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HomeMy WebLinkAboutPRECISION TECHNOLOGY - PDP200013 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTPRELIMINARY DRAINAGE & EROSION CONTROL REPORT 1501 ACADEMY CT. STE 203 | FORT COLLINS, CO 80524 | 970-530-4044 | www.unitedcivil.com PRECISION TECHNOLOGY Harmony Technology Park Fifth Filing Lot 2 Fort Collins, CO Prepared for: Precision Technology LLC 224 Canyon Avenue Unit 624 Fort Collins, CO 80521 Date: August 12, 2020 PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO i U20015_Drainage Report August 12, 2020 City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, Colorado 80521 RE: Precision Technology Fort Collins, Colorado Project Number: U20015 Dear Staff: United Civil Design Group, LLC. is pleased to submit this Preliminary Drainage and Erosion Control Report for the Precision Technology site in Fort Collins, Colorado. In general, this report serves to document the stormwater impacts associated with the proposed improvements related to the existing site. We understand that review by the City of Fort Collins is to assure general compliance with standardized criteria contained in the Fort Collins Stormwater Criteria Manual (FCSCM). This report was prepared in compliance with technical criteria set forth in both the Urban Drainage and Flood Control District (UDFCD) Urban Storm Drainage Criteria Manual and the Fort Collins Stormwater Criteria Manual. If you should have any questions or comments as you review this report, please feel free to contact us at your convenience. Sincerely, United Civil Design Group, LLC Nate Stroud, PE, LSIT Professional Engineer II PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO ii U20015_Drainage Report TABLE OF CONTENTS I. General Location and Description ................................................................................................................ 1 A. Location and Project Description .............................................................................................. 1 B. Description of Property ............................................................................................................ 2 C. Floodplains .............................................................................................................................. 2 II. Drainage Basins and Sub-Basins ................................................................................................................... 2 A. Major Basin Description ........................................................................................................... 2 B. Sub-Basin Description .............................................................................................................. 3 III. Drainage Design Criteria .............................................................................................................................. 3 A. Regulations .............................................................................................................................. 3 B. Directly Connected Impervious Area (DCIA) ............................................................................. 3 C. Hydrological Criteria ................................................................................................................ 3 D. Hydraulic Criteria ..................................................................................................................... 4 E. Modifications of Criteria .......................................................................................................... 4 IV. Drainage Facility Design............................................................................................................................... 4 A. General Concept ...................................................................................................................... 4 B. Specific Details ......................................................................................................................... 4 V. Erosion Control ............................................................................................................................................ 8 VI. Conclusions ................................................................................................................................................. 9 A. Compliance with Standards ...................................................................................................... 9 B. Drainage Concept .................................................................................................................... 9 C. Stormwater Quality .................................................................................................................. 9 VII. References ............................................................................................................................................. 10 APPENDICES APPENDIX A – Hydrology Calculations APPENDIX B – Hydraulic Calculations B.1 – Low Impact Development Calculations B.2 – Water Quality Calculations B.3 – Orifice Calculations (Reserved for Final Submittal) B.4 – Inlet Sizing Calculations (Reserved for Final Submittal) B.5 – Storm Pipe Calculations (Reserved for Final Submittal) B.6 – Curb Channel Calculations (Reserved for Final Submittal) B.7 – Weir Calculation (Reserved for Final Submittal) APPENDIX C – Referenced Materials APPENDIX D – Drainage Exhibits PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO 1 U20015_Drainage Report I. GENERAL LOCATION AND DESCRIPTION A. LOCATION AND PROJECT DESCRIPTION The Precision Tech II site (referred herein as “the site”) is the development of Lot 2, Harmony Technology Park Fifth Filing, located in the northwest quarter of Section 4, Township 6 North, Range 