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HomeMy WebLinkAboutLAKEVIEW ON THE RISE, AFFORDABLE HOUSING - PDP - PDP170014 - SUBMITTAL DOCUMENTS - ROUND 2 - DRAINAGE REPORTPreliminary Drainage and Erosion Control Report for Lakeview on the Rise Fort Collins, Colorado April 26, 2017 April 26, 2017 Mr. Wes Lamarque City of Fort Collins Water Utilities--Storm water 700 Wood Street Fort Collins, Colorado 80521 RE: Preliminary Drainage and Erosion Control Report Lakeview on the Rise Dear Wes: We are pleased to submit to you, for your review and approval, this Preliminary Drainage and Erosion Control Report for Lakeview on the Rise. All computations within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria. We appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. Respectfully, Aspen Engineering John Gooch, P.E. Principal TABLE OF CONTENTS DESCRIPTION PAGE I. GENERAL LOCATION AND DESCRIPTION 5 A. LOCATION 5 B. DESCRIPTION OF PROPERTY 5 II. DRAINAGE BASINS 6 A. MAJOR BASIN DESCRIPTION 6 B. EXISTING SUB-BASIN DESCRIPTION 6 C. PROPOSED SUB-BASIN DESCRIPTION 6 III. DRAINAGE DESIGN CRITERIA 7 A. REGULATIONS 7 B. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS 8 C. HYDROLOGIC CRITERIA 8 D. HYDRAULIC CRITERIA 8 E. VARIANCES 8 IV. DRAINAGE FACILITY DESIGN 8 A. GENERAL CONCEPT 8 B. SPECIFIC DETAILS 9 C. DETENTION POND 15 D. STREET CAPACITIES 16 V. STORM WATER QUALITY 16 A. GENERAL CONCEPT & SPECIFIC DETAILS 16 VI. EROSION CONTROL 16 A. GENERAL CONCEPT 16 VII. CONCLUSIONS 17 A. COMPLIANCE WITH STANDARDS & STORMWATER 17 OPERATIONS/ MAINTENANCE PROCEDURE B. DRAINAGE CONCEPT 18 C. STORM WATER QUALITY 18 D. EROSION CONTROL CONCEPT 18 E. EROSION CONTROL ESCROW ESTIMATE 18 REFERENCES 19 APPENDIX PAGE VICINITY MAP A RATIONAL METHOD HYDROLOGY, POND SIZING & LID’s B STORM SEWER PIPE SIZING C INLET & CONCRETE SIDEWALK CULVERT SIZING D SWALE SIZING E EROSION CONTROL & RIPRAP SIZING F PROPOSED AND EXISTING DRAINAGE BASIN EXHIBITS G 5 PRELIMINARY DRAINAGE AND EROSION CONTROL REPORT FOR LAKEVIEW ON THE RISE FORT COLLINS, COLORADO I. GENERAL LOCATION AND DESCRIPTION A. Location The Lakeview on the Rise project is located east of and adjacent to South College Avenue (U.S. Highway 287) and northeast of the intersection of Triangle Drive and South College Avenue. The property is bounded to the west by South College Avenue, to the north by an existing irrigation ditch, and to the south by Robert Benson Reservoir, and to the east by Provincetown Filing Three subdivision. The project site can also be described as situated in the northwest quarter of Section 13, Township 6 North, Range 69 West of the 6th P.M., City of Fort Collins, County of Larimer, State of Colorado. The site (property boundary) comprises approximately 20.089 acres (see vicinity map in Appendix A). B. Description of Property The project site currently contains an existing 20.089-acre vacant field comprised of primarily dirt with native weeds and grasses and portions of South College Avenue. The site also contains one existing commercial building that is currently unoccupied and will be removed prior to any proposed construction activities. Robert Benson Reservoir and an associated wetland area bound the proposed site to the south. The existing site has topography which generally slopes from the northwest to the south-southeast at approximately 2.9%, with varying slopes from 2.0% to 5.0%. The proposed development consists of 17 apartment buildings, a Clubhouse with pool, and associated street, water, sanitary sewer, storm sewer, and private infrastructure improvements, as well as intermittent green spaces and outdoor spaces. 6 II. DRAINAGE BASINS A. Major Basin Description The Lakeview on the Rise project is located within the City of Fort Collins Fossil Creek Reservoir Drainage Basin. The Fossil Creek Reservoir Drainage Basin generally flows from the northwest to southeast and ultimately outlets into the Poudre River. B. Existing Sub-Basin Description The existing site consists primarily of dirt with intermittent grasses and weeds. All existing onsite drainage is conveyed from the northwest to the south-southeast ultimately collecting in Robert Benson Reservoir, located along the south side of the property. The existing subject site is contained within one existing sub-basin (EX1). Existing basin EX1 contains approximately 21.54 acres and was modeled with the basin having an existing ‘c’ value of 0.25. The calculated existing 2-year runoff from basin EX1 is 6.12 cfs. Please refer to the rational calculations in Appendix B. C. Proposed Sub-Basin Description The proposed development consists of 17 apartment buildings, a Clubhouse with pool, and associated street, water, sanitary sewer, storm sewer, and private infrastructure improvements, as well as intermittent green spaces and outdoor spaces. All flows generated from the proposed site will be conveyed to two forebay/Rain Gardens, then to two proposed detention ponds, prior to being released into Robert Benson Reservoir. It is important to note that a small portion of the site (approximately 3.80 acres) along the western boundary consists of portions of South College Avenue and undeveloped land that is conveyed directly into Robert Benson Reservoir without detention or treatment, as historically occurs. All flows released into Robert Benson Reservoir will ultimately be conveyed to Fossil Creek Reservoir and into the Poudre River. The proposed public roads will be paved with asphalt, while the private drives and adjacent parking areas will be constructed of concrete or asphalt. Interior sidewalks will be constructed of concrete to serve pedestrians and provide access throughout the site. Runoff from the proposed site will be ultimately conveyed in two large spine storm drainage piping systems that will flow south towards the two proposed detention ponds. Distribution boxes, with multiple 12” ADS pipes installed out of the sides of the boxes, will be installed near the downstream ends of the two large spine storm drainage systems. The 12” ADS pipes will convey runoff from the site to the two 7 proposed forebay/Rain Garden basins. The forebays/Rain Gardens will provide approximately one (1) foot of ponding depth with base composed of bioretention sand media and gravel over a 6” perforated underdrain system installed at the bottom of the Rain Garden. One foot of depth will be provided in the Rain Garden to meet the LID criteria. Upon the forebays/ Rain Gardens filling up with runoff from the site, runoff will be filtered through the Rain Garden media and gravel and discharge into the proposed detention ponds via the 6” perforated pipes/underdrains. Per the Geotechnical report by Terracon, the site contains highly expansive clay materials, and as required, all roof drainage from the site and as much site area as possible, is required to be captured immediately by piping systems and conveyed away from the buildings and road infrastructure. Therefore, in meeting the requirements of the Geotechnical Report, the proposed forebays/Rain Gardens will be provided to mitigate infiltration of runoff into the sub-grade, as required, and to provide LID treatment for approximately 82 percent of the total site which includes the offsite area. Should the forebays/Rain Gardens fill up during major storm events, the forebays/Rain Gardens will overtop south and to the proposed detention ponds. The proposed detention ponds will be graded with relatively flat bottoms (0.5% to 2.0%) to allow for infiltration and pollutants to settle out of the runoff, prior to flows exiting the ponds via the proposed outlet structures and into Robert Benson Reservoir. The proposed detention ponds will discharge the combined 2-year historic release rate (6.12 cfs) directly into Robert Benson Reservoir. III. DRAINAGE BASIN CRITERIA A. Regulations The drainage design for the subject site is required to meet the current City of Fort Collins Stormwater and Erosion Control Standards and requirements, as well as the requirements of the Geotechnical Report by Terracon. Therefore, the drainage design for the subject site has been designed in accordance with these standards and provides for the site drainage being conveyed to downstream Rain Gardens and detention ponds, as required and applicable. The proposed project will be required to provide water quality and on-site detention, prior to the 2-year historic release rate from the site being conveyed into Robert Benson Reservoir, as historically occurs. 