head Performance Reduction(Calculated) MINOR MAJOR Depth for Grate Midwidth dG�to= 0.50 0.60 ft Depth for Curb Opening Weir Equation do b= 0.33 0.43 ft Grated Inlet Performance Reduction Factor for Long Inlets RFG.te= 0.57 0.68 Curb Opening Performance Reduction Factor for Long Inlets RFc rb= N/A N/A Combination Inlet Performance Reduction Factor for Long Inlets RFcombination= 0.57 0.68 MINOR MA30R Liet tal Inlet Interception Capacity(assumes clogged condition) Qa= 14.9 24.8 cfs Capacity Is GOOD for Minor and Major storms > Peak Q PenK aeQwneo= 4.4 20.9 cfs City of Fort Collins Criteria Cw=3.0 Co=0.67 MHFD-Inlet v5.03.xlsm,Inlet DP 6a 5/21/2024,3:03 PM MHFD-Inlet Version 5.03(August XZ MIN (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Project: Polestar Inlet ID: Inlet DP 7a T T,T Se"u` W T. OWN R C CROWN e / Gutter Geometry: Maximum Allowable Width for Spread Behind Curb T-CK= 13.0 ft Side Slope Behind Curb(leave blank for no conveyance credit behind curb) SMCK= 0.020 ft/ft Manning's Roughness Behind Curb(typically between 0.012 and 0.020) nmcK Height of Curb at Gutter Flow Line HcuR = 6.00 inches Distance from Curb Face to Street Crown TCRCWN= 16.0 ft Gutter Width W= 2.00 ft Street Transverse Slope Sx= 0.020 ft/ft Gutter Cross Slope(typically 2 inches over 24 inches or 0.083 ft/ft) SW= 0.083 ft/ft Street Longitudinal Slope-Enter 0 for sump condition So= 0.000 ft/ft Manning's Roughness for Street Section(typically between 0.012 and 0.020) nMEET= 0.016 Minor Storm Major Storm Max.Allowable Spread for Minor&Major Storm TIM = 16.0 16.0 ft Max.Allowable Depth at Gutter Flowline for Minor&Major Storm d,4m=1 6.0 12.0 inches Check boxes are not applicable in SUMP conditions r MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm MAJOR STORM Allowable Capacity is not applicable to Sump Condition Q,iio„= SUMP SUMP cfs MHFD-Inlet_v5.03.xism,Inlet DP 7a 5/21/2024,3:05 PM OR SAG LOCATION MHM-Inlet, Version 5.03(August 2023) Lo(C) H-Curb H-Vert Wo _ WF, W �-Lo(G) Design Information(Input) MINOR MAJOR User-Defined Combination Type of Inlet Type= User-Defined Combination Local Depression(additional to continuous gutter depression'a'from above) am,i= 2.00 inches Number of Unit Inlets(Grate or Curb Opening) No= 2 Water Depth at Flowline(outside of local depression) Ponding Depth= 5.4 5.4 inches Grate Information MINOR MAIOR r Override Depths Length of a Unit Grate Lo(G)= 3.00 ?nn feet Width of a Unit Grate W.= 2.00 feet Open Area Ratio for a Grate(typical values 0.15-0.90) A. = 0.31 Clogging Factor for a Single Grate(typical value 0.50-0.70) Q(G)= 0.50 0.50 Grate Weir Coefficient(typical value 2.15-3.60) C (G)= 3.00 Grate Orifice Coefficient(typical value 0.60-0.80) Co(G)= 0.67 Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo(C)= 3.00 a feet Height of Vertical Curb Opening in Inches H_rt= 6.00 inches Height of Curb Orifice Throat in Inches Hthmat= 6.00 inches Angle of Throat Theta= 0.00 degrees Side Width for Depression Pan(typically the gutter width of 2 feet) WP= 2.00 feet Clogging Factor for a Single Curb Opening(typical value 0.10) Ct(C)= 0.10 0.10 Curb Opening Weir Coefficient(typical value 2.3-3.7) C (C)= 3.00 u Curb Opening Orifice Coefficient(typical value 0.60-0.70) C.(C)= 0.67 Low Head Performance Reduction(Calculated) MINOR MAJOR Depth for Grate Midwidth dGr�= 0.45 0.45 ft Depth for Curb Opening Weir Equation dour = 0.28 0.28 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGra�= 0.63 0.63 Curb Opening Performance Reduction Factor for Long Inlets RFo,r = N/A N/A Combination Inlet Performance Reduction Factor for Long Inlets RI`Umwnmon= 0.63 0.63 MINOR MAIOR Total Inlet Interception Capacity(assumes clogged condition) Qacfs Inlet Capacity IS GOOD for Minor and Major Storms > Peak Q PEAK REQUIRE"= 1.O 4.4 cfs City of Fort Collins Criteria Cw=3.0 Co=0.67 MHFD-Inlet_v5.03.xism,Inlet DP 7a 5/21/2024,3:05 PM MHFD-Inlet Version 5.03(August XZ MIN (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Project: Polestar Inlet ID: Inlet Dp 3a T,. se u_ w T. STREET GROWN e / Gutter Geometry: Maximum Allowable Width for Spread Behind Curb T-CK= 13.5 ft Side Slope Behind Curb(leave blank for no conveyance credit behind curb) SMCK= 0.02I ft/ft Manning's Roughness Behind Curb(typically between 0.012 and 0.020) nmcK Height of Curb at Gutter Flow Line HcuR = 4.80 inches Distance from Curb Face to Street Crown TCROWN= 23.0 ft Gutter Width W= 2.00 ft Street Transverse Slope Sx= 0.020 ft/ft Gutter Cross Slope(typically 2 inches over 24 inches or 0.083 ft/ft) SW= 0.083 ft/ft Street Longitudinal Slope-Enter 0 for sump condition SO= 0.014 ft/ft Manning's Roughness for Street Section(typically between 0.012 and 0.020) nMEET= 0.016 Minor Storm Major Storm Max.Allowable Spread for Minor&Major Storm TM nx= 23.0 23.0 ft Max.Allowable Depth at Gutter Flowline for Minor&Major Storm d,4m=1 3.0 12.0 inches Allow Flow Depth at Street Crown(check box for yes,leave blank for no) r r MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Spread Criterion Q.11 =1 1.5 1 29.9 Ids Minor storm max.allowable capacity GOOD-greater than the design peak flow of 0.10 cfs on sheet'Inlet Management' M. storm max.allowable capacity GOOD-greater than the design peak flow of 1.70 cfs on sheet'Inlet Management' MHFD-Inlet_v5.03.xism,Inlet Dp 3a 5/21/2024,3:06 PM INLET ON • • 'AD MYFD-In et, Version.5 ugust Ln i c_ H-Curb H-Vert Wo W Lo(G) Design Information(Input) User-Defined MINOR MAIOR Combination Type of Inlet Type= User-Defined Combination Local Depression(additional to continuous gutter depression'a') aLOCAL= 2.0 inches Total Number of Units in the Inlet(Grate or Curb Opening) No= 2 Length of a Single Unit Inlet(Grate or Curb Opening) L.= 3.00 ft Width of a Unit Grate(cannot be greater than W,Gutter Width) Wo= 2.00 ft Clogging Factor for a Single Unit Grate(typical min.value=0.5) Cf(G)= 0.50 0.50 lClogging Factor for a Single Unit Curb Opening(typical min.value=0.1 C = 0.10 0.10 Epture 0<Allowable Street Capacity' MINOR MAIOR tal Inlet Interception Capacity Q= 0.11.5 cfstal Inlet Carry-Over Flow(flow bypassing inlet) Qb= 0.0 0.2 Cfs Percentage= C%= 100 gO MHFD-Inlet_v5.03.xism,Inlet Dp 3a 5/21/2024,3:06 PM Street Section at Neck down in Polaris Street +� Worksheet:Irregular Section-1 l o Uniform Flow Gradually Varied Flow Messages Solve For: Discharge Friction Method: Manning Formula Roughness Coefficient 1 0.G26 Flow Area,: 1 17.4 T Channel Slope: 0.0.05 tuft A'etted Perimeter: 62.5 it Elevation: 5,111.0D ft Hydraulic Radius: 3.3 in Elevation Range: 5,114.2tD5,111.t}ft TopVVidth: 62.47 ft Discharge: 29.25 cfs Normal Depth: 9.4 in Critical Depth: 7.9 in Critical Slope: {1.016 fttft Velocity: 1.66 ius 'velocity Head: I D.04 ft Specific Energy: 0.82 ft Froude Number: 0.560 Flow Type: Suberitical 'Edit Section � Options !Calculation Successful. Total Flow into the Street is Approx. is 20.9 cfs at dp 7a and 4.4 cfs at 6a. 29.25 cfs Capacity to ROW. Street Section at Neck down in Polaris Street 5111.25 5111.15 5111.1G i 5111.00 5110.95 - - 5110.90 5110.85 5110.80 ---------- - - - ----- ------ --------—---------------------------—---------- - ----------------------------------- 5110.75 5110.70 5110.65 5110.60 w 5110.55 5110.50 s110.as 5110.40 5110.35 - - -6 5110.30 5110:25 5110.20 5110.15 5110.10 5110.05 s110.00 5109.95 - - 0+00 0+05 0+10 0+15 0+20 0+25 0+30 0+35 0+40 0+45 0+50 0+55 0+60 11.1- Orchard Place - Flow Lines- 100 year event 7j Crass Section:North FL Uniform Flov: -,Ji,.IIYVared Flow Messages ,rye Print previ- 'd1;y Options Solve For Hir-rIPepN Ve-n"Formula 5111.30 Roughness CoeRiaent 0,616 FIow,Ges; 1T1 ft' 5111.Z0I' Channel Elope Q.D14 Rid Wetted Perimeter: T7.6 ft 5111.10 FJevallon: 6,11g - ft HYtlraulic Radius: 26 in -...._.__. _ .__.__.__ 5111.00 Elevation Range. 6,7142to.6,ti1.1fl Top Width. T7.60 ft 5110.90 Discharge: T0.66 cfs Normal DepRr, - sub.ab crfpeal Depm: ss 4n -� - -- s110.]0 Grilieel Slope: 1.G65 iGR - - - 5110.60 Velocity; d.12 ft]s - VelocltyHead Q.26 ft 511b.50 Spec Energy: O75 ft '110.40 FroudeNumeer', 154] 5110.30 ---- _- FlowType: 'iu1>ercrfllcal 1110.20 5110.10 5110.00 f'Edit Secdon (;+Opt- 10+40 i0+60 10+b5tationi+00 11+20 11140 Q,Calculation Successful. m.= - ❑p Can S Hn.C-Line =11 IC gn.,fwm Flow Gradaely VariedF h>Messages Lqi Print Preview Fq Options Snlvn For;Nmrrel Depth v y Fnctlan Methdd. '1AaRpty('pAiMk v'I 6nza6 Roughness CoefM1rvant 0.015 Flew prra: 15,4 ft 5112.69 Channel Slg Pe: 0Q14 flM Wer.Ferimeter: ft ]fl:0 .................__.._-- _.__._....... 5112.40 Elevation 5,110.4] ft in Hydeaulic�dius: 2S 6112.21l Elevation Range: 5,11D0to 5,112]R Top Widtll'. 10.Q1 ft 61120b piscM1arge: ]Q.6Q Normal DeptJ, S2 m 6111.80 Cntical DBPtn:. ].3 in c 5111.60 Crllira151npe aaa6 NR m 5111.40 Vel-i s w 5111.2g --dy Head: Qaa n s111.00 Sp ft Energy: S$1 tt 6110.B0 fff F nde Number. 156] --------/]I 6110.60 � I 5110.40 Flow Type. Supercr4lcel - - -.-.. 6uu.zb 610Mi, [j EdiE Secpon R Qptlors 13+0p ri-id anon 14+00 14+60 e Cai-I ign Successful. ...lee..s..i FIL : E�]Crass Section:South FL E- F �Unitarm Flnw Graduely Varied Fbw Messages. Lq Print Preview LOptions Solve For: No-IDepth y Friction Method. Manning Formula 5112.40 Roughness Goefficieirt 0,016 Flow Area. 18.0 ft 5112.20 ' GhannelSope: D014 Rift Wetted Perimeter: 3 It Slime Elevation: 5,'11020 ft Hydraulic Radim 28 In S1il.80 Elevation Ran ', 5,11}07 to 112.2fl Top W'itllh: ffi.3d ft ge 5. 5111.60 ..lc.._......._ Discharge: 73.hD efs Normal Depth: 6:9 In 5111.40 Crilleat Depth: 7,1 In 5111.20 GrI11cfll Slope' {F;B[{Fi ftm 5111.00 Velocity: 4.06' ft15 ru 5110.80 Velocity Head: D:Z6 ft 5110.50 Speciftc Energy.- U,7S ft 5110.40 Fr-de Number 1.541 5110.20 Flaw Type: Supercrtical 5110.00 5109.80 5109.60 'Edit Section %OPtions 2+50 3+Oti Station3+50 4+10 t8 Calculation Successful. W. Orchard Place Overflow p crass Sectlan,,w,0rchard Pl'Overflow tpTypa rote II ID Uniform Flow Gradually Varied Fbw I'l-eages Pnnt Frei- F,}Option, Salve Far: Normal Depth L Friction Method: M.-,F.-A. 5111.A0 I ' Roughness Goelficierrt G.034 Flow Area 10.5 ft' 5111.20 Channel Slope: r3.1143 %M Wattad Pefimeter: 15:7 It 5111.00 Devation: 5,110.00 ft Hydraulic Radius'. S.0 m 5110.60 Elevation Range: 5,1ib5.71n 51t12ft Top"Nidth: 15A1 It 5110.60 Gr pth: 16.t In 5110.40 Discharge: 73.k5 MS Normal De Itlml Depth:. 18.6 in s,5110.20 Critical Slope: R.61& fHR m 5110.00 _ Velocity: fi.95 fits w 5109.80 Velocity Head: O75 ft 5109.fi0 Speclfic Energy: 2a9 ft 5109.40 _ Froude Number 1- 5109.20 Flow Type: SucriGml 5109.00 5108.80 5108.60 0+00 0+10 0+26 0+3r6 0+40 0+50 i.'Edit Section Options St o a e Cnculathan Successful. 'rI r:ass r r -r. i Fl';-flo - CI 0�Crass Section:W.Orchard PI.Overflow �I I Unif.-flow Gradualy Varies Fbw Messages Lq Print P,-iew ['*Options Solve For INarmal Depth y FripbunMethod-. .IManning Formals 5112:fi0 5112.40 Roughness Coefficient 0.034 Flow Area 164 fj 5112.20 Chan I Slope: 0.a05 RM Wetted Perimeter. 28,4 R 5112.00 Elevation: 5,11@2& It Hydraulic Radius: 97 in 5111.80 Elevation Range: 5,1 U42ta 5,1124ft Top Width: 20.15 a 5111.60 Discharge: 427a ofs Normal Depth: ie3 In 5111.40 5111.20 Gritieel Depth:. 8.1 in a 5111.00 Criticel Stop.: 0.022 ftRi- b 5110.80 Velocity: 2.60. 7ftls w 5110.60 Velocity Head: 6.10 A 5110.40 5110.20 Specific Energy: 1,t3 'ft 5110.00 Fraude Number: 'DSU7 5109.50 Flow Ty p e. Suhcr6lcal 5109.60 5109.40 5109.20 5109.00 Edit Section Ma options 0+00 0+10 0+20 Stationo 0+40 0+5r1 QD Calculation.Successful. Urban Drainage and Flood Control District Modeling Hydraulic and Energy Gradients in Storm Sewers: October 6, 2009 6.3 Combined Junction Loss Equation V V2 2 V2 V2 Hi = HS =kbT + —k,, • 1�- ]+kU � =k Equation(13) 2g 2g 2g 2g 2g where, Hj=UD-Sewer junction loss Hs=Standard method junction loss kbT= Bend loss coefficient at truckling kbL= Bend loss coefficient at lateral VtT=Full flow velocity of trunk line at manhole Vj;=Full flow velocity of incoming lateral at manhole Vo=Full flow velocity of trunk line at manhole k=Head Loss Coefficient g=Acceleration due to Gravity Table 2-StormCAD Standard Method Conversions StormCAD Conversion Table Bend Angle K coefficient Conversion 0 0 0.05 -0 22.5 0.1 45 0.4 m 60 0.64 90 1.32 1 Lateral K coefficient Conversion Bend Non Angle Surcharged Surcharged 0 45 0.27 0.47 J 60 0.52 0.9 90 1 1.02 1 1.77 J 2 Laterals K coefficient Conversion 45 0.96 60 1.16 90 1.52 The engineering guidelines from this study provide the methodology needed to reach an HGL analysis result using StormCAD which replicates that of UD-Sewer. However, the following limitations apply: • The full pipe velocity should not exceed 18 fps • The conversion only applies for the storm sewer pipe sizes 42"or less • A regional storm sewer system should use UD-Sewer only Page 19 Scenario: 100 - Year 6.3-GRATE INLET 4.2-Type C Inlet(Storm) E `o N _ U E 0 q U 6.2 MH(Storm) O 4 C 61 ls�01tnl O-6 C-2.2 Type C Inlet C-2.2(Storm) O-2 2.3-18 INCH DOME INLET(Storm) /1 n C-2.1(Storm) u A C-1.1(Storm) C-1.2(Storm) O-1 1.3-Shallow Top MH(Storm) 1 B-GRATE INLET(Storm) C-5.1 (Storm) 0-5 2.2 GRATE INLET(Storm) C-1 B(Storm) 5.2-OUTLET STRUTURE(Storm) E `o rn M U 1.4-MH(Storm) n (P 0 3 1.5 MH(Storm) O-3 C� 0 j tS ASP°r 3.2 MH(Storm) 1.6 MH(Storm) n w N Cn E C' j s /sfOi �j 3.3-Type C Inlet(Storm) 1.7-MH(Storm) � 7) G 2A-Type C Inlet 1.8-MH(Storm) o�cc\ n (Storms) _w 0 1.9-MH(Storm) ° 3 1.3A-12"DROP IN NYLOPLASTIC INLET F 0 rn U 1.10-Type C Inlet 3.4-Type C Inlet(Storm) Storm CAD 3979701 Storm CAD Model.stsw Bentley Systems,Inc. Haestad Methods Solution Center [10.03.02.04] 5/20/2024 27 Siemon Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-755-1666 Page 1 of 1 Polestar — 100 Year Profiles DP01 Profile-1-100-Vear e a EE s oa .o ms s o. sv�aaa s.�osa s,vvrs.av ra,ti s v.v =o.o ay.o rsv.o ay.o vvo.o v=o.a vao.o vrso.o veo.v zay.o �=v.v =<v.v =rso.v zsv.v 3vo.v sta,00 IH�.0 3ay.v avo.o „o.o aay.v arsv.� aa�� svv v s.v v s,v.v srsv.v =ev.v rsay.v rsza.a rsao.v rsrsv.� rs�.o DPOIA Profile-1-100-Year a suv zo m - •v Fstom) v.p zo.v. zs.a ae.v ay.o as.o �nuns(f[) rsv.v ss.v �v.v �s.v so.v s..v ss.v vvv.v vvs.o vvv.v Polestar — 100 Year Profiles DPO18 Profile-1-100-Vear 90 DP02 Profile-1-100-Vear - _ I �o.nsM1 I 5,1 i�o it i. 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Year Current Time Step: 0.000 h FlexTable: Manhole Table Flow Hydraulic Hydraulic Headloss Elevation Elevation Velocity (Total Grade Grade Headloss Label (Ground) (Invert) (Out) Coefficient (ft) (ft) Out) (fus) Line(In) Line Method (Standard) (cfs) (ft) (Out)(ft) 1.10-Type CInlet 5,115.69 5,110.24 11.70 4.05 5,112.27 5,111.97 Standard 1.160 1.2A-Type CInlet 5,113.62 5,110.95 2.80 3.93 5,111.59 5,111.58 Standard 0.050 1.3-Shallow Top MH(Storm) 5,110.31 5,106.34 14.40 4.58 5,108.93 5,108.44 Standard 1.520 1.3A-12"DROP IN NYLOPLASTIC INLET 5,114.42 5,112.11 2.80 4.64 5,112.85 5,112.83 Standard 0.050 1.4-MH(Storm) 5,110.91 5,106.86 12.50 3.98 5,109.22 5,109.19 Standard 0.100 1.5 MH(Storm) 5,111.78 5,107.50 12.50 3.98 5,109.57 5,109.54 Standard 0.100 1.6 MH(Storm) 5,112.70 5,108.22 12.50 4.88 5,109.78 5,109.74 Standard 0.100 1.7-MH(Storm) 5,113.62 5,108.86 12.50 5.63 5,110.69 5,110.19 Standard 1.020 1.8-MH(Storm) 5,114.44 5,109.41 11.70 4.85 5,110.88 5,110.84 Standard 0.100 1.9-MH(Storm) 5,115.19 5,109.94 11.70 5.56 5,111.85 5,111.21 Standard 1.320 1 B-GRATE INLET(Storm) 5,110.02 5,106.49 4.40 2.49 5,108.95 5,108.95 Standard 0,050 2.2 GRATE INLET(Storm) 5,110.47 5,106.17 30.00 6.71 5,108.35 5,108.31 Standard 0.050 2.3-18 INCH DOME INLET(Storm) 5,107.56 5,105.92 0.00 0.00 5,107.56 5,107.56 Standard 0.050 3.2 MH(Storm) 5,109,04 5,104.46 8.00 4.53 5,106.48 5,106.32 Standard 0.520 3.3-Type C Inlet(Storm) 5,108.86 5,104.96 8.00 4.53 5,106.93 5,106.92 Standard 0.050 3.4-Type C Inlet(Storm) 5,110.08 5,106.01 7.20 4.07 5,107.76 5,107.75 Standard 0.050 4.2-Type C Inlet(Storm) 5,108.55 5,104.76 30.30 7,04 5,106.84 5,106.81 Standard 0.050 5.2-OUTLET STRUTURE(Storm) 5,107.54 5,102.75 49.52 5.15 5,106.30 5,106.28 Standard 0.050 6.2 MH(Storm) 5,110.45 5,104.90 0.10 0.09 5,105.98 5,105.98 Standard 0.640 6.3-GRATE INLET 5,108.56 5,105.51 0.10 0.24 5,105.98 5,105.98 Standard 0.050 C-2.2 Type D Inlet 5,109.51 5,105.77 31.10 6.90 5,107.97 5,107.93 Standard 0.050 X:\3970000.all\3979701\StormCAD\3979701 StormCAD Model.stsw file:///C:[Users/WaterR/AppData/Local/Temp/Bentley/StormCAD/ejyyszsc.xml 5/20/2024 Polestar — 2 Year Profiles DPOl Profile-L-2-Year 17 s ssa o.se s,ssa i mn lsm� �.— - 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ZL.(([J 11- 1.- 11- 11- zxo.o zso.o —.1 2so.o. 2co.o zio.¢ 9 0 2-o z.I- 31u.o Polestar — 2 Year Profiles DPOS Profile-I-2-Year EPF s,vo..6o s,voiso sv o I I s,toa � I s.v z P o.s Lv f z z.p ss 3.P s.s o.o x.s s.0 s..s s o 6.s �.P t e.o e.s e.P a s t.s is o tz t3 e is s t>> to s is o is s u t6 s tz o v te.o is s too s.s o P.2as xt.c st.s scanoo(¢)t DP06-Profile-1-2-V— s.tto. do nsn rmi s,v { st ��— Y I v — s,tos.lo 4 — 1 Page 1 of 1 Scenario: 2 -Year Current Time Step: 0.000 h FlexTable: Conduit Table Length Diameter (User Slope Manning's Flow Velocity Invert Invert HGL(In) HGL Label (in) Defined) (ft/ft) n (cfs) (ft/s) (Start) (Stop) (ft) (Out)(ft) (ft) (ft) (ft) C-1.1 (Storm) 30.0 27.1 0.003 0.013 6.90 4.00 5,106.17 5,106.09 5,107.11 5,106.96 C-1.2(Storm) 24.0 22.5 0.003 0.013 3.40 3.41 5,106.34 5,106.27 5,107.15 5,107.13 C-1.3(Storm) 24.0 84.5 0.005 0.013 2.90 3.86 5,106.86 5,106.44 5,107.45 5,107.34 C-1.4(Storm) 24.0 107.1 0.005 0.013 2.90 3.88 5,107.50 5,106.96 5,108.09 5,107.54 C-1.5(Storm) 24.0 101.8 0.006 0.013 2.90 4.15 5,108.22 5,107.60 5,108.81 5,108.15 C-1.6(Storm) 24.0 105.2 0.005 0.013 2.90 3.87 5,108.86 5,108.33 5,109.45 5,108.91 C-1.7(Storm) 24.0 89.1 0.005 0.013 2.70 3.79 5,109.41 5,108.96 5,109.98 5,109.67 C-1.8(Storm) 24.0 86.9 0.005 0.013 2.70 3.79 5,109.94 5,109.51 5,110.52 5,110.07 C-1.9(Storm) 24.0 58.3 0.003 0.013 2.70 3.31 5,110.24 5,110.04 5,110.87 5,110.79 C-2.2(Storm) 12.0 7.3 -0.007 0.013 7.20 9.17 5,105.87 5,105.92 5,107.16 5,106.85 C-3.2(Storm) 18.0 75.2 0.005 0.013 1.80 3.53 5,104.96 5,104.56 5,105.46 5,105.06 C-3.3(Storm) 18.0 173.7 0.005 0.013 1.60 3.47 5,106.01 5,105.06 5,106.49 5,105.52 C-A1.1 (Storm) 18.0 53.0 0.037 0.013 0.06 2.52 5,110.95 5,109.01 5,111.03 5,109.67 C-A1.2(Storm) 12.0 54.6 -0.010 0.013 0.06 1.72 5,111.56 5,112.11 5,112.21 5,111.65 C-1 B(Storm) 18.0 9.4 0.005 0.013 0.00 0.00 5,106.49 5,106.44 5,107.34 5,107.34 C-2.1 (Storm) 30.0 102.7 -0.005 0.013 7.20 4.90 5,105.26 5,105.77 5,106.66 5,106.10 C-3.1 (Storm) 18.0 58.1 -0.008 0.013 1.80 4.05 5,104.01 5,104.46 5,104.96 5,104.46 C-4.1 (Storm) 30.0 104.7 -0.005 0.013 11.90 5.78 5,104.19 5,104.76 5,105.92 5,105.29 C-5.1 (Storm) 42.0 19.8 0.005 0.013 18.59 6.22 5,102.75 5,102.66 5,104.07 5,103.89 C-6.1 (Storm) 15.0 81.3 -0.009 0.013 0.10 1.87 5,104.16 5,104.90 5,105.02 5,104.27 C-6.2 Storm 15.0 110.5 -0.005 0.013 0.10 1.46 5,105.01 5,105.51 5,105.64 5,105.13 X:\3970000.a11\3979701\Storm CAD\3979701 StormCAD Model.stsw file:///C:[Users/WaterR/AppData/Local/Temp/Bentley/StorfnCAD/x2r2fte2.xml 5/20/2024 Page 1 of 1 Scenario: 2 - Year Current Time Step: 0.000 h FlexTable: Manhole Table Flow Hydraulic Hydraulic Headloss Elevation Elevation Velocity (Total Grade Grade Headloss Label (Ground) (Invert) (Out) Coefficient (ft) (ft) Out) (fus) Line(In) Line Method (Standard) (cfs) (ft) (Out)(ft) 1.10-Type CInlet 5,115.69 5,110.24 2.70 3.22 5,111,05 5,110.87 Standard 1.160 1.2A-Type CInlet 5,113.62 5,110.95 0.06 1.40 5,111.04 5,111.03 Standard 0.050 1.3-Shallow Top MH(Storm) 5,110.31 5,106.34 3.40 2.87 5,107.34 5,107.15 Standard 1.520 1.3A-12"DROP IN NYLOPLASTIC INLET 5,114.42 5,112.11 0.06 1.48 5,112.21 5,112.21 Standard 0.050 1.4-MH(Storm) 5,110.91 5,106.86 2.90 3.71 5,107.48 5,107.45 Standard 0.100 1.5 MH(Storm) 5,111.78 5,107.50 2.90 3.71 5,108.12 5,108.09 Standard 0.100 1.6 MH(Storm) 5,112.70 5,108.22 2.90 3.71 5,108.84 5,108.81 Standard 0.100 1.7-MH(Storm) 5,113.62 5,108.86 2.90 3.71 5,109.67 5,109.45 Standard 1.020 1.8-MH(Storm) 5,114.44 5,109.41 2.70 3.63 5,110.00 5,109.98 Standard 0.100 1.9-MH(Storm) 5,115.19 5,109.94 2.70 3.63 5,110.79 5,110.52 Standard 1.320 1 B-GRATE INLET(Storm) 5,110.02 5,106.49 0.00 0.00 5,107.34 5,107.34 Standard 0,050 2.2 GRATE INLET(Storm) 5,110.47 5,106.17 6.90 4.07 5,107.13 5,107,11 Standard 0.050 2.3-18 INCH DOME INLET(Storm) 5,107.56 5,105.92 7.20 9.17 5,107.22 5,107.16 Standard 0.050 3.2 MH(Storm) 5,109,04 5,104.46 1.80 3.45 5,105.06 5,104.96 Standard 0.520 3.3-Type C Inlet(Storm) 5,108.86 5,104.96 1.80 3.45 5,105.47 5,105.46 Standard 0.050 3.4-Type C Inlet(Storm) 5,110.08 5,106.01 1.60 3.33 5,106.49 5,106.49 Standard 0.050 4.2-Type C Inlet(Storm) 5,108.55 5,104.76 11.90 5.36 5,105.94 5,105.92 Standard 0.050 5.2-OUTLET STRUTURE(Storm) 5,107.54 5,102.75 18.59 5.61 5,104.10 5,104.07 Standard 0.050 6.2 MH(Storm) 5,110.45 5,104.90 0.10 1.64 5,105.05 5,105.02 Standard 0.640 6.3-GRATE INLET 5,108.56 5,105.51 0.10 1.46 5,105.64 5,105.64 Standard 0.050 C-2.2 Type D Inlet 5,109.51 5,105.77 7.20 4.59 5,106.68 5,106.66 Standard 0.050 X:\3970000.all\3979701\StormCAD\3979701 StormCAD Model.stsw file:///C:[Users/WaterR/AppData/Local/Temp/Bentley/StormCAD/c2fkjjt2.xml 5/20/2024 21 APPENDIX D - WATER QUALITY CALCULATIONS WQ Pond Tributary Areas Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Calculated By: ARJ Checked By: Date: 5 17 24 pl-Sand Filter Area Basin (ac) %Imp.. Al 1.02 15.8% A2 0.60 50.1% A3 0.78 25.3% A4 1.23 65.0% A5 0.42 56.5% A6 1.03 68.7% A7 0.85 63.3% A8 0.58 83.8% A9.1 0.16 84.4% A9.2 0.03 54.5% A10 0.09 84.7% All 0.13 68.8% Al2 0.26 33.7% A13 0.40 61.0% A14 0.09 21.1% A15 0.49 23.5% A16 0.13 46.1%. A17 0.43 29.6% A18 0.70 46.6% A19 0.31 57.0% Total 9.73 50.3% WQCV Drain Time(hr): 12 Coefficient,a(Figure 3.2): 0.8 WQCV(in): 0.17 WQCV(ac-ft): 0.16 X13970000.all\3979701\Excel\Drainage\3979701 Drainage_Calcs_Template_ti1.07.xlsm Page 1 ofg 5/21/2024 WQ Pond Tributary Areas Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Calculated By: ARJ Checked By: Date: S 17 24 #2-Rain Garden Area Basin (ac) %Imp. BS 1.23 49.8%. B2 0.31 77.7% Total 1.55 WQCV Drain Time(hr): 12 Coefficient,a(Figure 3.2): 0.8 WQCV(in): 0.18 WQCV(ac-ft): 0.03 Xi3970000.a11\3979701\E.cel\Draiaage\3979701 Dremage_Cdl s T-plate_ti1.07.xsm :Page 2 ofg 5/21/2024 WQ Pond Tributary Areas Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Calculated By: ARJ Checked By: Date: 5 17 24 #3-Rain Garden Area Basin (ac) %Imp. Cl 0.28 47.0% C2 0.32 30.5% D8 0.19 90.5% D7 0.11 85.5% Total 0.90 55.0% WQCV Drain Time(hr): 12 Coefficient,a(Figure 3.2): 0.8 WQCV(in): 0.18 WQCV(ac-ft): 0.02 Xi3970000.a11\3979701\E.cel\Draiaage\3979701 Drai..W_Cdl s T-plate_ti1.07.xsm Page 3 ofg 5/21/2024 WQ Pond Tributary Areas Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Calculated By: ARJ Checked By: Date: 5 17 24 #4-Rain Garden Area Basin Jac) %Imp. D6 0.28 58.2% Total 0.28 58.2% WQCV Drain Time(hr): 12 Coefficient,a(Figure3.2): 0.8 WQCV(in): 0.18 WQCV(ac-ft): 0.01 X13970000.all\3979701\Excel\Drainage\3979701 Drainage_Calcs_Template_ti1.07.xlsm Page 4 d8 5/21/2024 WQ Pond Tributary Areas Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Calculated By: ARJ Checked By: Date: 5 17 24 #5-Rain Garden Area Basin (ac) %Imp. D5 0.29 67.3% D4 0.25 60.9% Total 