68 West of the 6th P.M., City of Fort Collins, Larimer County, Colorado. The property, consisting of approximately 4.65 acres, is located immediately north of Precision Drive, approximately 350-feet east of Technology Parkway and currently exists as vacant land in Harmony Technology Park. The proposed site improvements are limited to the 4.65 acres contained in Lot 2. The property is bounded by Precision Drive to the south, recently developed commercial businesses to the east and west, and an existing detention pond and park in the lot to the north. On site detention will not be provided with this site and was previously included in the Harmony Technology Park Stormwater Plan. A majority of the stormwater on the site currently drains southeast via sheet flow to existing drainage swales which is then collected by storm sewer infrastructure in Precision Drive and ultimately conveyed to a regional detention pond (Pond 110) at the intersection of Lady Moon Drive and Rock Creek Drive. There is also a small portion of the site that drains north via sheet flow to the existing Harmony Commons Pond which combines ponds 101, 301, and 600 from the previously mentioned master plan. Refer to the appendix for more information regarding the existing master plan and detention ponds. The proposed development of the site consists of the construction of a new commercial building with a 106,700-sf footprint. Associated with the building are proposed drive lanes, parking, utilities, and water quality features. On-site stormwater is largely designed to discharge to the existing stormwater infrastructure in Precision Drive. FIGURE 1: SITE VICINITY MAP In general, this report serves to provide an analysis of the drainage impacts associated with the development of site as it relates to existing and proposed drainage facilities on-site and to confirm that the development adheres to the requirements set forth in the master drainage study for the subdivision. Precision Dr Technology Pkwy Harmony Rd Ziegler Rd PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO 2 U20015_Drainage Report B. DESCRIPTION OF PROPERTY The project site currently exists as a vacant lot with native grasses and an existing imperviousness of approximately 2%. In its existing (non-historic) condition, a minor portion of the site drains to the existing Harmony Commons Pond to the north and a majority of the site drains to the southeast corner of the site to an existing drainage swale where it is collected by existing storm sewer infrastructure and ultimately conveyed to another existing detention pond (Pond 110). Below are summaries of key components of the site in its existing conditions. Land Use - The site’s current land use is commercial. Ground Cover - The site is currently covered with native grasses and weeds. The weed/grass cover is good (ie., heavy or dense cover with nearly all ground surfaces protected by vegetation). Existing Topography – Historically, the site slopes in two general directions: northerly and southeasterly. A majority of the property drains to the southeast corner to existing storm sewer infrastructure located within Precision Drive, and a minor portion of the property sheet flows to the north to the existing Harmony Commons Pond. Grades – In general, the site is sloped southeasterly at approximately 0.5% to 2.0%; the southern portion of the site is sloped northerly at approximately 0.5% to 2.0%. There is also a large drainage swale at the southeast corner with slopes between 20% and 33%. Soil Type - The USDA’s Web Soil Survey shows that the site consists of a “Type C” soil. The Web Soil Survey indicates the site is comprised of Nunn Clay Loam (1 to 3% slopes). The on-site soils provide slow infiltration. Utilities – Both wet and dry utilities are present in the Precision Drive right-of-way to the south of the site. Water, storm, and sanitary mains are all present within Precision Drive while dry utilities including fiber, electric, and gas are present in the south portion of the right-of-way of Precision Drive. There also appears to be gas and electric lines near the southeast corner of the site in the adjacent property. Drainage Features and Storm Sewer – Existing storm sewer is present at the southeast corner of the site as well as within Precision Drive. Regional detention ponds also exist to the north and southeast which collect runoff from the site. C. FLOODPLAINS The proposed development is not in a FEMA designated or City Designated floodplain. According to the FEMA Flood Insurance Rate Map Panel, the site is zoned as an area outside of the 500-year floodplain. The FEMA FIRM Map is included in the appendix. II. DRAINAGE BASINS AND SUB-BASINS A. MAJOR BASIN DESCRIPTION The proposed development is located within the McClellands Basin as delineated on the City of Fort Collins Stormwater Basin Map. The site has also been previously accounted for in the Harmony Technology Park Site Master Plan Drainage Report as well as the Harmony Technology Third Filing Drainage Study, and the proposed development will be in conformance with both of these studies. FIGURE 2: FLOODPLAIN MAP PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO 3 U20015_Drainage Report B. SUB-BASIN DESCRIPTION The existing site is located within sub-basin 180 of the HTP Third Filing and SWMM Basin 100 and 601 of the HTP Site Master Plan Drainage Report. The proposed site and project will be in conformance with both these reports. Improvements limited to a storm sewer extension was also provided from the HTP Fourth Filing project to the east of the site. In its developed condition, runoff from the site will largely be directed south and east to proposed bioretention ponds either via overland flow to surface improvements or via proposed storm sewer. A