8 B. Development Criteria Reference and Constraints Drainage criteria and constraints required by the City of Fort Collins and Terracon will be achieved and provided by the Lakeview on the Rise project. The capacity of the system will be self contained and release to Robert Benson Reservoir at a rate not to exceed the 2-year historic release rate of 6.12 cfs for the entire 21.54 acres, which includes all attributing onsite and offsite basins, including the half-width of South College Avenue along the proposed site. C. Hydrologic Criteria The Rational Method for determining surface runoff was used for the project site. The 2-year and 100-year storm event intensities were used in calculating runoff values. The City of Fort Collins intensity duration frequency curves were used to obtain rainfall data for each storm specified. Detention and water quality pond sizing was calculated using the latest City of Fort Collins Criteria as well as Urban Drainage Flood Control District sizing methods. Forebays/Rain Gardens sizing was calculated using the Design Procedure Form for Rain Garden Design spreadsheet developed by UDFCD. D. Hydraulic Criteria All hydraulic calculations within this report have been prepared in accordance with the City of Fort Collins Drainage Criteria and are also included in the Appendices. Final storm sewer pipe and inlet/curb cut sizing will be completed during final design using UDSewer and UDInlet from UDFCD, as well as other orifice/inlet control sizing spreadsheets. Final Swale sizing will also be completed during final design using AutoCad Civil 3D Hydraulic Software, while final erosion control/riprap sizing will be calculated using North American Green software. E. Variances No variances are being requested at this time. IV. DRAINAGE FACILITY DESIGN A. General Concept Twenty-nine proposed onsite drainage basins and one offsite basin have been created to analyze the drainage for the proposed development. 9 Basins 1-15 drain ultimately to a proposed detention/water quality pond located in the southwest corner of the site via overland flow, curb and gutter, and proposed storm sewer systems. The 100-year peak flow to be detained in the detention pond located in the southwest corner of the site will be approximately 39 cfs. Basins 16-29 drain ultimately to a second proposed detention/water quality pond located in the southeast corner of the site via overland flow, curb and gutter, and proposed storm sewer systems. The 100-year peak flow to be detained in the detention pond located in the southeast corner of the site will be approximately 35 cfs. Basin OS1 is an offsite basin that consists of portions of South College Avenue that will be conveyed directly to Robert Benson Reservoir undetained. The total 100-year peak flow to be detained in the two proposed detention ponds located onsite will be approximately 67 cfs. Detention Pond 100 (west) and Detention Pond 200 (east) provide approximately 3.21 acre-feet and 1.38 acre-feet of storage, respectively, which provide for the combination of detention and water quality within Rain Gardens, while having an allowed 2-year release rate of 6.12 cfs. The release rate for Pond 100 and Pond 200 will be 1.0 cfs and 5.12 cfs respectively. It's important to note that Pond 100 and Pond 200 have been sized to detain up to the 100-year event, while receiving the 100- year developed flow (66.9 cfs) from 21.54 acres, with the calculated overall 'c' value for the site being 0.72, versus the overall combined existing 'c' value of 0.25. Please refer to the rational calculations in Appendix B and the Proposed and Existing Drainage Basin Exhibits in Appendix G for additional information. The inlets and storm sewer system will be sized with final design. B. Specific Details Drainage to Detention Pond 100: The runoff from the following basins 1-15 will be collected in a proposed storm sewer system which will be ultimately be conveyed to a Detention Pond 100 located at the southwest corner of the site. Basin 1 Runoff in Basin 1 will be conveyed via overland flow and curb and gutter to a 5’ Type R inlet. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 1. 10 Basin 2 Runoff in Basin 2 will be conveyed via roof drains, overland flow, and a grass lined swale to the proposed storm sewer system at design point 2. Basin 3 Runoff in Basin 3 will be conveyed via overland flow, a grass lined swale and curb and gutter to a 5’ Type R inlet. Flows from the grass lined swale will pass through a curb cut and join runoff collected from the proposed roadway as it passes to the 5’ Type R inlet via curb and gutter. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 3. Basin 4 Runoff in Basin 4 will be conveyed via overland flow and curb and gutter. Runoff from the north side of Lorien Lane and the west half of Debra Drive flows to a 5’ Type R, on grade inlet. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 4. Basin 5 Runoff in Basin 5 will be conveyed via roof drains, overland flow and curb and gutter. Runoff in the east half of Debra Drive flows to a 5’ Type R inlet, on grade inlet. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 5. Basin 6 Runoff in Basin 6 will be conveyed via roof drains, overland flow, and a grass lined swale to the proposed storm sewer system at design point 6. Basin 7 Runoff in Basin 7 will be conveyed via roof drains, overland flow and curb and gutter to a 5’ Type R inlet. The 5’ Type R inlets discharges into a proposed storm sewer system at design point 7. Basin 8 Runoff in Basin 8 will be conveyed via roof drains, overland flow, and a grass lined swale to a 2’ diameter Nyloplast area inlet. The 2’ diameter Nyloplast area inlet discharges into a proposed storm sewer system at design point 8. Basin 9 Runoff in Basin 9 will be conveyed via roof drains, overland flow, a grass lined swale, and curb and gutter to two, 5’ Type R inlets. The 5’ Type R inlets discharge into a proposed storm sewer system at design point 9. 11 Basin 10 Runoff in Basin 10 will be conveyed via roof drains, overland flow and curb and gutter to a 5’ Type R inlet. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 10. Basin 11 Runoff in Basin 11 will be conveyed via overland flow and curb and gutter to a 5’ Type R inlet. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 11. Basin 12 Runoff in Basin 12 will be conveyed via roof drains, overland flow and curb and gutter to a 5’ Type R inlet. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 12. Basin 13 Runoff in Basin 13 will be conveyed via overland flow, a grass lined swale and curb and gutter to a 5’ Type R inlet. Flow from the grass lined swale will pass through a curb cut and join runoff collected from the south half of the proposed Debra Drive roadway. Flow is intercepted by a proposed 5’ Type R on grade inlet at design point 13. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 13. Carry over runoff will flow to design point 28. Basin 14 Runoff in Basin 14 will be conveyed via overland flow and a grass lined swale to the proposed detention pond located in the southwest portion of the site at design point 14. Basin 15 Runoff in Basin 15 will be conveyed via overland flow to the proposed Detention Pond 100 located in the southwest portion. The basin includes the proposed Detention Pond 100, located in the southwest portion of the site. Runoff is released at a controlled rate via a water quality control structure at design point 15. Drainage to Detention Pond 200: The runoff from the following basins 16-29 will be collected in a proposed storm sewer system which will be ultimately be conveyed to Detention Pond 200 located at the southeast corner of the site. 12 Basin 16 Runoff in Basin 16 will be conveyed via roof drains, overland flow and curb and gutter to a 5’ Type R inlet. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 16. Basin 17 Runoff in Basin 17 will be conveyed via roof drains, overland flow, and a grass lined swale to a 2’ diameter Nyloplast area inlet. The 2’ diameter Nyloplast area inlet discharges into a proposed storm sewer system at design point 17. Basin 18 Runoff in Basin 18 will be conveyed via roof drains, overland flow, and curb and gutter to a 5’ Type R inlet. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 18. Basin 19 Runoff in Basin 19 will be conveyed via overland flow, a grass lined swale, and curb and gutter to a 2’ diameter Nyloplast area inlet. Flows from the curb and gutter will pass through a curb cut and join runoff collected from the grass lined swale as it passes to the 2’ diameter Nyloplast area inlet. The 2’ diameter Nyloplast area inlet discharges into a proposed storm sewer system at design point 19. Basin 20 Runoff in Basin 20 will be conveyed via roof drains, overland flow, a grass lined swale to a 2’ diameter Nyloplast area inlet. The 2’ diameter Nyloplast area inlet discharges into a proposed storm sewer system at design point 20. Basin 21 Runoff in Basin 21 will be conveyed via roof drains, overland flow and curb and gutter to a 5’ Type R inlet. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 21. Basin 22 Runoff in Basin 22 will be conveyed via overland flow and curb and gutter to a 5’ Type R inlet. The 5’ Type R inlet discharges into a proposed storm sewer system at design point 22. Basin 23 Runoff in Basin 23 will be conveyed via roof drains, overland flow, a grass lined swale and curb and gutter to a 4’ x 4’, CDOT Type C inlet. Flows from the curb and gutter will pass through a curb cut and join runoff collected from the grass lined swale as it passes to the 4’ x 4’, CDOT Type C inlet. The 4’ x 13 4’, Type C inlet discharges into a proposed storm sewer system at design point 23. Basin 24 Runoff in Basin 24 will be conveyed via roof drains, overland flow, a grass lined swale to a 2’ diameter Nyloplast area inlet. The 2’ diameter Nyloplast area inlet discharges into a proposed storm sewer system at design point 24. Basin 25 Runoff in Basin 25 will be conveyed via roof drains, overland flow, a grass lined swale to a 2’ diameter Nyloplast area inlet. The 2’ diameter Nyloplast area inlet discharges into a proposed storm sewer system at design point 25. Basin 26 Runoff in Basin 26 will be conveyed via roof drains, overland flow, a grass lined swale to a 2’ diameter Nyloplast area inlet. The 2’ diameter Nyloplast area inlet discharges into a proposed storm sewer system at design point 26. Basin 27 Runoff in Basin 27 will be conveyed via overland flow to curb and gutter. Flow in the north and east half of the proposed roadway will drain to a 10’ Type R sump inlet. The 10’ Type R inlet discharges into a proposed storm sewer system at design point 27. Basin 28 Runoff in Basin 28 from the south half of the roadway, will be conveyed via overland flow and curb and gutter to a 10’ Type R sump inlet on Stoney Brook Road. The 10’ Type R inlet discharges into a proposed storm sewer system at design point 28. Basin 29 Runoff in Basin 29 will be conveyed via overland flow. The basin includes the proposed Detention Pond 200, located in the southeast portion of the site. Runoff is released at a controlled rate via a water quality control structure at design point 29. Offsite Drainage The runoff from the following basin drains offsite. Basin OS1 Runoff in Basin OS1 will be conveyed via overland flow and curb and gutter to Robert Benson Reservoir south of the site. The flows in Basin OS1 represent a portion of South College Avenue and undeveloped land in the southwest corner of the site. Runoff in College Avenue will be intercepted by 14 a 5’ Type R inlet and 10’ Type R inlet in the east flowline. Flow is piped to existing swales and discharges to Benson Reservoir. Runoff in OS1 will be released undetained. Overflow Conditions Basins 1-5: Should the inlets at the low points in these basins become obstructed and fail to collect the required drainage, the runoff will pass to Debra Drive and ultimately be conveyed to the detention pond located in the southwest corner of the site. Basins 6-12: Should the inlets at the low points in these basins become obstructed and fail to collect the required drainage, the runoff will pass through the proposed parking areas to Debra Drive and ultimately be conveyed to Detention Pond 100 located in the southwest corner of the site. Basin 13: Should the on-grade inlet at design point 13 in this basin become obstructed and fail to collect the required drainage, the runoff will pass to the low point in Stoney Brook Drive and ultimately be conveyed to Detention Pond 200 located in the southeast corner of the site. Basin 14-15: Should the on-grade inlet at design point 13 in this basin become obstructed and fail to collect the required drainage, the runoff will pass to the low point in Stoney Brook Drive and ultimately be conveyed to Detention Pond 200 located in the southeast corner of the site. Basins 16-22: Should the inlets at the low points in these basins become obstructed and fail to collect the required drainage, the runoff will pass through the private drive into Stoney Brook Road and ultimately be conveyed to Detention Pond 200 located in the southeast corner of the site. Basin 23: Should the CDOT Type C inlet at the low point in this basin become obstructed and fail to collect the required drainage, the runoff will pass into Stoney Brook Road and ultimately be conveyed to Detention Pond 200 located in the southeast corner of the site. Basins 24-26: Should the inlets at the low points in these basins become obstructed and fail to collect the required drainage, the runoff will pass to the low point in Stoney Brook Drive and ultimately be conveyed to Detention Pond 200 located in the southeast corner of the site. 15 Basins 27-28: Should the inlets at the low points in these basins located at the low point in Stoney Brook Drive become obstructed and fail to collect the required drainage, the runoff will pass to Detention Pond 200 located in the southeast corner of the site. C. Detention Pond Detention Pond 100 has been sized to provide water quality and detention for 8.57 acres of the total 21.54 acres of on-site and off-site areas. Detention Pond 100 will provide 3.21 acre-feet of available volume at an elevation of 5016.00, (0.13 ac-ft for water quality volume in the Rain Garden at an elevation of approximately 5015.00; 2.01 ac-ft of detention and water quality at an elevation of approximately 5015.00). Detention Pond 200 has been sized to provide water quality and detention for the 9.18 acres of the total 21.54 acres of on-site and off-site areas. Detention Pond 200 will provide 1.38 acre-feet of available volume at an elevation of 5009.00 (0.13 ac-ft for water quality within at the Rain Garden at an elevation of approximately 5008.5; 1.21 ac-ft of detention at an elevation of approximately 5008.75). The proposed detention ponds will allow for detention up to the 100-year storm event for the development. The lowest outlet elevation of the Detention Pond 100 (invert at the front of the outlet structure) is approximately 5010.00. The calculated 100- year water surface elevation of Detention Pond 100 is approximately 5015.00 with a release rate of 1.0 cfs. The lowest outlet elevation of the Detention Pond 200 (invert at the front of the outlet structure) is approximately 5003.00. The calculated 100-year water surface elevation of Detention Pond 200 is approximately 5008.75. The proposed detention pond outlet structures will be 18” RCP pipes with orifice control plates at the entrance of the pipes. Orifice sizing will be provided at final design, thus discharging the allowable 2-year historic release rate of 6.12 cfs combined into Robert Benson Reservoir. An Emergency Spillway will also be sized at final design and will be constructed along the south edges of Pond 100 and Pond 200. The proposed spillways on Pond 100 and Pond 200 will have overflow elevations of 5016.00 and 5009.00, respectively, with widths sized at final design. Should Pond 100 and Pond 200 overtop, runoff will be released south into Robert Benson Reservoir. Please refer to the Utility Plans for specific grading and overflow weir details. 