1 0.54 WQCV Drain Time(hr): 12 Coefficient,a(Figure 3.2): 0.8 WQCV(in): 0.20 WQCV(ac-ft): 0.01 Xi3970000.a11\3979701\Excel\Draiaage\3979701 Drai..W_Calcs T-plate_ti1.07.xsm Page5of8 5/21/2024 WQ Pond Tributary Areas Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Calculated By: AR1 Checked By: Date: 5 17 24 #6-Rain Garden Area Basin (aC) D3 0.16 69.8% D2 0.22 62.9% D1 0.35 64.1% Total 0.73 65.0% WQCV Drain Time(hr): 12 Coefficient,a(Figure 3.2): 0.8 WQCV(in): 0.20 WQCV(ac-ft): 0.01 Xi3970000.a11\3979701\E..el\Draiaage\3979701 Dremage_Cdl s T-plate_ti1.07.xsm Page 6 ofg 5/21/2024 Table 5.4-1.Drain Time Coefficients for WQCV Calculations Drain Time(h.) Coefficient(a) 12 0.8 40 1 1.0 Reference:The UD-BMP excel-based spreadsheet,RG and EDB tabs may be used to aid it calculating WQCV. Figure 5.4-1 WQCV Based on BMP Drain Time 0.500 4 0.450 I 0.400 24 hourdlaintfine c 0.350 WQCV=B(0.91P-1.19r�+0.7817 II 0.300 m 12-hrtlmintime a0.8 `y 0.250 24-hr drain lime a=0.9 40-hr drain time a=1.0 3 0.200 c 0.150 (.1 12 hour drain time Q 0.100 3 a.Oso 0.000 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Total Imperviousness Ratio(i=IBM00) Once the WQCV in watershed Inches Is found from Figure 3.2-12 or using Equation 3.2-1,the required BMP volume in acre-feet can be calculated as follows: Once the WQCV in watershed inches is found from Figure 3.2-12 or using Equation 3.2-1,the required BMP volume in acre-feet can be calculated as follows: V=(NQ�As1.2 Equation 7-2 Where:V=required volume,acre-ft A=tributary catchment area upstream,acres WQCV=Water Quality Capture Volume,watershed inches 1.2-to account for the additional 20%of required storage for sedimentation accumulation Xi3970000.a11\3979701\Excei\Draiaage\3979701 Drmvagc_Calcs_Te pI te_ti1.07.xlsm :Page 7 of8 5/21/2024 WQ Pond Tributary Areas Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Calculated By: ARJ Checked By: Date: 5 17 4 WATER QUALITY IN DETENTION POND Area Basin (ac) %Imp. Fl 3.92 31.2% El 2.24 41.1% E2 0.54 54.2% E3 0.31 59.0% Total 7.01 37.4% This table shows the WQ on-site treated in the WQCV Drain Time(hr): 40 Polestar Detention pond.This calculation Coefficient,a(Figure 3.2): 1.0 includes 20%contingency for sediment WQCV(in): 0.17 accumulation as shown in equaltion 7-2. WQCV(ac-ft): 0.12 PLEASE NOTE area on MHFD sheet was X13970000.all\3979701\Excel\Drainage\3979701 Drainage_Calcs_Template_ti1.07.xlsm Page 9 d8 5/21/2024 STAGE-STORAGEDETENTION BASIN MHFD-Detention,Version 4.06(July 2022) Project:Polestar Basin I0:Sand Fllter-multiplied area by 1.2 to account for sediment accumulation per PC criteria vauue�•v Zaouy�- zv omwoE I Depth Increment= 0.50 R --- -- Opt-I optional Example Zone Configuration(Retention Pond) Stage-Storage stage Override Length Width Area Override Area Volume Volume Descri Hon ft Stage R ft ft ft' Area ft' acre R' ac-R Watershed Information Media Surface - 0.00 - - - 3,022 0.069 Selected BMP Type= 5F 5106.5 - 0.50 - - - 3,962 0.091 1,746 0.040 Watershed Area= 11.68 acres 5107 - 1.00 - - - 5,067 0.116 4,003 0.092 Watershed length= 750 R 5107.5 - 1.50 - - - 5,855 0.134 6,734 0.155 Watershed Length to.Centroid= 450 It 5108 - 2.00 - - - 6,658 0.153 9,862 0.226 Watershed Slope= 0.010 ft/R 5108.5 - 2.50 - - - 7,637 0.175 13,436 0.308 Watershed Imperviousness= 50.30% percent 5109 - 3.00 - - - 81660 0.199 17,510 0.402 Percentage Hydrologic Soil Group A= 0.0% percent 5109.5 - 3.50 - - - 9,728 0.223 22,107 0.508 Percentage Hydrologic$oil Group B= 10.0% percent 5110 - 4.00 - - -- 10,840 0.249 27,249 0.626 Percentage Hydrologic$oil Groups C,/D= 90.0% percent 5110.5 - 4.50 - - - 12,308 0.278 32,986 0.757 Target WQCV Drain Time= 12.0 hours - - - - Locatlon for 1-hr Rainfall Depths=User Input -- - - -- After providing required inputs above including 1-hour rainfall defift,dick'Run CUHP'to generate runoff hydrograplss Usiig - - -the embedded Colorado Urban Hydmgmph Procedure. Optional User Overrides - - - - Water Qwllty Capture Volume(WQCV)= 0.161 -feet -feet -- - - - Excess Urban Runoff Volume(EURV)= 0.563 acre-feet acre-feet -- - - -- 2-yr Runoff Volume(P1=0.82 In.)= 0.353 arrefeet 0.82 inches - - - - 5-yr Runoff Volume(PI=1.09 in.)= 0.530 ac-feet inches - - - - 10-yr Runoff Volume(P1=1.4In.)= 0.795 acre-feet 1.40 inches -- -- - -- 25-yr Runoff Volume(P'1.=1.69 in.)= 1.115acre-feet inches - - - - 50-yr Runoff Volume(P1=1.99 in.)= IA04acre-feet inches - - - - IOD-yr Ruoff Volume(P1=2.86 in.)= 2.305 -feet 186 inches - - - - 500-yrRuroR Volume(PI=3.14 in.)= 2.587acre-feet inches - - - - ApproAmate 2-yr Detention Volume= 0.337 acre-feet - - - - Approximate 5-yr Detention Volume= 0.525 acre-feet - - - - Approximatel0-yr Detention Volume= 0.668acre-feet - - - - Approximate25-yr Detention Volume= 0.764 acre-feet - - - - Approximate 50-yr Detention Volume= 0.830acre-feet - - - - Approximate 100-yr Detention Volume= 1.208acre-feet - - - - Define Zones Basin Basin Geometry - - -Zone,1 Volume(WQCV)= 0.161 acre-feet - - - - Zone 2 Volume(User Defined-Zone 1)= 0.000 rn"eet Total detention - - - - lone 3 Volume(User Defined-Zones 1&2)= 0.000acne-feet volume is less than - - - - Total Detention Basin Volume= 0.161 acre-feet 100-year volume. Initial Surcharge Volume(ISV)= N/A R' - - - - Initial Surcharge Depth(ISD)= N/A it - - - - Total Available Detemion Depth(1-6�i)= user ft - - - - Depth al Trickle Channel(HR)= N/A It - - - - SI, of Trickle Clwnnol(57c)= N/A flirt - - - - Slopes of Main Basin SIdeS(Sic)= user H:V - - - - Basin Length-to-Width Ratio(R�)= User - - - - Initial Surcharge Area(Assv)= User ft' - - - - Surcharge Volume Length(LgV)= User ft - - - - Surcharge Volume Width(Wsv)= User ft Depth of Basin Floor(HF=R)= user ft - - - - Length of Basin Floor(L,_,)= User ft -- -- - -- Width of Basin Floor(WFrmR)= user it - - -Area of Basin Floor(A-R)= user ft' - - - - Volume of Basin Floor(V-R)= User ft' -- -- - -- Depth of Main Basin(Homo)= User it - - - - Length of Main Basin(LmA,,) user it - - - - Width of Main Basin(WMAjO= User ft - - - - Area of Main Basin(Annm)= user ft' - - - - Volume of Main Basin(Vm )= User ft' - - - - Calculated Total Basin Volume(V-)= unit acre-feet - - - - MHFD-Det-bon_v9 06-Send Flller.xlsm,Basin 5/17/2024,2:05 PM STAGE-STORAGEDETENTION BASIN MHFD-Detention,Version 4.06(July 2022) z0 4aa 15 930o d �4 5 3100 0 0 0.00 1.w 3.00 4.50 6.00 stage lR) —Length(ft) —Width(ft) —A-(SA) 01— 0.7W o.no o.5w e yK 0.140 o:38J v d ; 0.070 O.J. 0.o00 0.000 0.00 1.50 3Ao 4.50 6.00 Sdge IR.1 —Area lac.es� —Volume lac-k� MHFD-Oetenti0n_v9- -Saint Filler.xl ,Basin 5/11/M24,2:M PM DETENTIONBASIN OUTLET MHFD-Detention, Version 4.06(July 1011) Project:Polestar Basin ID: Sand Filter-multiplied area by 1.2 to account far sediment accumulation per FC criteria -(ZONES Estimated Estimated l E3 zo"e, Stage(ft) Volume(ac-ft) Outlet Type vava Zone 1(WQCV)l 1.55 0.161 Filtration Media ^ate Zone 2(User) 1.55 0.000 Weir&Pipe(Restrict) za"Ei,wax ORIFICE nEaMwl�xr oaIFlcEs Zone 3(User) 1.55 0.000 Weir&Pipe(Restrict) Example Zone Configuration(Retention Pond) Total(all zones) 0.161 User Input:Orifice at Underdrain Outlet(typically used to drain WQCV in a Filtration BMP) Calculated Parameters for Underdrain Underdrain Orifice Invert Depth=1 2.00 ft(distance below the filtration media surface) Underdrain Orifice Area= 0.0 ftz Underdrain Orifice Diameter=1 2.00 inches Underdrain Orifice Centroid= 0.08 feet User Input: Orifice Plate with one or more orifices or Elliptical Slot Weir(typically used to drain WQCV and/or EURV in a sedimentation BMP) Calculated Parameters for Plate Centroid of Lowest Orifice=MN/A ft(relative to basin bottom at Stage=0 ft) WQ Orifice Area per Row=MN/A ft' Depth at top of Zone using Orifice Plate= ft(relative to basin bottom at Stage=0 ft) Elliptical Half-Width= feet Orifice Plate:Orifice Vertical Spacing= inches Elliptical Slot Centroid= feet Orifice Plate:Orifice Area per Row= sq.inches Elliptical Slot Area= ft2 User Input: Stage and Total Area of Each Orifice Row(numbered from lowest to highest) Row 1(optional) Row 2(optional) Row 3(optional) Row 4(optional) Row 5(optional) Row 6(optional) Row 7(optional) Row 8(optional) Stage of Orifice Centroid(ft) N/A N/A N/A N/A N/A N/A N/A N/A Orifice Area(sq.inches) N/A N/A N/A N/A N/A N/A N/A N/A Row 9(optional) Row 10(optional) Row 11 optional Row 12(optional) Row 13(optional) Row 14(optional) Row 15(optional) Row 16(optional) Stage of Orifice Centroid(ft) N/A N/A N/A N/A N/A N/A N/A N/A Orifice Area(sq.inches) N/A N/A N/A N/A N/A N/A N/A N/A User Input: Vertical Orifice(Circular or Rectangular) Calculated Parameters for Vertical Orifice Not Selected Not Selected Not Selected Not Selected Invert of Vertical Orifice= N/A N/A ft(relative to basin bottom at Stage=0 ft) Vertical Orifice Area= N/A N/A ft Depth at top of Zone using Vertical Orifice= N/A N/A ft(relative to basin bottom at Stage=0 ft) Vertical Orifice Centroid= N/A N/A feet Vertical Orifice Diameter= N/A N/A inches User Input: Overflow Weir(Dropbox with Flat or Sloped Grate and Outlet Pioe OR Rectangular/Trapezoidal Weir and No Outlet Pipe) Calculated Parameters for Overflow Weir Zone 2 Weir Zone 3 Weir Zone 2 Weir Zone 3 Weir Overflow Weir Front Edge Height,Ho= 1.55 2.13 ft(relative to basin bottom at Stage=o ft) Height of Grate Upper Edge,Ht= 1.55 2.86 feet Overflow Weir Front Edge Length= 3.140 4.13 feet Overflow Weir Slope Length= 0.00 3.01 feet Overflow Weir Grate Slope= 0.00 4.00 H:V Grate Open Area/100-yr Orifice Area= 0.00 1.76 Horiz.Length of Weir Sides= 0.00 2.92 feet Overflow Grate Open Area w/o Debris= 0.00 8.63 ft, Overflow Grate Type= Close Mesh Grate Type C Grate Overflow Grate Open Area w/Debris= 0.00 8.63 fe Debris Clogging%=1 0% 0% % User Input:Outlet Pipe w/Flow Restriction Plate(Circular Orifice.Restrictor Plate,or Rectangular Orifice) Calculated Parameters for Outlet Pipe w/Flow Restriction Plate Zone 2 Restrictor Zone 3 Restrictor Zone 2 Restrictor Zone 3 Restrictor Depth to Invert of Outlet Pipe= 0.08 0.14 ft(distance below basin bottom at Stage=0 ft) Outlet Orifice Area= 0.79 4.91 ft2 Outlet Pipe Diameter= 12.00 30.00 inches Outlet Orifice Centroid= 0.50 1.25 feet Restrictor Plate Height Above Pipe Invert= 12.00 30.00 inches Half-Central Angle of Restrictor Plate on Pipe= 3.14 3.14 radians User Input:Emergency Spillway(Rectangular or Trapezoidal) Calculated Parameters for Spillway Spillway Invert Stage= ft(relative to basin bottom at Stage=0 ft) Spillway Design Flow Depth= feet Spillway Crest Length= feet Stage at Top of Freeboard= feet Spillway End Slopes= H:V Basin Area at Top of Freeboard= acres Freeboard above Max Water Surface= feet Basin Volume at Top of Freeboard= acre-ft Routed Hydro rah Results The user can override the default CUHP hydro roc hs and runoff volumes by entering new values in the Inflow H dro roc hs table 6Q81mns W throw h AF. Design Storm Return Period= EURV 2 Year IMMM NFL 25 Year 50 Year 100 Year 500 Year One-Hour Rainfall Depth(in)= N/A N/A 0.82 1.09 1.40 1.69 1.99 2.86 3.14 CUHP Runoff Volume(acre-ft)= 0.161 0.563 0.353 0.530 0.795 1.115 1.404 2.305 2.587 Inflow Hydrograph Volume(acre-ft)= N/A N/A 0.353 0.530 0.795 1.115 1.404 2.305 2.587 CUHP Predevelopment Peak Q(cfs)= N/A N/A 0.1 1.0 3.6 7.8 10.8 20.3 23.2 OPTIONAL Override Predevelopment Peak Q(cfs)= N/A N/A Predevelopment Unit Peak Flow,q(cfs/acre)= N/A N/A 0.01 0.08 0.31 0.67 0.93 1.74 1.98 Peak Inflow Q(cfs)= N/A N/A 5.5 8.4 12.9 18.6 23.4 38.3 42.8 Peak Outflow Q(cfs)= 0.2 24.3 2.0 4.1 7.1 13.3 18.0 32.2 36.6 Ratio Peak Outflow to Predevelopment Q= N/A N/A N/A 4.3 2.0 1.7 1.7 1.6 1.6 Structure Controlling Flow= Overflow Weir 1 Overflow Weir 2 Overflow Weir 1 Overflow Weir 1 Overflow Weir 2 Overflow Weir 2 Overflow Weir 2 Overflow Weir 2 verfiow Weir Max Velocity through Grate 1(fps)= N/A N/A N/A N/A N/A N/A N/A N/A N/A Max Velocity through Grate 2(fps)= N/A 3.27 N/A N/A 0.2 0.8 1.4 2.9 3.4 Time to Drain 97%of Inflow Volume(hours)= 11 12 13 13 13 12 11 9 9 Time to Drain 99%of Inflow Volume(hours)= 12 12 14 14 14 14 13 13 13 Maximum Ponding Depth(ft)= 1.55 3.75 1.88 2.11 2.47 2.89 3.12 3.65 3.80 Area at Maximum Ponding Depth(acres)= 0.14 0.24 0.15 0.16 0.17 0.19 0.20 0.23 0.24 Maximum Volume Stored(acre-ft)=1 0.161 0.565 1 0.207 0.242 1 0.301 0.380 0.424 0.542 0.574 MHFD-Detention_v4-06-Sand Filter.xlsm,Outlet Structure 5/17/2024,2:05 PM DETENTIONOUTLET MHFD Detention Version 4.06(7uly 1011 45 -500VR IN .....S00YROUT 40 -IMYRIN 100YR OUT -50YRIN 35 50YR OUT �25YR IN 25YR OUT 30 ---10YR OUT 25 -SYR IN ••SYR OUT _ ] C -2YR IN _ u 20 --2YROUT '- -EURVIN •EURV OUT 15 -WOCVIN .....WOCV OUT 10 ` 5 0 0.1 1 10 TIME(hr] 4 _500YR -100YR 3.5 -SWR -25YR _10YR 3 -5YR INN -2YR �EURV 2.5 �WOCV x x r a 0 2 z 0 z 0 d 1s 9/77 0.5 Mono 0.1 1 10 100 DRAIN TIME[hr] 30,000 40 O User Area[ft^2] -Interpolated Area[ft^2] 35 25,000 "-0--Summary Area]ft^2] -Volume[ft^3] ...i••Summary Volume[W3] 30 20,000 Outflow[cfs] •••0••summary Outflow[cfs] 25 x 15,000 20 0 O j O 15 10,000 10 Z 5,000 5 0 0 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 PONDING DEPTH[ft] S-A-V-D Chart Axis Override. X-axis Left Y-Axis Right Y-Axis minimum bound maximum bound MHFD-Detention_v4-O6-Sand Filter.xlsm,Outlet Structure 5/17/2024,2:05 PM DETENTIONBASIN OUTLET Outflow Hydrograph Workbook Filename.• Inflow Hydrographs The user can override the calculated inflow hydrographs from this workbook with inflow hydrographs developed in a separate program. SOURCE CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP Time Interval TIME WQCV[cfs] EURV[cfs] 2 Year[cfs] 5 Year[cfs] 10 Year[cfs] 25 Year[cfs] 50 Year[cfs] 100 Year[cfs] 500 Year[cfs] 5.00 min 0:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.19 0.34 0:15:00 0.00 0.00 0.23 0.74 1.24 0.86 1.25 1.90 2.19 0:20:00 0.00 0.00 1.89 2.79 3.78 2.49 3.14 4.80 5.55 0:25:00 0.00 0.00 4.42 6.75 10.48 5.95 7.60 13.45 15.74 0:30:00 0.00 0.00 5.55 8.42 12.93 15.98 20.55 32.67 36.77 0:35:00 0.00 0.00 5.16 7.80 11.80 18.59 23.45 38.28 42.80 0:40:00 0.00 0.00 4.60 6.78 10.22 17.97 22.47 36.26 40.46 0:45:00 0.00 0.00 3.90 5.83 8.86 15.83 19.77 32.84 36.64 0:50:00 0.00 0.00 3.29 5.04 7.48 14.21 17.74 29.24 32.60 0:55:00 0.00 0.00 2.81 4.28 6.34 11.89 14.87 25.21 28.11 1:00:00 0.00 0.00 2.50 3.77 5.63 9.97 12.51 22.00 24.57 1:05:00 0.00 0.00 2.27 3.40 5.11 8.71 10.99 19.93 22.27 1:10:00 0.00 0.00 1.96 3.07 4.62 7.35 9.31 16.51 18.48 1:15:00 0.00 0.00 1.67 2.64 4.14 6.17 7.83 13.51 15.15 1:20:00 0.00 0.00 1.40 2.19 3.48 4.93 6.25 10.35 11.60 1:25:00 0.00 0.00 1.19 1.83 2.77 3.87 4.88 7.67 8.60 1:30:00 0.00 0.00 1.06 1.63 2.34 2.90 3.65 5.62 6.32 1:35:00 0.00 0.00 1.00 1.53 2.09 2.33 2.93 4.39 4.95 1:40:00 0.00 0.00 0.97 1.37 1.91 1.98 2.47 3.63 4.09 1:45:00 0.00 0.00 0.95 1.24 1.79 1.75 2.17 3.09 3.49 1:50:00 0.00 0.00 0.94 1.15 1.70 1.59 1.97 2.73 3.08 1:55:00 0.00 0.00 0.82 1.08 1.60 1.49 1.83 2.46 2.78 2:00:00 0.00 0.00 0.73 1.00 1.44 1.42 1.74 2.28 2.58 2:05:00 0.00 0.00 0.55 0.75 1.08 1.07 1.29 1.67 1.89 2:10:00 0.00 0.00 0.41 0.55 0.78 0.78 0.94 1.22 1.37 2:15:00 0.00 0.00 0.30 0.41 0.57 0.57 0.68 0.89 1.00 2:20:00 0.00 0.00 0.22 0.29 0.41 0.41 0.50 0.65 0.73 2:25:00 0.00 0.00 0.16 0.21 0.29 0.29 0.35 0.46 0.52 2:30:00 0.00 0.00 0.11 0.14 0.21 0.21 0.25 0.33 0.37 2:35:00 0.00 0.00 0.08 0.10 0.14 0.15 0.18 0.23 0.26 2:40:00 0.00 0.00 0.05 0.07 0.09 0.10 0.12 0.15 0.17 2:45:00 0.00 0.00 0.03 0.04 0.05 0.06 0.07 0.09 0.10 2:50:00 0.00 0.00 0.01 0.02 0.02 0.03 0.03 0.04 0.05 2:55:00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 3:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MHFD-Detention_v4-06-Sand Filter.xlsm,Outlet Structure 5/17/2024,2:05 PM DETENTIONBASIN OUTLET MHFD-Detention, Version 4.06(July 1011) Summary Stage-Area-Volume-Discharge Relationships The user can create a summary S-A-V-D by entering the desired stage increments and the remainder of the table will populate automatically. The user should graphically compare the summary S-A-V-D table to the full S-A-V-D table in the chart to confirm it captures all key transition points. Stage Area Area Volume Volume Total Stage-Storage Stage Description [R] [R'] [acres] [R'] Jac-R] [crs] Media Surface-5106.00 0.00 3,022 0.069 0 0.000 0.00 For best results,include the 5106.5 0.50 3,962 0.091 1,746 0.040 0.16 stages of all grade slope 5107 1.00 5,067 0.116 4,003 0.092 0.18 changes(e.g.ISV and Floor) from the S-A-V table on 5107.5 1.50 5,855 0.134 6,734 0.155 0.19 Sheet'Basin'. 5107.55-WQCV 1.55 5,936 0.136 7,029 0.161 0.20 5108 2.00 6,658 0.153 9,862 0.226 3.05 Also include the inverts of all 5108.5 2.50 7,637 0.175 13,436 0,308 7.47 outlets(e.g.vertical orifice, 5109 3.00 8,660 0.199 17,510 0.402 15.45 overflow grate,and spillway, 5109.5 3.50 9,728 0.223 22,107 0.508 27.79 where applicable). 5109.6-100 YR 3.62 9,995 0.229 23,290 0.535 31.22 5110.0 4.00 10,840 0.249 27,249 0.626 40.18 5110.25 4.25 11,474 0.263 30,038 0.690 41.88 5110.5 4.50 12,108 0.278 32,986 0.757 43.52 MHFD-Detention_v4-06-Sand Filter.xlsm,Outlet Structure 5/17/2024,2:05 PM Design Procedure Form: Rain Garden(RG) UD-BMP(Version 3.07,March 2018) Sheet 1 of 2 Designer: ARJ Company: JR Engineering Date: May 8,2024 Project: Polestar Location: #2-Rain Garden;B1-132 1.Basin Storage Volume A)Effective Imperviousness of Tributary Area,la la= 55.5 % (100%if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio(i=Ia1100) i= 0.555 C) Water Quality Capture Volume(WQCV)for a 12-hour Drain Time WQCV= 0.18 watershed inches (WQCV=0.8*(0.91*i3-1.19*i2+0.78*i) D) Contributing Watershed Area(including rain garden area) Area= 67,518 sq ft E) Water Quality Capture Volume(WQCV)Design Volume VwOG,=0cu ft Vol=(WQCV/12)*Area F) For Watersheds Outside of the Denver Region,Depth of de= 0.43 in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWOCV OTHER= cu ft Water Quality Capture Volume(WQCV)Design Volume H) User Input of Water Quality Capture Volume(WQCV)Design Volume VwncvuSER= 1,199 cu ft (Only if a different WQCV Design Volume is desired) 2.Basin Geometry A)WQCV Depth(12-inch maximum) DwOcv= 7.5 in B)Rain Garden Side Slopes(Z=4 min.,horiz.dist per unit vertical) Z= 4.00 ft/ft (Use"0"if rain garden has vertical walls) C)Mimimum Flat Surface Area AM;,,= 749 sq ft D)Actual Flat Surface Area AA"1 d= 870 sq ft E)Area at Design Depth(Top Surface Area) AT,= 3143 sq ft F)Rain Garden Total Volume VT= 1,254 cu ft (VT=((ATop+AAO w)/2)*Depth) 3.Growing Media Choose One 18"Rain Garden Growing Media p Other(Explain): 4.Underdrain System Choose One A)Are underdrains provided? #YES p NO B)Underdrain system orifice diameter for 12 hour drain time i)Distance From Lowest Elevation of the Storage y= 2.3 ft Volume to the Center of the Orifice ii)Volume to Drain in 12 Hours V0112= 1,199 cu ft iii)Orifice Diameter,3/8"Minimum Do= 3/4 in No.2 UD BMP_v3.07.xlsm,RG 5/8/2024,4:20 PM Design Procedure Form: Rain Garden (RG) Sheet 2 of 2 Designer: ARJ Company: JR Engineering Date: May 8,2024 Project: Polestar Location: #2-Rain Garden;B1-B2 5.Impermeable Geomembrane Liner and Geotextile Separator Fabric Choose One O YES A) Is an impermeable liner provided due to proximity O NO of structures or groundwater contamination? 6.Inlet/Outlet Control Choose One O Sheet Flow-No Energy Dissipation Required A) Inlet Control Q Concentrated Flow-Energy Dissipation Provided Choose One 7.Vegetation Q Seed(Plan for frequent weed control) O Plantings O Sand Grown or Other High Infiltration Sod 8. Irrigation Choose One O YES A) Will the rain garden be irrigated? 0 NO Notes: No.2 LID BMP_v3.07.xlsm,RG 5/8/2024,4:20 PM Design Procedure Form: Rain Garden(RG) UD-BMP(Version 3.07,March 2018) Sheet 1 of 2 Designer: ARJ Company: JR Engineering Date: May 8,2024 Project: Polestar Village Location: Rain Garden No.3;Basins CI-C2 and D8 1.Basin Storage Volume A)Effective Imperviousness of Tributary Area,la la= 55.0 % (100%if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio(i=la/100) i= 0.550 C) Water Quality Capture Volume(WQCV)for a 12-hour Drain Time WQCV= 0.18 watershed inches (WQCV=0.8*(0.91*i3-1.19*i2+0.78*i) D) Contributing Watershed Area(including rain garden area) Area= 39,204 sq ft E) Water Quality Capture Volume(WQCV)Design Volume VwOG,=0cu ft Vol=(WQCV/12)*Area F) For Watersheds Outside of the Denver Region,Depth of de= 0.43 in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWOCV OTHER= cu ft Water Quality Capture Volume(WQCV)Design Volume H) User Input of Water Quality Capture Volume(WQCV)Design Volume VwncvuSER= 691 cu ft (Only if a different WQCV Design Volume is desired) 2.Basin Geometry A)WQCV Depth(12-inch maximum) Dwocv= 8.0 in B)Rain Garden Side Slopes(Z=4 min.,horiz.dist per unit vertical) Z= 4.00 ft/ft (Use"0"if rain garden has vertical walls) C)Mimimum Flat Surface Area AM;,,= 431 sq ft D)Actual Flat Surface Area AA"1 d= 567 sq ft E)Area at Design Depth(Top Surface Area) AT,= 1527 sq ft F)Rain Garden Total Volume VT= 698 cu ft (VT=((ATpp+AAO w)/2)*Depth) 3.Growing Media Choose One 18"Rain Garden Growing Media p Other(Explain): 4.Underdrain System Choose One A)Are underdrains provided? #YES p NO B)Underdrain system orifice diameter for 12 hour drain time i)Distance From Lowest Elevation of the Storage y= 2.3 ft Volume to the Center of the Orifice ii)Volume to Drain in 12 Hours V0112= 691 cu ft iii)Orifice Diameter,3/8"Minimum Do= 9/16 in No.3 UD BMP_v3.07.xlsm,RG 5/8/2024,4:20 PM Design Procedure Form: Rain Garden (RG) Sheet 2 of 2 Designer: ARJ Company: JR Engineering Date: May 8,2024 Project: Polestar Village Location: Rain Garden No.3;Basins Cl-C2 and D8 5.Impermeable Geomembrane Liner and Geotextile Separator Fabric Choose One O YES A) Is an impermeable liner provided due to proximity O NO of structures or groundwater contamination? 6.Inlet/Outlet Control Choose One O Sheet Flow-No Energy Dissipation Required A) Inlet Control Q Concentrated Flow-Energy Dissipation Provided Choose One 7.Vegetation Q Seed(Plan for frequent weed control) O Plantings O Sand Grown or Other High Infiltration Sod 8. Irrigation Choose One O YES A) Will the rain garden be irrigated? 0 NO Notes: No.3 LID BMP_v3.07.xlsm,RG 5/8/2024,4:20 PM Design Procedure Form: Rain Garden(RG) UD-BMP(Version 3.07,March 2018) Sheet 1 of 2 Designer: ARJ Company: JR Engineering Date: May 21,2024 Project: Polestar Village Location: Rain Garden No.4;Basins D6 1.Basin Storage Volume A)Effective Imperviousness of Tributary Area,la la= 60.5 % (100%if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio(i=la/100) i= 0.605 C) Water Quality Capture Volume(WQCV)for a 12-hour Drain Time WQCV= 0.19 watershed inches (WQCV=0.8*(0.91*i3-1.19*i2+0.78*i) D) Contributing Watershed Area(including rain garden area) Area= 12,197 sq ft E) Water Quality Capture Volume(WQCV)Design Volume Vwo�v=0cu ft Vol=(WQCV/12)*Area F) For Watersheds Outside of the Denver Region,Depth of de= 0.43 in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VwocV OTHER= cu ft Water Quality Capture Volume(WQCV)Design Volume H) User Input of Water Quality Capture Volume(WQCV)Design Volume VwncvUSER= 232 cu ft (Only if a different WQCV Design Volume is desired) 2.Basin Geometry A)WQCV Depth(12-inch maximum) DwOcv=0in B)Rain Garden Side Slopes(Z=4 min.,horiz.dist per unit vertical) Z= 4.00 ft/ft (Use"0"if rain garden has vertical walls) C)Mimimum Flat Surface Area AM;,,= 148 sq ft D)Actual Flat Surface Area AA"1 d= 177 sq ft E)Area at Design Depth(Top Surface Area) AT,= 475 sq ft F)Rain Garden Total Volume VT= 245 cu ft (VT=((ATpp+AAO w)/2)*Depth) 3.Growing Media Choose One 18"Rain Garden Growing Media p Other(Explain): 4.Underdrain System Choose One A)Are underdrains provided? #YES p NO B)Underdrain system orifice diameter for 12 hour drain time i)Distance From Lowest Elevation of the Storage y=F 2.3 ft Volume to the Center of the Orifice ii)Volume to Drain in 12 Hours V0112= 232 cu ft iii)Orifice Diameter,3/8"Minimum DO= 5/16 In LESS THAN MINIMUM. USE DIAMETER OF 3/8" No.4 UD BMP_v3.07.xlsm,RG 5/21/2024,12:44 PM Design Procedure Form: Rain Garden(RG) Sheet 2 of 2 Designer: ARJ Company: JR Engineering Date: May 21,2024 Project: Polestar Village Location: Rain Garden No.4;Basins D6 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric Choose One Q YES A) Is an impermeable liner provided due to proximity O NO of structures or groundwater contamination? 