portion of the site on the north and south sides will drain to Precision Drive (south) and Harmony Commons Pond (north). Additionally, a minor portion of the site, largely all pervious area, will continue to drain offsite to the west to existing bioretention ponds on the neighboring property. III. DRAINAGE DESIGN CRITERIA A. REGULATIONS The design criteria for this study are directly from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards Manual and the Urban Storm Drainage Criteria Manuals Volumes 2, and 3 (referred to herein as USDCM). B. DIRECTLY CONNECTED IMPERVIOUS AREA (DCIA) With the adoption of the USDCM, the City has also adopted the “Four Step Process” that is recommended in Volume 3 of the USDCM in selecting structural BMPs for the redeveloping urban areas. The following portions of this summary describe each step and how it has been utilized for this project: Step 1 – Employ Runoff Reduction Practices The objective of this step is to reduce runoff peaks and volumes and to employ the technique of “minimizing directly connected impervious areas” (MDCIA). This project accomplishes this by: Routing the roof and pavement flows through a bioretention facility and vegetated swales to increase time of concentration, promote infiltration and provide water quality. Step 2 – Provide Water Quality Capture Volume (WQCV) The objective of providing WQCV is to reduce the sediment load and other pollutants that exit the site. For this project WQCV is provided within the existing regional ponds offsite. The site will, however, provide additional water quality to meet the City’s Low Impact Development requirements through the use of onsite bioretention ponds. Step 3 – Stabilize Drainageways The site is not adjacent or near a major drainageway. Step 4 – Consider Need for Site Specific and Source Control BMPs Site specific and source control BMPs are generally considered for large industrial and commercial sites. The development of the site will include multiple site specific and source controls, including:  Dedicated maintenance personnel providing landscape maintenance and snow and ice management. C. HYDROLOGICAL CRITERIA City of Fort Collins Rainfall Intensity-Duration-Frequency Curves, provided by Figure RA-16 of the Fort Collins Stormwater Criteria Manual, are utilized for all hydrologic computations related to the site in its existing/historic and proposed conditions. Since this site is relatively small and does not have complex drainage basins, the peak flow rates for design points have been calculated based on the Rational Method as described in the USDCM and the City of Fort Collins Stormwater Criteria Manual (FCSCM) with storm duration set equal to the time of concentration for each sub-basin. This method was used to analyze the developed runoff from the 10-year (minor) and the 100-year (major) storm events. The Rational Method is widely accepted PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO 4 U20015_Drainage Report for drainage design involving small drainage areas (less than 160 acres) and short time of concentrations. Runoff coefficients are assumed based on impervious area and are given in the Appendices. D. HYDRAULIC CRITERIA The developed site will convey runoff to the proposed pond or underground treatment facility via swales, concrete channels, and pipes. The City of Fort Collins Stormwater Criteria Manual (FCSCM) and USDCM are referenced for all hydraulic calculations. In addition, the following computer programs are utilized:  Storm Sewer Extension for AutoCAD Civil3D  Hydraflow Express Extension for AutoCAD Civil3D  UD-Inlet by UDFCD Drainage conveyance facility capacities proposed with the development project, including storm sewer, swales, and inlet capacities, are designed in accordance with criteria outlined in the FCSCM and/or the Urban Drainage and Flood Control District’s Urban Storm Drainage Criteria Manual (UDFCD). E. MODIFICATIONS OF CRITERIA No drainage variances or modifications of drainage criteria are proposed for this project. IV. DRAINAGE FACILITY DESIGN A. GENERAL CONCEPT Developed runoff is designed to be conveyed in a safe and effective manner via swales, concrete channels, and storm sewer systems/inlets. Stormwater is designed to be released to either the Harmony Commons Pond to the north or existing stormwater infrastructure in Precision Drive to the south and ultimately to Pond 110. Onsite runoff from the improved site will be conveyed to bioretention ponds at the northeast and southeast corners of the site. Additionally, a minor portion of the site, largely all pervious area, will continue to drain offsite to the west to existing bioretention ponds on the neighboring property. B. SPECIFIC DETAILS Hydrology As previously stated, hydrology from the developed site is designed to comply with criteria set forth in the City of Fort Collins Stormwater Criteria Manual. Referenced tables, charts, formulas, etc. are included in the appendices. The area, time of concentration, and runoff of each proposed sub-basin is summarized in Appendix A. The following information outlines the basin characteristics and drainage patterns for each basin. On-site Basins The following basins provide proposed drainage delineations for the site in its improved condition. Refer to Appendix A for hydrology computations and Appendix B for calculations related to Water Quality, Low Impact Development, and other hydraulic features. Basin A Sub-basins A1-A4 (see Drainage Plan attached) are generally located around the south and east region of the site while sub- basins A1.1-A1.6 represent the east and north roof areas of the proposed buildings. These basins consist of roofs, concrete and asphalt paving and landscaping. Runoff within these basins is conveyed to bioretention Pond A via