16 D. Street Capacities Street capacity calculations for public roads have been analyzed and calculated, with the results provided in Appendix D. V. STORM WATER QUALITY A. General Concept & Specific Details The water quality of stormwater runoff must be addressed on all final design utility plans. Therefore, Best Management Practices (BMP's) for the treatment of stormwater runoff for the subject site will include grass/ sod-lined swales, riprap pads at culvert discharge points, permanent erosion control fabric at curb cuts and swale entrances into the ponds, grass scrubbing across the bottom of the detention ponds during first flush conditions, and proposed Rain Garden consisting of water quality catch basins located at the entrances to the detention ponds which will be incorporated into the detention pond design. These proposed water quality features will provide a mechanism for pollutants to settle out of the stormwater runoff before flows are directed into the detention ponds and ultimately to Robert Benson Reservoir. The proposed water quality/ detention facilities have adequate capacity and will provide all of the required water quality and detention up to the 100-year event for the developed condition of the subject site (21.54 acres), prior to releasing flows to Robert Benson Reservoir. VI. EROSION CONTROL A. General Concept Silt fence will be installed along the north, west, south, east and west property boundaries of the site to prevent sediment from leaving the site. In addition, silt fence is proposed around the perimeter of each block of buildings surrounded by curb and gutter to prevent sediment from entering proposed drive aisles and streets. A vehicle tracking pad will be placed at the site access point at US 287 and Lorien Lane. The exact location shall be provided during final design. 17 Straw Wattles and gravel inlet filters will be placed at proposed inlet locations to mitigate the build-up of sediment in the proposed inlet and manhole structures. Straw wattle check dams will also be installed at 300' intervals in the proposed swales throughout the site, as may be applicable. Erosion Control Calculations and the Erosion Control Escrow Amount will be provided during final design. Please refer to Appendix G for the Erosion Control Plan and Erosion Control Notes and Detail Sheets. VII. CONCLUSIONS A. Compliance with Standards & Stormwater Operations/Maintenance Procedure All computations within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria. The City of Fort Collins Storm water Utility will not maintain the on-site storm drainage facilities within the subject site. The owners of the subject site will maintain their on-site storm drainage facilities on a regular basis. The following shall be implemented for the private stormwater improvements’ operations/ maintenance procedures for the project on an annual or bi-annual basis: 1) Storm Sewer Inlets, pipes and flared-end-sections, curb cuts and concrete sidewalk culverts/chases, structures, manholes, and the LID water quality catch basins shall be cleaned through the removal of debris and sediment from the associated items to allow for adequate drainage through the site to the proposed detention facilities. 2) Pond sedimentation/ silting shall be removed to allow for adequate drainage along the bottom of the ponds and to prevent ponding and silting in of the pond bottoms. Grass scrubbing along the bottom of the ponds may be required to remove sediment and promote grass growth. 3) Re-vegetation through the use of Natural Seeding/ Sod shall be provided for disturbed areas and other permanent erosion controls shall be provided for areas where erosion has taken place and requires remediation back to the proposed condition shown in the plans. The Stormwater Operating/ Maintenance Procedures listed above are guidelines to the minimum procedures that shall be implemented for the site, with these and additional measures being utilized on an as-needed basis. 18 B. Drainage Concept The proposed drainage concepts presented in this study and shown on the utility plans adequately provide for the transmission of developed on-site runoff to the proposed detention ponds (Pond 100 and Pond 200), located southwest and southeast corners of the subject site. The proposed storm sewer system will provide for the 100-year developed flows to reach the proposed water quality and detention ponds, prior to flows being released downstream in accordance with the 2-year historic release rate of 6.12 cfs. If groundwater is encountered at the time of construction, a Colorado Department of Health Construction Dewatering Permit will be required. C. Storm Water Quality The preliminary design has addressed the water quality aspect of stormwater runoff. The proposed grass-lined detention ponds and Rain Gardens will provide an opportunity for stormwater pollutants to filter out of the stormwater runoff before flows are directed downstream to Robert Benson Reservoir. Furthermore, the proposed grass-sod-lined swales, riprap pads at culvert outlets, permanent erosion control fabric and other erosion control devises that may be utilized for side-slopes and embankments, grass scrubbing across the bottom of the detention ponds during first flush conditions, and the water quality basins incorporated into the detention pond designs will provide additional mechanisms for pollutants to settle out of the stormwater runoff before flows are directed south and ultimately to Robert Benson Reservoir. D. Erosion Control Concept Proposed erosion control concepts will adequately provide for the control of wind and rainfall erosion from the proposed development. Through the construction of the proposed erosion control concepts, the City of Fort Collins standards will be maintained. The proposed erosion control concepts presented in the preliminary report and shown on the erosion control plan are in compliance with the City of Fort Collins Erosion Control Criteria. E. Erosion Control Escrow Estimate The Erosion Control Escrow Estimate for the subject property will be provided at final design. 19 REFERENCES 1. Storm Drainage Design Criteria and Construction Standards by the City of Fort Collins, Colorado, May 1984, Revised January 1997, & Associated UDFCD Updates and New City of Fort Collins Stormwater Criteria manual, adopted January, 2012. 2. Erosion Control Reference Manual for Construction Sites by the City of Fort Collins, Colorado, January 1991, Revised January 1997, & Associated UDFCD Updates and New City of Fort Collins Stormwater Criteria manual, adopted January, 2012. 3. Urban Storm Drainage Criteria Manual Volume 1; Urban Drainage and Flood Control District, Denver, Colorado, June 2001. 4. Urban Storm Drainage Criteria Manual Volume 2; Urban Drainage and Flood Control District, Denver, Colorado, June 2001. 5. Urban Storm Drainage Criteria Manual Volume 3, Best Management Practices; Urban Drainage and Flood Control District, Denver, Colorado, August 2011. 17 APPENDIX 18 APPENDIX A 19 VICINITY MAP VICINITY MAP VICINITY MAP 20 APPENDIX B 21 RATIONAL METHOD HYDROLOGY TIME OF CONCENTRATION 2 year design storm Lakeview on the Rise 801-002 t c = t i + t L C f = 1.00 SUB-BASIN DATA INITIAL/OVERLAND TIME TRAVEL TIME FINAL REMARKS BASIN AREA C LENGTH SLOPE ti LENGTH CHANNEL SLOPE VELOCITY tL tc NO. (ac) (ft) (%) (min) (ft) TYPE(a) (%) (ft/s) (min) (min) 1 2 3 4 5 6 7 8 10 12 13 1 0.39 0.86 156 3.7 3.6 135 PA 2.8 3.23 0.7 5.0 Drains to West Detention Pond 2 0.46 0.72 20 20.0 1.2 316 GW 5.0 3.44 1.5 5.0 Drains to West Detention Pond 3 0.24 0.73 26 16.0 1.4 275 PA 3.7 3.73 1.2 5.0 Drains to West Detention Pond 4 0.95 0.56 328 2.6 13.3 290 PA 2.4 2.99 1.6 14.9 Drains to West Detention Pond 5 0.47 0.74 38 3.8 2.6 292 PA 2.4 2.99 1.6 5.0 Drains to West Detention Pond 6 0.27 0.66 14 14.5 1.3 178 GW 2.2 2.28 1.3 5.0 Drains to West Detention Pond 7 0.40 0.83 122 4.3 3.4 49 PA 3.5 3.62 0.2 5.0 Drains to West Detention Pond 8 0.26 0.80 5 5.0 0.7 135 GW 2.0 2.18 1.0 5.0 Drains to West Detention Pond 9 0.62 0.83 236 2.8 5.5 65 PA 3.0 3.35 0.3 5.8 Drains to West Detention Pond 10 0.51 0.82 130 2.2 4.5 12 PA 2.0 2.72 0.1 5.0 Drains to West Detention Pond 11 0.19 0.72 139 2.5 6.2 22 PA 1.3 2.18 0.2 6.4 Drains to West Detention Pond 12 0.22 0.83 86 2.5 3.4 16 PA 1.3 2.18 0.1 5.0 Drains to West Detention Pond t CC D i S  f 187 11  0 333 . ( . ) . 