6. Inlet/Outlet Control Choose One �Q Sheet Flow-No Energy Dissipation Required A) Inlet Control @)Concentrated Flow-Energy Dissipation Provided Choose One 7.Vegetation *Seed(Plan for frequent weed control) Q Plantings O Sand Grown or Other High Infiltration Sod S. Irrigation Choose One Q YES A) Will the rain garden be irrigated? NO Notes: No.4 LID BMP v3.07.xlsm,RG 5/21/2024,12:44 PM Design Procedure Form: Rain Garden(RG) UD-BMP(Version 3.07,March 2018) Sheet 1 of 2 Designer: ARJ Company: JR Engineering Date: May 8,2024 Project: Polestar Village Location: Rain Garden No.5;Basins D4 1.Basin Storage Volume A)Effective Imperviousness of Tributary Area,la la= 64.3 % (100%if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio(i=Ia1100) i= 0.643 C) Water Quality Capture Volume(WQCV)for a 12-hour Drain Time WQCV= 0.20 watershed inches (WQCV=0.8*(0.91*i3-1.19*i2+0.78*i) D) Contributing Watershed Area(including rain garden area) Area= 23,522 sq ft E) Water Quality Capture Volume(WQCV)Design Volume Vwo�v=0cu ft Vol=(WQCV/12)*Area F) For Watersheds Outside of the Denver Region,Depth of de= 0.43 in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VwOCV OTHER= cu ft Water Quality Capture Volume(WQCV)Design Volume H) User Input of Water Quality Capture Volume(WQCV)Design Volume VwncvuSER= 473 cu ft (Only if a different WQCV Design Volume is desired) 2.Basin Geometry A)WQCV Depth(12-inch maximum) Dwocv= 11 in B)Rain Garden Side Slopes(Z=4 min.,horiz.dist per unit vertical) Z= 4.00 ft/ft (Use"0"if rain garden has vertical walls) C)Mimimum Flat Surface Area AM;,,= 302 sq ft D)Actual Flat Surface Area AA"1 d= 309 sq ft E)Area at Design Depth(Top Surface Area) AT,= 742 sq ft F)Rain Garden Total Volume VT= 478 cu ft (VT=((ATpp+AAO w)/2)*Depth) 3.Growing Media Choose One 18"Rain Garden Growing Media p Other(Explain): 4.Underdrain System Choose One A)Are underdrains provided? #YES p NO B)Underdrain system orifice diameter for 12 hour drain time i)Distance From Lowest Elevation of the Storage y= 2.33 ft Volume to the Center of the Orifice ii)Volume to Drain in 12 Hours V0112= 473 cu ft iii)Orifice Diameter,3/8"Minimum Do= 1l2 in No.5 UD BMP_v3.07.xlsm,RG 5/8/2024,4:18 PM Design Procedure Form: Rain Garden (RG) Sheet 2 of 2 Designer: ARJ Company: JR Engineering Date: May 8,2024 Project: Polestar Village Location: Rain Garden No.5;Basins D4 5.Impermeable Geomembrane Liner and Geotextile Separator Fabric Choose One O YES A) Is an impermeable liner provided due to proximity O NO of structures or groundwater contamination? 6.Inlet/Outlet Control Choose One O Sheet Flow-No Energy Dissipation Required A) Inlet Control Q Concentrated Flow-Energy Dissipation Provided Choose One 7.Vegetation Q Seed(Plan for frequent weed control) O Plantings O Sand Grown or Other High Infiltration Sod 8. Irrigation Choose One O YES A) Will the rain garden be irrigated? 0 NO Notes: No.5 LID BMP_v3.07.xlsm,RG 5/8/2024,4:18 PM Design Procedure Form: Rain Garden(RG) UD-BMP(Version 3.07,March 2018) Sheet 1 of 2 Designer: ARJ Company: JR Engineering Date: May 8,2024 Project: Polestar Village Location: Rain Garden No.6;Basins D1-D3 1.Basin Storage Volume A)Effective Imperviousness of Tributary Area,la la= 65.0 % (100%if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio(i=la/100) i= 0.650 C) Water Quality Capture Volume(WQCV)for a 12-hour Drain Time WQCV= 0.20 watershed inches (WQCV=0.8*(0.91*i3-1.19*i2+0.78*i) D) Contributing Watershed Area(including rain garden area) Area= 31,799 sq ft E) Water Quality Capture Volume(WQCV)Design Volume VWQ v=0cu ft Vol=(WQCV/12)*Area F) For Watersheds Outside of the Denver Region,Depth of de= 0.43 in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWOCV OTHER= cu ft Water Quality Capture Volume(WQCV)Design Volume H) User Input of Water Quality Capture Volume(WQCV)Design Volume VwncvuSER= 646 cu ft (Only if a different WQCV Design Volume is desired) 2.Basin Geometry A)WQCV Depth(12-inch maximum) DwOcv=0in B)Rain Garden Side Slopes(Z=4 min.,horiz.dist per unit vertical) Z= 4.00 ft/ft (Use"0"if rain garden has vertical walls) C)Mimimum Flat Surface Area AM;,,= 413 sq ft D)Actual Flat Surface Area AA"1 d= 430 sq ft E)Area at Design Depth(Top Surface Area) AT,= 1283 sq ft F)Rain Garden Total Volume VT= 650 cu ft (VT=((ATpp+AAO w)/2)*Depth) 3.Growing Media Choose One 18"Rain Garden Growing Media p Other(Explain): 4.Underdrain System Choose One A)Are underdrains provided? #YES p NO B)Underdrain system orifice diameter for 12 hour drain time i)Distance From Lowest Elevation of the Storage y= 2.3 ft Volume to the Center of the Orifice ii)Volume to Drain in 12 Hours V0112= 646 cu ft iii)Orifice Diameter,3/8"Minimum Do= 9/16 in No.6 UD BMP_v3.07.xlsm,RG 5/8/2024,4:17 PM Design Procedure Form: Rain Garden (RG) Sheet 2 of 2 Designer: ARJ Company: JR Engineering Date: May 8,2024 Project: Polestar Village Location: Rain Garden No.6;Basins D1-D3 5.Impermeable Geomembrane Liner and Geotextile Separator Fabric Choose One O YES A) Is an impermeable liner provided due to proximity O NO of structures or groundwater contamination? 6.Inlet/Outlet Control Choose One O Sheet Flow-No Energy Dissipation Required A) Inlet Control Q Concentrated Flow-Energy Dissipation Provided Choose One 7.Vegetation Q Seed(Plan for frequent weed control) O Plantings O Sand Grown or Other High Infiltration Sod 8. Irrigation Choose One O YES A) Will the rain garden be irrigated? 0 NO Notes: No.6 LID BMP_v3.07.xlsm,RG 5/8/2024,4:17 PM 22 APPENDIX E - REFERENCES Polestar Village- Floodplain Modeling Report October 2023 5.0 HYDROLOGY 5.1 Discharges and Model Frequencies EPA SWMM version 5.2 (build 5.2.1) was used to model the hydrology of the site. The frequency modeled was the 100-year event. The discharges are below in Table 1, Plum Channel Flow Path Discharge Profile. For additional information, refer to the Modified- Table B.1.1 Plum Channel Flow Path Discharge Profile in Appendix J-5. Table 1-Plum Channel Flow Path Discharge Profile EFFECTIVE HEC 100 Year Discharge(cfs) RAS Effective HEC- Effective Corrective Cross-Section EPA SWMM RAS Hydraulics SWMM EffectiveProposed Result Location ELEMENT model/Result Hydrology Hydrology Model Mapped by /Result Anderson Modeled /Result Modeled 113(313out in 5271 CE models) 241 155 252 245 Upstream Study Limit 5190 NODE 23 --- --- --- 362 Pond Inflow 4872 (L)15 330 200 305 --- POND 4675 OUTFLOW 114 --- 174 Pond outflow C- 4277.999 1+115_pipe/1 214/140 167/139 290/242 187/140 Upstream of Rocky Road Culvert 15 overflow* *Discharge based on the sum ofpipe and overflow discharge Flow is presented as(total flow)/(Surface Flow) ---null value ####-New Station(referencing existing aGgrment)or Element Modeled 5.2 Revised Hydrologic Analysis The Polestar site is within the City of Fort Collins Floodplain, and the City of Fort Collins requested that JR Engineering incorporate the Polestar development's developed conditions SWMM model into the City Master Canal Importation Drainage Plan SWMM Model. In addition, the City of Fort Collins requested that JR Engineering revise the CLOMR inputs to match the Hydrology for the site and the proposed improvements to the site. In 2013/2014 Anderson Consulting Engineers was contracted by the City of Fort Collins to convert the effective hydrologic model for the Canal Importation Basin from ModSWMM to EPA SWMM111. In 2014 Anderson was hired by the City to Map the 100- year effective floodplain)21. JR Engineering has incorporated the revised Hydrology in a standalone Appendix - Appendix J at the end of this report to be referenced in this report and the Polestar drainage report. JR Engineering has prepared three SWMM models, which include the Corrected Effective Model, the Proposed Model, and the Ultimate Model for the site. Please refer to detailed sections in this Revised Hydrology Analysis outlining each SWMM model, and accompanying SWMM maps for additional information. The City of Fort Collins effective SWMM model)1I flows do not match flows modeled in 9 Polestar Village-Floodplain Modeling Report October 2023 the City's Effective HEC-RAS model�21. The effective 100-year flow rate overtopping the Scenic Views Pond (pond 313) cfs[2]. This flow does not match the modeled flow in the City's SWMM Modell'I of 156 cfs, as shown the 2014 Anderson report in Appendix J-5. JR Engineering has prepared four SWMM schematics maps to show the changes being made to 2014 Existing Model,the Corrected Effective Model,the Proposed Model, and the Ultimate Model for the site with the defined gravity outfall. The SWMM schematics are shown in Appendix J-3. SWMM output and input files are provided for each scenario for the 100-year event. The inputs for the Sub-Basins modified for each scenario are shown in the Appendix J-2.All of the SWMM models were run on EPA Storm Water Management Model -Version 5.2 (Build 5.2.1). 5.2.1 City Effective SWMM Model (2014 Anderson) - 100yr Canal Importation Hydrology Update.inp The Effective hydrologic model was developed by Anderson using EPA SWMM (build 5.0). The Effective Model is on NGVD29. When the City's SWMM hydrology model is re-run in the current software version 5.2. The runoff overtopping the Scenic Views Pond (Pond 313) is 0 cfs. Pond 313 floods, and there is no flow in the downstream link element of Pond 313.This error(warning 10),is a result of a code change between different versions of SWMM past 2014. Warning number 10 occurs when crest elevation is below downstream invert for regulator link. The 2014 Anderson SWMM model results show 156 cfs overtopping the Scenic Views Spillway. After a discussion with City Staff, the preferred way to model Pond 313 was to set the invert of the Pond at the spillway elevation so there is no inadvertent detention or storage modeled in Pond 313 and to avoid warning number 10. This change is reflected in the Corrected Effective SWMM model. 5.2.2 Corrected Effective Model- 100yr CE Canal Importation Hydrology Update.inp The Corrected Effective Model accounts for additional runoff that drains directly onto the site from the Locust Grove Filling No. 1 subdivision directly north of the site. This runoff (onto the Polestar site) was not accounted for in the previous model, and all of the runoff was assumed to drain directly onto Orchard Place to Junction J17, as shown in the Existing SWMM Schematic. JR Engineering's survey topo showed that Sub-Basin 17 should be broken up to account for the additional runoff that travels down Locust Grove Drive and drains directly onto the Polestar site. As a result, Sub-Basin 17 was broken up into two corresponding Sub-Basins (17E and 17W), as shown in the attached Corrected Effective SWMM Schematic in Appendix J-3. Sub-Basin 15 was also broken up into two Sub-Basins to account for the existing Polestar Site (EP) and existing lots from the Mountaire Subdivision (15E), as shown in the attached SWMM Schematic in Appendix J-3. The following is a list of 10 Polestar Village-Floodplain Modeling Report October 2023 changes made from the existing City Effective SWMM Model (2014 Anderson) to the Corrected Effective Model. • Broke up Sub-Basin 17 into Sub-Basins 17E and 17W to reflect the existing drainage topography and account for the runoff from Locust Grove Drive that drains directly onto the Polestar Site. • Broke Sub-Basin 15 to Sub-Basin EP and 15E to account for the drainage directly tributary to the Polestar site and separate runoff that is tributary to the Mountaire Subdivision. • For the impervious calculations, a typical value used in the existing model of 45% was applied for single-family detached residential areas for Sub-Basins 17W and 17E. For the existing Polestar site, the percent impervious was determined with survey information by JR Engineering. These updates resulted in a combined modified imperviousness of 29% in the Corrected Effective Model, compared to 34% in the original effective SWMM modeling, since the effective model assumed a portion of the existing Polestar site was impervious and did not utilize survey information. The topography on the existing Polestar site is primary grass, and the net composite percent impervious of the existing site is 3.7%. Table 2: Sub-Basin Effective vs. Existing Sub-Basin 2014 Anderson Effective Model Percent Corrected Effective Percent Sub-Basin Area(Acres) Impervious Model Sub-Basin Area(Acres) Impervious 17 25.5 45.0% EP 21.5 3.7% 15 30.0 25.0% 17W 10.2 45.0% -- 17E 14.8 45.0% -- 15E 9.0 45.0% Total 55.5 34.2% 55.5 29.0% • Removed Junction J113 and Conduit 113 to create positive drainage, to simplify the model, and to avoid modeling errors resulting from SWMM Warning 10. • Edited the stage-storage curve for Pond 313 curve name (313_AB*JR Edit) to reflect the pond being 100% full up to the spillway elevation at the start of the 100- year storm. The pond contours were revised using JR survey data. • Removed outlet offset from elements 110_overflow and 110_Pipe. • Updated outlet offset from 4 feet to 5 feet for link stability for element 116. • The rating table for 313 spillway overflow (313out JR Edit) was added with the same formula as 313 out but includes additional head. See the SWMM model. • Added a time series for the City of Fort Collins 2-year storm. • The Downstream outfall of Pond 315 contains a twin 24-inch RCP. The City's Effective Model only modeled one pipe. JR Engineering added an additional conduit (C-1) to account for the additional pipe. • The effective hydrology model did not establish a separate rating curve from the spillway to correctly model the flow going through the pipes for the Kimball Pond (Pond 315). Changed 315out to 315out Spillway added a separate rating curve based on the spillway overflow based on the attached calculation from the Ayres Update Hydrologic Analysis for West Plum Street Basin, as shown in Appendix J- 4. 11 Polestar Village- Floodplain Modeling Report October 2023 • Added an outlet 315out culverts to represent the twin 24-inch culvert outfall for the Kimball Pond(Pond 315). Added a rating curve for the culverts determined in MHFD-Culvert_v4.0 design workbook as shown in Appendix J-6. • Pond 315 -updated rating curve to support 0.14 feet of head to prevent flooding within the model. See storage rating curve 315*JR edit within SWMM. • Updated max depth of Pond 315 to be 5.1 feet. • Junction J37 was added to divert flow for between the dual 24-inch Rocky Road culverts. Table 3: Comparison of Scenic View Pond Modeling - Effective vs. Corrected Effective City Effective SWMM Model(2014 Anderson) Corrected Effective Model Storage Max.Vol., Max.Vol., OuMtf o. Max.HGL,ft Max.Vol., Max.Vol., Outflow Max.HGL,IT Element 1000 fe acre-ft 1000 ft, acre-ft ' cfs NAVD 88 cfs NAVD 88 313 151.26 3.47 156.14 5117.32 1 143.545 3.29 252.16 5117.47 Note: Storage Element 313 is the Scenic Views Pond. The CE Model the increased the flows to downstream properties in the mapped floodplain, as shown in Table B.1.1 Plum Channel Flow Path Discharge Profile, in Appendix J-5. 5.2.3 Proposed Model- I00yr Proposed Polestar- Canal Importation Hydrology Update.inp The Proposed Model incorporates the improvements to the Polestar Site and the Sub- Basins from the existing corrected effective model. Interim detention for the site is provided within storage element 23 (the proposed detention facility). The existing overflow spillway for Pond 313 (Scenic Views Pond) is currently undersized to handle the total peak 100-year inflow of 348.6 cfs. The current spillway for Pond 313 is 10 feet wide and 1.5 feet deep, and is set at an elevation of 5112.5 on the NGVD 29 datum. The total existing inflow exceeds the capacity of the spillway and spills over the pond embankment, which is acting as an overflow weir for 290 feet. The depth in the existing condition is approximately 2 feet. JR Engineering is proposing that the spillway be built at the same elevation as the NGVD 29 datum, but on the NAVD88 datum. JR Engineering's Design documents are on the NAVD 88 datum(5112.5+3.07=5115.57). The spillway will be modified by increasing the width and depth to convey flow at a greater depth than the City's required depth of 0.5 feet and convey flow at a depth of 1.75 feet. JR Engineering has asked for a variance to this criterion, as shown in the Appendix J-6, which includes an existing Cross-Section of the Scenic Views Pond Spillway, a proposed Cross-Section of the Scenic Views Pond Spillway, and the proposed Cross-Section of the Polestar Pond spillway. This modification will decrease the overall breadth of the floodplain, and it will serve as an interim improvement to the site. The updated Scenic Views overflow weir will contain the flows within the spillway section with 6-inches of freeboard, and there will be no embankment overtopping in the 100-year event. The impacts on volume, HGL, and outflow from this change are shown in Table 4. 12 Polestar Village-Floodplain Modeling Report October 2023 The outlet structure rating table for the proposed pond was developed using the (M1IFD- Detention_v4-06 workbook design tool), as shown in Appendix J-2 for an outlet structure with a restricted 42-inch pipe. The objective of the project's detention facility is to detain the site's runoff and improve downstream conditions with respect to runoff as much as possible in the allocated pond footprint. The interim detention facility detains the site's runoff and reduces peak flow with additional supplemental volume, as shown in Tables 6 and 7. The onsite detention requirement for the site is the runoff difference between the 100-year developed inflow runoff rate and the 2-year historic runoff,which is 4.88 acre-ft. The calculation for the onsite detention is shown in Appendix J-2. The following is a list of changes made from the Corrected Effective Model to the Proposed Model. • Converted element 313out from an outlet element to a weir element. See the attached exhibit for the Scenic Views Spillway pond in Appendix J-6. Note the Jacobs Spillway is on NAVD88, and the existing spillway is on NGVD29. SWMM still models positive drainage. The SWMM model was left on NVGD29. The difference is 3.07 feet (As referenced in the Anderson Report for the Plum Creek Channel�21). • Changed Sub-Basin EP to P. Sub-Basin P is 50%o impervious. Improvements to the Polestar site will not exceed 50%. • Updated and converted Junction 23 to a pond element for the Polestar Pond. • Added stage-storage curve for Pond 23. See SWMM Pond_23. • Added an additional Junction below the outfall for pond 23 (Junction J14). • Re-named element 15 to be M-15. Changed element to a broad trapezoidal element to reflect improvements to the Plum Creek Channel (see SWMM model). The flow is hydraulically modeled in HEC-RAS. • Created two outfall elements for Pond 23. One of the outfalls reflects the interim outfall (INTERIM_OUTLET), and the other outfall represents the spillway i.e., a weir sized for the Ultimate condition (SPILLWAY_OUTFALL). See the attached variance exhibit for Polestar Spillway(Appendix J.VI). • The hydraulics for the rating curve of the interim outlet(23_INTERIM_OUTLET) for a restricted 42-inch pipe was determined using an MHFD spreadsheet. • The weir coefficient for the Scenic View pond and Polestar pond were determined within OpenFlows FlowMaster based on a broad crested weir Cross-Section, as shown in Appendix J-6 Spillway Variance Request. Table 4: Comparison of Scenic View Pond Modeling - Corrected Effective vs. Proposed Corrected Effective Model Proposed Model Storage Max.Vol., Max.Vol., L HG ,ft Max. Max. Max.Vol, Max.Vol., Max.HGL,ft Element 1000 f? acre-ft Outflow, 1000 ft, acre-ft cfs NAVD 88 NAVD 88 313 143.545 3.29 252.16 5117.47 102.67 2.36 244.77 5116.95 Note: Storage Element 313 is the Scenic Views Pond To compare flows leaving the site between each respective model, refer to Table 3 below. For information on the ultimate condition, refer to the section about the ultimate condition provided in Section 5.2.4. 13 Polestar Village- Floodplain Modeling Report October 2023 In the 100-year event, 9.58 acre-ft of detention is provided in the Happy Heart/Polestar interim detention pond. The peak release rate leaving the site is reduced to 174 cfs from the effective flow of 330 cfs. The changes to the Corrected Effective hydrologic routing in conjunction with the proposed onsite and offsite pond improvements result in a net decrease of 100-year peak discharges as measured downstream of the Polestar property (Junction 15). Table 5: Flow Comparison Downstream of the Happy Heart Pond Model Element Flow (CFS) Effective flows (2014 HEC-RAS Model) (EF) 15 330 Effective Model (2014 SWMM Model) (E) 15 200 Corrected Effective Model (CE) SWMM Model 15 305 Proposed Model (PR) SWMM Model M-15 174 Note: Flow rounded to the nearest integer. Flow comparison is for flow leaving the site. 5.2.4 Ultimate Model—100yr Ultimate Polestar Regional Detention.inp The Ultimate SWMM Model incorporates improvements from the Canal Importation Basin Selected Plan Update Conceptual Design Report —Plum Channel Flow Path by Jacobs Engineering Group, Dated June 30th, 2022. The report outlines the ultimate improvements to the Plum Channel Flow Path. Jacobs Engineering Group has conceptually modified the Canal Importation model for the City of Fort Collins Capital Improvement plan[']. The Polestar detention facility will be converted into a regional detention facility with a deep underground gravity outfall in Orchard Place. The changes that are being made to the site in the ultimate condition are summarized below. 1. Conversion of Scenic Views retention pond to a detention pond. 2. Addition of a pipe outfall from the Scenic Views detention pond to the Happy Heart Farms Pond, also known as the future Polestar regional detention pond. 3. Increasing the volume of the onsite Polestar detention pond per the proposed ultimate outfall 4. Construction of the gravity storm sewer outfall in Orchard Place JR Engineering has provided an ultimate SWMM schematic and a map from Jacobs of the site, as shown in Appendix J-3 within the SWMM Maps. The ultimate SWMM model was incorporated in the conceptual Jacobs model (Plum Detention.inp). The outlet structure- rating table was developed using the (MHFD-Detention v4-06 workbook design tool) as shown in Appendix J-2 for an outlet structure with a restricted 30-inch pipe. It is important to note that the JR ultimate SWMM model does not replace the Jacobs model. The purpose of the ultimate model is to show the Polestar site can provide detention in the ultimate condition. 