downspouts, inlets, curb and gutter, and storm sewer. Runoff conveyed to bioretention Pond A is discharged to the existing storm sewer stub from the property to the east which is conveyed to the storm sewer system within Precision Drive and ultimately south to regional detention Pond 110 at the intersection of Lady Moon Drive and Rock Creek Drive. Basin B PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO 5 U20015_Drainage Report Sub-basins B1-B2 are generally located around the northeast corner of the site. These sub-basins represent on-site drainage basins where runoff is captured and conveyed to a bioretention Pond B. These basins consist of concrete and asphalt paving and landscaping. Sub-basin B1 largely consists of the pond area - runoff within this area drains directly to the pond via sheet flow. Runoff within sub-basin B2 is conveyed to the Pond B via curb and is conveyed to bioretention Pond B via a curb cut and swale. An outlet structure is proposed with the bioretention Pond B and is designed to release stormwater to the proposed storm sewer infrastructure and ultimately to bioretention Pond A. Basin C Sub-basins C1 and C1.1-C1.6 are generally located on the south side of the site. These sub-basins consist primarily of roofing, concrete walks, and landscaped area. Runoff within these basins is conveyed to Precision via sheet flow and storm sewer/roof drains. Basin D Basin D1 consists primarily of landscaped area and concrete pavement. Due to grading constraints, runoff developed within this basin drains off-site undetained via sheet flow and ultimately to the existing bioretention pond southwest of the site. The impervious area from Basin D1 is only 1,079 square feet (sidewalk) and no negative impacts are foreseen from this small amount of additional impervious area being drained to the existing rain garden at the southeast corner of the neighboring property to the east. Basin E Basin E1, similar to Basin D1, consists primarily of landscaped area concrete pavement. Due to grading constraints, runoff developed within this basin drains off-site undetained to the west via sheet flow and ultimately to the existing bioretention pond northwest of the site. The impervious area from Basin E1 is approximately 1,900 square, of which 1,400 square feet is already existing. Therefore, the additional impervious area generated from Basin E1 is only 500 square feet. Due to the minor increase in impervious area, no negative impacts are foreseen for this additional impervious area draining to the existing rain garden at the northeast corner of the neighboring property to the west. Basin F Sub-basins F1-F2 are generally located around the north end of the site. These sub-basins consist of concrete and asphalt paving and landscaping. Runoff within these basins drains off-site undetained to the north via sheet flow and ultimately to the existing Harmony Commons Pond. Detention and Water Quality Water Quality Standard water quality is provided for this site in the offsite regional detention ponds, Harmony Common Ponds to the north and Pond 110 to the south of the site. The development of this site will require less water quality than originally assumed as per the Regional Detention Pond Comparison Chart on the following page. Additional water quality per the City’s newer Low Impact Development requirements will be provided on site. See Low Impact Development section later in the report. Detention Stormwater Detention is provided for this site in the offsite regional detention ponds, Harmony Common Ponds to the north and Pond 110 to the south of the site. The development of this site will require less stormwater detention than originally assumed as per the Regional Detention Pond Comparison Chart on the following page so no additional onsite detention is necessary. The HTP Site Master Plan Drainage Report allows for a developed impervious value of up to 80% for the proposed site with flow being released undetained from the site to Harmony Commons Pond (north) or Pond 110 (south). The HTP Site Master Plan Drainage Report had accounted for approximately 0.78 acres of area from the proposed site draining to the north to Harmony Commons Pond and 3.90 acres of area of the proposed site draining to the south to Pond 110. In its developed condition, 4.24 acres of the site will drain to the south and 0.44 acres of the site will drain to the north. Although more area PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO 6 U20015_Drainage Report will be draining to the south now, the imperviousness is at 72% and ultimately less impervious area will be draining to Pond 110. Below is a comparison of the areas and imperviousness for the existing and proposed basins. Regional Detention Pond Comparison Chart: Pond Previously Planned Area (sf) Proposed Area (sf) Master Plan Proposed Imperviousness (%) Developed Imperviousness (%) Master Plan Proposed Impervious Area (Assumes 80% Imperviousness) Proposed Impervious Area (sf) Harmony Commons (north) 34,035 19,008 80% 54.7% 27,228 11,722 Pond 110 (south) 169,668 184,693 80% 72.3% 135,734 133,533 Refer to the existing drainage exhibit in the appendix for more information on these areas and how the existing basin line associates with the proposed site. Low Impact Development (LID) In December of 2015, Fort Collins City Council adopted the revised Low Impact Development (LID) policy and criteria which requires developments within City limits to meet certain enhanced stormwater treatment requirements in addition to more standard treatment techniques. The proposed development will be required to meet the newly adopted LID criteria which requires the following: - Treat no less than 75% of any newly added impervious area using one or a combination of LID techniques. - Treat no less