13 0.49 0.66 11 12.3 1.2 461 PA 2.1 2.79 2.8 5.0 Drains to West Detention Pond 14 0.46 0.26 14 2.4 4.4 582 GW 3.6 2.92 3.3 7.7 Drains to West Detention Pond 15 2.65 0.25 186 3.6 14.1 138 GW 1.0 1.54 1.5 15.6 Drains to West Detention Pond 16 1.03 0.77 245 2.5 7.2 120 PA 1.0 1.91 1.0 8.3 Drains to East Detention Pond 17 0.27 0.75 14.5 5.4 1.4 186 GW 2.0 2.18 1.4 5.0 Drains to East Detention Pond 18 0.46 0.85 112 3.0 3.5 65 PA 2.0 2.72 0.4 5.0 Drains to East Detention Pond 19 0.22 0.48 15 12.8 1.9 134 GW 3.3 2.80 0.8 5.0 Drains to East Detention Pond 20 0.64 0.74 15 12.8 1.1 268 GW 2.0 2.18 2.1 5.0 Drains to East Detention Pond 21 0.65 0.83 193 1.8 5.8 140 PA 2.0 2.72 0.9 6.6 Drains to East Detention Pond 22 0.30 0.83 150 3.0 4.3 86 PA 2.6 3.11 0.5 5.0 Drains to East Detention Pond 23 1.58 0.44 178 2.0 13.1 811 GW 2.0 2.18 6.2 19.4 Drains to East Detention Pond 24 0.18 0.65 28 13.7 1.9 67 GW 2.0 2.18 0.5 5.0 Drains to East Detention Pond 25 0.82 0.57 29 5.5 3.0 209 GW 1.5 1.89 1.8 5.0 Drains to East Detention Pond 26 0.24 0.41 29 5.0 4.1 268 GW 2.0 2.18 2.1 6.1 Drains to East Detention Pond 27 0.63 0.78 103 3.2 4.1 147 PA 1.8 2.58 1.0 5.0 Drains to East Detention Pond 28 0.34 0.77 32 3.0 2.4 272 PA 1.8 2.58 1.8 5.0 Drains to East Detention Pond 29 1.82 0.28 160 12.0 8.4 223 GW 1.4 1.82 2.0 10.5 Drains to East Detention Pond OS1 3.80 0.63 25 2.0 3.5 1545 PA 0.9 1.81 14.3 17.8 OFFSITE BASIN Note: a) Codes the channel type for velocity calculations. PA = Paved, PL = Pasture & Lawns, GW = Grassed Waterway ASPEN ENGINEERING 8:59 AM 4/19/2017 TIME OF CONCENTRATION 100 year design storm Lakeview on the Rise 801-002 t c = t i + t L C f = 1.25 SUB-BASIN DATA INITIAL/OVERLAND TIME TRAVEL TIME FINAL REMARKS BASIN AREA C LENGTH SLOPE ti LENGTH CHANNEL SLOPE VELOCITY tL tc NO. (ac) (ft) (%) (min) (ft) TYPE(a) (%) (ft/s) (min) (min) 1 2 3 4 5 6 7 8 10 12 13 1 0.39 0.86 156 3.70 1.5 135 PA 2.80 3.23 0.7 5.0 2 0.46 0.72 20 20.00 0.6 316 GW 5.00 3.44 1.5 5.0 3 0.24 0.73 26 16.00 0.7 275 PA 3.70 3.73 1.2 5.0 4 0.95 0.56 328 2.60 9.9 290 PA 2.40 2.99 1.6 11.5 5 0.47 0.74 38 3.80 1.3 292 PA 2.40 2.99 1.6 5.0 6 0.27 0.66 14 14.50 0.8 178 GW 2.20 2.28 1.3 5.0 7 0.40 0.83 122 4.30 1.3 49 PA 3.50 3.62 0.2 5.0 8 0.26 0.80 5 5.00 0.3 135 GW 2.00 2.18 1.0 5.0 9 0.62 0.83 236 2.80 2.0 65 PA 3.00 3.35 0.3 5.0 10 0.51 0.82 130 2.20 1.6 12 PA 2.00 2.72 0.1 5.0 11 0.19 0.72 139 2.50 3.3 22 PA 1.30 2.18 0.2 5.0 12 0.22 0.83 86 2.50 1.3 16 PA 1.30 2.18 0.1 5.0 t CC D i S  f 187 11  0 333 . ( . ) . 12 0.22 0.83 86 2.50 1.3 16 PA 1.30 2.18 0.1 5.0 13 0.49 0.66 11 12.30 0.7 461 PA 2.10 2.79 2.8 5.0 14 0.46 0.26 14 2.40 4.1 582 GW 3.60 2.92 3.3 7.4 15 2.65 0.25 186 3.60 13.1 138 GW 1.00 1.54 1.5 14.6 16 1.03 0.77 245 2.50 3.1 120 PA 1.00 1.91 1.0 5.0 17 0.27 0.75 14.5 5.40 0.6 186 GW 2.00 2.18 1.4 5.0 18 0.46 0.85 112 3.00 1.4 65 PA 2.00 2.72 0.4 5.0 19 0.22 0.48 15 12.80 1.5 134 GW 3.30 2.80 0.8 5.0 20 0.64 0.74 15 12.80 0.5 268 GW 2.00 2.18 2.1 5.0 21 0.65 0.83 193 1.80 2.1 140 PA 2.00 2.72 0.9 5.0 22 0.30 0.83 150 3.00 1.6 86 PA 2.60 3.11 0.5 5.0 23 1.58 0.44 178 2.00 11.0 811 GW 2.00 2.18 6.2 17.2 24 0.18 0.65 28 13.70 1.2 67 GW 2.00 2.18 0.5 5.0 25 0.82 0.57 29 5.50 2.2 209 GW 1.50 1.89 1.8 5.0 26 0.24 0.41 29 5.00 3.5 268 GW 2.00 2.18 2.1 5.5 27 0.63 0.78 103 3.20 1.6 147 PA 1.80 2.58 1.0 5.0 28 0.34 0.77 32 3.00 1.0 272 PA 1.80 2.58 1.8 5.0 29 1.82 0.28 160 12.00 7.7 223 GW 1.40 1.82 2.0 9.8 OS1 3.80 0.63 25 2.00 2.3 1545 PA 0.90 1.81 14.3 16.6 Note: a) Codes the channel type for velocity calculations. PA = Paved, PL = Pasture & Lawns, GW = Grassed Waterway ASPEN ENGINEERING 8:59 AM 4/19/2017 Basin Roof Area (sqft) Asphalt Area (sqft) Concrete Area (sqft) Gravel Area (sqft) Lawn Area (sqft) Total Area Total Area Composite No. "C=0.90" "C=0.95" "C=0.90" "C=0.41" "C=0.25" (sqft) (acre) "C" 1 1,044 10,355 3,687 0 1,739 16,825 0.39 0.86 2 13,786 0 532 0 5,543 19,861 0.46 0.72 3 0 4,567 2,770 0 3,114 10,451 0.24 0.73 4 0 11,807 6,154 3,019 20,280 41,260 0.95 0.56 5 6,588 5,180 3,258 0 5,292 20,318 0.47 0.74 6 6,272 0 988 0 4,348 11,608 0.27 0.66 7 6,272 7,234 1,554 0 2,461 17,521 0.40 0.83 8 9,392 0 0 0 1,780 11,172 0.26 0.80 9 1,558 17,217 4,178 0 4,250 27,203 0.62 0.83 10 12,466 5,310 1,485 0 3,009 22,270 0.51 0.82 11 0 3,530 2,156 0 2,614 8,300 0.19 0.72 12 4,218 2,884 1,096 0 1,216 9,414 0.22 0.83 13 1,044 7,268 4,606 0 8,443 21,361 0.49 0.66 14 0 0 165 0 19,785 19,950 0.46 0.26 15 0 0 433 0 115,171 115,604 2.65 0.25 16 6,346 20,573 6,929 0 10,852 44,700 1.03 0.77 17 8,766 0 447 0 2,700 11,913 0.27 0.75 Developed Weighted Runoff Coefficients Lakeview on the Rise 801-002 17 8,766 0 447 0 2,700 11,913 0.27 0.75 18 8,766 6,952 2,142 0 2,132 19,992 0.46 0.85 19 1,044 150 2,226 0 6,142 9,562 0.22 0.48 20 20,052 0 1,216 0 6,673 27,941 0.64 0.74 21 5,790 13,735 4,492 0 4,092 28,109 0.65 0.83 22 0 8,924 2,044 0 2,076 13,044 0.30 0.83 23 9,809 5,632 2,331 6,386 44,771 68,929 1.58 0.44 24 4,594 0 144 0 2,946 7,684 0.18 0.65 25 10,028 0 7,789 0 17,938 35,755 0.82 0.57 26 0 0 2,465 0 7,832 10,297 0.24 0.41 27 0 14,495 6,978 0 6,077 27,550 0.63 0.78 28 0 8,453 2,744 0 3,603 14,800 0.34 0.77 29 0 0 4,038 0 75,398 79,436 1.82 0.28 OS1 0 73,990 16,700 0 74,768 165,458 3.80 0.63 Total SITE 137,835 228,256 95,747 9,405 467,045 938,288 21.54 0.58 Total Acreage 3.16 5.24 2.20 0.22 10.72 21.54 aspen engineering 9:02 AM 4/19/2017 Impervious Ratio Basin Roof Area (sqft) Asphalt Area (sqft) Concrete Area (sqft) Gravel Area (sqft) Lawn Area (sqft) Total Area Imperviousness No. (sqft) Ratio 1 1,044 10,355 3,687 0 1,739 16,825 90% 2 13,786 0 532 0 5,543 19,861 67% 3 0 4,567 2,770 0 3,114 10,451 72% 4 0 11,807 6,154 3,019 20,280 41,260 49% 5 6,588 5,180 3,258 0 5,292 20,318 72% 6 6,272 0 988 0 4,348 11,608 59% 7 6,272 7,234 1,554 0 2,461 17,521 83% 8 9,392 0 0 0 1,780 11,172 76% 9 1,558 17,217 4,178 0 4,250 27,203 85% 10 12,466 5,310 1,485 0 3,009 22,270 82% 11 0 3,530 2,156 0 2,614 8,300 70% 12 4,218 2,884 1,096 0 1,216 9,414 83% 13 1,044 7,268 4,606 0 8,443 21,361 62% 14 0 0 165 0 19,785 19,950 6% 15 0 0 433 0 115,171 115,604 5% 16 6,346 20,573 6,929 0 10,852 44,700 76% 17 8,766 0 447 0 2,700 11,913 71% 18 8,766 6,952 2,142 0 2,132 19,992 85% 19 1,044 150 2,226 0 6,142 9,562 38% 20 20,052 0 1,216 0 6,673 27,941 70% 21 5,790 13,735 4,492 0 4,092 28,109 84% 22 0 8,924 2,044 0 2,076 13,044 85% 23 9,809 5,632 2,331 6,386 44,771 68,929 31% 24 4,594 0 144 0 2,946 7,684 58% 25 10,028 0 7,789 0 17,938 35,755 50% 26 0 0 2,465 0 7,832 10,297 28% 27 0 14,495 6,978 0 6,077 27,550 79% 28 0 8,453 2,744 0 3,603 14,800 77% 29 0 0 4,038 0 75,398 79,436 10% OS1 0 73,990 16,700 0 74,768 165,458 57% Total SITE 137,835 228,256 95,747 9,405 467,045 938,288 51% Total Acreage 3.16 5.24 2.20 0.22 10.72 21.54 51% aspen engineering 9:02 AM 4/19/2017 Business: Commercial areas Neighborhood areas Residential: Single-family Multiunit (detached) Multiunit (attached) Half-acre lot or larger Apartments Industrial: Light areas Heavy areas Parks, cemeteries: Playgrounds: Schools: Railroad yard areas: Undeveloped areas: Historical Flow Analysis Greenbelts, agricultural Off-site flow analysis (when land use not defined) Streets: Paved Gravel (packed) Driveways and sidewalks: Roofs: Lawns, sandy soil Lawns, clayey soil *Refer to Figures RO-3 through RO-5 in Runoff Chapter Land Use or Surface Characteristics Percent Imper-viousness 95 85 * 60 75 * 80 80 90 5 10 50 15 2 45 0 0 100 40 90 90 aspen engineering 9:46 PM 2/13/2017 Rational Method 2 Year Design Storm Lakeview on the Rise 801-002 Design Point Basins tc Length Type Slope Velocity Travel Pipe Travel tc' C Intensity Area Direct Runoff Other Runoff Total Runoff Location (min) (ft) (a) (%) (ft/s) (min) (min) (min) (in/hr) (ac) (cfs) (cfs) (cfs) 1 1 5.0 -- -- -- -- 0.0 0.0 5.0 0.86 2.85 0.39 0.95 0.00 0.95 2 2 5.0 -- -- -- -- 0.0 0.0 5.0 0.72 2.85 0.46 0.93 0.00 0.93 3 3 5.0 -- -- -- -- 0.0 0.0 5.0 0.73 2.85 0.24 0.50 0.00 0.50 4 4 14.9 -- -- -- -- 0.0 0.0 14.9 0.56 1.87 0.95 0.99 0.00 0.99 5 5 5.0 -- -- -- -- 0.0 0.0 5.0 0.74 2.85 0.47 0.99 0.00 0.99 6 6 5.0 -- -- -- -- 0.0 0.0 5.0 0.66 2.85 0.27 0.50 0.00 0.50 7 7 5.0 -- -- -- -- 0.0 0.0 5.0 0.83 2.85 0.40 0.95 0.00 0.95 8 8 5.0 -- -- -- -- 0.0 0.0 5.0 0.80 2.85 0.26 0.58 0.00 0.58 9 9 5.8 -- -- -- -- 0.0 0.0 5.8 0.83 2.71 0.62 1.41 0.00 1.41 10 10 5.0 -- -- -- -- 0.0 0.0 5.0 