14 Polestar Village-Floodplain Modeling Report October 2023 The following is a list of changes made from the Proposed Model to the Ultimate Model. • Started with the February 2022 Jacobs model. • Brought in proposed elements into the SWMM model for the Polestar site as shown in the SWMM Map. • Added Sub-Basins P and 17W from the proposed model tributary to the storage node for pond 23. (See SWMM Map) • Added Sub-Basin 17E and 15W to the model. (See SWMM Map). • Updated the stage-storage of the detention facility at storage node 23 to reflect the ultimate pond. See SWMM for stage-storage. • Used Jacobs outlet rating for 313out. • Used the Jacobs pond grading for the stage-storage for pond 313. See SWIVIM model. • Defined two elements for the outfall of Pond 313. 313_SPILLWAY for the spillway and 313 out for the ultimate gravity outfall. Set 313—SPILLWAY to reflect the proposed JR spillway (See SWMM Model). • Updated the stage-storage for the Polestar detention pond to reflect the ultimate regional detention facility. See SWMM model (Polestar—Ultimate—Pond). • The hydraulics for the rating curve of the ultimate outlet (23_ULTIMATE_OUTLET) were determined using a MHFD spreadsheet to account for onsite WQ and a restrictor plate for a 30-inch Pipe, as shown in Appendix J-2. • Made element 115_pipe and 16_pipe double barrel 24-inch RCP. From single barrel 24-inch concrete pipes to reflect the actual existing condition. • Changed the name of 315out to 315_culverts to represent the twin 24-inch culvert outfall for the Kimball pond. Added a rating curve (315out Culverts) for the culverts determined in MHFD-Culvert v4.0 design workbook as shown in Appendix J-5. Table b: Comparison of Storage Elements in the Proposed Model and the Ultimate Model Proposed Model Ultimate Model Storage Max.Vol., Max.Vol., Max. Max. HGL,ft Max.Vol., Max.Vol., Max. Max.HGL,ft Element 1000 ft3 acre-ftOutflow 1000 ft3 acre-ft Outflow, cfs NAVD 88 cfs NAVD 88 313 102.67 2.36 244.77 5116.95 411.216 9.44 53.62 5109.96 23 417.098 9.58 173.75 5108.89 585.81 13.45 38.48 5107.14 Note: Storage Element 313 is the Scenic Views Pond. Storage Element 23 is the Polestar/Happy Heart Farms Pond. 5.3 Onsite and Ultimate Detention Calculations - Polestar/Happy Heart Farm Detention Pond The onsite detention requirement for the site is the runoff difference between the 100-year developed inflow rate and the 2-year historic runoff, which is 4.88 acre-ft. The calculation for the onsite detention is shown in Appendix J-2. The proposed detention provided onsite within the interim condition is 6.75 acre-ft up to the pond spillway elevation at 5107.79 ft (NAVD 88). 15 Polestar Village-Floodplain Modeling Report October 2023 Jacobs calculated the ultimate volume (Happy Heart Detention Pond) within the Canal Importation - Basin Selected Plan Updates dated February 2022 as 8.3 acre-ft. The total ultimate detention volume was calculated by adding the Happy Heart Detention pond of volume 8.3 acre-ft with the required interim (onsite) detention volume of 4.88 acre-ft for the Polestar site for a total volume of 13.18 acre-ft. Table 7 summarizes the detention pond changes in Table 7. TABLE 7 - Polestar/Happy Heart Farm Detention Summary Provided Volume Additional Volume WQCV Total Peak Required Volume Graded To Spillway Provided (acre-ft) Outflow Condition acre-ft acre-ft) acre-ft cfs Interim 4.88 6.75 1.87 1.2 176 Ultimate 13.18 14.89 1.71 1.2 38.48 For the ultimate condition, JR Engineering has provided a pond layout that exceeds the ultimate detention requirements, as specified in Table 7. In the ultimate model, the site is releasing at a lower rate of 38.48 cfs vs.the Jacobs release rate of 47.01 cfs. JR Engineering designed the ultimate pond within the allocated footprint to provide detention to exceed the 13.18 acre-ft required volume (calculated from the Jacob Canal Importation report + Polestar site). The modeled volume in the Ultimate SWMM Model is 13.45 Acre-ft, as shown in Table 8 below. The Jacobs Canal Importation model release rate is not explicitly stated in the report E31. Table 8 shows the volume in the ultimate model and the volume provided in the ultimate Jacobs model with each model's respective release rates. TABLE 8: Jacobs Plum Model vs JR Ultimate SWMM Model Happy Heart Farms/Polestar Detention Pond Polestar/Happy Heart Farm Detention Pond 23 SWMM Model Max Volume in SWMM Total Peak Outflow JR-Ultimate Model 13.45 acre-ft 38.48 cfs Jacobs Model 8.3 acre-ft 47.01 cfs 5.4 Hydrology Summary The City Effective SWMM Model (2014 Anderson) did not provide an accurate representation of the existing hydrology and needed to be revised in order to accurately map the existing floodplain. The existing 2014 Anderson SWMM model includes an error for the Scenic Views Pond, Pond 313 (warning 10), and the Corrected Effective model accounts for additional sub- Sub-Basins not included in the previous model and fixes the error for Pond 313 (warning 10) for SWMM Version 5.2.1. The revised hydrology (Corrected Effective Model) takes into account more accurate data and information based on the JR Engineering survey of the existing topography. These revisions include the additional runoff source from the 16 Polestar Village-Floodplain Modeling Report October 2023 Locust Grove subdivision that currently drains onto the existing Polestar site. Existing storm infrastructure updates and corrections were worked out between JR Engineering and the City of Fort Collins as part of the hydrology review process to develop a Corrected Effective Model, Proposed Model, and an Ultimate Model. The comment response(s)have been provided in the hydrology portion of digital Appendix K within a Microsoft Word document. The Corrected Effective SWMM model shows that certain homeowners downstream of the site are currently experiencing adverse impacts from flows and runoff that are greater than what is currently mapped,as shown in Appendix J-5 within the Modified Table B.1.1 Plum Channel Flow Path Discharge Profile. JR Engineering has prepared four SWMM schematics to show the changes being made to the site and provided input and output files for each scenario for the 100-year event. The benefits of revising the hydrology were to ensure the runoff on the Polestar site is accurately modeled and to ensure that detention is accurately calculated for the Polestar development. The improvements to the site reduce total runoff leaving the site compared to the Corrected Effective model, are equal to, or lower than the Effective Model. The proposed SWMM model includes the development's modifications to the Polestar site, and the Ultimate Model includes the planned outfall for the Scenic Views Pond(Pond 313)and the outfall for the Polestar detention facility(Pond 23). 17 Appendix J Hydrology Appendix J-1 Vicinity Map W MULBERRY ST 1 � o I J I = I I H uiQ a > v ORCHARD PL co Z cl) W J J J > °' m O co Y W ELIZABETH ST I I I I ------- _-- \1 I I J i i I I 1 1 � I I W PROSPECT RD \ VICINITY MAP SCALE: 1"=1000' VICINITY MAP 1000 500 0 1000 2000 POLESTAR VILLAGE JOB NO. 3979701 ORIGINAL SCALE: 1" = 1000' 6-5-2022 SHEET 1 OF 1 A Westrian Company Centennial%3-740-M•Colorado�ft 719-593-M Fat Com 97&491-90•www7 ineeri Can Appendix J-2 Calculations and Exhibits SWMM INPUTS Subdivision:Polestar Project Name: Polestar Location:Fort Collins Project No.:39797.01 Calculated By: ARJ Checked By: Date: 2/7/23 2014 SWMM -100yr Canal Importation Hydrology Update Basin inputs City of Fort Collins Default Inputs City of Fort Collins Horton inputs Tributary Area Width L=A/W Slope %Impery N-Impery N-Pery Store Imperv. Dstore perv. Zero%imperv. Storage(max) Storage(min) Decay Rate Sub-basin 17 25.5 3968.00 279.93 1.00% 45.0% 0.016 0.11 0.1 0.31 25 0.51 0.5 6.48 15 30.0 4356.00 300.00 2.00% 25.0% 0.016 o.11 0.11 0.31 25 0.51 0.5 6.48 Note:Only these two basin in the existing Hydrology were modified. Note:City of Fort Collins 2018 Criteria Recommends 1 for Zero%imperv.In the existing SWMM model this was 25. Note:City of Fort Collins 2018 Criteria Recommends 0.25 for N-Perv.In the existing SWMM model this mas 0.1. Existing SWMM INPUTS Basin inputs City of Fort Collins Default Inputs City of Fort Collins Horton inputs Tributary Area Width L=A/W Slope %Impery N-Impery N-Pery Store Imperv. Dstare perv. Zero%imperv. Storage(max) Storage(min) Decay Rate Sub-basin EP 21.5 1205.33 777.00 1.64% 3.7% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 17W 10.2 1481.04 300.00 0.60% 45.0% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 17E 24.8 2148.96 300.00 1.33% 45.0% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 15E 9.0 1306.80 300.00 1.19% 45.0% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 Proposed SWMM INPUTS Basin inputs City of Fort Collins Default Inputs City of Fort Collins Horton inputs Tributary Area Width L=A/W Slope %Impery N-Impery N-Pery Store Imperv. Dstore perv. Zero%imperv. Storage(max) Storage(min) Decay Rate Sub-basin P 21.5 1572.48 595.58 0.86% 50.0% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 17W 10.2 1481.04 300.00 0.60% 45.0% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 17E 14.8 2148.96 300.00 1.33% 45.0% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 15E 9.0 1306.80 300.00 1.19% 45.0% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 Ultimate SWMM INPUTS Basin inputs City of Fort Collins Default Inputs City of Fort Collins Horton inputs Tributary Area Width L=A/W Slope %Impery N-Impery N-Pery Store Imperv. Dstore perv. Zero%imperv. Storage(max) Storage(min) Decay Rate Sub-basin P 21.5 1572.48 595.58 0.86% 50.0% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 17W 10.2 1481.04 300.00 0.60% 45.0% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 17E 14.8 2148.96 300.00 1.33% 45.0% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 15E 9.0 1306.80 300.00 1.19% 45.0% 0.016 0.25 0.1 0.3 1 0.51 0.5 6.48 X:\3970000.all\3979701\Exoel\DminsgeU979701 Drainage_Cales_Template_v2.07.xlsm Page 1 of 2/9/2023 REQUIRED POLESTAR DETENTION POND VOLUME The onsite detention for the site i.e. the required runoff difference between the 100 year developed inflow rate and the 2-year historic runoff is 4.88 Acre-ft. In the SWMM model. P - 100 year developed inflow 1.61*106 Gallons of total runoff EP - 2-year existing inflow 0.02*106Gallons of total runoff (1.61*106- 0.02*106) gallons ( 1 ft3 )* ( 1 acre _ 4.88 Acre-ft. 7.4805gallons 43,560 f t3 Time vs. Runoff 140 120 100 — Ln LL 80 °C: 2 Year Existing(Basin EP) n 60 cc 100 Year Developed(Basin P) 40 20 0 0:00:00 1:12:00 2:24:00 3:36:00 4:48:00 6:00:00 7:12:00 8:24:00 Time P- Peak Runoff—119.98 CFS EP -2 Year Peak Runoff—2.31 CFS Io lr Polestar Pond 100 year Drain Time The Polestar Detention Facility meets Colorado Revised Statute (CRS) §37-92-602 (8) by continuously releasing and/or infiltrating at least 97%of all of the runoff from a rainfall event that is less than or equal to a 5-year storm within 72 hours after the end of the event.The Pond continuously releases or infiltrates at least 99%of the runoff within 120 hours after the end of events greater than a 5-year storm. PRPOPOSED -WATER QAULITY FOR POLESTAR DETENTION POND WQ Pond Tributary Areas Subdivision: Polestar Project Name: Polestar Location: Fort Collins Project No.: 39797.01 Calculated By: ARJ Checked By: Date: 8 7 23 WATER QUALITY IN DETENTION POND Area Basin (ac) %Imp. F1 3.87 31.6% E1 2.20 41.4% E2 0.45 55.7% E3 0.45 55.9% Total 6.97 37.8% This table shows the WQ on-site treated in the Polestar Detention pond.This calculation Coefficient,a(Figure WQCVDraiigure hr): 40 includes 20%contingencyfor sediment 3.2): 1.0 accumulation as shown in equaltion 7-2.PLEASE WQCV(in): 0.17 NOTE area on MHFD sheet was multiplied by 1.2 WQCV(ac-ft): 0.12 X:\3970000.all\3979701\Excel\Drainage\3979701 Drainage_Calcs_Template_v2.07.xlsm Page I of 1 8/7/2023 Table 5.4-1.Drain Time Coefficients for WQCV Calculations Drain Time(hrs) Coefficient(a) 12 0.8 40 1.0 Reference:The UD-BMP excel-based spreadsheet,RG and EDB tabs may be used to aid h calculating WQCV. Figure 5.4-1 WQCV Based on BMP Drain Time 0.500 0450 40 hour drain time . i I y 0.400 X_ 24 hour drain time c 0.350 -p WQCV=a(0.91i3-1.19F-+O.780 op at 0.300 w 12-hr drain time a=0.8 � y 0250 24-hr drain time a=0.9 —40 2 40-h r dra in time a=1.0 - 0.200 C 0.150 12 hour drain time 0.100 0.050 ' 0.000 0 0.1 0.2 0.3 0.4 0:5 0.6 0.7 0.8 0.9 1 Total Imperviousness Ratio(i=la/10O) Once the WQCV in watershed inches is found from Figure 3.2-12 or using Equation 3.2-1,the required BMP volume in acre-feet can be calculated as follows: Once the WQCV in watershed inches is found from Figure 3.2-12 or using Equation 3.2-1,the required BMP volume in acre-feet can be calculated as follows: V= 0!21�Axl.2 Equation 7-2 Where:V=required volume,acre-ft A-tributary catchment area upstream,acres WQCV s Water Quality Capture Volume,watershed inches 1.2=to account for the additional 20%of required storage for sedimentation accumulation X:\3970000.all\3979701\Excel\Drainage\3979701 Drainage_Calcs_Template_v2.07.xlsm Page I of 1 8/7/2023 PROPOSED POLESTAR DETENTION POND I �/ W ORGHARD PL ti - j i \ -- -- 1 — _ — — — — — — — — — — — o � � I u l CL 5105 r / n \ POLESTAR DETENTION POND I �' 3 A36 A3c A3 A3 A3 ;A3c A3c A3 A3 t lip t t I 100 YEAR WSELV 5108.89 - NAVD 88 - \ VOLUME 9.44 ACRE-FT LL-00 ca do" J / ............... ............. ............. \ I I II It A it li it `L" PROPOSED GRADING POLESTAR F —I d JOB NO. 3979701 8/26/2023 SHEET 1 OF 1 60 30 0 60 10 J-R ENGOMMIXING A Westrian Company ORIGINAL SCALE: 1" = 60' ca turd 303-740-M-Colorado WV M-0-M Fort coins gm 4gi-m•www' STAGE-STORAGEDETENTION BASIN MHFD-Detention,Version 4.06(July 1011) Project:Polestar-Interim Detention Pond(PLEASE NOTE:THE AREA ON THIS MHFD SHEET WAS MULTIPLIED BY 1.2 TO ACCOUNT FOR SEDIMENTATION FOR WQCV) Basin ID: J F10E5 onmce De mIncrement= 1.00 R Optional pti0re POo' Example Zone Configuration(Retention Pond) Stage-Storage Stage Override Length Width Area Override Area Volume Volume Description ft stage R ft ft ft2 Area ft� acre R' ac fit Watershed Information Top of Mlcropool - 0.00 - - - 66 0.002 Selected BMP Type= EDB 5103 - 0.19 - - - 382 0.009 43 0.001 Watershed Area= 8.36 acres 5104 - 1.19 - - - 20,275 0.465 10,371 0.238 Watershed length= 1,149 R 5105 - 2.19 - - - 59,591 1.368 50,303 1.155 Watershed Length to.Centroid= 689 It 5106 - 3.19 - - - 87,449 2.00B 123,823 2.843 Watershed Slope= 0.011 Rift 5107 - 4.19 - - - 99,692 2.289 217,394 4.991 Watershed Imperviousness= 37.SWo percent 5108 - 5.19 - - - 106,050 2.435 320,265 7.352 Percentage Hydrologic Soil Group A= 0.0% percent 5109 - 6.19 - - - 112,486 1582 429,533 9.861 Percentage Hydrologic Soil Group B= 34.0% percent 5110 - 7.19 - - -- 119,103 2.734 545,328 12.519 Percentage Hydrologic$oil Groups percent - - - - Target WQCV Drain Time= 40.0 hours - - - - Locatlon for 1-hr Rainfall Depths=User Input -- - - -- After providing required inputs above including 1-roar rainfall - - - depths,dick'Run CUHP'to generate runoff hydrograplss using - - -the embedded Colorado Urban Hydrogmph Procedure. Optional User Overrides - - - - Water Quality Capture Volume(WQCV)= 0.121 -feet -feet -- - - - Excess Urban Runoff Volume(EURV)= 0.305 acre-feet acre-feat -- - - -- 2-yr Ruroff Volume(P1=0.82 In.)= 0.183 acre-feet 0.82 inches - - - - 5-yr Ruroff Volume(PI=1.09 in.)= 0.285 -feet inches - - - - 10-yrRuroff Volume(P1=1.4In.)= 0.460 acre-feet 1A0 inches -- -- - -- 25-yr Runoff Volume(P'1.=1.69 in.)= 0.702acre-feet inches - - - - 5&yr Runoff Volume(PI=1.99 in.)= 0.908 acnfeet inches - - - - 100-yr Ruroff Volume(P1=2.86 in.)= 1.565 -feet 2.86 inches - - - - 500-yr Runoff Volume(P1=3.14 in.)= 1.769 -feet inches - - - - Approximate 2-yr Detention Volume= 0.172 acre-feet - - - - Approximate 5-yr Detention Volume= 0.277 acre-feet - - - - Approximatel0-yr Detention Volume= 0.372 cre-feet - - -Approximate25-yr Detention Volume= 0.437 acre-feet - - - - Approximate 5D-yr Detention Volume= 0.478acre-feet - - - - Approximate 100-yr Detention Volume= 0.720 acnfeet - - - - Set zone 1 as WQLV - - - - Define Zones and Basin Geometry - - - - Zone 1 Volume(WQCV)= 0.12 acre-feet - - - - Zone 2 Volume(User Defined-Zone 1)= 0.00 cre-feet - - - - Zone 3 Volume(100-year-Zones 182)= 0.60acre-feet - - - - TotalDetentionBasinVolume= 0.72 acre-feet - - - - Initial Surcharge Volume(ISV)= user R' - - - - Initial Surcharge Depth(ISD)= ft - - - - Total Available Detemion Depth(Hti)= user ft - - - - Depth of Trickle Channel(Hrc)= user R - - - - Slope of Trickle Clwnrel(STIC= user ft/ft - - - - Slopes of Main Basin SIdeS(Sic)= Iser H:V - - - - Bmin Length-to-Width Ratio(R�) Initial Surcharge Area(Azv)= user R' - - - - Surcharge Volume Length(Lsv)= ft - - - - Surcharge Volume Width(Wsv)= user R _ Depth or Basin Floor(HFMR)= user ft - - - - Length of Basin Floor(L­)= user ft -- -- - -- Width of Basin Floor(WFMR)= user it - - -Area of Basin Floor(Al-R)= user ft' - - - - Volume of Basin Floor(V-R)= user ft' -- -- - -- Depth of Main Basin(Hmnw)= user ft - - - - Length of Main Basin(Lmm user R - - - - Width of Main Basin(Wmm = user R - - -Area of Main Basin(Amnm)= user R' - - - - Volume of Main Basin(VmArn)= user ft' - - - - Calculated Total Basin Volume(V[opi)= user acre-feet - - - - MHFD-Oetention_v406-Interim Pond.*m,Basin 81T/2023,11:17 AM STAGE-STORAGEDETENTION BASIN MHFD-Detention,Version 4.06(July 2022) 20 119- 1s e4400 d g;10 sesaa a� x 2 s zsg00 o 0 0.00 2.00 4.00 6.00 Uo Stage)R) —Length(ft) —Width(R) —Area(sq.k) 2.7. 11620 2056 9:390 C M yyM 1.320 - 6.2fi0 v d ; O.fie6 3:13t1 0.000 0.000 0.00 2.00 4.00 6.00 8.00 stage lR.) —Area lages� —Volume lac-kl MHF0.O tention_W-W-Interim Poi .klsm,Basin 8'7/2023,11:11 AM DETENTIONBASIN OUTLET MHFD-Detention, Version 4.06(July 2022) Project:Polestar-Interim Detention Pond(PLEASE NOTE:THE AREA ON THIS MHFD SHEET WAS MULTIPLIED BY 1.2 TO ACCOUNT FOR SEDIMENTATION FOR WQCV) Basin ID: zaxea mex Estimated Estimated oxc, Stage(ft) Volume(ac-ft) Outlet Type -...-... ranrx wv 'one 1(WQCV) 0.90 0.121 Orifice Plate 01 Zone 2(User) 0.90 0.000 Orifice Plate zow1NAx omrWE Paxuxexr omncEs le 3(100-year) 1.83 0.599 Weir&Pipe(Restrict) Example Zone Configuration(Retention Total(all zones) 0.720 User Input:Orifice at Underdrain Outlet(typically used to drain WQCV in a Filtration BMP) Calculated Parameters for Underdrain Underdrain Orifice Invert Depth=1 N/A ft(distance below the filtration media surface) Underdrain Orifice Area=1 N/A ftz Underdrain Orifice Diameter= N/A inches Underdrain Orifice Centroid= NJA feet User Input: Orifice Plate with one or more orifices or Elliptical Slot Weir(typically used to drain WOCV and/or EURV in a sedimentation BMP) Calculated Parameters for Plate Centroid of Lowest Orifice= 0.00 ft(relative to basin bottom at Stage=0 ft) WQ Orifice Area per Row= 5.278E-03 fe Depth at top of Zone using Orifice Plate= 0.90 ft(relative to basin bottom at Stage=0 ft) Elliptical Half-Width= N/A feet Orifice Plate:Orifice Vertical Spacing= N/A inches Elliptical Slot Centroid= N/A feet Orifice Plate:Orifice Area per Row= 0.76 sq.inches(diameter=1 inch) Elliptical Slot Area= N/A ft, User Input: Stage and Total Area of Each Orifice Row(numbered from lowest to highest) Row 1(required) Row 2(optional) Row 3(optional) Row (optional) JRow 5(optional) Row 6(optional) Row 7(optional) Row 8(optional) Stage of Orifice Centroid(ft) 0.00 0.30 0.60 Orifice Area(sq.inches) 0.76 0.76 0.76 Row 9(optional) Row 10(optional) Row 11(optional) Row 12(optional) ow 13(optional Row 14(optional) Row 15(optional)Row 16 optional Stage of Orifice Centroid(ft) Orifice Area(sq.inches) User Input: Vertical Orifice(Circular or Rectangular) Calculated Parameters for Vertical Orifice Not Selected Not Selected Not Selected Not Selected Invert of Vertical Orifice= N/A ft(relative to basin bottom at Stage=0 ft) Vertical Orifice Area= N/A ft Depth at top of Zone using Vertical Orifice= N/A ft(relative to basin bottom at Stage=0 ft) Vertical Orifice Centroid= N/A feet Vertical Orifice Diameter= N/A inches User Input: Overflow Weir(Droobox with Flat or Sloped Grate and Outlet Pipe OR Rectangular/Trapezoicial Weir and No Outlet Pipe) Calculated Parameters for Overflow Weir Zone 3 Weir Not Selected Zone 3 Weir Not Selected Overflow Weir Front Edge Height,Ho= 1.00 N/A ft(relative to basin bottom at Stage=0 ft)leight of Grate Upper Edge,H,= 5.00 N/A feet Overflow Weir Front Edge Length= 5.00 N/A feet Overflow Weir Slope Length= 16.49 N/A feet Overflow Weir Grate Slope= 4.00 N/A H:V Grate Open Area/100-yr Orifice Area= 12.70 N/A Horiz.Length of Weir Sides= 16.00 N/A feet Overflow Grate Open Area w/o Debris= 57.39 N/A ft Overflow Grate Type= Type C Grate N/A Overflow Grate Open Area w/Debris= 57.39 N/A ft2 Debris Clogging%=1 0% N/A % User Input:Outlet Pipe w/Flow Restriction Plate(Circular Orifice,Restrior Plate,or Rectangular Orifice) Calculated Parameters for Outlet Pipe w/Flow Restriction Plate Zone 3 Restrior Not Selected Zone 3 Restricto Not Selected Depth to Invert of Outlet Pipe= 0.07 N/A ft(distance below basin bottom at Stage=0 ft) Outlet Orifice Area= 4.52 N/A ft Outlet Pipe Diameter= 42.00 N/A inches Outlet Orifice Centroid= 0.96 N/A feet Restror Plate Height Above Pipe Invert= 20.00 inches Half-Central Angle of Restror Plate on Pipe= 1.52 N/A radians User Input:Emergency Spillway or Trapezoidal) Calculated Parameters for Spillway Spillway Invert Stage 4.98 ft(relative to basin bottom at Stage=0 ft) Spillway Design Flow Depth= T1106 feet Spillway Crest Length feet Stage at Top of Freeboard= feet Spillway End Slopes= 2.50 H:V Basin Area at Top of Freeboard= acres Freeboard above Max Water Surface= 1.41 feet Basin Volume at Top of Freeboard= acre-ft Routed Hydro rah Results The user can override the default CUHP h dro ra hs and runoff volumes 1,y enterinq new values in the Inflow H dro ra hs table Columns W throw h AF. Design Storm Return Period= 2 Year 5 Year 10 Year 25 Year 50 Y 100 Year S00 Year One-Hour Rainfall Depth(in)= N/A N/A 0.82 1.09 1.40 1.69 1.99 2.86 3.14 CUHP Runoff Volume(acre-ft)= 0.121 0.305 0.183 0.285 0.460 0.702 0.908 1.565 1.769 Inflow Hydrograph Volume(acre-ft)= N/A N/A 0.183 0.285 6.460 0.702 0.908 1.565 1.769 CUHP Predevelopment Peak Q(cfs)= N/A N/A 0.1 0.3 1.4 3.6 5.0 9.6 11.0 PTIONAL Override Predevelopment Peak Q(cfs)= N/A N/A Predevelopment Unit Peak How,q(cfs/acre)= N/A N/A 0.01 0.04 0.17 0.43 0.60 1.15 1.32 Peak Inflow Q(cfs)= N/A N/A 1.6 2.6 4.4 7.2 9.3 15.7 17.6 Peak Outflow Q(cfs)= 0.1 1.8 0.1 0.6 1.6 3.2 4.6 9.1 10.5 Ratio Peak Outflow to Predevelopment Q= N/A N/A N/A 2.1 1.1 0.9 0.9 0.9 1.0 Structure Controlling Flow= Plate Overflow Weir 1 Overflow Weir 1 Overflow Weir 1 verflow Weir J Overflow Weir 1 Overflow Weir 1 Overflow Weir 1 Overflow Weir 1 Max Velocity through Grate 1(fps)= N/A 0.03 0.00 0.0 0.0 0.1 0.1 0.2 0.2 Max Velocity through Grate 2(fps)= N/A N/A N/A N/A N/A N/A N/A N/A N/A Time to Drain 97%of Inflow Volume(hours)= 38 46 48 49 46 43 41 34 32 Time to Drain 99%of Inflow Volume(hours)= 40 51 52 53 52 50 49 46 45 Maximum Ponding Depth(it)= 0.90 1.32 1.02 1.16 1.29 1.44 1.53 1.79 1.85 Area at Maximum Ponding Depth(acres)= 033 0.58 0.39 0.45 0.55 0.61 0.77 1.00 1.06 Maximum Volume Stored(acre-ft)= 0.122 0.306 0.166 0.220 0.284 0.376 1 0.448 1 0.670 1 0.742 MHFD-Detention_v4-06-Interim Pond.xlsm,Outlet Structure 8110/2023,11:46 AM DETENTIONOUTLET MHFD Detention, Version 4.06(July 1011) 20 -SOOYR IN .....500YR OUT 18 �1ODYR IN 100YROUT 16 SOYR IN 5UYR OUT 25YR IN 14 25YR OUT �10YR IN 12 10YR OUT I- -SYRIN .....SYR OUT - 3 10 � �2YR IN - LL 2YROUT 8 EURV IN •EURV OUT 6 - _W4CV IN - .....W=OUT 4 2 0 0.1 1 TIME[hr] 2 -SWYR -100YR 1.8 -SOYR -25YR 1.6 -10YR -5YR 1.4 -2YR EURV 00, �w4N 1.2 x O 1 z S a 0.8 0.6 0.4 0.2 0 0.1 1 110 DRAIN TIME,[hr] O User Area[ft^2] 450,000 _Interpolated Area.