than 50% of any newly added impervious area using one or a combination of LID techniques when at least 25% of any newly added pavement is provided with permeable pavement. The following measures are implemented with this proposed development: I. Bioretention Bioretention is designed to remove sediment and pollution from stormwater runoff via infiltration through an engineered sand media. This slows the conveyance rate of storm water runoff, reduces runoff and provides a flow path across a vegetated surface. Two bioretention ponds are proposed with the site improvements and are utilized to convey and treat stormwater prior to release to Precision Drive. Bioretention Pond A Sub-basins A1-A4 and A1.1-A1.6, with 92,558-sf of proposed impervious area, are designed to be conveyed to a bioretention Pond A. The proposed impervious area treated through this bioretention pond includes proposed concrete and asphalt paving and roof areas in Basin A. Approximately 2,610-cf of volume in the bioretention pond, with up to one foot of depth, is designed specifically for water quality. This volume slightly exceeds the required WQCV for Basin A (2,541-cf). This pond is located at the southeast corner of the site and provides up to one foot of depth specifically for bioretention and WQCV purposes for the A Basins. Ponding above the initial one foot of depth will be conveyed through an outlet structure to existing downstream storm sewer infrastructure. Additionally, overflow paths have also been designed and considered in relation to bioretention Pond A to ensure that developed stormwater be managed in a safe and effective manner. Sub-basins B1-B2, with 18,714-sf of proposed impervious area, are designed to be conveyed to bioretention Pond B. PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO 7 U20015_Drainage Report and WQCV purposes for the B Basins. Ponding above the initial one foot of depth will be conveyed through an outlet structure to proposed storm sewer infrastructure and ultimately to bioretention Pond A. Additionally, overflow paths have also been considered in relation to bioretention Pond B to ensure that developed stormwater be managed in a safe and effective manner. The two bioretention ponds noted above treat approximately 75% of the proposed impervious area of the site. Refer to Appendix B for calculations. Below is a summary of the bioretention ponds: Pond Bottom of Pond Elevation Bioretention WSEL Bioretention Volume Required (cf) Bioretention Volume Provided (cf) Pond A 4908.50 4909.50 2,541 2,610 Pond B 4911.00 4912.00 494 648 Drainage Summary A basin summary table is included below: Proposed Basins Basin Area %I C2 C100 Q2 Q100 (acre) (cfs) (cfs) A1 0.27 2% 0.25 0.31 0.18 0.79 A2 0.12 86% 0.87 1.00 0.30 1.20 A3 0.17 86% 0.86 1.00 0.42 1.70 A4 0.09 90% 0.95 1.00 0.25 0.90 A1.1 0.06 90% 0.95 1.00 0.17 0.64 A1.2 0.06 90% 0.95 1.00 0.16 0.58 A1.3 0.47 90% 0.95 1.00 1.26 4.63 A1.4 0.45 90% 0.95 1.00 1.21 4.43 A1.5 0.46 90% 0.95 1.00 1.23 4.53 A1.6 0.50 90% 0.95 1.00 1.34 4.93 A Total 2.64 81% 0.87 1.00 6.52 24.35 B1 0.06 2% 0.25 0.31 0.05 0.20 B2 0.53 81% 0.83 1.00 1.16 5.24 B Total 0.59 73% 0.76 0.95 1.21 5.44 C1 0.59 29% 0.47 0.58 0.55 2.48 C1.1 0.04 90% 0.95 1.00 0.12 0.43 C1.2 0.06 90% 0.95 1.00 0.16 0.57 C1.3 0.13 90% 0.95 1.00 0.34 1.24 C1.4 0.10 90% 0.95 1.00 0.28 1.01 C1.5 0.06 90% 0.95 1.00 0.15 0.57 C1.6 0.06 90% 0.95 1.00 0.15 0.56 C Total 1.03 55% 0.67 0.84 1.74 6.86 D1 0.09 26% 0.44 0.55 0.12 0.50 E1 0.11 37% 0.52 0.66 0.17 0.73 F1 0.08 2% 0.25 0.31 0.06 0.26 F2 0.30 77% 0.78 0.98 0.66 2.88 F Total 0.38 60% 0.66 0.83 0.72 3.15 Proposed Total 4.85 71% 0.78 0.98 10.47 41.03 PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO 8 U20015_Drainage Report In its improved condition, the total site imperviousness is approximately 71% and well below the assumed 80% in the HTP Site Master Plan Drainage Report; therefore, the site drainage is in compliance with the HTP Site Master Plan Drainage Report. Standard Operating Procedures (SOPs) In order for physical stormwater Best Management Practices (BMPs) to be effective, proper maintenance is essential. Maintenance includes both routinely scheduled activities, as well as non-routine repairs that may be required after large storms, or as a result of other unforeseen problems. Standard Operating Procedures should clearly identify BMP maintenance responsibility. BMP maintenance is typically the responsibility of the entity owning the BMP. Identifying who is responsible for maintenance of BMPs and ensuring that an adequate budget is allocated for maintenance is critical to the long-term success of BMPs. Maintenance responsibility may be assigned either publicly or privately. For this project, the privately owned BMPs including grass swales and the bioretention pond, are to be maintained by the property owner. Storm Sewers There are multiple storm sewer networks proposed with the site improvements. Related to conveyance of runoff to the bioretention ponds, multiple roof drain systems are interconnected to storm sewer infrastructure which outfalls to the bioretention ponds. Additional roof drains on the south side of the site are interconnected as well but outfall to existing storm sewer within Precision Drive. All storm sewers will be private and are sized to accommodate the flows from the 100- year storm event. Hydraulic computations of these systems will be provided with the initial final compliance submittal. Inlets There are multiple inlets proposed with the site improvements, including nyloplast drain basins, a Type D Inlet, a Type C Inlet, and Curb inlets. The Curb Inlets are designed in a sump condition to capture runoff produced in Basins A2 and A3. On-site drain basins are designed in a sump condition and are designed to convey runoff produced