0.82 2.85 0.51 1.20 0.00 1.20 11 11 6.4 -- -- -- -- 0.0 0.0 6.4 0.72 2.63 0.19 0.36 0.00 0.36 12 12 5.0 -- -- -- -- 0.0 0.0 5.0 0.83 2.85 0.22 0.51 0.00 0.51 13 13 5.0 -- -- -- -- 0.0 0.0 5.0 0.66 2.85 0.49 0.92 0.00 0.92 14 14 7.7 -- -- -- -- 0.0 0.0 7.7 0.26 2.45 0.46 0.29 0.00 0.29 15 15 15.6 -- -- -- -- 0.0 0.0 15.6 0.25 1.83 2.65 1.23 0.00 1.23 16 16 8.3 -- -- -- -- 0.0 0.0 8.3 0.77 2.39 1.03 1.87 0.00 1.87 Routing Flow Time (tL Runoff ) 17 17 5.0 -- -- -- -- 0.0 0.0 5.0 0.75 2.85 0.27 0.59 0.00 0.59 18 18 5.0 -- -- -- -- 0.0 0.0 5.0 0.85 2.85 0.46 1.11 0.00 1.11 19 19 5.0 -- -- -- -- 0.0 0.0 5.0 0.48 2.85 0.22 0.30 0.00 0.30 20 20 5.0 -- -- -- -- 0.0 0.0 5.0 0.74 2.85 0.64 1.36 0.00 1.36 21 21 6.6 -- -- -- -- 0.0 0.0 6.6 0.83 2.59 0.65 1.39 0.00 1.39 22 22 5.0 -- -- -- -- 0.0 0.0 5.0 0.83 2.85 0.30 0.71 0.00 0.71 23 23 19.4 -- -- -- -- 0.0 0.0 19.4 0.44 1.64 1.58 1.13 0.00 1.13 24 24 5.0 -- -- -- -- 0.0 0.0 5.0 0.65 2.85 0.18 0.33 0.00 0.33 25 25 5.0 -- -- -- -- 0.0 0.0 5.0 0.57 2.85 0.82 1.34 0.00 1.34 26 26 6.1 -- -- -- -- 0.0 0.0 6.1 0.41 2.67 0.24 0.26 0.00 0.26 27 27 5.0 -- -- -- -- 0.0 0.0 5.0 0.78 2.84 0.63 1.41 0.00 1.41 28 28 5.0 -- -- -- -- 0.0 0.0 5.0 0.77 2.85 0.34 0.75 0.00 0.75 29 29 10.5 -- -- -- -- 0.0 0.0 10.5 0.28 2.17 1.82 1.12 0.00 1.12 OS1 OS1 17.8 -- -- -- -- 0.0 0.0 17.8 0.63 1.72 3.80 4.10 0.00 4.10 Routing 1 1 5.0 -- 0.0 5.0 0.86 2.85 0.39 0.95 0.00 0.95 2 1,2 5.0 132.0 PA 0.4 1.2 1.8 6.8 0.79 2.56 0.84 1.70 0.00 1.70 3 1,2,3 6.8 58.0 PA 0.4 1.2 0.8 7.7 0.77 2.46 1.08 2.06 0.00 2.06 MH 1-5 7.7 113.0 PA 0.4 1.2 1.6 9.2 0.69 2.28 2.50 3.91 0.00 3.91 MH 1-5 9.2 271.0 PA 0.4 1.2 3.8 13.0 0.69 1.98 2.50 3.39 0.00 3.39 6 6 5.0 -- 0.0 5.0 0.66 2.85 0.27 0.50 0.00 0.50 7 6,7 5.0 44.0 PA 0.4 1.2 0.6 5.6 0.76 2.75 0.67 1.40 0.00 1.40 8 6-8 5.6 0.0 PA 0.4 1.2 0.0 5.6 0.77 2.75 0.93 1.96 0.00 1.96 9 6-9 5.6 150.0 PA 0.4 1.2 2.1 7.7 0.79 2.45 1.55 3.02 0.00 3.02 11 6-11 7.7 61.0 PA 0.4 1.2 0.9 8.6 0.79 2.35 2.25 4.21 0.00 4.21 12 6-12 8.6 60.0 PA 0.4 1.2 0.8 9.4 0.80 2.27 2.47 4.46 0.00 4.46 Design Point Basins tc Length Type Slope Velocity Travel Pipe Travel tc' C Intensity Area Direct Runoff Other Runoff Total Runoff Location (min) (ft) (a) (%) (ft/s) (min) (min) (min) (in/hr) (ac) (cfs) (cfs) (cfs) Routing Flow Time (tL Runoff ) 14 14 7.7 -- 0.0 7.7 0.26 2.45 0.46 0.29 0.00 0.29 15 1-15 15.1 -- 0.0 15.1 0.56 1.87 8.57 8.94 0.00 8.94 16 16 8.3 -- 0.0 8.3 0.77 2.39 1.03 1.87 0.00 1.87 17 16,17 8.3 177.0 PA 0.4 1.2 2.5 10.7 0.76 2.15 1.30 2.13 0.00 2.13 MH 16,17 10.7 31.0 PA 0.4 1.2 0.4 11.2 0.76 2.11 1.30 2.09 0.00 2.09 18 18 5.0 -- 0.0 5.0 0.85 2.85 0.46 1.11 0.00 1.11 19 18,19 5.0 29.0 PA 0.4 1.2 0.4 5.4 0.73 2.78 0.68 1.38 0.00 1.38 20 18-20 5.4 44.0 PA 0.4 1.2 0.6 6.0 0.74 2.68 1.32 2.61 0.00 2.61 21 18-21 6.0 86.0 PA 0.4 1.2 1.2 7.2 0.77 2.51 1.97 3.79 0.00 3.79 MH 18-21 7.2 18.0 PA 0.4 1.2 0.3 7.5 0.77 2.48 1.97 3.74 0.00 3.74 22 22 5.0 -- 0.0 5.0 0.83 2.85 0.30 0.71 0.00 0.71 22 16-22 11.2 173.0 PA 0.4 1.2 2.4 13.6 0.77 1.95 3.56 5.35 0.00 5.35 MH 16-22 13.6 62.0 PA 0.4 1.2 0.9 14.5 0.77 1.90 3.56 5.22 0.00 5.22 23 23 19.4 -- 0.0 19.4 0.44 1.64 1.58 1.13 0.00 1.13 MH 23 19.4 201.0 PA 0.4 1.2 2.8 22.2 0.44 1.52 1.58 1.05 0.00 1.05 MH 16-23 22.2 146.0 PA 0.4 1.2 2.0 24.2 0.67 1.45 5.15 5.00 0.00 5.00 24 24 5.0 0.0 5.0 0.65 2.85 0.18 0.33 0.00 0.33 26 24-26 5.0 139.0 PA 0.4 1.2 1.9 6.9 0.55 2.55 1.23 1.74 0.00 1.74 27 24-27 6.9 16.0 PA 0.4 1.2 0.2 7.2 0.63 2.52 1.87 2.97 0.00 2.97 MH 16-27 24.2 -- 0.0 24.2 0.66 1.45 7.01 6.71 0.00 6.71 28 16-28 24.2 5.0 PA 0.4 1.2 0.1 24.3 0.66 1.45 7.35 7.08 0.00 7.08 29 16-29 24.3 33.0 PA 0.4 1.2 0.5 24.7 0.59 1.44 9.18 7.76 0.00 7.76 ALL 1-29 24.7 24.7 0.57 1.44 17.74 14.65 0.00 14.65 OFFSITE Note: a) Codes the channel type for velocity calculations. PA = Paved, PL = Pasture & Lawns, GW = Grassed Waterway ASPEN ENGINEERING 9:09 AM 4/19/2017 Rational Method 100 Year Design Storm Lakeview on the Rise 801-002 Design Point Basins tc Length Type Slope Velocity Travel Pipe Travel tc' C C*Cf Intensity Area Direct Runoff Other Runoff Total Runoff Location (min) (ft) (a) (%) (ft/s) (min) (min) (min) (in/hr) (ac) (cfs) (cfs) (cfs) 1 1 5.0 -- -- -- -- 0.0 0.0 5.0 0.86 1.00 9.95 0.39 3.84 0.00 3.84 2 2 5.0 -- -- -- -- 0.0 0.0 5.0 0.72 0.90 9.95 0.46 4.08 0.00 4.08 3 3 5.0 -- -- -- -- 0.0 0.0 5.0 0.73 0.91 9.95 0.24 2.17 0.00 2.17 4 4 11.5 -- -- -- -- 0.0 0.0 11.5 0.56 0.70 7.28 0.95 4.82 0.00 4.82 5 5 5.0 -- -- -- -- 0.0 0.0 5.0 0.74 0.93 9.95 0.47 4.31 0.00 4.31 6 6 5.0 -- -- -- -- 0.0 0.0 5.0 0.66 0.82 9.95 0.27 2.18 0.00 2.18 7 7 5.0 -- -- -- -- 0.0 0.0 5.0 0.83 1.00 9.95 0.40 4.00 0.00 4.00 8 8 5.0 -- -- -- -- 0.0 0.0 5.0 0.80 1.00 9.95 0.26 2.54 0.00 2.54 9 9 5.0 -- -- -- -- 0.0 0.0 5.0 0.83 1.00 9.95 0.62 6.21 0.00 6.21 10 10 5.0 -- -- -- -- 0.0 0.0 5.0 0.82 1.00 9.95 0.51 5.09 0.00 5.09 11 11 5.0 -- -- -- -- 0.0 0.0 5.0 0.72 0.90 9.95 0.19 1.70 0.00 1.70 12 12 5.0 -- -- -- -- 0.0 0.0 5.0 0.83 1.00 9.95 0.22 2.15 0.00 2.15 13 13 5.0 -- -- -- -- 0.0 0.0 5.0 0.66 0.83 9.95 0.49 4.03 0.00 4.03 14 14 7.4 -- -- -- -- 0.0 0.0 7.4 0.26 0.32 8.70 0.46 1.27 0.00 1.27 15 15 14.6 -- -- -- -- 0.0 0.0 14.6 0.25 0.32 6.60 2.65 5.53 0.00 5.53 16 16 5.0 -- -- -- -- 0.0 0.0 5.0 0.77 0.96 9.95 1.03 9.77 0.00 9.77 17 17 5.0 -- -- -- -- 0.0 0.0 5.0 0.75 0.94 9.95 0.27 2.56 0.00 2.56 18 18 5.0 -- -- -- -- 0.0 0.0 5.0 0.85 1.00 9.95 0.46 4.57 0.00 4.57 19 19 5.0 -- -- -- -- 0.0 0.0 5.0 0.48 0.60 9.95 0.22 1.32 0.00 1.32 20 20 5.0 -- -- -- -- 0.0 0.0 5.0 0.74 0.93 9.95 0.64 5.94 0.00 5.94 21 21 5.0 -- -- -- -- 0.0 0.0 5.0 0.83 1.00 9.95 0.65 6.42 0.00 6.42 22 22 5.0 -- -- -- -- 0.0 0.0 5.0 0.83 1.00 9.95 0.30 2.98 0.00 2.98 Routing Flow Time (tL ) Runoff 23 23 17.2 -- -- -- -- 0.0 0.0 17.2 0.44 0.55 6.08 1.58 5.25 0.00 5.25 24 24 5.0 -- -- -- -- 0.0 0.0 5.0 0.65 0.81 9.95 0.18 1.43 0.00 1.43 25 25 5.0 -- -- -- -- 0.0 0.0 5.0 0.57 0.72 9.95 0.82 5.86 0.00 5.86 26 26 5.5 -- -- -- -- 0.0 0.0 5.5 0.41 0.51 9.63 0.24 1.15 0.00 1.15 27 27 5.0 -- -- -- -- 0.0 0.0 5.0 0.78 0.98 9.95 0.63 6.16 0.00 6.16 28 28 5.0 -- -- -- -- 0.0 0.0 5.0 0.77 0.96 9.95 0.34 3.26 0.00 3.26 29 29 9.8 -- -- -- -- 0.0 0.0 9.8 0.28 0.35 7.80 1.82 5.03 0.00 5.03 OS1 OS1 16.6 -- -- -- -- 0.0 0.0 16.6 0.63 0.79 6.20 3.80 18.49 0.00 18.49 Routing 1 1 5.0 -- 0.0 5.0 0.86 1.00 9.95 0.39 3.84 0.00 3.84 2 1,2 5.0 132.0 PA 0.4 1.2 1.8 6.8 0.79 0.98 8.96 0.84 7.40 0.00 7.40 3 1,2,3 6.8 58.0 PA 0.4 1.2 0.8 7.7 0.77 0.97 8.59 1.08 8.98 0.00 8.98 MH 1-5 7.7 113.0 PA 0.4 1.2 1.6 9.2 0.69 0.86 7.97 2.50 17.07 0.00 17.07 MH 1-5 9.2 271.0 PA 0.4 1.2 3.8 13.0 0.69 0.86 6.92 2.50 14.81 0.00 14.81 6 6 5.0 -- 0.0 5.0 0.66 0.82 9.95 0.27 2.18 0.00 2.18 7 6,7 5.0 44.0 PA 0.4 1.2 0.6 5.6 0.76 0.95 9.59 0.67 6.10 0.00 6.10 8 6-8 5.6 0.0 PA 0.4 1.2 0.0 5.6 0.77 0.96 9.59 0.93 8.55 0.00 8.55 9 6-9 5.6 150.0 PA 0.4 1.2 2.1 7.7 0.79 0.99 8.57 1.55 13.18 0.00 13.18 11 6-11 7.7 61.0 PA 0.4 1.2 0.9 8.6 0.79 0.99 8.22 2.25 18.39 0.00 18.39 Design Point Basins tc Length Type Slope Velocity Travel Pipe Travel tc' C C*Cf Intensity Area Direct Runoff Other Runoff Total Runoff Location (min) (ft) (a) (%) (ft/s) (min) (min) (min) (in/hr) (ac) (cfs) (cfs) (cfs) Routing Flow Time (tL ) Runoff 22 22 5.0 -- 0.0 5.0 0.83 1.00 9.95 0.30 2.98 0.00 2.98 22 16-22 7.9 173.0 PA 0.4 1.2 2.4 10.3 0.77 0.96 7.62 3.56 26.17 0.00 26.17 MH 16-22 10.3 62.0 PA 0.4 1.2 0.9 11.2 0.77 0.96 7.37 3.56 25.31 0.00 25.31 23 23 17.2 -- 0.0 17.2 0.44 0.55 6.08 1.58 5.25 0.00 5.25 MH 23 17.2 201.0 PA 0.4 1.2 2.8 20.0 0.44 0.55 5.60 1.58 4.83 0.00 4.83 MH 16-23 20.0 146.0 PA 0.4 1.2 2.0 22.0 0.67 0.84 5.32 5.15 22.86 0.00 22.86 24 24 5.0 0.0 5.0 0.65 0.81 9.95 0.18 1.43 0.00 1.43 26 24-26 5.0 139.0 PA 0.4 1.2 1.9 6.9 0.55 0.69 8.91 1.23 7.60 0.00 7.60 27 24-27 6.9 16.0 PA 0.4 1.2 0.2 7.2 0.63 0.79 8.81 1.87 12.96 0.00 12.96 MH 16-27 22.0 -- 0.0 22.0 0.66 0.82 5.32 7.01 30.69 0.00 30.69 28 16-28 22.0 5.0 PA 0.4 1.2 0.1 22.1 0.66 0.83 5.31 7.35 32.37 0.00 32.37 29 16-29 22.1 33.0 PA 0.4 1.2 0.5 22.6 0.59 0.73 5.25 9.18 35.41 0.00 35.41 ALL 1-29 22.6 22.6 0.57 0.72 5.25 17.74 66.87 0.00 66.87 Note: a) Codes the channel type for velocity calculations. PA = Paved, PL = Pasture & Lawns, GW = Grassed Waterway ASPEN ENGINEERING 9:08 AM 4/19/2017 25 POND SIZING Volume Provided Project: LVOR Basin Description: Pond 100 Contour Contour Depth Incremental Cumulative Elevation Area (ft) Volume Volume (sq. ft) Avg. End Avg. End (cu. ft) (cu. ft) 10.000 1.96 N/A N/A 0.00 11.000 499.75 1.000 250.86 250.86 12.000 7,318.53 1.000 3909.14 4160.00 13.000 18,138.04 1.000 12728.29 16888.29 14.000 32,798.69 1.000 25468.37 42356.65 15.000 46,444.30 1.000 39621.50 81978.15 16.000 58,670.54 1.000 52557.42 134535.57 VOLUME PROVIDED Project: LVOR Basin Description: POND 200 Contour Contour Depth Incremental Cumulative Elevation Area (ft) Volume Volume (sq. ft) Avg. End Avg. End (cu. ft) (cu. ft) 3.000 5.07 N/A N/A 0.00 4.000 627.69 1.000 316.38 316.38 5.000 3,886.40 1.000 2257.05 2573.43 6.000 8,905.57 1.000 6395.98 8969.41 7.000 13,740.39 1.000 11322.98 20292.39 8.000 19,585.24 1.000 16662.82 36955.21 8.500 7,423.72 0.500 6752.24 43707.45 9.000 34,693.02 0.500 10529.19 54236.64 31 LID Summary Lakeview on the Rise, Fort Collins, Colorado 801-002 New Area (Entire Site) 772,830 sf Site Imperivious Area 371,148 Reqd. Min. Impervious Area to be Treated (75% of Total ImperviousArea) 278,361 sf Area Treated by LID Treatment Method #1 (RAIN GARDEN) (Basin 1-15) 171,054 sf Area Treated by LID Treatment Method #1 (RAIN GARDEN) (Basin 16-29) 200,094 sf Total Impervious Area Treated 371,148 sf Percent LID Treatment Provided for Impervious Site Area 100% LID TABLE Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia = 47.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 0.470 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.16 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 373,118 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = 4,930 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = 0.00 in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER = 0.0 cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum) DWQCV = 12 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 AMin = 3287 sq ft D) Actual Flat Surface Area AActual = 3942 sq ft E) Area at Design Depth (Top Surface Area) ATop = 7436 sq ft F) Rain Garden Total Volume VT= 5,689 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media (SEE LANDSCAPE PLANS AND CIVIL PLANS) 4. Underdrain System A) Are underdrains provided? B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y = ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 = N/A cu ft iii) Orifice Diameter, 3/8" Minimum DO = N/A in Design Procedure Form: Rain Garden (RG) AGW ASPEN ENGINEERING May 23, 2017 Lakeview on the Rise Pond 100 FORT COLLINS, CO Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO RainGardenSizing-LVOR-SW-Pond100, RG 5/23/2017, 10:18 AM Sheet 2 of 2 Designer: Company: Date: Project: Location: 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is an impermeable liner provided due to proximity of structures or groundwater contamination? 6. Inlet / Outlet Control A) Inlet Control 7. Vegetation 8. Irrigation A) Will the rain garden be irrigated? Notes: Design Procedure Form: Rain Garden (RG) AGW ASPEN ENGINEERING May 23, 2017 Lakeview on the Rise Pond 100 FORT COLLINS, CO Choose One Choose One Choose One Sheet Flow- No Energy Dissipation Required Concentrated Flow- Energy Dissipation Provided Plantings Seed (Plan for frequent weed control) Sand Grown or Other High Infiltration Sod Choose One YES NO YES NO RainGardenSizing-LVOR-SW-Pond100, RG 5/23/2017, 10:18 AM Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia = 51.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 0.510 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.17 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 399,712 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = 5,569 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = 0.00 in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER = 0.0 cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum) DWQCV = 12 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 5.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin = 3713 sq ft D) Actual Flat Surface Area AActual = 3876 sq ft E) Area at Design Depth (Top Surface Area) ATop = 7424 sq ft F) Rain Garden Total Volume VT= 5,650 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media (SEE LANDSCAPE PLANS AND CIVIL PLANS) 4. Underdrain System A) Are underdrains provided? B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y = ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 = N/A cu ft iii) Orifice Diameter, 3/8" Minimum DO = N/A in Design Procedure Form: Rain Garden (RG) AGW ASPEN ENGINEERING May 23, 2017 Lakeview on the Rise Pond 200 FORT COLLINS, CO Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO RainGardenSizing-LVOR-SE-Pond200, RG 5/23/2017, 10:19 AM Sheet 2 of 2 Designer: Company: Date: Project: Location: 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is an impermeable liner provided due to proximity of structures or groundwater contamination? 6. Inlet / Outlet Control A) Inlet Control 7. Vegetation 8. Irrigation A) Will the rain garden be irrigated? Notes: Design Procedure Form: Rain Garden (RG) AGW ASPEN ENGINEERING May 23, 2017 Lakeview on the Rise Pond 200 FORT COLLINS, CO Choose One Choose One Choose One Sheet Flow- No Energy Dissipation Required Concentrated Flow- Energy Dissipation Provided Plantings Seed (Plan for frequent weed control) Sand Grown or Other High Infiltration Sod Choose One YES NO YES NO RainGardenSizing-LVOR-SE-Pond200, RG 5/23/2017, 10:19 AM 22 APPENDIX C 23 STORM SEWER PIPE SIZING (TO BE PROVIDED AT FINAL DESIGN) Project Description Friction Method Manning Formula Solve For Full Flow Capacity Input Data Roughness Coefficient 0.013 Channel Slope 0.00400 ft/ft Normal Depth 1.00 ft Diameter 1.00 ft Discharge 2.25 ft³/s Results Discharge 2.25 ft³/s Normal Depth 1.00 ft Flow Area 0.79 ft² Wetted Perimeter 3.14 ft Hydraulic Radius 0.25 ft Top Width 0.00 ft Critical Depth 0.64 ft Percent Full 100.0 % Critical Slope 0.00724 ft/ft Velocity 2.87 ft/s Velocity Head 0.13 ft Specific Energy 1.13 ft Froude Number 0.00 Maximum Discharge 2.42 ft³/s Discharge Full 2.25 ft³/s Slope Full 0.00400 ft/ft Flow Type SubCritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % 12-in Pipe 2/13/2017 9:53:32 PM Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2 GVF Output Data Normal Depth Over Rise 100.00 % Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 1.00 ft Critical Depth 0.64 ft Channel Slope 0.00400 ft/ft Critical Slope 0.00724 ft/ft 12-in Pipe 2/13/2017 9:53:32 PM Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2 Project Description Friction Method Manning Formula Solve For Full Flow Capacity Input Data Roughness Coefficient 0.013 Channel Slope 0.00400 ft/ft Normal Depth 1.50 ft Diameter 1.50 ft Discharge 6.64 ft³/s Results Discharge 6.64 ft³/s Normal Depth 1.50 ft Flow Area 1.77 ft² Wetted Perimeter 4.71 ft Hydraulic Radius 0.38 ft Top Width 0.00 ft Critical Depth 1.00 ft Percent Full 100.0 % Critical Slope 0.00656 ft/ft Velocity 3.76 ft/s Velocity Head 0.22 ft Specific Energy 1.72 ft Froude Number 0.00 Maximum Discharge 7.15 ft³/s Discharge Full 6.64 ft³/s Slope Full 0.00400 ft/ft Flow Type SubCritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % 18-in Pipe 2/13/2017 9:53:56 PM Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2 GVF Output Data Normal Depth Over Rise 100.00 % Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 1.50 ft Critical Depth 1.00 ft Channel Slope 0.00400 ft/ft Critical Slope 0.00656 ft/ft 18-in Pipe 2/13/2017 9:53:56 PM Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2 Project Description Friction Method Manning Formula Solve For Full Flow Capacity Input Data Roughness Coefficient 0.013 Channel Slope 0.00400 ft/ft Normal Depth 2.00 ft Diameter 2.00 ft Discharge 14.31 ft³/s Results Discharge 14.31 ft³/s Normal Depth 2.00 ft Flow Area 3.14 ft² Wetted Perimeter 6.28 ft Hydraulic Radius 0.50 ft Top Width 0.00 ft Critical Depth 1.36 ft Percent Full 100.0 % Critical Slope 0.00613 ft/ft Velocity 4.55 ft/s Velocity Head 0.32 ft Specific Energy 2.32 ft Froude Number 0.00 Maximum Discharge 15.39 ft³/s Discharge Full 14.31 ft³/s Slope Full 0.00400 ft/ft Flow Type SubCritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % 24-in Pipe 2/13/2017 9:54:18 PM Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2 GVF Output Data Normal Depth Over