[ft^2] 3 •�••Summary Area[ft^2] 400,000 _Volume[ft^3] 2 •-i••Summary Volume[ft^3] 350,000 -Outflow[cfs] 300,000 •••0••Summary Outflow[cf5] 2 In r 250,000 0 .: z0o;oao S 4% 150,000 i a 100,000 5 50,000 0 0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 PONDING DEPTH[ft] S-A-V-D Chart Axis Override. X-axis Left Y-Axis Right Y-Axis minimum bound maximum bound MHFD-Detention_v4-O6-Interim Pond.xlsm,Outlet Structure 8110/2023,11:46 AM DETENTIONBASIN OUTLET Outflow Hydrograph Workbook Filename.• Inflow Hydrographs The user can override the calculated inflow hydrographs from this workbook with inflow hydrographs developed in a separate program. SOURCE CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP terval TIME WQCV[cfs] EURV[cfs] 2 Year[cfs] 5 Year[cfs] 10 Year[cfs] 25 Year[cfs] 50 Year[cfs] 100 Year[cfs] 500 Year[cfs] min 0:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0:10:00 o.00 0.00 0.00 0.00 0.00 0.00 0.00 0.04 0.07 0:15:00 0.00 0.00 0.05 0.16 0.27 0.19 0.27 0.42 0.49 0:20:00 0.00 0.00 0.41 0.63 0.86 0.57 0.73 1.18 1.39 0:25:00 0.00 0.00 1.07 1.73 2.84 1.52 2.00 3.90 4.71 0:30:00 o.0o 0.00 1.53 2.43 4.11 4.86 6.48 10.88 12.42 0:35:00 0.00 0.00 1.64 2.60 4.36 6.47 8.43 14.38 16.27 0:40:00 0.00 0.00 1.64 2.55 4.28 7.17 9.25 15.55 17.53 0:45:00 0.00 0.00 1.54 2.43 4.06 7.11 9.15 15.67 17.64 0:50:00 0.00 0.00 1.45 2.31 3.80 6.95 8.93 15.25 17.17 0:55:00 0.00 0.00 1.37 2.18 3.57 6.50 8.38 14.58 16.42 1:00:00 0.00 0.00 1.30 2.05 3.35 6.07 7.85 13.93 15.68 1:05:00 0.00 0.00 1.24 1.96 3.18 5.68 7.36 13.36 15.05 _ 1:10:00 0.00 0.00 1.17 1.87 3.04 5.25 6.82 12.33 13.91 1:15:00 0.00 0.00 1.10 1.77 2.91 4.86 6.32 11.35 12.82 10 1:20:00 0.00 0.00 1.03 1.65 2.71 4.44 5.77 10.21 11.53 1:25:00 0.00 0.00 0.96 1.52 2.48 4.03 5.23 9.12 10.30 1:30:00 0.00 0.00 0.89 1.41 2.25 3.62 4,68 8.10 9.14 1:35:00 0.00 0.00 0.83 1.31 2.05 3.22 4.16 7.16 8.08 1:40:00 0.0o 0.00 0.79 1.22 1.91 2.89 3.73 6.41 7.25 1:45:00 0.00 0.00 0.76 1.14 1.80 2.64 3.41 5.84 6.60 1:50:00 0.00 0.00 0.73 1.08 1.70 2.44 3.14 5.34 6.04 1:55:00 0.00 0.00 0.69 1.02 1.60 2.26 2.91 4.89 5.53 2:00:00 0.00 0.00 0.64 0.95 1.48 2.09 2.69 4.48 5.07 2:05:00 0.00 0.00 0.57 0.85 1.32 1.87 2.40 3.98 4.50 2:10:00 0.00 0.00 0.51 0.75 1.16 1.65 2.12 3.50 3.95 2:15:00 0.00 0.00 0.45 0.66 1.01 1.45 1.85 3.04 3.43 2:20:00 0.00 0.00 0.39 0.57 0.87 1.25 1.59 2.62 2.95 2:25:00 0.00 0.00 0.34 0.48 0.73 1.06 1.35 2.20 2.48 2:30:00 0.00 0.00 0.29 0.41 0.61 0.88 1.11 1.80 2.02 2:35:00 0.00 0.00 0.24 0.33 0.49 0.70 0.88 1.42 1.59 2:40:00 0.00 0.00 0.19 0.26 0.38 0.54 0.67 1.06 1.19 2:45:00 0.00 0.00 0.15 0.21 0.30 0.39 0.49 0.78 0.88 2:50:00 0.00 0.00 0.12 0.17 0.25 0.30 0.37 0.59 0.67 2:55:00 0.00 0.00 0.10 0.14 0.21 0.23 0.29 0.45 0.51 3:00:00 0.0o 0.00 0.09 0.12 0.17 0.18 0.23 0.34 0.39 3:05:00 0.00 0.00 0.07 0.10 0.14 0.14 0.18 0.26 0.30 3:10:00 0.00 0.00 0.06 0.08 0.12 0.11 0.14 0.20 0.23 3:15:00 0.00 0.00 0.05 0.07 0.10 0.09 0.11 0.15 0.17 100 3:20:00 0.00 0.00 0.04 0.06 0.08 0.07 0.09 0.12 0.13 3:25:00 0.00 0.00 0.04 0.05 0.06 0.06 0.07 0.09 0.11 3:30:00 0.00 0.00 0.03 0.04 0.05 0.05 0.06 0.07 0.08 3:35:00 0.00 0.00 0.02 0.03 0.04 0.04 0.05 0.06 0.07 3:40:00 0.00 0.00 0.02 0.02 0.03 0.03 0.03 0.05 0.05 3:45:00 0.00 0.00 0.01 0.02 0.02 0.02 0.03 0.03 0.04 3:50:00 0.00 0.00 0.01 0.01 0.02 0.02 0.02 0.02 0.03 3:55:00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.02 0.02 50 4:00:00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 4:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 00 4:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 4:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 50 F 4:35:00 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 4:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 .00 4:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 5:15:00 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 i 5:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:55:00 0.00 0.00 0.00 0.00 0.00 o.0o 0.00 0.00 0.00 600:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MHFD-Detention_v4-06-Interim Pond.xlsm,Outlet Structure 8110/2023,11:46 AM DETENTIONBASIN OUTLET MHFD-Detention, Version 4.06(July 1011) Summary Stage-Area-Volume-Discharge Relationships The user can create a summary S-A-V-D by entering the desired stage increments and the remainder of the table will populate automatically. The user should graphically compare the summary S-A-V-D table to the full S-A-V-D table in the chart to confirm it captures all key transition points. Stage Area Area Volume Volume Total Stage-Storage Stage Description [ft] [R'j [acres] [R'] [ac-ftj [crs] For best results,include the stages of all grade slope changes(e.g.ISV and Floor) from the S-A-V table on Sheet'Basin'. Also include the inverts of all outlets(e.g.vertical orifice, overflow grate,and spillway, where applicable). MHFD-Detention_v4-06-Interim Pond.xlsm,Outlet Structure 8110/2023,11:46 AM ULTIMATE POLESTAR DETENTION POND t .. �. • ; il 100 YEAR WSELV �• I • I �•-•- o �-�•. .��.5� _ —� • • I • it="i1i I.r ter' 'i.' 1 � v.. e��+- • �. '' �� � ��R,IIIII "Ilc Is . ;� •��_ it — .__:._.__ ����.�a��s �_� I ����_�����I ACC =C ` •• N �� �► i Wh • HAPPY HEART FARMS DETENTION POND BY JACOBS ENGINEERING GROUP 1 2 3 4 5 6 N - CONCEPTUAL � -_ � I � , `� , � �� PROPOSED 18 -„ ,- p w PROPOSED 18 PROPOSED CURB PROPOSED 18 - - - - NOT FOR TYP.RCP - ( ) RCP (TYP.) INLETS (TYP.) ( ) CONSTRUCTION �' - RCP TYP. 0 50 100 200 = / / 1 - - - - - �� I \ PROPOSED CURB - //J vl INLETS (TYP.) _ PROPOSED 72 PROPOSED - - �� _ i _ c � � — — —_ , , c - -= - - - � �,� 'I —% -N� NHO ,E_:_ _ — � ; RA SCALE FEET _ PROPOSED JUNCTION PROPOSED - - - 1 �� =�� SOP �D- GRAPHIC H I C - - - M- - - -Me - - - JUNCTION Q -- - - �- _ ' w'- - VAULT-- _TYP. - --\ - 41 +00 - - TYP. ( ) - _ , r--- G J / L ( ) - — i_ - - - N VAULT TYP. == - - - cd ORCHARD PLACE ) - -w- - - -� N- -VAU-LT (TYP.) o I 40+00 PROPOSED PR6ROSE0-6l�TLET 3 +0 38+00 37+00 36+0 35+00 ` - 34+00 y -FES_ STRUCTURE + 32+00 31 +00 30+00 29+00 28+00 27+00 o c� 33 00 PROPOSED / PROPOSED 60„ _ _ I N << III o _- PROPOSED PROPOSED I � o LL I I rr � �' 5102 0 36 RCP , 5 0 - MANHOLE ,� ,� PROPOSED 60 �, '� i ! :S �_48 RCP / 66 RCP = /, I�I i - �` MANHOLE ` � 1 _ - _ �. I i SCE (TYP ) �� ,- /; I�`, I -` _ , _ . � I I1 \ t - PROPOSED- - ( �I i - 1� - �' m o VIEWS 49+00 4 s - (TYP.) 1°\ III 1 - 47+00 9 EXISTING 100 YR -,_ I\ - 11 ll O N D 46-f-0 0 0 8 _ _,� , ;_, _ �, PROPOSED OUTLET 45 44+00 3+0 PLUM _ � `, -- � ' ROCKY f��OAD - FLOODPLtAIN - -= /� o �o ��. - STRUCTUR I �, / - _- oU ,S _ CHANNEL \� \ PLAN AND ) �_ -- - ` PfLLW/�Y \. \ s,o J �„ o OfQ , EXISTING __- w > Cl , 9F'F 5�2+ PROPOSED POND �- \ \ \ \\� w WAL 00 �: A `� _ PROFILE, SEE - --- - \ _ _ . PLUM 1- �'o L5 4+ - _ GRADING FOR 9.8 AC-FT �' HAP HEART ` �- — r _ _ i� �� DWG PC-C-003 CHANNEL ) j/ �` L v �o - —'�' - 3+00 51o4 100',YEAR VOLUME FARMS ND - - 1 _ / 1 l� -� - 5 PROPOS� 60 I - -- - : . J 0 - y, - S %- U w Q 0 _ 3 Q 4 1 0 _ �-- _ I = MAN OLE ' TYP.) >� I I s7o EMERGENCY w= ,..SPILLWAY I PLUM l I �< EXISTING / \ I PROPOSED Q <Q EMERGENCY � I o CURB INLETS ' �\ � I I 1 zz i SPILLWAY Q CHANNEL F- i . � o� w t w V)F w �� (TYP.) 24" RCP m � �� BcL CANAL... - = O _ EXISTING _ s v t o - - � , I - 0w \ iI-PV _ , MLLJ Z= O � \�\ PROPOSED POND GRADING ^�J - - ' J i �� �� ._ - _ s = V)w Ir FOR 8.3 AC-FT 1�4-YEAR v "" i eh � , ,� ,\ �� n � � � VOLUME -- I ' I��, �I � ti � .I Q� f ; 1 Cf,Lij <= - �._ _J.�----- .- �� �..�� _- 1 � - � - NOTES o = B 1. VERTICAL DATUM: NORTH AMERICAN VERTICAL = wo DATUM OF 1988 (NAVD88) z Y w 5125 0 0 0 o z 5125 o� 0 o - Q� J 0Of cn Q U Q o0 Of w O OZ 5120 `'d N ~ 51 20 0 C z� > EMER ENC SPI LWAI ,� Y 0 00 o z o zo _U ELEV. 5114.5 o o '� o 'n w U)o z Q J Ln Ln I I `n J `n I I -� ` Ld 0 U �� = I Q � coo II II I QON II v � 0z 5115 w> � oz z o �''> 0000z o (3 Ln 5115 �w 0 0'z + — °'z + — ,n o0 z = Qcn PR POS D OUTLET w oo cn w 0 STRUCTURE AT = U� II z z z UI= "� II z z c0� on U Q Q z wm SCENIC VIEWS �z Q �� �z Q �= I oo II z w J �� � _ 00 N � �� � - co � Q o 0 0 5110 POND cn� cn � � � co cn� cn � co CO w> 0Mz 5110 Q � u p z Z �z + o - r , Q J Q � �� �oONoL > > 0 0' z a- o wo EMERGENCY SP L WAY �v II z Z Q o ILL oQ ELEV. 5105.3 �j < 00 - _ � o om cn� cn � co co 510 5 V" Q _U w �,O 5105 mmmmmmmmm PROPOSED OU LET Q J STRUCTURE AT HAPPY H ART z I Li PROPOSEDFARMS POND C - O 5100 0�1 I—]- 5100 0 36 ' RC -0.35� - _ w STA. 0+5 .72 ES -0.52 ° w IN ERT ELEV 5102.00 TA. 4+88.12 _ 5095 N ELEV. 5100.01 5095 w� 0„ RCP, Z . J N I ma Mauna SED 30" RCP, 15.4 LF 7. ,5 �nN0n �w + -GRADE 117.6 LF �Zn Q `s,` p V Ind o O z co '�� — W 5090 Ln II �.�. LnN rn� _ I 5090 Q J Z �n o Q STA. 42+ 4.43 w w o`oo - � w ro 48»' RC-P� 0.55� ° W — 0 O II II � U, �I - I VER ELEV. 5098.00 060o orLci I I I o — � z - � = oow - c � = + ow -0. 61/ -i JOB J ± no' � � z0o �� 66 RCP, a � Q > o i � III o °' � � III 29 .4 LF w 5085 > z 0 u 0 �4 Qy4+F 2 5085 z z Q Q I_- - W� 0� Q ozS O I I I II � � o' II � � � � � � � � -. � 66 � - � WZW D z � z - 66" RCP U Q o o D 5080 > z � z 313.8 LF 5080 Z W J z z - z 0 o � Q � � U D 5075 5075 1"=100' 5070 5070 VERIFY SCALE BAR IS ONE INCH ON ORIGINAL DRAWING. 7 0 1" DATE JANUARY 2022 5065 5065 PROJ D3345400 55+ 00 54+ 00 53+ 00 52+ 00 51 +00 50+ 00 49+ 00 48+ 00 47+ 00 46+ 00 45+ 00 44+ 00 43+ 00 42+ 00 41 +00 40+ 00 39+ 00 38+ 00 37+ 00 36+ 00 35+ 00 34+ 00 33+ 00 32+ 00 31 +00 30+ 00 29+ 00 28+ 00 27+ 00 DWG PC-C-001 SHEET 1 of 4 FILENAME: PC-P&P.dwg STAGE-STORAGEDETENTION BASIN MHFD-Detention,Version 4.06(July 2022) Project:Polestar-Ultimate Detention Pond(PLEASE NOTE:THE ABU ON THS MNFD SHEET WAS MULTIPLIED BY 1.2 TO ACCOUNT FOR SEDIMENTATION FOR WQCV) Basin ID: J F10E5 onmce De mIncrement= 1.00 R Optional ptiore POOL Example Zone Configuration(Retention Pond) Stage-Storage Stage Override Length Width Area Override Area Volume Volume Description ft stage ft ft ft ft2 Area ft� acre R' ac-R Watershed Information Top of MICMPool - 0.00 - - - 32 0.001 Selected BMP Type= EDB 5099 - 0.99 - - - 12,276 0.282 6,M2 0.140 Watershed Area= 8.36 acres 5100 - 1.99 - - - 42,526 0.976 33,493 0.769 Watershed Length= 1,149 R 5101 - 2.99 - - - 62,048 1.424 85,780 1.969 Watershed Length to.Centroid= 689 It 5102 - 3.99 - - - 69,405 1.593 151,506 3.478 Watershed Slope= 0.011 Rift 5103 - 4.99 - - - 75,067 1.723 223,742 5.136 Watershed Imperviousness= 37.8Wo percent 5104 - 5.99 - - - 80,847 1.856 301,699 6.926 Percentage Hydrologic Soil Group A= 0.0% percent 5105 - 6.99 - - - 86,761 1992. 385,503 8.850 Percentage Hydrologic$oil Group B= 34.0% percent 5106 - 7.99 - - -- 93,012 2.135 475,390 10.913 Percentage Hydrologic$oil Groups C,/D= 66.0% percent 5307 - 8.99 - - - 99,265 2.279 571,528 13.120 Target WQCV Drain Tim= 40.0 hours Sias - 9.99 - - - 105,638 2.425 673,979 15.472 Location for 1-hr Rainfall Depths=User Input 5109 -- 10.99 - - -- 112,095 2.573 782,845 17.972 After providing required inputs above including 1-hour rainfall 5110 - 11.99 - - - 118,779 2.727 898,282 20.622 depths,dick'Run CUHP'to generate runoff hydrographe Using - - - - the embedded Colorado Urban Hydrograph Procedure. Optional User Overrides - - - - Water Quality Capture Volume(WQCV)= 0.121 acnfeetacre-feat -- - - - Excess Urban Runoff Volume(EURV)= 0.305 acre-feet acre-feat -- - - -- 2-yr Ruroff Volume(P1=0.82 In.)= OAR3 acre-feet 0.82 inches - - - - 5-yr Ruroff Volume(PI=1.09 in.)= 0.285acre-feet inches - - - - 10-yr Runoff Volume(P1=1.4In.)= 0.460 acre-feet 1.40 inches -- -- - -- 25-yr Ruroff Volume(Pi.=1.69 in.)= 0.702acre-feet inches - - - - 5&yr Runoff Volume(PI=1.99 in.)= 0.908acre-feet inches - - - - 100-yr Ruroff Volume(P1=2.86 in.)= 1.565 acre-feet 186 inches - - - - 500-yr Ruroff Volume(P1=3.14 in.)= 1.769acre-feet inches - - - - Approximate 2-yr Detention Volume= 0.172 acre-feet - - - - Approximate 5-yr Detention Volume= 0.277 acre-feet - - - - Approximatel0-yr Detention Volume= 0.372acre-feet - - - - Apprulmate25-yr Detention Volume= 0.437 acre-feet - - - - Approximate 5D-yr Detention Volume= 0.478acre-feet - - - - Approximate IMyr Detention Volume= 0.720acre-feet - - - - Set zone 1 as WQCV - - - - Define Zones and Basin GeometrV - - - - Zone 1 Volume(WQCV)= 0.12 acre-feet - - - - Zone 2 Volume(User Defined-Zone 1)= 0.00 ac-feet - - - - Zone 3 Volume(10D-year-Zones 1&2)= 0.60acre-feet - - - - TotalDetentionBasinVolume= 0.72 acre-feet - - - - Initial Surcharge Volume(ISV)= user R' - - - - Initial Surcharge Depth(ISD)= ft - - - - Total Available Detemion Depth(Hri)= User R - - - - Depth of Trickle Channel(Hrc)= user R - - - - Slope of Trickle Clwnrol(STIC= user ft/ft - - - - Slopes of Main Basin SIdeS(Sic)= user H:V - - - - Basin Length-to-Width Ratio(RU ) Initial Surcharge Area(Azv)= user R' - - - - Surcharge Volume Length(Lay)= ft - - - - Surcharge Volume Width(Wsv)= User R _ Depth or Basin Floor(HFMR)= User ft - - - - Length of Basin Floor(1-­)= user ft -- -- - -- Width of Basin Floor(WFMR)= user R - - -Area of Basin Floor(A-R)= user ft' - - - - Volume of Basin Floor(V-R)= user ft' -- -- - -- Depth of Main Basin(Hmnw)= user ft - - - - Length of Main Basin Lmst, user ft - - - - Width of Main Basin(Wmm = user R - - - - Area of Main Basin(Amnm)= user R' - - - - Volume of Main Basin(v- = user R' - - - - Calculated Total Basin Volume(Vtvpi)= unit acre-feet - - - - MHF6petaaon_0,05-Ultimate Pond.Ism,Basin 817/2023,2:20 PM STAGE-STORAGEDETENTION BASIN MHFD-Detention,Version 4.06(July 2022) 20 I.A. 15 89100 $$$3,m 59000 �4 5 nM 0 0 0.00 3.00 fi-00 9.00 12.m 5[age(R) —Leegth(ft) —Width(ft) —A-(SA) 2.7. 20.— 2055 5.8o C yK 1.320 30.32o v d ; 0.fi85 Sim 0.om a.am 0.00 3A0 6.00 9.00 12.w surge(a.) —Area�ages� —Volume lac-k� MHF6pet¢a.0 O9 5-Uffi-e Pold.Ism,Bodo W7=23,2:M PM DETENTIONBASIN OUTLET MHFD-Detention,Version 4.06(July 2022) Project:Polestar-Ultimate Detention Pond(PLEASE NOTE:THE AREA ON THS MHFD SHEET WAS MULTIPLIED BY 1.2 TO ACCOUNT FOR SEDIMENTATION FOR WQC% Basin ID: ZONzCNE 2 Estimated Estimated I �jZONE' Stage(ft) Volume(ac-ft) Outlet Type V0A"'��upTWO I Zone 1(WQCV) 0.93 0.121 Orifice Plate Zone 2(User) 0.93 0.000 Orifice Plate ZONEAND] °RIFlCE aEaraNEx.-% D E Zone 3(100-year) 1.94 0.599 Weir&Pipe(Restrict) Example ZoneConfiguration(Retention Pond) Total(all zones) 0.720 User Inout:Orifice at Underdrain Outlet(tvoically used to drain WOCV in a Filtration BMP) Calculated Parameters for Underdrain Underdrain Orifice Invert Depth= N/A ft(distance below the filtration media surface) Underdrain Orifice Area= N/A ft? Underdrain Orifice Diameter= N/A inches Underdrain Orifice Centroid= N/A feet User Inout: Orifice Plate with one or more orifices or Elliptical Slot Weir(tvoically used to drain WOCV and/or EURV in a sedimentation BMP) Calculated Parameters for Plate Centroid of Lowest Orifice= 0.00 ft(relative to basin bottom at Stage=0 ft) WQ Orifice Area per Row=TN/ ft? Depth at top of Zone using Orifice Plate= 1.00 ft(relative to basin bottom at Stage=0 ft) Elliptical Half-Width= feet Orifice Plate:Orifice Vertical Spacing= N/A inches Elliptical Slot Centroid= feet Orifice Plate:Orifice Area per Row= 0.95 sq.inches(diameter=1-1/16 inches) Elliptical Slot Area= fLz User Input: Stage and Total Area of Each Orifice Row(numbered from lowest to highest) Row 1(required) Row 2(optional) Row 3(optional) ow 4(option Row 5(optional) Row 6(optional) Row 7(optional) Row 8(optional) Stage of Orifice Centroid(ft) 0.00 0.33 0.67 Orifice Area(sq.inches) 0.95 0.95 0.95 Row 9(optional) Row 10(optional) Row 11(optional) 12(option ow 13(optionali Row 14(optional) Row 15(optional) Row 16(optional) Stage of Orifice Centroid(ft) Orifice Area(sq.inches) User Input: Vertical Orifice(Circular or Rectangular) Calculated Parameters for Vertical Orifice Not Selected Not Selected Not Selected Not Selected Invert of Vertical Orifice= N/A ft(relative to basin bottom at Stage=0 ft) Vertical Orifice Area= N/A ft, Depth at top of Zone using Vertical Orifice= N/A ft(relative to basin bottom at Stage=0 foertical Orifice Centroid= N/A feet Vertical Orifice Diameter= N/A inches User Input: Overflow Weir(Drovbox with Flat or Sloped Grate and Outlet Pipe OR Rectangular/Trapezoidal Weir and No Outlet Pioe) Calculated Parameters for Overflow Weir Zone 3 Weir Not Selected Zone 3 Weir Not Selected Overflow Weir Front Edge Height,Ho= 1.00 N/A ft(relative to basin bottom at Stage#IBigot of Grate Upper Edge,Ht= 4.00 N/A feet Overflow Weir Front Edge Length= 5.00 N/A feet Overflow Weir Slope Length= 12.37 N/A feet Overflow Weir Grate Slope= 4.00 N/A H:V Grate Open Area/100-yr Orifice Area= 15.56 N/A Horiz.Length of Weir Sides= 12.00 N/A feet Overflow Grate Open Area w/o Debris= 43.05 N/A ftz Overflow Grate Type= Type C Grate N/A Overflow Grate Open Area w/Debris= 43.05 N/A ftz Debris Clogging%= 0% N/A % User Input:Outlet Pioe w/Flow Restriction Plate(Circular Orifice.Restrictor Plate.or Rectangular Orifice) Calculated Parameters for Outlet Pine w/Flow Restriction Plate Zone 3 Restrictor Not Selected Zone 3 Restrictoi Not Selected Depth to Invert of Outlet Pipe= 0.00 N/A ft(distance below basin bottom at Stage=0 ft) Outlet Orifice Area= 2.77 N/A ftz Outlet Pipe Diameter= 30.00 N/A inches Outlet Orifice Centroid= 0.79 N/A feet Restrictor Plate Height Above Pipe Invert= 16.50 inches Half-Central Angle of Restrictor Plate on Pipe= 1.67 N/A radians User Input:Emergency Spillway(Rectangular or Trapezoidal) Calculated Parameters for Spillway Spillway Invert Stage 8.78 ft(relative to basin bottom at Stage=0 ft) Spillway Design Flow Depth= 0.26 feet Spillway Crest Length= 36.80 feet Stage at Top of Freeboard= 11.28 feet Spillway End Slopes= 2.50 H:V Basin Area at Top of Freeboard=[]]�acre-ft acres Freeboard above Max Water Surface= 2.2 (feet Basin Volume at Top of Freeboard= Routed Hydro rah Results The user can override the default CUHP hydrographs and runoff volumes by entering new values in the Inflow Hydrographs table(Columns W through AF). Design Storm Return Period= W CV V,_ 2 Year 5 Year _1.0Year �Yeiat r One-Hour Rainfall Depth(in)= N/A N/A 0.82 1.09 1.40 1.69 1.99 2.86 3.14 CUHP Runoff Volume(acre-ft)= 0.121 0.305 0.183 0.285 0.460 0.702 0.908 1.565 1.769 Inflow Hydrograph Volume(acre-ft)= N/A N/A 0.183 0.285 0.460 0.702 0.908 1.565 1.769 CUHP Predevelopment Peak Q(cfs)= N/A N/A 0.1 0.3 1.4 3.6 5.0 9.6 11.0 OPTIONAL Override Predevelopment Peak Q(cfs)= N/A N/A Predevelopment Unit Peak Flow,q(cfs/acre)= N/A N/A 0.01 0.04 0.17 0.43 0.60 1.15 1.32 Peak Inflow Q(cfs)= N/A N/A 1.6 2.6 4.4 7.2 9.3 15.7 17.6 Peak Outflow Q(cfs)= 0.1 2.5 0.2 0.8 1.8 3.6 5.0 9.9 11.5 Ratio Peak Outflow to Predevelopment Q= N/A N/A N/A 2.6 1.3 1.0 1.0 1.0 1.0 Structure Controlling Flow= Plate Overflow Weir 1 Overflow Weir 1 verflow Weir verflow Weir I Overflow Weir 1 Overflow Weir 1 Overflow Weir 1 Overflow Weir 1 Max Velocity through Grate 1(fps)= N/A 0.06 0.00 0.0 0.0 0.1 0.1 0.2 0.3 Max Velocity through Grate 2(fps)= N/A N/A N/A N/A N/A N/A N/A N/A N/A Time to Drain 97%of Inflow Volume(hours)= 38 41 44 43 39 36 33 27 25 Time to Drain 99%of Inflow Volume(hours)= 40 46 48 48 47 45 43 39 38 Maximum Pending Depth(ft)= 0.93 1.39 1.06 1.18 1.31 1.46 1.56 1.83 1.89 Area at Maximum Pending Depth(acres)= 0.26 0.56 0.32 0.41 0.50 0.61 0.68 0.86 0.91 Maximum Volume Stored(acre-ft)= 0.123 1 0.308 0.158 0.202 1 0.261 1 0.349 0.413 0.613 1 0.675 MHFD-Detention_v4-06-Ultimate Pond.xlsm,Outlet Structure 8/7/2023,2:21 PM DETENTIONOUTLET MHFD-Detention.Version 4.06(July 2022) zo S00VR IN .....5OOYR OUT 18 100YR IN _ — —IOOYR OUT 16 �SOYR IN _ —50YR OUT �25YR IN 14 25YR OUT 10YR IN 12 ———10YR OUT 5YR IN IA •••••SYfl OUT 3 10 �2YR IN O LL ———2YR OUT 8 —EURVIN •EURVOUT f WQCV IN 6 .. ..Wgcv our 4 2 0 0.1 1 TIME[hrl z —500YR �SOpYR 1:8 —50YR —MYR 1.6 —10YR _SYR 1.4 —2YR 00, L=EURV W4CV x L2 O 1 O 2 G 2 a 0.8 0:6 0.4 0.2 0 0.1 1 10 DRAIN TIME.[hr] 800,000 O User Area[W2] —Interpolated Area[W2] 700,000 .