within smaller interior basins to the proposed storm sewer and bioretention ponds. The Type D and Type C inlets are used as outlet structure for the proposed bioretention ponds and will convey 100-yr storm events from the ponds to downstream storm sewer infrastructure. All inlets on the site are sized to provide adequate capacity and convey the 100-year storm event. Hydraulic computations of these systems will be provided with the initial final compliance submittal. V. EROSION CONTROL A separate Erosion Control Report / Storm Water Management Plan (SWMP) will be prepared for the site in accordance with the Stormwater Discharge Permit for Colorado Department of Public Health and Environment as the site will disturb an area greater than 1-acre. The Erosion Control Report will be completed during the Final Compliance phase of the project and will include more detailed information on the sediment and erosion control items for this project. It is intended that the proposed improvements will comply with Erosion Control Criteria per the FCSCM, and all Erosion Control Materials will be provided with the Final Drainage Report. At a minimum, the following temporary BMP’s will be installed and maintained to control on-site erosion and prevent sediment from traveling off-site during construction:  Silt Fence – a woven synthetic fabric that filters runoff. The silt fence is a temporary barrier that is placed at the base of a disturbed area.  Vehicle Tracking Control – a stabilized stone pad located at points of ingress and egress on a construction site. The stone pad is designed to reduce the amount of mud transported onto public roads by construction traffic.  Riprap – Riprap will be used downstream of all storm sewer outfalls to control erosion of the receiving channels.  Inlet Protection – acts as a sediment filter. It is a temporary BMP and requires proper installation and maintenance to ensure their performance.  Straw Wattles – wattles act as a sediment filter in swales around inlets. They are a temporary BMP and require proper installation and maintenance to ensure their performance. PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO 9 U20015_Drainage Report The contractor shall store all construction materials and equipment and shall provide maintenance and fueling of equipment in confined areas on-site from which runoff will be contained and filtered. Temporary Best Management Practices (BMP’s) will be inspected by the contractor at a minimum of once every two weeks and after each significant storm event. VI. CONCLUSIONS A. COMPLIANCE WITH STANDARDS Storm drainage calculations have followed the guidelines provided by the Urban Storm Drainage Criteria Manuals Volumes 1, 2 and 3 and the City of Fort Collins Stormwater Criteria Manual. B. DRAINAGE CONCEPT The drainage system has been designed to convey the runoff to the designated design points and the existing public infrastructure and regional detention ponds in an effective, safe manner. No negative impacts are anticipated to the City of Fort Collins Master Drainage Plan, to the HTP Site Master Plan, or to downstream properties or infrastructure due to the proposed improvements. C. STORMWATER QUALITY Multiple long-term stormwater quality measures have been selected for the site that will provide treatment of stormwater prior it to being discharged from the site. For this site this includes grass swales, two bioretention ponds and offsite regional detention ponds that include stormwater quality. PRELIMINARY DRAINAGE & E ROSION CONTROL REPORT PRECISION TECHNOLOGY FORT COLLINS, CO 10 U20015_Drainage Report VII. REFERENCES 1. City of Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, November 2017. 2. Urban Storm Drainage Criteria Manual Volume 1 and 2, Urban Drainage and Flood Control District, Denver, Colorado, June 2001, Revised April 2008. 3. Final Drainage and Erosion Control Study for Harmony Technology Park Site Master Plan, Stantec, Fort Collins, Colorado, May 2008. 4. Final Drainage and Erosion Control Study for Harmony Technology Park Third Filing, Stantec, Fort Collins, Colorado, May 2008. 5. Final Drainage and Erosion Control Report for Harmony Technology Park Fourth Filing, Aspen Engineering, Fort Collins, Colorado, January 2014. 6. Natural Resources Conservation Service Web Soil Survey at: websoilsurvey.nrcs.usda.gov/app 7. Preliminary Flood Insurance Rate Map, FEMA, Panel 0994F, https://hazards.fema.gov/femaportal/ 8. Stormwater Discharges Associated with Construction Activity, Stormwater Management Plan Preparation Guides, State of Colorado, www.colorado.com APPENDIX A HYDROLOGY CALCULATIONS RUNOFF COEFFICIENTS AND % IMPERVIOUS Precision Technology, Fort Collins, CO Existing Basins Basin Design Pt. Composite Total Total Roof (1) Asphalt Concrete (1) Gravel (1) Lawns (3) Imperviousness C2 C100 acres sf %I = 90% %I = 100% %I = 100% %I =40% %I=2% C=0.95 C=0.95 C=0.95 C=0.50 C=0.25 sf sf sf sf sf (%I) A1 A1 0.27 11,833 - - - - 11,833 2.0% 0.25 0.31 A2 A2 0.12 5,261 - 3,534 1,092 - 636 86.1% 0.87 1.00 A3 A3 0.17 7,448 - 5,306 1,219 - 923 86.2% 0.86 1.00 A4 A4 0.09 3,960 - - 3,960 - - 90.0% 0.95 1.00 A1.1 A1.1 0.06 2,810 2,810 - - - - 90.0% 0.95 1.00 A1.2 A1.2 0.06 2,529 2,529 - - - - 90.0% 0.95 1.00 A1.3 A1.3 0.47 20,260 20,260 - - - - 90.0% 0.95 1.00 A1.4 A1.4 0.45 19,409 19,409 - - - - 90.0% 0.95 1.00 A1.5 A1.5 0.46 19,853 19,853 - - - - 90.0% 0.95 1.00 A1.6 A1.6 0.50 21,591 21,591 - - - - 90.0% 0.95 1.00 A Total A Total 2.64 114,954 86,452 8,839 6,271 - 13,391 80.5% 0.87 1.00 B1 B1 0.06 2,797 - - - - 2,797 2.0% 0.25 0.31 B2 B2 0.53 22,953 - 15,739 3,153 - 4,061 81.3% 0.83 1.00 B Total B Total 0.59 25,750 - 15,739 3,153 - 6,859 72.7% 0.76 0.95 C1 C1 0.59 25,812 - - 8,037 - 17,776 29.4% 0.47 0.58 C1.1 C1.1 0.04 1,861 1,861 - - - - 90.0% 