Rise 100.00 % Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 2.00 ft Critical Depth 1.36 ft Channel Slope 0.00400 ft/ft Critical Slope 0.00613 ft/ft 24-in Pipe 2/13/2017 9:54:18 PM Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2 Project Description Friction Method Manning Formula Solve For Full Flow Capacity Input Data Roughness Coefficient 0.013 Channel Slope 0.00400 ft/ft Normal Depth 2.50 ft Diameter 2.50 ft Discharge 25.94 ft³/s Results Discharge 25.94 ft³/s Normal Depth 2.50 ft Flow Area 4.91 ft² Wetted Perimeter 7.85 ft Hydraulic Radius 0.63 ft Top Width 0.00 ft Critical Depth 1.74 ft Percent Full 100.0 % Critical Slope 0.00583 ft/ft Velocity 5.28 ft/s Velocity Head 0.43 ft Specific Energy 2.93 ft Froude Number 0.00 Maximum Discharge 27.90 ft³/s Discharge Full 25.94 ft³/s Slope Full 0.00400 ft/ft Flow Type SubCritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % 30-in Pipe 2/13/2017 9:54:34 PM Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2 GVF Output Data Normal Depth Over Rise 100.00 % Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 2.50 ft Critical Depth 1.74 ft Channel Slope 0.00400 ft/ft Critical Slope 0.00583 ft/ft 30-in Pipe 2/13/2017 9:54:34 PM Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2 Project Description Friction Method Manning Formula Solve For Full Flow Capacity Input Data Roughness Coefficient 0.013 Channel Slope 0.00400 ft/ft Normal Depth 3.00 ft Diameter 3.00 ft Discharge 42.18 ft³/s Results Discharge 42.18 ft³/s Normal Depth 3.00 ft Flow Area 7.07 ft² Wetted Perimeter 9.42 ft Hydraulic Radius 0.75 ft Top Width 0.00 ft Critical Depth 2.12 ft Percent Full 100.0 % Critical Slope 0.00560 ft/ft Velocity 5.97 ft/s Velocity Head 0.55 ft Specific Energy 3.55 ft Froude Number 0.00 Maximum Discharge 45.37 ft³/s Discharge Full 42.18 ft³/s Slope Full 0.00400 ft/ft Flow Type SubCritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % 36-in Pipe 2/13/2017 9:54:51 PM Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2 GVF Output Data Normal Depth Over Rise 100.00 % Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 3.00 ft Critical Depth 2.12 ft Channel Slope 0.00400 ft/ft Critical Slope 0.00560 ft/ft 36-in Pipe 2/13/2017 9:54:51 PM Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2 24 APPENDIX D 25 *INLET, *CONCRETE SIDEWALK CULVERT SIZING, PUBLIC STREET CAPACITIES (*TO BE PROVIDED AT FINAL DESIGN) Major Storm Design contraints: Local: The depth of water over the crown shall not exceed 6 inches. Arterial and Major Arterial: Depth of water not to exceed 6 inches above the crown or 18 inches above gutter flowline. * Road width equals the width of pavement covered by water for one side of the road out from the edge of gutter pan. Vertical Curb & Gutter Design Point 3 4 5 13 27 28 Input *Width of road section from edge of gutter pan (ft.): 16.00 16.00 16.00 16.00 16.00 16.00 Road elevation at end of road width (ft.): 0.41 0.41 0.41 0.41 0.41 0.41 Flood water elevation (ft.): 0.91 0.91 0.91 0.91 0.91 0.91 Gutter slope (ft/ft): 0.038 0.023 0.023 0.021 0.028 0.028 Cross slope of road (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 Cross slope of sidewalk (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 Sidewalk width (ft.): 4.50 4.50 4.50 4.50 4.50 4.50 Detachment width (ft.): 5.50 5.50 5.50 5.50 5.50 5.50 Cross slope of detachment (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 Street Capacity Computes flow capacities for a given section of Road Lakeview on the Rise 801-002 Cross slope of detachment (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 Cross slope behind back of walk (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 Output Check flood depth over gutter flowline (< 1.5 ft.) OK OK OK OK OK OK Theoretical Capacity (cfs): 121.17 93.86 93.86 90.93 103.45 103.45 Theoretical Velocity (ft/s): 5.93 4.60 4.60 4.45 5.07 5.07 Reduction Factor: 0.62 0.78 0.78 0.79 0.74 0.74 Allowable Capacity (cfs): 75.71 73.36 73.36 72.09 76.20 76.20 Q100 2.17 4.82 4.31 4.03 6.16 3.26 Driveover Curb & Gutter Design Point 3 4 5 13 27 28 Input *Width of road section from edge of gutter pan (ft.): 16.00 16.00 16.00 16.00 16.00 16.00 Road elevation at end of road width (ft.): 2.00 2.00 2.00 2.00 2.00 2.00 Flood water elevation (ft.): 2.50 2.50 2.50 2.50 2.50 2.50 Gutter slope (ft/ft): 0.038 0.023 0.023 0.021 0.028 0.028 Cross slope of road (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 Cross slope behind back of walk (decimal): 0.02 0.02 0.02 0.02 0.02 0.02 Output Theoretical Capacity (cfs): 124.22 96.22 96.22 93.22 106.05 106.05 Theoretical Velocity (ft/s): 6.59 5.11 5.11 4.95 5.63 5.63 Reduction Factor: 0.62 0.78 0.78 0.79 0.74 0.74 Allowable Capacity (cfs): 77.61 75.20 75.20 73.90 78.12 78.12 Q100 2.17 4.82 4.31 4.03 6.16 3.26 ASPEN ENGINEERING 3:57 PM 4/5/2017 Minor Storm Design constraints: Local: No curb-topping. Flow may spread to crown of street. Collector: No curb-topping. Flow spread must leave at least one lane width free of water. Major Arteial: No curb-topping. Flow must leave at least 1/2 of roadway width free of water in each direction. Vertical Curb & Gutter Design Point 3 4 5 13 27 28 Input Flood water elevation (ft.): 0.50 0.50 0.50 0.50 0.50 0.50 Gutter flowline elevation (ft.): 0.00 0.00 0.00 0.00 0.00 0.00 Cross slope of road (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 Gutter slope (ft/ft): 0.038 0.023 0.023 0.021 0.028 0.028 Street Capacity Computes flow capacities for a given section of Road Lakeview on the Rise 801-002 Gutter slope (ft/ft): 0.038 0.023 0.023 0.021 0.028 0.028 Output Lateral spread of water from edge of gutter pan: 16.50 16.50 16.50 16.50 16.50 16.50 Theoretical Capacity (cfs): 26.38 20.43 20.43 19.79 22.52 22.52 Theoretical Velocity (ft/s): 7.42 5.75 5.75 5.57 6.34 6.34 Reduction Factor: 0.62 0.78 0.78 0.79 0.74 0.74 Allowable Capacity (cfs): 16.48 15.97 15.97 15.69 16.59 16.59 Q2 0.50 0.99 0.99 0.92 1.41 0.75 Driveover Curb & Gutter Design Point 3 4 5 13 27 28 Input Flood water elevation (ft.): 0.39 0.39 0.39 0.39 0.39 0.39 Gutter flowline elevation (ft.): 0.00 0.00 0.00 0.00 0.00 0.00 Cross slope of road (ft/ft): 0.02 0.02 0.02 0.02 0.02 0.02 Gutter slope (ft/ft): 0.038 0.023 0.023 0.021 0.028 0.028 Output Lateral spread of water from edge of gutter pan: 13.80 13.80 13.80 13.80 13.80 13.80 Theoretical Capacity (cfs): 16.56 12.83 12.83 12.43 14.14 14.14 Theoretical Velocity (ft/s): 6.44 4.99 4.99 4.83 5.50 5.50 Reduction Factor: 0.62 0.78 0.78 0.79 0.74 0.74 Allowable Capacity (cfs): 10.35 10.03 10.03 9.85 10.42 10.42 Q2 0.50 0.99 0.99 0.92 1.41 0.75 ASPEN ENGINEERING 3:56 PM 4/5/2017 26 APPENDIX E 27 SWALE SIZING (TO BE PROVIDED AT FINAL DESIGN) 28 APPENDIX F 29 EROSION CONTROL & RIPRAP SIZING & EROSION CONTROL ESCROW ESTIMATE (TO BE PROVIDED AT FINAL DESIGN) 30 APPENDIX G 31 PROPOSED & EXISTING DRAINAGE BASIN EXHIBITS, EROSION CONTROL PLAN, & EROSION CONTROL NOTES AND DETAILS SHEET 12 6-12 8.6 60.0 PA 0.4 1.2 0.8 9.4 0.80 1.00 7.92 2.47 19.48 0.00 19.48 MH 6-12 9.4 67.0 PA 0.4 1.2 0.9 10.3 0.80 1.00 7.61 2.47 18.74 0.00 18.74 13 1-13 5.0 -- 0.0 5.0 0.66 0.83 9.95 0.49 4.03 0.00 4.03 MH 1-13 13.0 89.0 PA 0.4 1.2 1.2 14.3 0.73 0.92 6.66 5.45 33.33 0.00 33.33 FES 1-13 14.3 57.0 PA 0.4 1.2 0.8 15.1 0.73 0.92 6.51 5.45 32.56 0.00 32.56 14 14 7.4 -- 0.0 7.4 0.26 0.32 8.70 0.46 1.27 0.00 1.27 15 1-15 15.1 -- 0.0 15.1 0.56 0.70 6.51 8.57 38.96 0.00 38.96 16 16 5.0 -- 0.0 5.0 0.77 0.96 9.95 1.03 9.77 0.00 9.77 17 16,17 5.0 177.0 PA 0.4 1.2 2.5 7.5 0.76 0.95 8.67 1.30 10.74 0.00 10.74 MH 16,17 7.5 31.0 PA 0.4 1.2 0.4 7.9 0.76 0.95 8.48 1.30 10.51 0.00 10.51 18 18 5.0 -- 0.0 5.0 0.85 1.00 9.95 0.46 4.57 0.00 4.57 19 18,19 5.0 29.0 PA 0.4 1.2 0.4 5.4 0.73 0.91 9.71 0.68 6.01 0.00 6.01 20 18-20 5.4 44.0 PA 0.4 1.2 0.6 6.0 0.74 0.92 9.37 1.32 11.40 0.00 11.40 21 18-21 6.0 86.0 PA 0.4 1.2 1.2 7.2 0.77 0.96 8.78 1.97 16.56 0.00 16.56 MH 18-21 7.2 18.0 PA 0.4 1.2 0.3 7.5 0.77 0.96 8.67 1.97 16.35 0.00 16.35 ASPEN ENGINEERING 9:08 AM 4/19/2017 MH 6-12 9.4 67.0 PA 0.4 1.2 0.9 10.3 0.80 2.18 2.47 4.29 0.00 4.29 13 1-13 5.0 -- 0.0 5.0 0.66 2.85 0.49 0.92 0.00 0.92 MH 1-13 13.0 89.0 PA 0.4 1.2 1.2 14.3 0.73 1.91 5.45 7.65 0.00 7.65 FES 1-13 14.3 57.0 PA 0.4 1.2 0.8 15.1 0.73 1.87 5.45 7.47 0.00 7.47 ASPEN ENGINEERING 9:09 AM 4/19/2017