•a-.Summary Area[ftA2] —Volume[ftA3] 600,000 ••4••Summary Volume[ftA3] Outflow[Cfs] ••i••00,000 Summary Outflow[cfs] 5 f � 400,000 O N 300,000 rs 200,ODO 100,000 0,00 2.00 4.00 6.00 8.00 10.00 12.00 PONDING DEPTH[ft] S-A-V-D Chart Axis Override X-axis Left Y-Axis Right Y-Axis minimum bound maximum bound MHFD-Detention_v4-06-Ultimate Pond.xlsm,Outlet Structure 6/7/2023,2:21 PM DETENTIONBASIN OUTLET Outflow Hydrograph Workbook filename: Inflow Hvdroaraohs The user can override the calculated inflow hydrographs from this workbook with inflow hydrographs developed in a separate program. SOURCE CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP erval TIME WQCV[cfs] EURV[cfs] 2 Year[cfs] 5 Year[cfs] 10 Year[cfs] 25 Year[cfs] 50 Year[cfs] 100 Year[cfs] 500 Year[cfs] in 0:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.04 0.07 0:15:00 0.00 0.00 0.05 0.16 0.27 0.19 0.27 0.42 0.49 0:20:00 0.00 0.00 0.41 0.63 0.86 0.57 0.73 1.18 1.39 0:25:00 0.00 0.00 1.07 1.73 2.84 1.52 2.00 3.90 4.71 0:30:00 0.00 0.00 1.53 2.43 4.11 4.86 6.48 10.88 12.42 0:35:00 0.00 0.00 1.64 2.60 4.36 6.47 8.43 14.38 16.27 0:40:00 0.00 0.00 1.64 2.55 4.28 7.17 9.25 15.55 17.53 0:45:00 0.00 0.00 1.54 2.43 4.06 7.11 9.15 15.67 17.64 0:50:00 0.00 0.00 1.45 2.31 3.80 6.95 8.93 15.25 17.17 0:55:00 0.00 0.00 1.37 2.18 3.57 6.50 8.38 14.58 16.42 1:00:00 0.00 0.00 1.30 2.05 3.35 6.07 7.85 13.93 15.68 1:05:00 0.00 0.00 1.24 1.96 3.18 5.68 7.36 13.36 15.05 1:10:00 0.00 0.00 1.17 1.87 3.04 5.25 6.82 12.33 13.91 1:15:00 0.00 0.00 1.10 1.77 2.91 4.86 6.32 11.35 12.82 10 1:20:00 0.00 0.00 1.03 1.65 2.71 4.44 5.77 10.21 11.53 1:25:00 0.00 0.00 0.96 1.52 2.48 4.03 5.23 9.12 10.30 1:30:00 0.00 0.00 0.89 1.41 2.25 3.62 4.68 8.10 9.14 1:35:00 0.00 0.00 0.83 1.31 2.05 3.22 4.16 7.16 8.08 1:40:00 0.00 0.00 0.79 1.22 1.91 2.89 3.73 6.41 7.25 1:45:00 0.00 0.00 0.76 1.14 1.80 2.64 3.41 5.84 6.60 1:50:00 0.00 0.00 0.73 1.08 1.70 2.44 3.14 5.34 6.04 1:55:00 0.00 0.00 0.69 1.02 1.60 2.26 2.91 4.89 5.53 2:00:00 0.00 0.00 0.64 0.95 1.48 2.09 2.69 4.48 5.07 2:05:00 0.00 0.00 0.57 0.85 1.32 1.87 2.40 3.98 4.50 2:10:00 0.00 0.00 0.51 0.75 1.16 1.65 2.12 3.50 3.95 2:15:00 0.00 0.00 0.45 0.66 1.01 1.45 1.85 3.04 3.43 2:20:00 0.00 0.00 0.39 0.57 0.87 1.25 1.59 2.62 2.95 2:25:00 0.00 0.00 0.34 0.48 0.73 1.06 1.35 2.20 2.48 2:30:00 0.00 0.00 0.29 0.41 0.61 0.88 1.11 1.80 2.02 2:35:00 0.00 0.00 0.24 0.33 0.49 0.70 0.88 1.42 1.59 2:40:00 0.00 0.00 0.19 0.26 0.38 0.54 0.67 1.06 1.19 2:45:00 0.00 0.00 0.15 0.21 0.30 0.39 0.49 0.78 0.88 2:50:00 0.00 0.00 0.12 0.17 0.25 0.30 0.37 0.59 0.67 2:55:00 0.00 0.00 0.10 0.14 0.21 0.23 0.29 0.45 0.51 3:00:00 0.00 0.00 0.09 0.12 0.17 0.18 0.23 0.34 0.39 3:05:00 0.00 0.00 0.07 0.10 0.14 0.14 0.18 0.26 0.30 3:10:00 0.00 0.00 0.06 0.08 0.12 0.11 0.14 0.20 0.23 3:15:00 0.00 0.00 0.05 0.07 0.10 0.09 0.11 0.15 0.17 100 3:20:00 0.00 0.00 0.04 0.06 0.08 0.07 0.09 0.12 0.13 3:25:00 0.00 0.00 0.04 0.05 0.06 0.06 0.07 0.09 0.11 3:30:00 0.00 0.00 0.03 0.04 0.05 0.05 0.06 0.07 0.08 3:35:00 0.00 0.00 0.02 0.03 0.04 0.04 0.05 0.06 0.07 3:40:00 0.00 0.00 0.02 0.02 0.03 0.03 0.03 0.05 0.05 500 3:45:00 0.00 0.00 0.01 0.02 0.02 0.02 0.03 0.03 0.04 3:50:00 0.00 0.00 0.01 0.01 0.02 0.02 0.02 0.02 0.03 3:55:00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.02 0.02 4:00:00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 400 4:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 300 4:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 4:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 0 4:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 200 4:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100 5:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 5:35:00 1 0.00 1 0.00 0.00 0.00 0.00 1 0.00 0.00 0.00 0.00 I 5:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:00:00 0.00 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MHFD-Detention_v4-06-Ultimate Pond.xlsm,Outlet Structure 8/7/2023,2:21 PM DETENTIONOUTLET MHFD-Detention, Version 4.06(July 2022) Summary Stacie-Area-Volume-Discharoe Relationships The user can create a summary S-A-V-D by entering the desired stage increments and the remainder of the table will populate automatically. The user should graphically compare the summary S-A-V-D table to the full S-A-V-D table in the chart to confirm it captures all key transition points. Sra a g g Stage Area Area volume volume DTAN Now-Shore e Description [ft] [R'] [acres] [R'] lac-ft] ICN For best results,include the stages of all grade slope changes(e.g.ISV and Floor) from the S-A-V table on Sheet'Basin'. Also include the inverts of all outlets(e.g.vertical orifice, overflow grate,and spillway, where applicable). MHFD-Detention v4-06-Ultimate Pond.xlsm,Outlet Structure 8/7/2023,2:21 PM Stage Discharge Project Name: Polestar Subdivision:Polestar Project No.:39797.01 Location:Fort Collins Calculated By: ARJ Checked By: Date: 3/15/23 INTERIM-OUTLET ULTIMATE-OUTLET WQ orifice plate,42"Pipe and Overflow Structure WQ orifice plate,30"Pipe w/Restrictor plate and Overflow Structure Head(ft) Discharge(cfs) Head(ft) Discharge(cfs) 0 0.00 0 0.00 0.5 0.03 0.5 0.04 0.9 0.06 0.93 0.07 1 0.06 1 0.08 1.5 4.08 1.5 4.10 2 14.13 2 14.16 2.5 27.55 2.5 17.44 3 31.55 3 19.82 3.5 35.11 3.5 21.94 4 38.33 4 23.88 4.5 41.30 4.5 25.67 5 44.07 5 27.34 5.5 46.68 5.5 28.92 6 49.15 6 30,41 6.51 51.50 6.5 31.84 7 53.75 7 33.26 7.151 54.41 7.5 34.51 SEE WQCV STAGE IN RED 8 35.77 8.5 36.99 9 38.17 9.5 39.32 10 40.43 SEE WQCV STAGE IN RED NOTE:In the Jacobs SWMM model the outfall was modeled as a 30 unrestricted pipe. Appendix J-3 SWMM Maps Zt Legend _1 z Lu 0 T Junction L7 4� LLJ # _-N17 Outfall Z Storage Z Conveyance Element 'Tow 7 C7 - - - - Non-Routing Element 7i_ 0-4 - , ... - I 1L A'wl Wt, � " 4",�qf . I�� --- ,, , - - I I 1 1 1 1 11 k I � I t - - - .I . I c AA T 4? A41 Outlet L c CIO r 4 N, A 10, 91 C3 Subbasin A A "7* Ei 7= 4 > , I , - a 0 7 n4 4- 4k C-ir 4 tali, Vigil "IMP' i:A, sai 4'* �h*. *f --Z A.# uj it 4 .4 AN _,7, ^'It uj 71. 7 z ;1V In, I d Uj AIM 428 Spil _AL F28 410 j 0 1 411.- 11%, '04 A,� jik,* A 0 .4 71W, r D 4 1 7 4M 1-1 Z� - ,��I 4 1- . _ . k 41 ,--Wjlr 7 4 F2 I A oi 'i '4 oil C 'A _4 VO' -A �xi' 4 0 4 E7 7 13cl� 44mft A" pop 859 4 _1304 311 WNW.4l"",r PI F 02 J3 10 J105 pip, F7p i 7pe 103 �ipe 1 15-pip vetflow p [MI ovemow Mulberry Street ....... iL 05 % Mulberry Street J945 J709 3 J148 311 outfall q Al, �7 7. 4k x 7- V, 8 utfall Y41 4 308 8 e - -4 15 xe: J J108 108 'PIn 8 J8 AL C) 1143 __7 IT 0 79 J711 > LO It 11� ;j..i J5 21 J21 i 442 Spill A 713[JUtt k1l 1,3-11�21 M2 712 Ou fall 713 0 J712 J713 J121 13 71- A 4w J17 M7 LU 310 J117 [go ilo-pipe k;m-1 If* J0 114 uvtfutow e Er- 4�1 J113 0-_ N F_ 313 15 L) ac. 5 il 0 f"�A f; F,g7p—i p--el 316 93 J714 15_pipe F 1-61 1-D J513 71 utfall -pipe 18 overfil) LL q, J120 J10 423 _Af J115 655 854 IF 856 J116 4 J118 e .Mi I LL 12 Cl) 5 M JI/IJL #MWM&..Jm - 22 322 7 r <1 201 4 18 3 A31 319 C C 715 Outfall 'k, GC 224 _7 R 950 si* a- 8 0 Inlet J42 A, -950 kylin Ailli�v %7- GIC 117 0 3 2 uttall r 7� InIbt2 19 533a A2 8�,2 Ail J533 IsOyline J418 1141) e 118 533 A�25 543 N PIN "14 �77�f acL 14 J523 83 7 3.3 543 J543 US 299 2 324 9 523 ac 318 A24 p PP_3 rn_� 12.8 ac. J583 9 r, A22 PP 1 Spill 22 A21 A2 Elizabeth Street 3 8701 529 PIP 7 5 J519 529out 7 J589 =& 4 519out �,ja 1.4 6 1 7 9 1.6 J579 J569 (N N 118 1 7 299 Outfall MIA&I 869 J549 17k ij: 579 A 549 outfa Aw AL CID 366 Skyli -367 X_-) JSS9 445 Spill r -71, ALA 11 1 6i ir Ai" e ir��t e /'50'9 J719 719 -pipe _4; 119 Stora 719 0 f 59. 70 802 A17 CL 98 J94 1:0 0 200 400 800 a 378 Outfall is 115�� Q 368 JM Ili L C8 378 Feet 370 Ada 395 -2 7-, Al a 14 e 1.7 J93 )s F-7 11 871 Avery LowFlow 1,2,_ 588 ac. DRAWN BY- BNA 399 272 110 Avery Outlet 0 DESIGNED BY: MMC 1, 300 861 274 577a 520 Outfall 862 557 J550 4 ------ CHECKED BY- AMH ON40 okuh! I 302 A14 4- PROJECT NUMBER: 276 16 570 jy In 'F COFC2012.01 187 V 1!4!kill, e If 4L 560 -3 720 Ou '88-PiPe 4 4.3 h20 A FC20 DATE: 30 303— R e 16-3- 98 741 C) L6-2 4 07/01/2014 J34 0.8 C_ 6-2 4/13 290 ac. 446 Spill 306 % 587 1587 Is 16-1 - 47 Outfall SHEET: 396 L597:�j LO IB-1 390 00 f 87�3 V) z_ LLJ z � � z Ld wwOtw— cn w w i- QQwwzSo � LEGEND NOTE IN THE SWMM MODEL THERE IS w c-' =w w z F- Z } mo � m � -5 XX XX — BASIN NAME BASINS HATCHED IN GREY ARE ADDITIONAL RUNOFF FROM TIME 0 o — cn Of o N CONDUIT NOT IMPACTED OR TRIBUTARY SERIES HYDROGRAPHIC 401 — n > a_ w > o Q X.X X.X — BASIN AREA H OUTLET TO THE PROPOSED SITE WHERE OVER FLOW PV&L DITCH 1n o o :z o z o CHANGES SPILLS INTO THE SCENIC VIEWS z = a- a- CD CL z w � D FLOW ARROW FOR ELEMENT JUNCTION POND I.E. POND 313. ~ Q Q Q O 0 Q X POND BASIN DELINEATIONS FROM 2014 Z CANAL IMPORTATION BASIN — Ln CD EFFECTIVE BASIN DELINEATION Uj c�I 0000 CO ow oLn0M EL:11 � N r� w Q c I I C� xz Q � I I 0- Q m ❑ 00 I I Li w 00 CD LLJ O 0 � L 9 L ,:�1 ♦ Z J it: � cm i i rr �►rr Q �j cc _if5 W. MULBERR Y ST 0- 0 cu c� zn— CC _75 C Q - 1 "Ilk Q) Q) i t ' _ J17: 198.4 C w •.. r� FS 1 t� 1 1 •l 17 !�� r POND 313: 348.7 CFS O '� t ! da 2.9" + " �f 1 EE T ;� y — — — J17 — — ❑ ORCHARD PL T n nu ,w,,..,. 17 J11 �. +>� I D 1POND1 5PIP:E 200 FS 11 313 J10 ED _ RFLOW J113 y — 15 _ 6—PIPE 811P0I_POE 10 �J116 ❑� VERFL DW J118856 J88 854 5 15_OVERFLOW6OVEREll El �Z POND 313: 156.2 CFS NODE 853: 209.3 CFS � 1 ~ �' rL •a. , ALj I 23.1 ' ���, 15 o " III �z 30 W PL UM ST - I Fn W z6 I c SCENIC VIEWS O N L �rrrrim o- I r0 r0 O Q < n I ^II Z Q t O Lu WEST EL/ZA BETH ST. J J o m m v v w 0 � w z w o 0 < Y Q w _ > w o = U_ F- z Q W a- w U CD Z 1— 0 Q o J W O 300 150 0 300 600 ORIGINAL SCALE: 1" = 300' SHEET 1 OF 4 JOB No. 39797.01 V) z_ LLJ LLJ Ld zm � z W L.Li 0 cn w m �— QQWwzSm � LEGEND NOTE wN � WZC)f IN THE SWMM MODEL THERE IS m w w w z Wiz } = mp ADDITIONAL RUNOFF FROM TIME Q p a m cn ~ L Q BASINS HATCHED IN GREY ARE � a 1u m w w o ~ �' rx_x*,� XX — BASIN NAME c❑ CONDUIT NOT IMPACTED OR TRIBUTARY WHERE OVEDR OFLOW PV8cL0DITCH J Lu o p z p Z zo TO THE PROPOSED SITE F- wmmwm � Uj X.X X.X — BASIN AREA SPILLS INTO THE SCENIC VIEWS z = m m U m z w El PROPOSED CONDUIT CHANGES POND I.E. POND 313. aaopa FLOW ARROW FOR ELEMENT H OUTLET BASIN DELINEATIONS FROM 2014 CANAL U N X POND JUNCTION IMPORTATION BASIN ? o N00 0000 0 PROPOSED POND J � MODIFIED BASIN DELINEATION o Ln O °� PROPOSED JUNCTION U I I I 0 N r� w Q c I I Q c� xz � I I 0- Q m o 00 I I LLJ w 00 CD LLJ O 0 � L 3 - ,rr U < ,a ).E a C!) = do cc n o �1 W. MULBERRY ST. cu t ! #6 \ 5 _C Q U I dr1 7W O H r 10.2 I 17E 14.8 13_� •. � ► '� ' ` .L , � � -<� 117: 195.8 CFS �_ -}• I �*441 Ell J11 ORCHARD PL 110_PIPE _ 313out:252.2 CFS— — � M • 310 313 POND 23: 321.9 CFS f J10 I f 1110_OVERFLOW' a - _ 1� 15_PIPE 6_PIPE f r L3 _ 315 8_PIPE 0 10 I I PLILI u� J115�J 316 �J116 116 '�54 J118 � POND 313 :348.6 CFS � J88 OW ❑ I I ❑ D 110_OVE RFL ' y 65 I � ��\ _ I 16_OVERFLOW _ t i 115_OVERFLOW 15: 311.6 CFS l '~ EP I I a _ I I 23.1 �� 21 .5 15E W PL UM S� III �� % �0 9 I w Z W c SCEN/C I/IEWS z �� o Q II z \ Q Q n w w m WEST EL/ZABETH ST. - Q Q w p p U U ~ LLJZ Ld Q 7 Y Q W _ > W p = p U U (� F- z Q Ld :2 w > Ld T U Q U v' CD � � CD LL Q D LLJ o t ~ 0 \ W Ld < 0 U Ld rr � 0 300 150 0 300 600 U ORIGINAL SCALE: 1" = 300' SHEET 2 OF 4 JOB No. 39797.01 V) z_ LLJ Ld zm � z LAL.Li 0 cn w m I- QQWwzSm � LEGEND NOTE wN � WZC)f IN THE SWMM MODEL THERE IS m w w w z Wiz } = mp ADDITIONAL RUNOFF FROM TIME Q Q a m cn ~ Lu Q BASINS HATCHED IN GREY ARE _ � a w m w w mo �' Fr rx_x*,� XX — BASIN NAME c❑ CONDUIT NOT IMPACTED OR TRIBUTARY WHERE OVEDR OFLOW PV8cL0DITCH J Lu o p z p Z zo TO THE PROPOSED SITE F- wmml�' mJcnl X.X X.X — BASIN AREA SPILLS INTO THE SCENIC VIEWS z = m m 0 m z w El PROPOSED CONDUIT CHANGES POND I.E. POND 313. � � aQaaooa FLOW ARROW FOR ELEMENT H OUTLET BASIN DELINEATIONS FROM 2014 CANAL U N X POND JUNCTION IMPORTATION BASIN ? o N00 0000 0 PROPOSED POND J � MODIFIED BASIN DELINEATION o Ln O °� PROPOSED JUNCTION U I I I 0 N r� w Q I I Q c� xz � I I w Q m 000 I I w w (j CL 0UCD CD O 0 � L w4" - I"Now ,► + • i ,:�1 . z • • _ F=Q fir`- i / . F � k; ,!►.r Q C!� i w � i �• } c I t 75 ' T i ' �- • r U LL ► '�` 40 .• I O loot 111l I 17W « w • r _� Jdew 'ea.0 Q 10.2 J 17E •r- 1.6 fife A__� , ' NODE 23:361.8 CFS J17: 95.8 CFS' I m f - _t + r INTERIM-OUTLET: 93.6 CFS i r ; ` , 313out: 244.8 CFS: 13 ' y f _ 2.9 _ - - II ^ J14.176 CFS -a J17 � 17 I r. J11 EE � 110_PIPE — - - a_ ORCHARD PL T ' ~ 4�� C-1 INTERIM_OUTFAL:_ J37 313 , — c, � a i J10 I I l 110_OVERFLU I I � I `_PIPE r��. 23 M-15 J14 _6PIPE �-. • � � I - _ 315 • r r a 10 ♦ - I I ��� \ •� I J11511/8 316 ♦�J116 116 !�54 J118 - , U� - �— I � 8 LOW 65 I I I ❑ D `� SPIL L WAY_OUTEAI I_ 16_OVERFLOW 110_OVERF D i � I I 115_OVERFLOW I J. 4'•., vim. . \ 11 y�� 3 348.6 CFS I (;SPILLWAY 82.3 CFS M-15:176 CFS z �' rLa�A.�, j I 23.1 ' �� J 15E o • f I I ��� // W PL UM ST W 21 .5 ItI c SCENIC VIEWS c� Ida z 0 ID Q ^II Z \ Q nn r 0 * _ -1iz ' w w m m m WEST ELIZASETH ST. =mamma < < Ld Q o z o r Y o " Q w _ > W o = � U_ Q F z � Q w W U) Q U, U Z F- Q 0 O (l Ld U) Ld Q < J l O O c/) 300 150 0 300 600 ORIGINAL SCALE: 1" = 300' SHEET 3 OF 4 JOB No. 39797.01 V) z_ LLJ Ld zm � z W L.Li 0 cn w m �— QQWwzSm � LEGEND NOTE wN � WZC)f IN THE SWMM MODEL THERE IS m w w w z Wiz } = mp BASINS HATCHED ADDITIONAL RUNOFF FROM TIME U o - u w m o N ("X_X� XX BASIN NAME El CONDUIT SERIES HYDROGRAPHIC 401 — ccn p > m w > o Q YELLOW WERE NOT 0 0 U3 0 z O X.X X.X — BASIN AREA MODIFIED WHERE OVER FLOW PV&L DITCH J n m � z o' >- 0 _ PROPOSED CONDUIT SPILLS INTO THE SCENIC VIEWS z z a- a- (D CL z w POND I.E. POND 313. � � QQQQU0Q D FLOW ARROW FOR ELEMENT H OUTLET BASIN DELINEATIONS FROM 2014 CANAL X POND J JUNCTION IMPORTATION BASIN z 0 PROPOSED POND PROPOSED JUNCTION MODIFIED BASIN DELINEATION 0 z Ln O m 0 M wLd U p N � � I I ww Q I I Q c� xz � I I 0- Q m o 00 I I Li w 10 CD LLJ O 0 � L ` Y ,q f c� U Q • c/) C c� L CL - - — - - W. MULBERRYST. E O • • O � rn 75 q co U c JACOBS OUTFLOW 47.01 CFS Q V JR ENGINEERING OUTFLOW: 38.48 CFS I ,r Q _ p 313out: 55.15 CFS 10 2 J 14.8 I i A_., ,. FIN _ r - _ - < .7C 313: 348 7 S � , mf Q ;Z • • le17_1 / ` +• ! .� .,r 'r _ _ 2.9 J L_ Ld J141 C10_2 J17 C2 C5_1 E404 T 313ou t J6 J15 ORCHARD -w, !- - S¢ �f 1 E i..r — - - PL f 110_PIPE -1 C1_2 23: 221.2 CFS J10 310 � 1110_OVERFLOW' I I I \ 1115 I I — 23 C7 't C1_1 �� `� � � 315 r t f J115 - - �. , • I w - El ' JACOBS INFLOW: 0 CFS SP 65 I I I ❑ D �� /� ILLWAY_OUTFAL_i_ JR ENGINEERING 32.99 CFS 15E THERE IS A SUMP W 9 TWO INLETS HERE Now' I'L . III 23.1 -� � 21 .5 W PLUM ST o II — i d� 313_SPILLWAY. 0 CFS o C SCENIC I//EWS �, J;' SPILLWAY_OUTFALL: 0 CFS z a o ,I o \ I - rs II z ID Q Q 0 will WEST ELIZABETH ST. w w m m m J J Q Q � z p Q Ld 3 Y Q w _ > w o = p U J U W Z 0 Q Ld w U) 0 U z_ cill U) o Q Ld o' J < � O � J � 300 150 0 300 600 ORIGINAL SCALE: 1" = 300' SHEET 4 OF 4 JOB No. 39797.01 Appendix J-4 Offsite Photos and Calculations POND 315 OUTFALL - DUEL 24" RCP EAST OF KIMBALL STEET •r �I Nj ROCKY ROAD - DUEL 24" STORM UTILITY MARKINGS - (ON WEST SIDE) I �I 1 d3 f v POND 316 INFLOW PEAR STREET- (FACING WEST) fF 1 r I UPDATE OF HYDROLOGIC ANALYSIS FOR WEST PLUM STREET BASIN CANAL -rMP0RTAT.z0N BASIN Prepared for City of Fort Collins Stormwater Utility P.O. Box 580 Fort Collins, Colorado 80522 AWE ASSOCIATES formerly Resource Consultants & Engineers P.O. Box 270460 Fort Collins, Colorado 80527 (970) 223-5556, FAX (970) 223-5578 Ayres Project No. 34-0296.00 - _ - - W-PLUM10.RPT - ;' October 1995 4' Revised April 1996 � aA ASSOCIATES 832 :. . ' RESOURCE by date sheet of CONSULTANTS, chkd by date job no INC. subject Cis �t �/ Gam,,-i T.r.i e�Y)rc,T Fort Collins, Colorado 7 6Y �� /v �• F=y Ae-5 ygzz 2 . 3o ew LAC so .2.SL S-CU or. c1r//EY c�-�rjy,>/ _ f�/. /'i /- r„id-rr_-:'• %ri+�;� Fy,,v ,r-/,-r-• 1-74 r Z file�v 7afa T W H W td 114l:, aw 2 y I Z (•35 /,97 /. !07 31 3S S, e,3 < 2oK :t<rn77;FYr 72 CwJ J6 L 55 I y 6O 9S-5Y /, 3 y In 95 I i f RESOURCE by date sheet--- o' CONSULTANTS, chkd. by date job no. INC. subject Fort Collins, Colorado -3!12 R ze!"61' X! /Op :5 3 2, S All I lq7, 7 7 1, 3 & 41 4J- 0 &(I rOW9 kW4-y A-7-mi 4,9... 1c)I VOLUAA& Doc)-7q4 CW—LT&L 0 p 0 Or 4L'&-�49wy- edc� /PV RC;OURCC by date— men-9 CONS TkNT chkd. by— date job no INC. subject - - «: .«e: \ 3\ Fort Collins, Colorado JAI / $\\ ' IT, \ . � \ \ \�� NZ (D -t't Inj CHART 2 10,000 F— 168 I 8,000 EXAMPLE t" 1S6 6,000 0.36 i.gh.e 13.0 bat 6. 121 5,000 0.46"' (3) 144 4,000 Hw 4 Mw S. e• 132 3,000 0 (1etl) 6 s. , ti 120 m 2,000 19 1.1 6.3 e• 131 :.: 4.6 4' toe '0 L tees 3• 4. i j 96 : 1,000 3. 800 3• 84 el 600 �f 2.500j 72 j 2. 2. N I 300 • U N i// = 1.5 I W z L 60 J_ = 200 ��% Q I.s 1.5 54 O // W 100 J W L 48 s 60/ v 60 I.0 LLa2 N SO//i I.0 C 40 Q L0 G j w 36 0 w gG�LE ENTYPECE W W a S3 20 (U Il.ee.a o .6 .e a a 30 f21 Yllau a eeelerw W .e u e 2T 0 (31 Oaiem lns T 7 e 6 7 N To .C4M 111 0131 Pel.el 21 4 n� p u4p 01 IM. •6 eee eva6M �H.; IvwIn •6 , 3 0 e44 0 .telu, er was .6 Ie tu.elnu6. _ 2 ' 15 e 1.0 s 12 HEADWATER DEPTH FOR C. M. PIPE CULVERTS WITH INLET CONTROL W IK.W 0!.V6LIC R0603 AK M43 182 CHART 6 2000 — 1000 goo J srr. t,.— , .6 WOWS o OUTLET CULVERT ILO.R56 PULL 120 600 iw wl.l eSRw w ...RI•M,saWS Rr M .g 500 106 .nwu pbJR• . R. M.M RkR•r• 10 400 96 !00 g4 OP. O yp C �F 200 T2 It y 66 �O ''!•cp ?I'Y UU 2 60 O l<J U S4 /Sn 00 00 F x 3 = 4g O °�� F� a g0 U t 00 = 42 =H4 60 = / a SO o S6 ' ( Vj 40 33 300 6 27 /� 0 10 j4p0 {/ 500 /2 500 10 Ig % 20 g i� 6: 1 S � S 4 12 3 2 HEAD FOR STANDARD C. M. PIPE CULVERTS FLOWING FULL n a 0.024 RURUU 0/ "L1C MAM YR. rou 186 3 ac 2 I .0' do CannoP Exceed Top of Pipe I.O DIA 0 0 10 20 30 40 50 60 70 80 90 100 DISCHARGE (Q) C.F.S 6 8 5 7 I— H w 4 e I w w _ 9 L" u U do Cannot Exceed Top of Pipe a �- 3 5 ,- _ 7 x � t- a. a 0 2 D A. w 0 100 200 300 400 500 600 700 800 900 1000 I= DISCHARGE (Q ) C.F.S. Q' ;Z 14 F- FE U 12 10 8 6 do Cannot Exceed Top of Pipe i 13' 4 DI 0 1000 2000 3000 4000 DISCHARGE (0) C.F.S. Figure 7.4.3- 4 CRITICAL DEPTH CIRCULAR PIPE ( From : U.S. Dept. of Commerce, Bureau of Public Roads, Dec. 1965) 7.4---15 � a r,•. t r a • K.}.. t : fill .• no's � '- �® NOW • lit - r a ®®Ill® �®IN 5 k Trn j: j 5 :1 \ :'r' r 1 d,._ t> a,'..,; a�...�..ai:a a ria s✓..; - t ✓`",-. r •e•� ..r:w M+�tn..pG - s 'EJf •v`ytl CF}�....y1 + .1.i�.S} i{ I!A'.5�t_..cli +' �_ea.e^.fi .rY1. •4..,'•i� �• _ tt r 4 = • V r& Lv - y S + i' LL� s ti 1 zl t ._ ... S i.` J45. it ,. .... .�x.� �. .. ..•, .r .... ' '. RESOURCE by date I v-b B-e 8 sheet of CONSULTANTS, chkd. by date job no. r 4 r r INC. subject a.d Fort Collins, Colorado �p A Lbrtt' T3 Nq cl API a-W0.y — - 4) (too,N) - 9 4o ti I; I (971) (98z) \ -- 400 4o1 397 rd G OCOAfo ----- �06 8 �l N' N , Xa 'S1. '�'r�.cT.,5�'K �✓;yr`t 4pZ,E�' .yu x>< �a - �-r LL cl CO 1 ... _ i 1 ol +' � a,). Y\ Y izi �hSa'S�i'1�EiAa�'�i:`��'�FF'?F ht t. f�:•�`_N"t.n �:.t �^! .s iSs ��.i,r J��- f ey Sir.•'z4 Y��' ��.r•-�irn ne �-- •'... ',` i f MHFD-Culvert, Version 4.00(May2020) Project: Kimball Detention(Pond 315 Culverts) ID: CO-*V.m e I° o 1- ......i.............} M : >keY Design Information(Input): Circular Culvert: Barrel Diameter in Inches D= 24 inches Inlet Edge Type(Choose from pull-down list) Grooved Edge Projecting OR: Box Culvert: Barrel Height(Rise)in Feet H(Rise)=�ft Barrel Width(Span)in Feet W(Span)= ft Inlet Edge Type(Choose from pull-down list) Number of Barrels #Barrels= 2 Inlet Elevation at Culvert Invert Elev IN= 5096.6 ft Outlet Elevation OR Slope So= 0.005 ft/ft Culvert Length L= 440 ft Manning's Roughness n= 0.013 Bend Loss Coefficient Kb= 0 Exit Loss Coefficient K.= 1 Design Information(calculated): Entrance Loss Coefficient K.= 0.20 Friction Loss Coefficient Kf= 5.43 Sum of All Loss Coefficients Ks= 6.63 Minimum Energy Condition Coefficient KEIo = 0.0028 Orifice Inlet Condition Coefficient Cd= 0.67 Calculations of Culvert Capacity out Out): Backwater calculations required to obtain Outlet Control Flowrate when HWo<0.75*Culvert Rise Headwater Tailwater Inlet Inlet Outlet Controlling Flow Surface Surface Control Control Control Culvert Control Elevation Elevation Equation Flowrate Flowrate Flowrate Used ft ft Used cfs) (cfs) (cfs 5096.60 5095.20 No Flow WS<inlet 0.00 0.00 0.00 N/A 5096.85 5095.20 Min.Energy.E n. 0.50 #N/A #N/A #N/A 5097.10 5095.20 Min.Energy.E n. 2.32 #N/A #N/A #N/A 5097.35 5095.20 Min.Energy.E n. 5.06 #N/A #N/A #N/A 5097.60 5095.20 Min.Energy.E n. 8.68 #N/A #N/A #N/A 5097.85 5095.20 Regression E n. 12.62 #N/A #N/A #N/A 5098.10 5095.20 Regression E n. 17.28 27.88 17.28 INLET 5098.35 5095.20 Regression E n. 22.62 29.43 22.62 INLET 5098.60 5095.20 Regression E n. 27.94 30.91 27.94 INLET 5098.85 5095.20 Regression E n. 32.94 32.33 32.33 OUTLET 5099.10 5095.20 Regression E n. 37.42 33.69 33.69 OUTLET 5099.35 5095.20 Regression E n. 41.46 35.00 35.00 OUTLET 5099.60 5095.20 Regression E n. 45.10 36.28 36.28 OUTLET 5099.85 5095.20 Regression E n. 48.44 37.51 37.51 OUTLET 5100.10 5095.20 Regression E n. 51.54 38.71 38.71 OUTLET 5100.35 5095.20 Regression E n. 54.44 39.88 39.88 OUTLET 5100.60 5095.20 Regression E n. 57.22 41.02 41.02 OUTLET 5100.85 5095.20 Regression E n. 59.82 42.12 42.12 OUTLET 5101.10 5095.20 Regression E n. 62.30 43.21 43.21 OUTLET 5101.35 5095.20 Regression E n. 64.70 44.26 44.26 OUTLET 5101.60 5095.20 Regression E n. 67.04 45.30 45.30 OUTLET 5101.85 5095.20 Regression E n. 69.30 46.31 46.31 OUTLET 5102.10 5095.20 Regression E n. 71.48 47.30 47.30 OUTLET 5102.35 5095.20 Regression E n. 73.62 48.28 48.28 OUTLET Processing Time: 00.16 Seconds MHFD-Culvert v4.0.)dsm,Culvert Rating 3/17/2023,3:07 PM MHFD-Cu/vert, Version 4.00(May2020) Project: Kimball Detention(Pond 315 Culverts) ID: STAGE-DISCHARGE CURVE FOR THE CULVERT 5103.6 5102.6 • o ❑ • p ❑ • - ❑ 5101.E ZAI El o ❑ ♦ o ❑ El j 5100.6 m (D ♦ ❑ w' ♦ ❑ m � as ♦ C ❑ R 5099.E ZL El ♦ 0 ❑ ♦ L ❑ ♦ T] 5098.E El zL ♦ ❑ o ♦ ❑ L ♦ ❑ 5097.E a 5096.E Z i 0 20 40 60 80 Discharge (cfs) i-Inlet Control 0 Outlet Control •Stage-Discharge MHFD-Culvert_v4.0.xlsm,Culvert Rating 3/17/2023,3:07 PM Stage Discharge Project Name: Polestar Subdivision: Polestar Project No.: 39797.01 Location: Fort Collins Calculated By: ARJ Checked By: Date: 3/15/2023 Q=C*L*H^1.5 C-2 7 Pond 315 Outlet Pond-Double Barrel Culvert Outlet L=Weir Length See Attached MHFD-Culvert_4.0 Spreadsheet H=Height Pond 315-24"Double Barrel Culvert Outlet Pond 315-Weir Discharge Elevation Stage(ft) Discharge(cfs) Energy Equation Elevation Stage(ft) Weir Length(ft) Discharge(cfs) 5096.60 0.00 0.00 No Flow(WS< inlet) 5100.40 0 0 0.00 5096.85 0.25 0.50 Min.Energy.Eqn. 5100.60 0.2 11.6 2.80 5097.10 0.50 2.32 Min.Energy.Eqn. 5100.80 0.4 15.3 10.45 5097.35 0.75 5.06 Min.Energy.Eqn. 5101.00 0.6 19.6 24.59 5097.60 1.00 8.68 Min.Energy.Eqn. 5101.20 0.8 24.3 46.95 5097.85 1.25 12.62 Regression Eqn. 5101.40 1 43.2 116.64 5098.10 1.50 17.28 INLET 5101.50 1.1 59.9 186.59 5098.35 1.75 22.62 INLET 5101.60 1.2 63.5 225.38 5098.60 2.00 27.94 INLET 5101.70 1.3 75.3 301.35 5098.85 2.25 32.33 OUTLET 5101.801 1.41 871 389.111 5099.10 2.50 33.69 OUTLET offset 3.8 feet from culvert invert at 5096.6 5099.35 2.75 35.00 OUTLET 5099.60 3.00 36.28 OUTLET 5099.85 3.25 37.51 OUTLET 5100.10 3.50 38.71 OUTLET 5100.35 3.75 39.88 OUTLET 5100.60 4.00 41.02 OUTLET 5100.85 4.25 42.12 OUTLET 5101.10 4.50 43.21 OUTLET 5101.35 4.75 44.26 OUTLET 5101.60 5.00 45.30 OUTLET 5101.85 5.25 46.31 OUTLET 5102.10 5.50 47.30 OUTLET 5102.35 5.75 48.28 OUTLET Appendix J-5 Flow Comparison r t N; I• ` v 'iei a � . •.. ' Mulberry Flow Path t • Path ` New Flow=463.3 �q Mulberry Flaw Path Mulberry FlawNew Flow=114:9 , �• %D+fference=57.1 New Flow=641.3 "' l` a 3 `Ya Difference=6A 9 °I Difference=28.3 k � Plum Flow Path New Flow=193.3 rl i 1. t r 1 'sl %Difference=49.8 PIUm FIawPalll -h� ! *'� a� i• �!.f _,,� ::ti: - _+ �z. Vt New Flaw=200.4 "' ' ' -: 'a tr• Plum Flow Path ° X-j ` Plum Flow Path %Differenc®-36.3 , + r �. -. .� New Flow_50.6 a New Flow=154-5 --- �" Plum Flaw Path 1 Plum Flow Path "t °!a D+fference=-4.5 Z %Difference=51.5 t New Flow=352.2 -' Plum Flow Path ! y 3t ,. New Flow=407 New Flow=434.6 R f Difference Q-11.3 '. % Difference=-16A (J� - t- - -- %Difference--13.4 Plum Flow Path New Flow=63.8 r �•, Difference < Ellzab@th FIOw Path .t 1 �l-~ F �v ' a- " New Flow=200-5 -Ai- r'x- LLJ I e Plum Flow Path r'�'e,. '+ �,r - ' rvt °le Difference=0.3 �SpOr 'r= - � 0 New Flaw 192 6 l. Clearuiew Flow Path _ f o Clearview Flow Path Difference=10 1 _ ., New Flow=257.8 New Flow-4d5.8 a i eiz.aa�ria t Elizabeth Flow Perth r` _r t 3ifift.' °re Difference--25.1 _ y - New Flow 10.5 �". LL J r A Differ@nce--4Q.1 �7� Plum Flaw Path ..3"utlt %Difference=101.9 ■ ..=i New Flow=354.9 1 Difference�-25.9 r i m k -, ►' ;.. Clearvlew Flow Path ll �- �, � _ yq - 3 ,• New Flow=426 " i Z o� to Clearvlew Flow Patty r {` �' - �; o Difference=-41 S Z +D New Flow=226.5 �" rl #3*ti - • - s .9 Canal Importation Flow Path {] °! Difference-6.3 � + 'u '� kW,' - _ LIZ - . Clearview Flaw Path 'e New Flow=521.9 �� .°�_: .'r New Flow-396.8 � '',.�v ,•� °Ja Difference--2.6 � W •" Clearview Flow Path .F " a %Difference=13 t° ,__. �'-!4 -,+ T .� Z „� _ Clearview Flaw Path : •a y - Z 6' a 1 New Flow=334.5 _ a w pgaSPE4FRB - �lrl ' !e03 - °1C1'6fferNew le Difference ow ��942.9 y '^ Difference •10.1 Ca �' `f •� 4, sr '-1 +•Vki ; �4 - . e ���. r - j. _ . �- -� _ �-�rCanal Importation Flow Path NewFlow_5"c6.1 Difference--2.441 Canal Impartation Flow Path New Flow_481.4 IZ Canal Impartatlan Flaw Path %Difference=0.7 W >,r : 5 ti,k New Flaw a°429.1 �" as %Difference--7.5 ' ! Canal Importation Flow at New Flow=256.7 f rb Difference=-9.9 t ' Canal Importation Flow Path �' r '•' l I. -- New Flow=718.7 artation Flow Path ' Canal Importation Flow Path IN analIm p as Difference=4+1.3 r W New Flaw=436.4 r• New Flaw=196,3 °f- Difference 6-6 � - ro.Difference=•3.3 +k" _- F.1 1r\l L }y,. 