0.95 1.00 C1.2 C1.2 0.06 2,508 2,508 - - - - 90.0% 0.95 1.00 C1.3 C1.3 0.13 5,450 5,450 - - - - 90.0% 0.95 1.00 C1.4 C1.4 0.10 4,429 4,429 - - - - 90.0% 0.95 1.00 C1.5 C1.5 0.06 2,484 2,484 - - - - 90.0% 0.95 1.00 C1.6 C1.6 0.06 2,457 2,457 - - - - 90.0% 0.95 1.00 C Total C Total 1.03 45,002 19,189 - 8,037 - 17,776 55.2% 0.67 0.84 D1 D1 0.09 4,019 - - 1,079 - 2,940 25.6% 0.44 0.55 E1 E1 0.11 4,840 - - 1,900 - 2,940 36.5% 0.52 0.66 F1 F1 0.08 3,673 - - - - 3,673 2.0% 0.25 0.31 F2 F2 0.30 12,910 - 9,818 - - 3,092 76.5% 0.78 0.98 F Total F Total 0.38 16,583 - 9,818 - - 6,765 60.0% 0.66 0.83 4.85 211,148 105,641 34,396 20,440 - 50,671 70.5% 0.78 0.98 Notes: (1) Recommended % Imperviousness Values per Table 4.1-3 Surface Type - Percent Impervious in Fort Collins Stormwater Criteria Manual (2) Runoff C is based Table 3.2-2. Surface Type - Runoff Coefficients and Table 3.2-3. Frequency Adjustment Factors in Fort Collins Stormwater Manual (3) Runoff C for Lawns based off of Lawns, Clayey Soil, Avg Slope 2-7% Proposed Total Proposed Basins Areas Composite Runoff Coefficients (2) Date: 8/12/2020 P:\U20015 - PRCS Precision Tech II\Reports\Drainage\Calculations\U20015-Drain Calcs 2-YEAR TIME OF CONCENTRATION Precision Technology, Fort Collins, CO Existing Basins Basin Design Pt. Area C(1) Length Slope ti (2) Length Slope Cv Velocity (3) tt (4) Check tc? Total Length tc (5) acres ft % min ft % fps min min Urban? ft min min A1 A1 0.27 0.25 22 5.0% 4.2 149 0.5% 20 1.4 1.8 6.0 Yes 171 11 6.0 A2 A2 0.12 0.87 41 2.0% 2.2 118 3.0% 20 3.5 0.6 2.7 Yes 159 11 5.0 A3 A3 0.17 0.86 24 2.0% 1.7 147 2.0% 20 2.8 0.9 2.5 Yes 171 11 5.0 A4 A4 0.09 0.95 37 5.0% 1.0 50 0.5% 20 1.4 0.6 1.6 Yes 87 10 5.0 A1.1 A1.1 0.06 0.95 61 2.1% 1.7 1 33.0% 20 11.5 0.0 1.7 Yes 62 10 5.0 A1.2 A1.2 0.06 0.95 56 2.1% 1.6 1 33.0% 20 11.5 0.0 1.6 Yes 57 10 5.0 A1.3 A1.3 0.47 0.95 156 2.1% 2.6 1 33.0% 20 11.5 0.0 2.6 Yes 157 11 5.0 A1.4 A1.4 0.45 0.95 146 2.1% 2.6 1 33.0% 20 11.5 0.0 2.6 Yes 147 11 5.0 A1.5 A1.5 0.46 0.95 138 2.1% 2.5 1 33.0% 20 11.5 0.0 2.5 Yes 139 11 5.0 A1.6 A1.6 0.50 0.95 128 2.1% 2.4 1 33.0% 20 11.5 0.0 2.4 Yes 129 11 5.0 A Routed A Routed 2.64 0.87 128 2.1% 3.7 832 0.5% 20 1.4 9.8 13.5 Yes 960 15 13.5 B1 B1 0.06 0.25 9 25.0% 1.6 91 0.5% 20 1.4 1.1 2.7 Yes 100 11 5.0 B2 B2 0.53 0.83 60 2.0% 3.0 250 0.5% 20 1.4 2.9 6.0 Yes 310 12 6.0 B Routed B Routed 0.59 0.76 60 2.0% 3.7 676 0.1% 20 0.4 25.2 28.9 Yes 736 14 14.1 C1 C1 0.59 0.47 68 2.0% 7.5 557 0.7% 20 1.7 5.5 13.0 Yes 625 13 13.0 C1.1 C1.1 0.04 0.95 53 2.1% 1.5 1 33.0% 20 11.5 0.0 1.5 Yes 54 10 5.0 C1.2 C1.2 0.06 0.95 60 2.1% 1.6 1 33.0% 20 11.5 0.0 1.6 Yes 61 10 5.0 C1.3 C1.3 0.13 0.95 90 2.1% 2.0 1 33.0% 20 11.5 0.0 2.0 Yes 91 11 5.0 C1.4 C1.4 0.10 0.95 106 2.1% 2.2 1 33.0% 20 11.5 0.0 2.2 Yes 107 11 5.0 C1.5 C1.5 0.06 0.95 61 2.1% 1.7 1 33.0% 20 11.5 0.0 1.7 Yes 62 10 5.0 C1.6 C1.6 0.06 0.95 46 2.1% 1.4 1 33.0% 20 11.5 0.0 1.4 Yes 47 10 5.0 C Total C Total 1.03 0.67 - - - - - - - D1 D1 0.09 0.44 15 5.0% 2.7 12 2.0% 15 2.1 0.1 2.8 Yes 27 10 5.0 E1 E1 0.11 0.52 15 5.0% 2.4 12 2.0% 15 2.1 0.1 2.5 Yes 27 10 5.0 F1 F1 0.08 0.25 8 25.0% 1.5 1 2.0% 10 1.4 0.0 1.5 Yes 9 10 5.0 F2 F2 0.30 0.78 6 5.0% 0.8 188 0.5% 20 1.4 2.2 3.0 Yes 194 11 5.0 F Total F Total 0.38 0.66 - - - - - - - Notes: (1) C=Cx*Cf (2)ti = [1.87(1.1-CxCf)L1/2]/S1/3, S= slope in %, L=length of overland flow (300' max) (3)V=CvS0.5, S=watercourse slope in ft/ft, UDFCD Equation RO-4 (4)tt=L/(V*60 sec/min) (5)tc check (for urban or developed areas only) = total length/180 + 10 (6)min tc = 5 min Proposed Basins Travel/Channelized Time of Flow (tt) ti+tt tc Check for Urbanized Basins Final tc (6) Date: 8/12/2020 P:\U20015 - PRCS Precision Tech II\Reports\Drainage\Calculations\U20015-Drain Calcs 100-YEAR TIME OF CONCENTRATION Precision Technology, Fort Collins, CO Existing Basins Basin Design Pt. Area C(1) Length Slope ti (2) Length Slope Cv Velocity (3) tt (4) Check tc? Total Length tc (5) acres ft % min ft % fps min min Urban? ft min min A1 A1 0.27 0.31 22 5.0% 3.9 149 0.5% 20 1.4 1.8 5.7 Yes 171 11 5.7 A2 A2 0.12 1.00 41 2.0% 0.9 118 3.0% 20 3.5 0.6 1.5 Yes 159 11 5.0 A3 A3 0.17 1.00 24 2.0% 0.7 147 2.0% 20 2.8 0.9 1.6 Yes 171 11 5.0 A4 A4 0.09 1.00 37 5.0% 0.6 50 0.5% 20 1.4 0.6 1.2 Yes 87 10 5.0 A1.1 A1.1 0.06 1.00 61 2.1% 1.1 1 33.0% 20 11.5 0.0 1.1 Yes 62 10 5.0 A1.2 A1.2 0.06 1.00 56 2.1% 1.1 1 33.0% 20 11.5 0.0 1.1 Yes 57 10 5.0 A1.3 A1.3 0.47 1.00 156 2.1% 1.8 1 33.0% 20 11.5 0.0 1.8 Yes 157 11 5.0 A1.4 A1.4 0.45 1.00 146 2.1% 1.7 1 33.0% 20 11.5 0.0 1.7 Yes 147 11 5.0 A1.5 A1.5 0.46 1.00 138 2.1% 1.7 1 33.0% 20 11.5 0.0 1.7 Yes 139 11 5.0 A1.6 A1.6 0.50 1.00 128 2.1% 1.6 1 33.0% 20 11.5 0.0 1.6 Yes 129 11 5.0 A Routed A Routed 2.64 1.00 128 2.1% 1.6 832 0.5% 20 1.4 9.8 11.4 Yes 960 15 11.4 B1 B1 0.06 0.31 9 25.0% 1.5 91 0.5% 20 1.4 1.1 2.5 Yes 100 11 5.0 B2 B2 0.53 1.00 60 2.0% 1.1 250 0.5% 20 1.4 2.9 4.1 Yes 310 12 5.0 B Routed B Routed 0.59 0.95 60 2.0% 1.6 676 0.1% 20 0.4 25.2 26.8 Yes 736 14 14.1 C1 C1 0.59 0.58 68 2.0% 6.1 557 0.7% 20 1.7 5.5 11.6 Yes 625 13 11.6 C1.1 C1.1 0.04 1.00 53 2.1% 1.0 1 33.0% 20 11.5 0.0 1.0 Yes 54 10 5.0 C1.2 C1.2 0.06 1.00 60 2.1% 1.1 1 33.0% 20 11.5 0.0 1.1 Yes 61 10 5.0 C1.3 C1.3 0.13 1.00 90 2.1% 1.3 1 33.0% 20 11.5 0.0 1.3 Yes 91 11 5.0 C1.4 C1.4 0.10 1.00 106 2.1% 1.5 1 33.0% 20 11.5 0.0 1.5 Yes 107 11 5.0 C1.5 C1.5 0.06 1.00 61 2.1% 1.1 1 33.0% 20 11.5 0.0 1.1 Yes 62 10 5.0 C1.6 C1.6 0.06 1.00 46 2.1% 1.0 1 33.0% 20 11.5 0.0 1.0 Yes 47 10 5.0 C Total C Total 1.03 0.84 0 0.0% - 0 0.0% 0 - - - - - - D1 D1 0.09 0.55 15 5.0% 2.3 12 2.0% 15 2.1 0.1 2.4 Yes 27 10 5.0 E1 E1 0.11 0.66 15 5.0% 1.8 12 2.0% 15 2.1 0.1 1.9 Yes 27 10 5.0 F1 F1 0.08 0.31 8 25.0% 1.4 1 2.0% 10 1.4 0.0 1.4 Yes 9 10 5.0 F2 F2 0.30 0.98 6 5.0% 0.3 188 0.5% 20 1.4 2.2 2.5 Yes 194 11 5.0 F Total F Total 0.38 