5 Feet ' �� ,..... r ^ r ' !. ii - i^6•bt'+a-... �__.x• _ �^r►�`.� Mldc 4 eat - � ��~ r�� sty .y • ��:. I'- s.o COFC2012.01_CI Basin Hydrologic Conversion_Report.docx 13 ANdERSON CONSU[TINCI ENGINEERS, INC. Table B.1.1 Plum Channel Flow Path Discharge Profile Discharge (cfs) HEC-Ras Sation EPA SWMM Element 100-year/Result to Description be Mapped 10-year 2-year 5271 113 241 67 10 Upstream Study Limit 4872 15 330 76 18 4277.999 115_pipe/115_overflow* 214 140 73 14 Upstream of Rocky Street Culvert 4277 115_pipe/115_overflow* 214/140 73 14 Rocky Street Culvert Overtopping 3993 16_pipe/16_overflow* 234/160 79 24 3816 16_pipe/16_overflow* 234/160 79 24 3544 116 221 70 13 2999.999 18_pipe/18_overflow* 377/349 117 46 Upstream of Gallup Road Culvert 2999 18_overflow 349 92 23 Gallup Road Overtopping 2661 18_pipe/18_overflow* 377/349 117 46 2570 118 375 116 46 1323 20 424 153 69 938 220-322 444 1 168 84 Upstream of Glenmoor Pond * Discharge based on the sum of pipe and overflow discharges Modified - Table B.1.1 Plum Channel Flow Path Discharge Profile Discharge(cfs) Effective HEC RAS-STATION EPA SWMM ELEMENT Effective HEC-RAS hydraulics model/Result Effective SWMM hydrology model Corrective Effective Proposed Result Mapped by Anderson /Result Modeled /Result Modeled Location 5271 113(313out in CE models) 241 155 252 245 Upstream Study Limit 5190 NODE 23 --- --- --- 362 Pond Inflow 4872 (L)15 330 200 305 --- 4675 POND OUTFLOW J14 --- --- 174 Pond outflow 4277.999 C-1+115_pipe/115_overflow* 214/140 167/139 290/242 187/140 Upstream of Rocky Road Culvert 4277 C-1+115_pipe/115_overflow* 214/140 167/139 290/242 187/140 Rocky Road Culvert Overtopping 3993 C-1+16_pipe/16_overflow* 234/160 193/160 313/253 201/142 3816 C-1+16_pipe/16_overflow* 234/160 193/160 313/253 201/142 3544 (L)116 221 180 229 176 2999.999 18_pipe/18_overflow* 377/349 354/327 285/258 285/257 Upstream of Gallup Road Culvert 2999 18_overflow 349 327 258 257 Gallup Road Overtopping 2661 18_pipe/18_overflow* 377/349 354/327 285/258 285/257 2570 (L)118 375 352 284 281 1323 (L)20 424 406 356 356 938 (L)220-322 1 444 1 434 1 391 1 390 lUpstream of Glenmoor Pond *Discharge based on the sum of pipe and overflow discharges Flow is presented as(total flow)/(Surface Flow) ---null value XXXX-New Station or Element Modeled Appendix J-6 Spillway Variance Request �3th J•R ENGINEERING 50 YEARS OF EXCELLENCE VARIANCE REQUEST Date: May 161h 2023 From: Joseph Frank, PE Subject: Scenic Views and Polestar Spillway Variance Request I am writing to request a variance from the 2018 Stormwater City of Fort Collins criteria regarding the spillway requirements for Scenic Views Pond and Polestar/Happy Heart Detention pond. Specifically, the variance is for: Chapter 8, Section 3.5—Spillway Max Flow Depth • Emergency overflow depth shall be no more than six inches (6") at the crest during the 100-year storm. The Scenic Views Pond and Polestar/Happy Heart Detention pond are located in the City of Fort Collins floodplain termed"Plum Street Flow Path" and have higher than average peak inflows. Scenic View Pond Spillway Existing condition for Scenic Views Pond: The existing spillway has a depth of 1.5 feet and width of 10 feet. The existing spillway elevation is at (5115.57 on the NAVD 88 datum) and (5112.5 on the NVGD 29 datum). The flow from the pond (349 cfs = peak pond inflow per corrected effective SW1V M model) surpasses the capacity of the spillway,causing it to overflow and overtops the embankment at an approximate depth of 2.02 feet. The water then spills over the eastern portion of the retention pond for a distance of approximately 290 ft, see existing scenic views pond spillway section in Appendix A.1. Proposed condition: JR Engineering is proposing to modify the overflow spillway while maintaining the existing spillway elevation of 5115.57 as to not impact volume within the pond. The proposed spillway has a crest length of 51 feet and will result in an overflow depth 1.75 feet at 349 cfs, which exceeds the city's required depth of six inches. See the scenic views spillway improvement section in Appendix A.1. Justification for Variance: The proposed improvements are intended to increase the emergency overflow spillway capacity and improve the existing spillway by providing additional riprap protection. This modification will decrease the overall breadth of the floodplain, reduce the emergency overflow depth from 2.02 feet to 1.75 feet and serve as an improvement to the existing scenic views retention pond. The spillway variance is necessary to increase the emergency capacity and prevent overtopping of the existing embankment. Please refer to exhibits and calculations in Appendix A.1 for additional information. ❑ 7200 South Alton Way ❑ 25188 Genesee Trail Road ❑ 5475 Tech Center Drive ❑ 2900 South College Avenue Suite C400 Suite 110 Suite 235 Suite 3D Centennial,CO 80112 Golden,CO 80401 Colorado Springs,CO 80919 Fort Collins,CO 80525 303-740-9393 9 Fax 303-921-7320 303-740-9393 9 Fax 303-921-7320 719-593-2593 9 Fax 303-921-7320 970-491-9888•Fax 303-921-7320 �3th j-R ENGINEERING 50 YEARS OF EXCELLENCE Polestar Detention Pond Spillway Proposed Polestar/Happy Heart Farms Spillway: The proposed spillway has a crest length of 36.8 feet and will result in an overflow depth 2.21 feet at 362 cfs (peak pond inflow per proposed SVO M model), which exceeds the city's required depth of six inches. This spillway is intended to remain in place when the ultimate regional pond is constructed which will result in an overflow depth of 1.61 feet at 221 cfs. See the Polestar detention facility spillway section in Appendix B.1. Justification for Variance: The request is to allow for the same approach as the Concept Canal Importation Master Plan by Jacobs and prevent the flow from the emergency spillway from being directed towards existing structures and homes downstream. By narrowing the spillway and allowing the overflow depth to exceed six inches the spillway will better direct flows between houses and towards the improvements in the drainage easement to the east of the Polestar development. Refer to exhibits and calculations in Appendix B.1 for additional information. ❑ 7200 South Alton Way ❑ 25188 Genesee Trail Road ❑ 5475 Tech Center Drive ❑ 2900 South College Avenue Suite C400 Suite 110 Suite 235 Suite 3D Centennial,CO 80112 Golden,CO 80401 Colorado Springs,CO 80919 Fort Collins,CO 80525 303-740-9393 9 Fax 303-921-7320 303-740-9393 9 Fax 303-921-7320 719-593-2593 9 Fax 303-921-7320 970-491-9888•Fax 303-921-7320 �3th J•R ENGINEERING 50 YEARS OF EXCELLENCE Appendix A. 1 ❑ 7200 South Alton Way ❑ 25188 Genesee Trail Road ❑ 5475 Tech Center Drive ❑ 2900 South College Avenue Suite C400 Suite 110 Suite 235 Suite 3D Centennial,CO 80112 Golden,CO 80401 Colorado Springs,CO 80919 Fort Collins,CO 80525 303-740-9393 9 Fax 303-921-7320 303-740-9393 9 Fax 303-921-7320 719-593-2593 9 Fax 303-921-7320 970-491-9888•Fax 303-921-7320 \ II` 51 ./�f 11 I- /� • `� \, / III / \ l��l // \ 'r=II / �� II SCENIC VIEWS SPILLWAY— , _ — — // r 1 ( — — �> 1 ` \ �� / 1 ( f777 — — f o -L — W ORCHARD PL PLUM DRAINAGE CHANNEL I 0'% � \ SCENIC VIEWS \ / SPILLWAY r I I —— 110 / — J l II II' _5j 1 �\ RAIN GARDEN / 05 SCENIC VIEWS RETENTION POND POLESTAR SPILLWAY \ I \ POLESTAR DETENTION POND A3c A.3 A3 A3 A3 A3c A3c A3 A3 A3 A3c A3 A3 A3c ( — \ 1 \ 0 r I rf STILLING BAIN _ \ m l ta 01 ` V \, \ � O Fie F3 F3c I 'F F3 3 F3c INON- lze l J _ 1 QJ ( I r PROPOSED GRADING as — POLESTAR JOB NO. 3979701 6/6/2023 SHEET 1 OF 1 J-R ENGOMMUNG A Westrian Company Cent MN 303-740--M•Cdoido*IVS 719-5 20 Fort Coin 970-491-M•WWWWOMFGM EXISTING SCENIC VIEWS - SPILLWAY TOTAL LENGTH 290.00' TOTAL INFLOW INTO THE POND = 348.6 CFS APPROXIMATE DEPTH 2.0 FT WSEL BASE ON 100-YR PEAK INFLOW RATE. (NO ATTENUATION PER CRITERIA) BERM ELEV=5117.07 DEPTH OVER EMBANKMENT 0.5 FEET BERM ELEV=5117.07 =1 I=1 I=1 1= 1= 1= 1= 1= 1= 1= 1= 1= 1= 1= 1= I o ____ = 1 = 1 = 1 = 1 = 1 = 1 = 1 = 1 I—I= 1 = 1 = 1 = 1 = 1 = _ = WEIR EELV=5115. n = _ _ _ _ Hill 100 YEAR EMERGENCY OVERFLOW FROM JR CE SWMM MODEL = 252 CFS APPROXIMATE DEPTH 1.9 FT 3.75' 10.00' 3.75' WSEL BASED ON ROUTED 100-YEAR POND OUTFLOW RATE EXISTING SPILLWAY CAPACITY UNDER DEPTH OVER EMBANKMENT 0.4 FEET EMBANKMENT - 47.8 CFS EX. SCENIC VIEWS - SPILLWAY 6 3 0 6 12 POLESTAR JOB NO. 3979701 03/20/2023 ORIGINAL SCALE: 1" = 6' SHEET 1 OF 1 4V J'R ENGOMERING A Westrian Company Fart Cain 970-491-W•www SCENIC VIEWS - SPILLWAY IMPROVEMENT TOTAL INFLOW INTO SCENIC VIEWS POND IN SWMM 348.65 OVERFLOW MODELED IN SWMM WHEN SCENIC VIEWS POND 100 YEAR EMERGENCY OVERFLOW = 348.65 CFS IS 100% FULL W/ A FLOW DEPTH OF 1.75 FT AND 0.5 FEET OF FREE BOARD 1.40 FT DEEP AT 244.76 CFS WSEVV BASED ON 100-YR PEAK INFLOW RATE (NO ATTENUATION PER CRITERIA) 0.85 FEET OF FREEBOARD WSEVL BASED ON ROUTED 100-YR POND OUTFLOW RATE BERM ELEV=5117.82 BERM ELEV=5117.82 — _ 2.5 — =6� 17Hi n n WEIR E LEV=5115.57� oO oO oO O O�OO 171 5.63' 51.00' TYPE M RIP RAP © 2' DEPTH 5.63' TYPE II BEDDING 1' THICKNESS SCENIC VIEWS - SPILLWAY 6 3 0 6 12 POLESTAR JOB NO. 3979701 03/20/2022 ORIGINAL SCALE: 1" = 6' SHEET 1 OF 1 10 J-R ENGOMMIRING A Westrian Company Centerriial 303-740--M•CobMdo Strips M-M-2590 Fort Coins 9M 491-M•www' Scenic Views Pond Broad Crested Weir Project Description Solve For Crest Length Input Data Discharge 348.61 cfs Headwater Elevation 5,117.32 ft Crest Elevation 5,115.57 ft Tailwater Elevation 0.00 ft Crest Surface Type Gravel Crest Breadth 20.00 ft Results Crest Length 51.0 ft Headwater Height Above 1.75 ft Crest Tailwater Height Above Crest -5,115.57 ft Weir Coefficient 2.95 ft^(1/2)/s Submergence Factor 1.000 Adjusted Weir Coefficient 2.95 ft^(1/2)/s Flow Area 89.3 ftz Velocity 3.90 ft/s Wetted Perimeter 54.5 ft Top Width 51.02 ft Bentley Systems,Inc. Haestad Methods Solution FlowMaster Scenic Views Pond.fm8 Center [10.03.00.03] 2/9/2023 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown,CT 06795 USA +1-203-755-1666 Chapter 12 Storage CREST OF EMERGENCY SPILLWAY EMBANKMENT WIDTH EMERGENCY OVERFLOW WSEL FLOW BEYOND TOP OF 100-1EAR WSEL �'� EMBANKMENT DETENTION Z3 BASIN >F 1 1 3' MIN 1' MIN SOIL RIPRAP 2D5o FREEBOARD TOP OF FOOTING AT OR BELOW EXTENDED RIPRAP BOTTOM OF SOIL RIPRAP LPSTREAM OF WALL CONCRETE OVERFLOW WALL (WALL AND REINFORCING DESIGNED BY ENGINEER) EMERGENCY SPILLWAY PROFILE AS NEEDED TO PASS THE IC0-"R UNDETAINED OR MORE 3" TO 4" EMERGENCY OVERFLOW WSEL 1' MIN TOPSOIL COVER FREEBOA3D CREST OF EMERGENCY SPILLWAY Z 2.5 SOIL RIPRAP 20yp EMERGENCY SPILLWAY SECTION AND SPILLWAY CHANNEL 35 30 - . - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 ac . . . . . . _ . . . - - . . . . . . - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e20 . .. . . . . .- . . . . . . - . . . - . . . . . . . . - . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . - --- . . . . . s TYPE H TYPE 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 g — . . . . . . - - - - - - - . . . . . . . . . . . . . . . . .. - . . . . . . . . . . . . . . . . 0 0 5 10 15 20 25 30 Unit Discharge(cfs/ft) Figure 12-21. Embankment protection details and rock sizing chart(adapted from Arapahoe County) September 2017 Urban Drainage and Flood Control District 12-33 Urban Storm Drainage Criteria Manual Volume 2 �3th J•R ENGINEERING 50 YEARS OF EXCELLENCE Appendix B. l ❑ 7200 South Alton Way ❑ 25188 Genesee Trail Road ❑ 5475 Tech Center Drive ❑ 2900 South College Avenue Suite C400 Suite 110 Suite 235 Suite 3D Centennial,CO 80112 Golden,CO 80401 Colorado Springs,CO 80919 Fort Collins,CO 80525 303-740-9393 9 Fax 303-921-7320 303-740-9393 9 Fax 303-921-7320 719-593-2593 9 Fax 303-921-7320 970-491-9888•Fax 303-921-7320 POLESTAR DETENTION FACILITY - SPILLWAY TOTAL FLOW INTO THE POND IN SWMM IN THE INTERIM PROPOSED CONDITION 361.8 CFS TOTAL FLOW INTO POND IN SWMM IN THE ULTIMATE CONDITION 221.2 CFS 100 YEAR EMERGENCY OVERFLOW = 361.8 CFS 100 YEAR EMERGENCY OVERFLOW = 221.2 CFS W/ A FLOW DEPTH OF 2.21 FT W/ A FLOW DEPTH OF 1.61 FT FREEBOARD 0.50 FT 1.13 FT OF FREE BOARD PROVIDED WSEL BASE ON 100—YR PEAK INFLOW RATE. WSEL BASE ON 100—YR PEAK INFLOW RATE. (NO ATTENUATION PER CRITERIA) (NO ATTENUATION PER CRITERIA) 50.50' TOTAL WIDTH 48.00' AT FLOW DEPTH BERM ELEV=5110.50 BERM ELEV=5110.50 5 = 2.5 — - TOTAL DEPTH 2.71 FT rJ O� O� O� OF\ pO� - SIZED FOR ULTIMATE CONDITION WITH WEIR ELEV=5107.79 O O O O AT LEAST 6 INCHES OF FREEBOARD - 3" TOPSOIL COVER TYPE II BEDDING_ TYPE H RIP RAP © 3' DEPTH - = 1' THICKNESS 6.85' 36.80' 6.85' 3" TOPSOIL COVER ONSITE - SPILLWAY DETAIL 6 3 0 6 12 POLESTAR JOB NO. 3979701 08/07/2023 ORIGINAL SCALE: 1" = 6' SHEET 1 OF 1 10 J-R ENGOMMIRING A Westrian Company Centerriial 303-740--M•CobMdo Strips M-M-2590 Fort Coins 9M 491-M•www' Polestar Interim Broad Crested Weir - 1 Project Description Solve For Headwater Elevation Input Data Discharge 361.80 cfs Crest Elevation 5,107.79 ft Tailwater Elevation 0.00 ft Crest Surface Type Gravel Crest Breadth 25.00 ft Crest Length 36.8 ft Results Headwater Elevation 5,110.00 ft Headwater Height Above 2.21 ft Crest Tailwater Height Above Crest -5,107.79 ft Weir Coefficient 2.99 ft^(1/2)/s Submergence Factor 1.000 Adjusted Weir Coefficient 2.99 ft^(1/2)/s Flow Area 81.3 ftz Velocity 4.45 ft/s Wetted Perimeter 41.2 ft Top Width 36.80 ft Bentley Systems,Inc. Haestad Methods Solution FlowMaster Polestar Pond.fm8 Center [10.03.00.03] 8/23/2023 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown,CT 06795 USA +1-203-755-1666 Ultimate Polestar - Broad Crested Weir Project Description Solve For Headwater Elevation Input Data Discharge 221.20 cfs Crest Elevation 5,107.79 ft Tailwater Elevation 0.00 ft Crest Surface Type Gravel Crest Breadth 25.00 ft Crest Length 36.8 ft Results Headwater Elevation 5,109.40 ft Headwater Height Above 1.61 ft Crest Tailwater Height Above Crest -5,107.79 ft Weir Coefficient 2.93 ft^(1/2)/s Submergence Factor 1.000 Adjusted Weir Coefficient 2.93 ft^(1/2)/s Flow Area 59.4 ftz Velocity 3.73 ft/s Wetted Perimeter 40.0 ft Top Width 36.80 ft Bentley Systems,Inc. Haestad Methods Solution FlowMaster Polestar Pond.fm8 Center [10.03.00.03] 8/23/2023 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown,CT 06795 USA +1-203-755-1666 Chapter 12 Storage CREST OF EMERGENCY SPILLWAY EMBANKMENT WIDTH EMERGENCY OVERFLOW WSEL FLOW BEYOND TOP OF 100-1EAR WSEL �'� EMBANKMENT DETENTION Z3 BASIN >F 1 1 3' MIN 1' MIN SOIL RIPRAP 2D5o FREEBOARD TOP OF FOOTING AT OR BELOW EXTENDED RIPRAP BOTTOM OF SOIL RIPRAP LPSTREAM OF WALL CONCRETE OVERFLOW WALL (WALL AND REINFORCING DESIGNED BY ENGINEER) EMERGENCY SPILLWAY PROFILE AS NEEDED TO PASS THE IC0-"R UNDETAINED OR MORE 3" TO 4" EMERGENCY OVERFLOW WSEL 1' MIN TOPSOIL COVER FREEBOA3D CREST OF EMERGENCY SPILLWAY Z 2.5 SOIL RIPRAP 20yp EMERGENCY SPILLWAY SECTION AND SPILLWAY CHANNEL 35 30 - . - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 ac . . . . . . _ . . . - - . . . . . . - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e20 . .. . . . . .- . . . . . . - . . . - . . . . . . . . - . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . - --- . . . . . s TYPE H TYPE 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 g — . . . . . . - - - - - - - . . . . . . . . . . . . . . . . .. - . . . . . . . . . . . . . . . . 0 0 5 10 15 20 25 30 Unit Discharge(cfs/ft) Figure 12-21. Embankment protection details and rock sizing chart(adapted from Arapahoe County) September 2017 Urban Drainage and Flood Control District 12-33 Urban Storm Drainage Criteria Manual Volume 2 �3th J•R ENGINEERING 50 YEARS OF EXCELLENCE Appendix C. l ❑ 7200 South Alton Way ❑ 25188 Genesee Trail Road ❑ 5475 Tech Center Drive ❑ 2900 South College Avenue Suite C400 Suite 110 Suite 235 Suite 3D Centennial,CO 80112 Golden,CO 80401 Colorado Springs,CO 80919 Fort Collins,CO 80525 303-740-9393 9 Fax 303-921-7320 303-740-9393 9 Fax 303-921-7320 719-593-2593 9 Fax 303-921-7320 970-491-9888•Fax 303-921-7320 From: Theodore Bender <tbender@fcgov.com> Sent: Monday, May 1, 2023 5:11 PM To: Joey Frank;Andrew Joyce; Kenneth Merritt Cc: Heidi Hansen; Dan Mogen; Matt Simpson; Ken Sampley Subject: Polestar Variance Response Attachments: Downstream Structures.jpg Hello JR Team, Thank you for your patience as we work through this variance request. During our review, it came to our attention that the correct minimum freeboard requirement at the spillway may not be the "6-inches"that we had been discussing, but potentially 12-inches. This requirement is based on the need to provide 12-inches of freeboard from the (primary) 100- year WSEL to the top of embankment(please see Chapter 8, Section 3.4, 15Y bullet of the City 2018 Stormwater Criteria Manual). Typically, a detention pond overflow spillway is the secondary outlet with the primary outlet being a pipe at lower stage. The only outlet from the Scenic View Pond is the overflow spillway. This situation created the need for additional internal discussion and did slow down our response. We understand the Polestar development project would improve the Scenic View spillway and we have taken this into consideration. We'd like to emphasize that currently there are no residential structures located directly below this spillway. It is our understanding the Polestar development would like to place residential structures directly below (to the north and south)the primary Scenic View spillway. This has been the main driver in our internal discussion to maintain safety for the future residents of this site. The result of our internal discussion is that City staff has agreed the 12-inches of freeboard, above the overflow WSEL, will not be required. Instead,we like to ask these structure directly below the Scenic View spillway be elevated in relation to their adjacent BFE. Here is our response for the two detention ponds: Polestar Pond (Happy Heart/Eastern pond) The 6-inches of freeboard at this pond measured from the 100-yr WSE to the top of the pond embankment is approved. The main concern at this pond is that we not direct flow from the emergency spill towards any existing downstream structures. As we discussed in the past,we asked our master planning consultant to narrow up the conceptual design weir cross-section for this reason. The full master planned improvement at this location also includes an outlet pipe that would run beneath Orchard Place to the north. The proposed Polestar spillway weir dimensions are acceptable if the hydraulics show these existing downstream structures are not impacted. As a part of the hydraulics phase of the CLOMR, please focus on this area and provide a figure to show these downstream structures will not be impacted. An additional cross-section (or two) may be needed and appropriately placed to provide confidence in the floodplain and floodway width in this area. If the CLOMR hydraulics show the proposed Polestar spillway weir dimensions direct flow towards these existing downstream structures, we would ask that it be modified and remodeled. Thank you for including the stability and potential erosion to this spillway section in your analysis. From the CLOMR hydraulics study,we plan to review the flow depths and velocities in this area to make sure the proposed solution is able to protect the area from excessive erosion. Scenic Views Pond (Western pond) City staff discussed the freeboard at the Scenic View Pond in detail. I understand from your email last week you no longer wish to pursue a variance request at this location. Please send us a spillway cross-section similar the eastern pond to show the 100-yr WSE,freeboard, and associated elevations of the crest and berm. The 6-inches of freeboard suggested at this pond measured from the 100-yr WSE to the top of the pond embankment is 1 acceptable. As mentioned above, we would like to ask your team to provide 18-inches of freeboard from the highest adjacent BFE for the structures immediately east(downstream) of the Scenic View pond (image attached). This BFE would be developed by your team as a part of the upcoming hydraulics portion of the CLOMR. Because these structures will be placed downstream of the primary outlet to this pond,we feel this level of flood risk reduction is necessary. Our decision is grounded in public safety and the safety of the new residents downstream of this spillway. As with the eastern pond,thank you for including the stability and potential erosion to this weir section for the Scenic View Pond in your analysis. We will review this as well with the hydraulics portion of the CLOMR. Again,thank you for your patience. I know this timeline has not been ideal for your client. This is a complicated project in a high flood risk area. This project is more complicated than other CLOMR requests;this CLOMR proposal is to change both the hydrology and hydraulics for this site,while most CLOMRs only propose to change the hydraulics. Please reach out if you'd like to discuss. We are happy to chat further. -TRB Theodore R.Bender,PE,CFM Stormwater Engineering Manager Master Planning and Floodplain Management of Fart Collins 14ff�"I'e1Fd'�Ef 700 Wood Street Fort Collins, CO 80522-0580 (970) 221-6503 tbender@fcgov.com 2 �3th J•R ENGINEERING 50 YEARS OF EXCELLENCE Appendix D. l ❑ 7200 South Alton Way ❑ 25188 Genesee Trail Road ❑ 5475 Tech Center Drive ❑ 2900 South College Avenue Suite C400 Suite 110 Suite 235 Suite 3D Centennial,CO 80112 Golden,CO 80401 Colorado Springs,CO 80919 Fort Collins,CO 80525 303-740-9393 9 Fax 303-921-7320 303-740-9393 9 Fax 303-921-7320 719-593-2593 9 Fax 303-921-7320 970-491-9888•Fax 303-921-7320 July 26,2023 Polestar Gardens,Inc 850 S Overland Trail,#15 Fort Collins,CO RE. Letter of Intent for casements for rateni on pond anpruvtown"tzsr Final easement documents will be reviewed by an attorney for Saddle Ridge commory Cor;drmfr': Association. Dear Development Review Coordinator: The Saddle Ridge Commons Condominium Association is the owner of Tract A that abuts' Village Property.We understand that as part of the Polestar Gardens development project,e.eE (Polestar Gardens)will be required to make Improvements to the existing retention pond.:tde f5ac: Ridge Commons)agree to work with Polestar to obtain the needed easements for these tmproverner`4 pending approval from the Association's attorney. Sincerely, The Board of directors Saddle Ridge Commons Condominium Association Signature -- 'c Date 23 APPENDIX F - MAPS \ I I I BASIN SUMMARY TABLE w wLLJ z ? � � �J ( I I Tributary Area Percent tz tioo Qz Qloo = > c� z u' /I \ \ \ I J I P ) I � I(� � - -ten \ r LU� � � � w � m � ( I I ( ) I .� Sub-basin (acres) Impervious Cz Cioo min min cfs cfs ci o J/ ORCHARDPL = � m � � � 1o � o � _ I 17W v � 1� ( JAI h �� / \ �� r�� I I ! 1 (�� l ) ( I = = o L / ) / \�� -� / ( I I/ Ip Al 1.02 16% 0.17 0.21 11.0 11.0 0.4 0.8 I jm � Qm, (nLU ,1jm � N - ` LOCUST GROVE ; 11 \\� ) I I l l I I I t f\ l 1 `_ - - 7 \ TH/RD F/L/NG / I \ - ( I / l I\ / ( I I) �/ / /r�/�(( A2 0.60 50% 0.49 0.49 8.0 6.0 0.7 1.2 J Ld 0 m0 U 0 o 7- 0 _ / /- (nmmzm >- ( = ° AOy - / \ I / "` -` � - / I / IIIC /" f` / / I ) / o / \� A3 0.78 25% � wmmwm � 6 � 77 .11 �, 0.24 0.24 8.0 6.0 0.5 0.8 I z = mO_ 0CLZwz I `\ I I 1 / ( \ I / I _ J / / I ` A4 1.23 65% 0.63 0.63 8.0 6.0 1.9 3.2 \ I - - ° \ ( / 1 0 -� '\ 1 1\ / /n A5 Q.42 57/0 0.57 0.57 8.0 6.0 0.6 1.0 w I�l - - - - 5120 = - - /I \ 1 J Iv/ I / Z \ I // \ / �\ - ' / I �� � ��/ \ o g I 11. � �i X \I11 \1 1 �, \ // - - - .)/�/ J 1 / I \ ��� / �\ � -'T ���"I / / \\ _ A6 1.03 69% 0.67 0.67 8.0 6.0 1.7 2.8 > PLUM ST v N I 99 II -- 1 - - �I \ _k / c I� I \ _ - - - ' �' 0 -) I n z Ln ( 1 00 1 r:/ ,z W I ` I 1 / / <\ 1 A7 0.85 63% 0.60 0.60 8.0 6.0 1.2 2.1 CD \ I _ 2 '3 4 I 2 r � � - � ' I \ I \ (� 1 \ / 1 IJI ( � � ° tk (nN000O Z+ d�° I Q I ) / \ J / \ I - - / /\ / 1 A 8 U.58 84/0 0.81 0.81 8.0 6.0 1.1 1.9 /� I D-' 0O Ln 511$� I �\-1 I ti / / \\\� _-�vl// ) / \ / / / C / \ A9.1 0.16 84% 0.85 0.85 8.0 6.0 0.3 0.6 I O� w LC� O 0) r G - - -- 5115 A9.2 0.03 54% 1.08 1.08 8.0 6.0 0.1 0.1 N I� L/I - -- - - S - - - - S -- 1.06%_ - - - Ld ---_ - - - _ _ '-��_ _ - - - A10 0.09 85% 0.86 0.86 11.0 11.0 0.2 0.3 ELIZ BE B- T Q X z I I _ W. ORCHARD PL 1.70� - _ _ I I \ All 0.13 69% 0.68 0.68 11.0 11.0 0.2 0.3 J J i o it CD -- m - - - Al2 0.26 34% 0.32 0.32 11.0 11.0 0.2 0.3 - - - - m = - _= / KEY MAP cn 00 _ - - --- - c s TT��„ ` - - - -- - - - - - - `� \ 00 / - ` __ - - - - - 1 A13 0.40 61°% 0.63 0.63 11.0 11.0 0.5 0.9 SCALE: NTS J 3 4 4 - \�- 1 \ I A0 1 ( -\ r) I A14 0.09 21°i° 0.21 o.z1 11.0 11.0 0.0 0.1 0 o 0.T T-r II � L 414 l / o ° TTTI- h I I 1®0 6 8 9 , l I \ 1 / I . // ) \ 1\ A15 0.49 24/0 0.22 0.22 11.0 11.0 0.2 0.4 to �5115 A16 0.13 46°% 0.43 0.43 11.0 11.0 0.1 0.2 LEGEND A 17 0.43 30°% 0.29 0.29 11.0 11.0 0.3 0.5 / 1 • 1 - J \ r o - -6100 EXISTING MAJOR CONTOUR c� 313 � I �5110 M 5110 _ 1X ___ �{ .� \ \ ) \ \ /) \ \ 1 \ A18 0.70 47% 0.45 0.45 11.0 11.0 0.7 1.2 \ I I A19 0.35 52% 0.49 0.49 8.0 6.0 0.4 0.7 = - - - - - EXISTING INTERMEDIATE CONTOUR SCENIC V12 �5105 � � \ �1 OOYR �\ � ` J � \ \ POND 1.23 50% 0.49 U. 11.0 11.0 1.3 2.2 `• s. ', _ _ 1 - , / I I ° •610� PROPOSED MAJOR CONTOUR � � 1 � S1 \ \ \ ( I ( 1 I B2 0.31 78/0 0.75 0.75 11.0 6.0 0.5 0.9 !'•° ° ' "���` os� 23 � :� I / y \ \ I ) I (./ ° PROPOSED INTERMEDIATE CONTOUR �.�' CI 0.28 47% 0.48 0.48 5.0 5.0 0.4 0.7 EE SHEET 28/ \\ \=r) \ ( ) I ° OO EXISTING STORM SEWER/RCP C2 0.32 31% 0.30 0.30 10.0 10.0 0.2 0.4 31% POLESTA DETENTION PON '\\ / 111 \ \,��`I \ . - - - D1 0.35 64°% 0.61 0.61 10.0 10.0 U.5 0.8 • PROPOSED STORM SEWER/RCP o '" \ 1 J - F� oh / ) / o �, v \) \// \ D2 0.22 63% 0.60 0.60 11.0 11.0 0.3 0.5 CL U I 0 11 2 I 5 7 i TE r \�� I Q I / // 1 / �-- D3 0.16 70% 0.67 0.67 10.0 9.0 0.2 0.4 PROPOSED SWALE U _ T ACT B ;- /�' ) ° � _�y /) ( / \ I D4 0.25 61°% 0.58 0.58 10.0 10.0 0.3 0.5 A BASIN ID chi - \ A: BASIN DESIGNATION r 1 o � o J \ ` I D5 0.29 67% 0.65 0.65 11.0 8.0 0.4 0.7 ayi c� ,^ 1 2 _ /� l ► (� J 1 \ II / I D6 0.28 60°% 0.57 0.57 12.0 11.0 0.3 0.6 B C B: %RIMPER IOUS / II J ) / ) I / 1, 1 D7 0.11 85% 0.83 0.83 10.0 5.0 0.2 0.3 c� l l 0.87 0.87 8.0 5.0 0.4 0.7 75 - II DRAINAGE DISCHARGE � o E1 2.24 41°% 0.65 0.65 14.0 14.0 2.8 4.8 1 DESIGN POINT J� c \ (\ 1 ( / I ! E2 0.54 54% 0.62 0.62 12.0 12.0 0.7 1.2 \ 4 �s � II l\/ ` \ � PROPOSED FLOW DIRECTION 17q 3 \ 21 51p5 \ ) \ 1 " '��0 \ E3 0.31 59°% 0.74 0.74 11.0 11.0 0.5 0.8 I 1. 11 1,92 31% 0,11 0,11 13.0 13.0 2.6 4.4 BASIN DRAINAGE AREA OS 1 0.61 15°% 0.14 0.14 11.0 11.0 0.2 0.3 \% 3 - rC I ,� �`^ I ( I\ � 1 OS2 0.09 51°% 0.49 0.49 11.0 11.0 0.1 0.2 Ld n 1 I J I lr # POND / Design Point Table 0 � Tributary Qz Q100 p DP (cfs) (ifs) NOTES: SITE IS GREATER THAN 20 ACRES. 1.1 1.0 4.3 T 1 I I f \ THE RATIONAL METHOD HAS BEEN USED TO 4 I Q I ) I `J I I ) \ I I / 1 1.2 2.5 10.8 SIZE INDIVIDUAL STORM PIPES AND DRAINS. 1.3 2.9 12.5 I _ v \ ( REFER TO SWMM MAPS PROVIDED IN ' - - - - 1.4 3.4 14.4 APPENDIX E OF THE DRAINAGE REPORT FOR \ L ADDITIONAL INFORMATION ON INFLOWS IN AND W. P M ST= y ---� \ ` , 1.5 6.9 30.0 OUT OF SITE AND INFORMATION REGARDING \ �5 ,� W PLUM ST / / OFFSITE BASINS AND HISTORIC BASINS. \ / \ '� '� � C r 1.6 7.2 31.1 \ � \ - - / y / Z� y\s o\ s / - - _s11 - \ I / 0 2.1 1.8 7.8 3.1 1.1 4.6 NOTES 4.1 1.0 4.2 4.2 1.6 7.2 THIS PROPERTY IS LOCATED WITHIN A CITY REGULATED 100-YEAR CANAL o 1 I li I \ I / IMPORTATION FLOODPLAIN AND FLOODWAY AND MUST COMPLY WITH t I l \ �,\ / A a / �J 1 i ( ( o \- - \ 4.3 1.8 8.1 CHAPTER 10 OF THE CITY MUNICIPAL CODE. 0 \ RESIDENTIAL USES IN THE 100-YEAR FLOODPLAIN MUST BE ELEVATED cn - - 5.1 11.9 30.3 ABOVE THE REGULATORY FLOOD PROTECTION ELEVATION. RESIDENTIAL USES w EET 29� , J, J I� e \ 5.2 11.9 73.0 ARE PROHIBITED WITHIN THE FLOODWAY. W m I t ) A FLOODPLAIN USE PERMIT IS REQUIRED FOR ANY WORK WITHIN THE \` \ o ✓ - / \ r, 10a 0.2 0.9 100-YEAR FLOODPLAIN. A NO-RISE CERTIFICATION IS REQUIRED FOR ANY �.TR /�1� I I I I I \ -� J / I /\ WORK WITHIN THE FLOODWAY. z \ \ \ 36 I \ I / \ I �) J / 1 11a 0.2 1.1 • CRITICAL FACILITIES ARE PROHIBITED WITHIN THE 100-YEAR FLOODPLAIN. (51 ) I i^�� r/ \ \ I \ 12a 1.2 4.9 THE APPLICANT IS AWARE THAT THE CURRENT PLAN DOES NOT MEET N \ 1/ I / / REGULATORY FLOODPLAIN REQUIREMENTS AS PROPOSED AND IS CONTINUING 0 Q\AI \ ' J (� 1 I I I ,� \ I 13a 0.6 3.1 THROUGH THE PLANNING PROCESS AT THE APPLICANT'S OWN RISK. II \ N Q Q o I BUILDING AND CONSTRUCTION PERMITS FOR STRUCTURES NOT MEETING z \ 4 a f 9 ` (- l 1 ` \ ` �I✓ r J G l I I/ 14a 0.8 3.4 FLOODPLAIN REQUIREMENTS WILL BE HELD UP IF THE LOMR IS NOT (0 REGULATORY. 15a 0.8 3.3 >-• >- 1 \� (-' �\ I I THE INTERIM POND OUTFALL IS PRIVATE AND WILL REQUIRE AN EASEMENT w w m m ° 16a 0.9 3.8 FROM ADJACENT PROPERTY OWNERS. J J w o m o // \ j - \ \•`S�\ ' `5 * .01 I \ ( I / \ \\ l/ \ 17a 1.2 5.4 o 0 < Y \ Q � w z w /i✓ I \ \ / o ? \ _ N - - - ^� \ _ `� I F- \� 1 / 18a 1.0 4.5 = > w o I Ld �� -._� s ✓ �� C� �� -� - ,/ - _ _\ \ _ � \ \ \ \ / 19a o.4 2.0 0 p4 S �\ •___ - �\ \ / \ / 1b 1.3 5.6 1d 0.5 2.1 \ / - --� '' � _ �\ I� _ I \ 1e 11.8 70.6 2a 3.3 15.6 W LL 1 2b 0.5 2.8 CD z 2c 0.2 0.9 Q Q 2d 0.7 3.2 i 2e 11.9 73.0 ! - �I p / 3a 2.8 13.3 Ld (r\ ,, � 5118 � II \ \ ) \ I / I 3d 1.0 4.2 � � C� � i Q Q 3e 0.1 1.7 80 40 0 80 160 � z 4a 2.5 12.0 �' - / T \\ I - -- _ JJ o JI �l 4d 0.7 3.2 ORIGINAL SCALE: 1 = 80 Know what's below. J MINEMINE5a 0.6 2.8 Call before you dig. O o - _ 5d 0.4 2.0 J - - W ELIZASETH ST - _ _ ` -\ CL / _ i- i i' /'r �� - J / - - � - = 6a 4.4 20.9 _ _ _ _ _ _ ,�==L J _ - _ _ _ / _ 6d 0.3 1.5 ENGINEERS STATEMENT � -1 � - - � \` \ �\j � �- - - -\� , 7a 1.0 4.4 PREPARED np p JR - - � o - � �� \ \ 7d 0.2 1.1 ENGINEERI LP R�L��IJ�/IJ � ( ( > \ I ) I 8a 1.1 5.8 �n n� 3399 8d 0.6 3.0 �LJ\"J�� ��W 0.4 UCIVODA SHEET 27 OF 689.1A DAT� ' COLORADO P.E.9.2a 2.7 11.7 E� FOR AND ON BEHALF OF JR ENGINEERING, LLC /ONAL JOB No. 39797.01 CJ 1 I \ 1\ I\ \ \ 1 �1 I NOTES: 77— Luz w SITE IS GREATER THAN 20 ACRES. w z w w 10. \ I / \ 1 - - - 1 / THE RATIONAL METHOD HAS BEEN USED TO = > 0 z � ^�° SIZE INDIVIDUAL STORM PIPES AND DRAINS. ~ m w w w z �� - / ♦ ' IN 1 7 W , ' I 1 // I II I h \ APPENDIXREFER O EWOFMTHEP DRAINAGE FOR ORCHARD PL = Q Q Cr- = = o 0 0 0 _ cn w ADDITIONAL INFORMATION ON INFLOWS IN AND I o w m w w p N OUT OF SITE AND INFORMATION REGARDING > w - > w m J o00o zo 1 ( - OS1 I w (,� \ i \ _ \ / ( / I OFFSITE BASINS AND HISTORIC BASINS. 0 m m z m >- 0 = ♦ I T I/ I � � I \ -- � I I / I I I 1 � � wmmwm � � � LOCUS GROVE I \ / i IBM z = mmc� mzwz � ' _ _ / ♦ ► �/ , J _ l ♦ THIRD FIL ING - 7Q ♦ 1 /I III �i - - NOTES � I �� MB LU > PLUM ST THIS PROPERTY IS LOCATED WITHIN A CITY REGULATED 100-YEAR CANAL Z N \5120. , ♦ / I / ( I 11 ) - - ' / 1 I I / / I IMPORTATION FLOODPLAIN AND FLOODWAY AND MUST COMPLY WITH O OS2 I a C I ( ( CHAPTER 10 OF THE CITY MUNICIPAL CODE. �/ Uj N 00 Q0 / I RESIDENTIAL USES IN THE 100-YEAR FLOODPLAIN MUST BE ELEVATED I O z Ln� � � I L � 0.0951% \ \ ( ( \ o ABOVE THE REGULATORY FLOOD PROTECTION ELEVATION. RESIDENTIAL USES I LL_ W 0 —_ - X fU 5120 L - - I \ I I r \ � 11 ( ( ' /� \ ARE PROHIBITED WITHIN THE FLOODWAY. 0 � I� - \ A FLOODPLAIN USE PERMIT IS REQUIRED FOR ANY WORK WITHIN THE w ^ 100-YEAR FLOODPLAIN. A NO-RISE CERTIFICATION IS REQUIRED FOR ANY U�' X z I I I 29 /I{ ll I III 1 \ \ _ - - - - _ - - _ // / ,{ WORK WITHIN THE FLOODWAY. - ELIZABETH ST 0 J ^ I I r _ _ - - - - _ / I I ` I CRITICAL FACILITIES ARE PROHIBITED WITHIN THE 100 YEAR FLOODPLAIN. w m , j I THE APPLICANT IS AWARE THAT THE CURRENT PLAN DOES NOT MEET Q 0 00 i 'n / I REGULATORY FLOODPLAIN REQUIREMENTS AS PROPOSED AND IS CONTINUING KEY MAP 0 00 El �II Z �� I 1 / THROUGH THE PLANNING PROCESS AT THE APPLICANT'S OWN RISK. scn�E: NTs W X 2 3 4 �5 0 / f W 8 - = I� - / / v ! 1 \ I BUILDING AND CONSTRUCTION PERMITS FOR STRUCTURES NOT MEETING J I I 24 41% I / I ` ,/ _- II III �. \ I I FLOODPLAIN REQUIREMENTS WILL BE HELD UP IF THE LOMR IS NOT 0 0 G I \ -- (r� i III I I REGULATORY. �• 1 III i III I THE INTERIM POND OUTFALL IS PRIVATE AND WILL REQUIRE AN EASEMENT 11 I I 0 I �\ �� FROM ADJACENT PROPERTY OWNERS. II I _ _ 5115 i ul� \ LEGEND — I I — L - - - - -- - - - -5115- -�� - - - - - - - —T� - - �/ \ �� _ // r� 93 II 1� _ 6100 EXISTING MAJOR CONTOUR V _ _ __ - - -_ - _ _-�- - _ EXISTING INTERMEDIATE CONTOUR Anx _ ° °° s1 c� _ �100 PROPOSED MAJOR CONTOUR � s' - - - - S - - -- S -- - S - - - - - w -► • 1 ___ _ =_ - - - - -- - W ` - - - S - 70%- -- - - - S - - - - - S `� PROPOSED INTERMEDIATE CONTOUR S - S --_______�\ — - - — - - - - - - - — — - - - - - - .$R�##ARD-RL -� +l �fEL -- - S - - - - - - - - Q HARD- -I -- - - = -� -, -� � -7, � �:! EXISTING STORM SEWER/RCP 0 r + 5109.003e vM - - -�` - ----- T PROPOSED STORM SEWER/RCP c o - - - - - - - - - ► U - - - - Y. - - - - - X - - - - - L- - - x _, — X — - x� .. - - - - - 169. o • - - - - - _ - - - - - - PROPOSED SWALE c _ 0.31 59% o� BASIN ID Acn I� 0.5454% 5.1 A: BASIN DESIGNATION !�'l ) i -� Y �� O I I 4 1 O 4 0o I B C B: AREA (AC) �1 \ ` I I ( I C: % IMPERVIOUS m rn h T Jl 2 I I 1 . . . I I t I o75 2 3 / I 4 I OUTL T I I 5 6 I Q DRAINAGE DISCHARGE a U L I 8 I \ � � o I O I DESIGN POINT a) o G I � I I 9 � � \ 1 c� � o � 5��5 D I I L �0 I �► PROPOSED FLOW DIRECTION I �p _ 70 I - - O OVERFLOW SWALE W/ TYPE o \ C NLET I BASIN DRAINAGE AREA I I — - � I- - - - — - - - - - �- - - ��= - - -- - 100YR g — - - - - - - - - - - - - - - - - � I I / w I Yf� 5110 !: • ,. F1 I I # POND i 5110 I ' ----------- ----- ---- ---__-. _ ----°-- 3.9231% ---- -------♦ 000 I I I I — e TRACT A, THE SECOND REPLA T OF SCENIC I' % I% I 5 \ I O VIEWS, P.a D. REC. NO. 98027263 l I 1 � SCENIC VIEWS POND T �, .T 16 11 .98 FOREBAY / ENERGY p DISSIPATION STRUCTURE ^� I I I 1 81 S7 S 0 I �, �' If � ! I Al I I ;~ . / o WY I V \ 1 1.02 16% I :.:�...:�: • ,• I \ \ EMERGENCY OVERFLOW -_ 1 �'�� �, ' y \ i I I \ \ 36.8 FT SPILLWAY t - - - - - ELEVATION 5107.79 ° � 0 I yS` EFFECTIVE FLOODWAY BOUNDARY �( \\ 100YR_ \ ul - - GI N I.� I I \ �C�fQ' HEADWALL I DRAINAGE CHANNEL i � I � � I I \ o \ I 3 10 11 12 13 /14 15 6 17 18 WATER QUALITY PROVIDED F E 1 I I 0 \ / 3 5 6 7 8 I 0.12 ACRE-FT I \ I I \ l I j J I ,1— �.0 L \ i o ( 100 YEAR VOLUME PROVIDED 9.44 ACRE-FT I _ \ \ I I I I \ I� Ld mm NEW ME ENELI li \ i 1 / 100 YR-WSELV 5108.89L— ' \ 1 J 100 YEAR VOLUME REQUIRED - �s I \ \ \ 4.88 ACRE-FT q - z: � - d d FL 182% -- _ -- Bl \ I O N 1.23 0% \ L � / \ Q _ J y "z ° F I w l l z " Q Q - _ - - - - ) EFFECTIVE 100 YEAR FLOODPLAIN O In m MELE LANE — }g0 `� J bi J m L — HOKU LANE \ _ — — ,, moo \ \ 6 a z Y o� - 5120 /Aor - - — \ - — — 1 �\ S104 _ > o w o Ld = 2 L R \ Gy I , M ,�I � ' , , 1 ■�"� \ 1 s-4. 20 , , 21 2_ , 5AO5 NL 2.17% 1 100 -- Ld 1 1 I \v1.03% - 1 I I I I �� - �� ; .- 40 20 0 40 80 LiJ Know what s below. C� i � •� � I of --�- ,I 4d 24 I I rnl C1 O D8 Call before you dig. ORIGINAL SCALE: 1 = 0 Q Q - \ 15 \\ \ � � `\ � � � 2 I \�O I �nl o.2s 7% � � Ld Q � 3„ 3 \ 1 5 I I II i J - a 28 I I I 'I --- I O 0 ' 62 k I w CL 0.31 8% 5 % � - - - ENGINEER'S STATEMENT p 1.23 m \ N 3 2 \`\ F ` I 29► ; , I IP. IL m I PREPARED p o JR � \\ �\ '•. � � �\ \ \ A7 � � � I P' . o .,d I -- ENGINEERI 20 \ �� \ \ 0.85 3% \ 3 , 7 O O In 3399 D7 �,° ., o SHEET 28 OF 68 EllJOSEPH MA 0 IN12 7 U� oO l .•• DATA-- COLORADO P.E. S SEE SHEET 29 FOR AND ON BEHALF OF JR ENGINEERING, LLC /ONA� JOB No. 39797.01 SEE SHEET 28 17 7 7- _m7 OE LUZ o Q w Of LLJ k_j D Li 1 I \ N1.03% / { � /� \ ORCHARDPL ~ >_ ORCHARD 1 LJ I _ I � � w LU I � > ZDQ � 1pp _j� zo MMwM0 � o� I zzmm0mzw =) O D < < < 00 < \ V 15 3 7 I I 3 w I �� ON \ 1 <\\\\ \\\ I 1 I•. \�13 v ) � I PLUMJI CDA4 B2 N 00 I 28' 5 % E zN � I I o � N (n 20 \ \ , 0.85 3% \ \ I 3 - 7 \ \ - ELIZABE E- T Q O J I I � _ � � \ l IZ 0:� m _ � VA \ \ • ' T '� I / I KEY MAP L0 CL 00 TRACT B \) SCALE: NTS J � � \ \ t I I \ 4 36 I II 0 o O 24 a" � • qg I� I � C2 I 4 � LL \ v I I � 125 N I _ _ LEGEND _ / _ _ EXISTING MAJOR CONTOUR o.2s o% � V A \ �� 6 9'L� y \ �� �� W PMU S'T �\ --- - - - - EXISTING INTERMEDIATE CONTOUR 2 \ / T , -�-� W. PLUM STD- �� G o- - - - - S I ) $100 PROPOSED MAJOR CONTOUR hs W / PROPOSED INTERMEDIATE CONTOUR _ _ /\\ \X� \ \� I / / / /p„ 5 , - - - - 0EXISTING STORM SEWER/RCP _ - - -511 - -- H - lot PROPOSED STORM SEWER/RCP V occ V -2 / / / 0.58 4% I - - 5 - - _ ■ Q„ \ PROPOSED SWALE C U 0.03 4% I I \ I I l ,� BASIN ID m l 9 0/ / I I I D4 A: BASIN DESIGNATION B C B: AREA AC • c F,� 110.2561% a C: % IMPERVIOUS ¢ c� ° I ° rn DRAINAGE DISCHARGE 38 - - - - - N _ �,� DESIGN POINT ° I I I 3 \ \ @• J q I 41 PROPOSED FLOW DIRECTION All �� I I BASIN DRAINAGE AREA 0.16 0% - - - 8 0.43 0% POND w 1 #_ O A10 / I > I E Cl 117 \ TR A*t A 43 = m m \V \ 36 �' ' m I m \ LOT 1, BLOCK 1, \\V \ \ • , / ► > I \ II NOTES: v THE SECOND REPLA T OF SCENIC VIEWS, P.U.D. REC. NO. 98027263 \V A " ' .81 Al3 I -I ° ° _ I \ SITE IS GREATER THAN 20 ACRES. u \ \ \ 0 3 �® 0.4061% Al2 ' ' `,�`°� - - I•� \ THE RATIONAL METHOD HAS BEEN USED TO \ / �\ � \ \ �� 0.26 4% c3` - D2 SIZE INDIVIDUAL STORM PIPES AND DRAINS. �\\ \ \ REFER TO SWMM MAPS PROVIDED IN \ ro/ II \ �- APPENDIX E OF THE DRAINAGE REPORT FOR \ \ \ + I /p� 45 I I \ ADDITIONAL INFORMATION ON INFLOWS IN AND OUT OF SITE AND INFORMATION REGARDING OFFSITE BASINS AND HISTORIC BASINS. \ � \ 15115� 100II MOUNTA/RE SUBD/l//S/ON 00 D1 \ BOOK M, PAGE 54 NOTES Al 0.35 4% I I I 1 ) THIS PROPERTY IS LOCATED WITHIN A CITY REGULATED 100-YEAR CANAL —Eli �7 I \ - - IMPORTATION FLOODPLAIN AND FLOODWAY AND MUST COMPLY WITH � - � CHAPTER 10 OF THE CITY MUNICIPAL CODE. S 4 0.12 6% ! >� 201% I " \ RESIDENTIAL USES IN THE 100-YEAR FLOODPLAIN MUST BE ELEVATED 7 . ? o I _ -- \ ABOVE THE REGULATORY FLOOD PROTECTION ELEVATION. RESIDENTIAL USES 9 -- ' \ 1 ARE PROHIBITED WITHIN THE FLOODWAY. s� \� A15 N \_ \ �' A FLOODPLAIN USE PERMIT IS REQUIRED FOR ANY WORK WITHIN THE zd d 0.4s 4% \ J \ - _ ` _ 100-YEAR FLOODPLAIN. A NO-RISE CERTIFICATION IS REQUIRED FOR ANY WORK WITHIN THE FLOODWAY. N \ _ _ - 1 ` 4.6 - - , - - -� /y S>> . CRITICAL FACILITIES ARE PROHIBITED WITHIN THE 100-YEAR FLOODPLAIN. U Q \ I IIII fi— I I I 11 \ T 0 A19 a S - - • THE APPLICANT IS AWARE THAT THE CURRENT PLAN DOES NOT MEET \ N cy cl:� TROY 0CHELTREE & SONNY I o __ 1 REGULATORY FLOODPLAIN REQUIREMENTS AS PROPOSED AND IS CONTINUING 11 Z Q Q OCHEL TREE 6' i 0.35 2% \ - \� ) 3z �- / THROUGH THE PLANNING PROCESS AT THE APPLICANT'S OWN RISK. � RECO.UIT C20210059013 M DEED \� L -� �- s \ 5115 F 11 // - - �I BUILDING AND CONSTRUCTION PERMITS FOR STRUCTURES NOT MEETING O FLOODPLAIN REQUIREMENTS WILL BE HELD UP IF THE LOMR IS NOT >- �> REGULATORY. J J m p>p m THE INTERIM POND OUTFALL IS PRIVATE AND WILL REQUIRE AN EASEMENT Q Q � o z o FROM ADJACENT PROPERTY OWNERS. U) ( o < Y Q U AARON/ STERN/ 1 \ I = > Ld _✓055a YN FAM/L w Y TRUST C�� \ - - o QUIT CLAIM DEED / .� \_� \ \ - - -- - - \ �^ \ L o U RE-C. NO. 202001101925117 J� 51181 ,� \ ecw / 1 ✓ABED ROSS \\ \ 0 �j 1 I w WARRANTY DEED REC. NO. 20210070204 J 19 ��� a_\ " 51 IX � , � , �� _ -, i � � L,� 0 � � � � �. �� / 1 , Q Q 51 8 1 40 20 0 40 80 Z_ ) / 1 I ► �/l� l�,I I \ ,� — _ / Il ,,11 /\� I �l> >II �� _ IIr�J I I��vI � _ _ / / I � 1 ' Know what's be OW. Q i c E\_ ORIGINAL SCALE: 1 = 40\J Cal I before you dig. —jp ENGINEER'S STATEMENT 77- PREPARED n�IE n nn �(� �/J •�FPI�� JR ENGINEERI LP RD L� 11V11 L1V LMA LN L1 X\••a I\ O 7 IF(a W 3399 ; JOSEPH MA C�O ]27G�MC�U�Ol SHEET 29 OF 68 .• DATA•'• COLORADO P.E. ONAL FOR AND ON BEHALF OF JR ENGINEERING, LLC JOB No. 39797.01 LLJ w = » -) �O \ - � r / � J I I II / 1 � I / \ �' / ` ww z —t �o �� %� �—/ �/ X v I \� / y ICI ► Ih \ \ - - - - - / I 1 I \ _ -§ °° o ORCHARD PL w — 4.00 , — - - - / I I / / \ \ � / I " ao < cn wQ � o o �I III �I \ I!II \ I I f/ /� \\ —\:� i�'/ ��/ \ 1 ~ � � < < < < 00a W 1 r �\ I \ / \ 1 Ifl— ZN -1.06% -_ -- - - S - - - - S - - - - - - - S - - - - - - - -- - - - - -� _ _� pop c9 36 FUTURE RCP - - - - I W. ORCHARD PIL _ _� - ---�------ ==S- T S -Cs} -� S -`�-- - - S� ©� � �\\ z pNp Ln Ld - - - -51—r —r —- \ I — — — — — — 1Q — o \ \ ELIZABETH ST Q O J I I \/l� I I O I I \ / - \ \ Ld Q m r TT I ��5 I\1-1I�I1II III I __ - - - II \/i _ ^ ✓ a (\ � II ~ O 00 �_ -rT OUKEY MAP J CD �o02 3 4 OUTLO 5 6 7 9 1/ / SCALE: I ( I TRACT A, o I �r THE SECOND REPLA T OF 55 LEGEND OO�I - - - - - - - - ACCESS R 100 100 YEAR WSELVL SCENIC MEWS, PUD. 0- LL REC NO 98027263 .\ \\\ \ I I o I o � � o� ACCESS ROAD - o I - � I�- \ 1 / o �? II 1 I I \I \ \ SADDLE RIDGE COMMONS 6100 EXISTING MAJOR CONTOUR V \ \ / CONDOMINIUM ASSOCIATION 7 I I I _ o ' _ QUIT CLAIM DEED I L� I j I I 5105 °O r �I �i'\ \ EXISTING INTERMEDIATE CONTOUR r� / I REC. NO. 20020075>5 I I I I I '�'� o0 0 0 °o g o ° 30 RCP \ \\\U \ \ \\ \ 1� �\\ \ � , ' � \ II (_�11 I •••�:.:;i'.�•�"-.�::': :• aOC / o0 / 0 0 I LOCATION 1A 5100 FUTURE OUTFALL I " -- 100 PROPOSED MAJOR CONTOUR NI TACT: A > INVERT 5098 \ / PROPOSED INTERMEDIATE CONTOUR 510o I � � — — ' F= LO cr EXISTING STORM SEWER RCP O \ / PROPOSED STORM SEWER/RCP PROPOSED SWALE l / Io\� OND n \ cc �\\\ SCENIC / =\ PROPOSED FLOW DIRECTION 'n 36.8 T SPILLWAY J ELEVATION 5107.79 � BASIN DRAINAGE AREA / I 1 L( 3\ 5 6 7 8 0 11 1213 1 TE II II "y UM� � I - -\ • C POND `CD rn \ \ ! I I o v 75 I \\\ PROVIDED VOLUME: 13.45 ACRE-FT \ f 'I REGIONAL DETENTION � / � � I I , a U_ _ -- _ � _ - FT / � •� \II \ I // I // (� \\ \✓\ \\ \ \\\ 100 YR WSEL 5107.14 DETENTION FROM THE JACOBS 1/2022 I / CONCEPTUAL DESIGN PLAN FOR THE I I ) l \ \ I CANAL IMPORTATION BASIN 8.3 ACRE-FT I I 9 1,0 I I 11 12 \ \ I 1119 4 I I 21 2 I DETENTION REQUIRED FOR THE POLESTAR \ I \ I \ \\ \ \ \ \ I I I. " \ / I ONSITE IMPROVEMENTS 4.88 ACRE-FT 1 w TOTAL REQUIRED VOLUME 13.18 ACRE-FT h ( \ o TR CT B — �- k \ \ 5110 \ l _ I m V 33 I \ 34 I 1_ II J,/ c 8 ` o I I I _ G rE ` —— 17 I II I TR I s f I I I I � , CT B I I \\ \\ 4 — - - � w PLUrtST W PLUM ST J J Z 3-7I I I A \ I I \ Q N Q a \ \ \\ \ ii ��\ �/ / \ \ \ , 00 ✓ I� /� a1 I I II / III f\` 110 - - - I r I ► r m m 3 3 I I I I v m A \ b\ w w z w ` vv v y v\ �v` vvv — ✓ , E �` ► I Q z Q F- IVNV \ \ / I / w o z 0 D A T OF \\ \ I i \ EC<\O. 9802 ACT A 43 I � — \ SCENIC /E�OR \ 36 w I I / W 0 I! 45 I I % I 11 —I . \ l L CL 1 \ Q W Ld \ / Q 48 _ � I � 177— LL-J — � D L ITT-7-r- I I W ' SHEET OF 1 1 \\/ r \ `� _ � / 60 30 0 60 120 Know what's below. — I IJ7 ,F L T T \ / _ � �_ Cal l before you di JOB No. 39797.01 -tt _ L \ \ �� 4R8�' 6�CHELTREE & \/ l \ I \ \ �\ - / / / \ / ORIGINAL SCALE. 1 = 60 y g 24 APPENDIX G -LID EXHIBIT ��/ - 7 THIRD /LING I w ��I /J \ � �� - I I I I ( �\ r I 1 - � /' z � LLJ Nw c 5120 1 / ti Ir�/ I ✓ - - - c \� 1 w w ot- / �J I \\ 1 � aQw � w � o_ t— ^� -- 77 1 \ \ I I 1 o I wc ) L_ LUZ UNTREATED AREA I 1 I � I \ \ r r � Z � � w — LLJ m I III \ \ y I / / I \ ORCHARD PL m w o- _ = 0 / P IJ I cWilw > oQGE 1_ - z ,x _ .. ,W I Z /� 1 / \ / / i \ 77ITF, ooUo `` zo \' - 2 3 4 5 6 / W - 2 . 4T � , II \ / � I � wo_ o_ wo_ � cnt— ,�, / • P� I I ^ 1 "'�-- --- - - I � oI �`�1 D F I � � I=- aQaQooa \,\ qD � >• !'I 1 -- - - — — - - - - 5--� _ 511 — `� W co � \ hx I / __ - _ -PLUM ST V N _ _ ° �Z10 - - / ZLn CAP' — — _ - - -- - S W — S - - — S =_ — =S=1.06% S — - - - SW.- P- -.-HAR S — �,1.70%, --► ^��� -—�=_ � — _ -+� � pip cD \��P ' — — — — - - - — — -0o.- � s - - — s —o--� s tee- - -- s�—� I � 00 Ln — — — w — I — �; - '� �► I O Z Ln O W. ORCHARD PL 510.0 / o 0 � ------- — — — — — — — — — E � I I I --- - - - - - - - - - i - �w Q N I I 0.s, s _ %Q ELIZABETHST X z I / - _ 4 4 \J \ w Q LO °° 000 1 / / 1_1 1 —1T_ /TT � CD \ I I I �[��� f �- r-r--rr-w r '�i-- r �� o�� 1 2 I I 1 2 3 / 4 OUTLOT A 5 �6 7/�� 8 9 i I I / I KEY MAP (n 0000 SCALE: NTS J TRACT A �, r, 5�15 I E SECOND REPLA T OF \ I + V o \ _ SCENIC WEW - P.U.D. — — I _ — O i c �J I \ \ LEGEND a- o REC. NO. 98272 3 -- - - - — — - - - - - - — — — — — — — — — — \- - - \\ \l\ \ AJ ZiO COMMONS p J � I I 110 � I 1 5110 � --- o i / \ �'- �— _ �1 —6100 EXISTING MAJOR CONTOUR / CO OM/N/U ASJOC4A4T/ON I I��c, ——— ———— — —— A/M DEED >� SAND FILTER # 1/ 5 REC. NO. 2002007515\ _ — — — — — — — EXISTING INTERMEDIATE CONTOUR \ \ \ I I C' ..::.r:•. _- I �� ��5105 I 1 \ i — G100 PROPOSED MAJOR CONTOUR "r N �\ TRAC A ;: 1 0. rN / PROPOSED INTERMEDIATE CONTOUR rn 1 SCENIC VIEWS - - I \- - 1 \\ `r . ...: \ \ I r p EXISTING STORM SEWER/RCPUA co � 8 //\ \ \\ \ \ \� I ;I..1`'• r I I �, 23 _ • PROPOSED STORM SEWER/RCP Q d5 UUZ < / PROPOSED SWALE o 0 I I — — 516 — — ,, �7 8 31% POLESTA DETENT I \ — — — / PROPOSED FLOW DIRECTION Q U \� . r I I - -- - - � ,� iON PON 1 \ f � —\\ I / o • I \\ \ STORM ONTROL BOX I o / / \ \\ / / BASIN DRAINAGE AREA 3 10 11 12 13 14 15 17 181 \ \ I p � h WATER QUALITY PROVIDED \ \ \\ I 3;C 4 5� 6s 75 48 1 AJC AJ AJ AJ hJC AJC HJ AJC 0.12 ACRE-FT G \ I y I 4 t I urea %MMiiME PROVIDED 9.44 ACRE-FT TR ACT B 100 YR-WSELV 5108.89 — — 1 \ / • r 100 YEAR VOLUME REQUIRED Qj 4.88 ACRE-FT SAND FILTER # 1 _� 0 Li MFI F I ANE — HOKU LANE J 1 8 /RR P/P y UNTREATED AREA RAIN GARDEN # 2 r 3 \ -- RAIN GARDEN # 2 �' `r RAIN GARDEN # 3 /� J I - g4 I g' 1 C I I I'11■ '12 19 t tl 21 22 I S 51o5 \ \> \ RAIN GARDEN # 3 w TRACT B RAIN GARDEN # 4 r1 03% .. // \ \ m TE I - \\ RAIN GARDEN # 5 CA 4 �\ �� 'a _ � 15 3 vv , 27 4 FW2 I z FE2 zI \\ I J ,25� ( 33 I 34 RAIN GARDEN # 6 I 28 o I I GTE 29 - / 4 AREAS TREATED IN DETENTION POND FOR WQ 30 19 \ ° \\ ,32 - ° - 35 0.,, UNTREATED IMPERV AREA v - TRACT B v 23 I- - 31 RAIN GARDEN 4 A n4 ti >\ � �� l'/� - - - - - -- — ���yyy _ 3.4 -E z 869 = _ o 'j o \ -y _— _ W P/—UM ST W T W PL UM ST W EE z SCENIC ►�E v v A v \ - 3 �° - - — _ ,_ , - - - LID/WQ TREATMENT UNTREATED AREA r0 \ \ s 3 2 4 - _ , V / / V J O / / i- 0 X r Treatment Method Impervious Area Treated -SF Total Area-SF Percent Treated cfl 0LW d 39 I 91 SAND FILTER#1 213,418 II �II N Q Q ��, / i \ \ \ \ \ c1,9 i Y,00 G iv j I —`a I RAIN GARDEN #2 37,445 L j � — — � RAIN GARDEN #3 21,579 302,762 82.9% � >- / 38 - 3 TRA / v RAIN GARDEN #4 15,160 J J m m � I \ �. gq I i I RAIN GARDEN #5 15,160 U U w z w \ b ✓ \ �' RAIN GARDEN # 5 o cn N o p \ ° 1 v WQ- Detention Pond 60,907 60,907 16.7/ I I > U) Q w OT ZjLUC ,, \ / `�,� o , A10� — — Untreated Area 1,455 1,455 0.4% o p v A T OF ` \ ? 1 \ I cr Note Basln Flforthe Pond was subtracted from Pond Calc due to rass buffers and to not account for the area of the Pond H.P 511,Z� � � b \TRACT Ai ILL] 43 0 �: �, � � �► TRACT A � I � I c scENrc urEws c �\ ��� o� 36 ze I 1 Q 4R � "cr� RAIN GARDEN # 6 � / Z Q 44 I W � 4% - ` z— - I � Q 1 J / Q LLj - - - � C11 - Z (711-7 11-I�I _III l 4 SHEET 1 OF 1 60 30 o so 120 Know what's below. J � � \` F I 1 � � _ �\ \ p _`� � /RRS /P or ,� _1�1— , -1 \�i _��i� �� y.. __.._. —__ _ — r 1 \ RR i --- c > I \ ORIGINAL SCALE: 1 = 60 Call before you dig. JOB No. 39797.01