0.83 - - - - - - - Notes: (1) C=Cx*Cf (2)ti = [1.87(1.1-CxCf)L1/2]/S1/3, S= slope in %, L=length of overland flow (300' max) (3)V=CvS0.5, S=watercourse slope in ft/ft, UDFCD Equation RO-4 (4)tt=L/(V*60 sec/min) (5)tc check (for urban or developed areas only) = total length/180 + 10 (6)min tc = 5 min Proposed Basins Travel/Channelized Time of Flow (tt) ti+tt tc Check for Urbanized Basins Final tc (6) Date: 8/12/2020 P:\U20015 - PRCS Precision Tech II\Reports\Drainage\Calculations\U20015-Drain Calcs RATIONAL METHOD PEAK RUNOFF Precision Technology, Fort Collins, CO Existing Basins Basin Design Pt. Area 2-Year 100-Year acre tc tc C2 C100 I2 I100 Q2 Q100 min min in/hr in/hr cfs cfs A1 A1 0.27 6 6 0.25 0.31 2.67 9.31 0.18 0.79 A2 A2 0.12 5 5 0.87 1.00 2.85 9.95 0.30 1.20 A3 A3 0.17 5 5 0.86 1.00 2.85 9.95 0.42 1.70 A4 A4 0.09 5 5 0.95 1.00 2.85 9.95 0.25 0.90 A1.1 A1.1 0.06 5 5 0.95 1.00 2.85 9.95 0.17 0.64 A1.2 A1.2 0.06 5 5 0.95 1.00 2.85 9.95 0.16 0.58 A1.3 A1.3 0.47 5 5 0.95 1.00 2.85 9.95 1.26 4.63 A1.4 A1.4 0.45 5 5 0.95 1.00 2.85 9.95 1.21 4.43 A1.5 A1.5 0.46 5 5 0.95 1.00 2.85 9.95 1.23 4.53 A1.6 A1.6 0.50 5 5 0.95 1.00 2.85 9.95 1.34 4.93 A Routed A Routed 2.64 14 11 0.87 1.00 1.92 7.42 4.40 19.58 B1 B1 0.06 5 5 0.25 0.31 2.85 9.95 0.05 0.20 B2 B2 0.53 6 5 0.83 1.00 2.67 9.95 1.16 5.24 B Routed B Routed 0.59 14 14 0.76 0.95 1.92 6.71 0.87 3.79 C1 C1 0.59 13 12 0.47 0.58 1.98 7.16 0.55 2.48 C1.1 C1.1 0.04 5 5 0.95 1.00 2.85 9.95 0.12 0.43 C1.2 C1.2 0.06 5 5 0.95 1.00 2.85 9.95 0.16 0.57 C1.3 C1.3 0.13 5 5 0.95 1.00 2.85 9.95 0.34 1.24 C1.4 C1.4 0.10 5 5 0.95 1.00 2.85 9.95 0.28 1.01 C1.5 C1.5 0.06 5 5 0.95 1.00 2.85 9.95 0.15 0.57 C1.6 C1.6 0.06 5 5 0.95 1.00 2.85 9.95 0.15 0.56 C Total C Total 1.03 - - 0.67 0.84 - - 1.74 6.86 D1 D1 0.09 5 5 0.44 0.55 2.85 9.95 0.12 0.50 E1 E1 0.11 5 5 0.52 0.66 2.85 9.95 0.17 0.73 F1 F1 0.08 5 5 0.25 0.31 2.85 9.95 0.06 0.26 F2 F2 0.30 5 5 0.78 0.98 2.85 9.95 0.66 2.88 F Total F Total 0.38 - - 0.66 0.83 - - 0.72 3.15 Totals 8.01 34.61 Proposed Basins Runoff Coefficients Rainfall Intensity Peak Discharge Date: 8/12/2020 P:\U20015 - PRCS Precision Tech II\Reports\Drainage\Calculations\U20015-Drain Calcs APPENDIX B HYDRAULIC CALCULATIONS LOW IMPACT DEVELOPMENT SUMMARY Precision Technology, Fort Collins, CO Basin Proposed Impervious Area LID Treatment Area Treated % of Site Treated (sf) (sf) (%) A1 237 Bioretention Pond A 237 0% A2 4,529 Bioretention Pond A 4,529 3% A3 6,422 Bioretention Pond A 6,422 4% A4 3,564 Bioretention Pond A 3,564 2% A1.1 2,529 Bioretention Pond A 2,529 2% A1.2 2,276 Bioretention Pond A 2,276 2% A1.3 18,234 Bioretention Pond A 18,234 12% A1.4 17,468 Bioretention Pond A 17,468 12% A1.5 17,868 Bioretention Pond A 17,868 12% A1.6 19,432 Bioretention Pond A 19,432 13% A Total 92,558 Bioretention Pond A 92,558 62% B1 56 Bioretention Pond B 56 0% B2 18,658 Bioretention Pond B 18,658 13% B Total 18,714 Bioretention Pond B 18,714 13% C1 7,588 None - 0% C1.1 1,675 None - 0% C1.2 2,257 None - 0% C1.3 4,905 None - 0% C1.4 3,986 None - 0% C1.5 2,236 None - 0% C1.6 2,211 None - 0% C Total 24,859 None - 0% D1 1,030 None - 0% E1 1,769 None - 0% F1 73 None - 0% F2 9,880 None - 0% F Total 9,953 None - 0% Total Site 148,882 111,271 75% Low Impact Development (LID) Treated Areas Date: 8/12/2020 P:\U20015 - PRCS Precision Tech II\Reports\Drainage\Calculations\U20015-Drain Calcs WATER QUALITY - LOW IMPACT DEVELOPMENT Precision Technology, Fort Collins, CO Required Onsite Water Quality Capture Volume for LID Basin Area Area Imperviousness Watershed WQCV* (Extended Detention) (sf) (acres) (%) (inches) (cf) Basin A - Bioretention Pond A A1 11,833 0.272 2% 0.01 12 A2 5,261 0.121 86% 0.30 130 A3 7,448 0.171 86% 0.30 184 A4 3,960 0.091 90% 0.32 106 F2 12,910 0.296 77% 0.25 265 A1.1 2,810 0.065 90% 0.32 75 A1.2 2,529 0.058 90% 0.32 68 A1.3 20,260 0.465 90% 0.32 542 A1.4 19,409 0.446 90% 0.32 519 A1.5 19,853 0.456 90% 0.32 531 A1.6 21,591 0.496 90% 0.32 578 A Total 114,954 2.639 81% 0.27 2,541 Basin B - Bioretention Pond B B1 2,797 0.064 2% 0.01 3 B2 22,953 0.527 81% 0.27 515 B Total 25,750 0.591 73% 0.23 494 Total WQ Provided onsite in Bioretention Pond A and B 3,035 * Based on 12 hr storage forunderground detention Date: 8/12/2020 P:\U20015 - PRCS Precision Tech II\Reports\Drainage\Calculations\U20015-Drain Calcs APPENDIX C REFERENCED MATERIALS This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jun-17-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA This unofficial copy was downloaded on Jan-27-2020 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact City of Fort Collins Utilities 700 Wood Street Fort Collins, CO 80524 USA United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Larimer County Area, Colorado Precision Tech II Natural Resources Conservation Service August 4, 2020 9 Custom Soil Resource Report Soil Map 4485220 4485240 4485260 4485280 4485300 4485320 4485340 4485360 4485220 4485240 4485260 4485280 4485300 4485320 4485340 4485360 498770 498790 498810 498830 498850 498870 498890 498910 498930 498950 498970 498990 498770 498790 498810 498830 498850 498870 498890 498910 498930 498950 498970 498990 40° 31' 8'' N 105° 0' 52'' W 40° 31' 8'' N 105° 0' 42'' W 40° 31' 3'' N 105° 0' 52'' W 40° 31' 3'' N 105° 0' 42'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 50 100 200 300 Feet 0 15 30 60 90 Meters Map Scale: 1:1,090 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 74 Nunn clay loam, 1 to 3 percent slopes 4.5 100.0% Totals for Area of Interest 4.5 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. Custom Soil Resource Report 11 An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 12 Larimer County Area, Colorado 74—Nunn clay loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol: 2tlpl Elevation: 3,900 to 5,840 feet Mean annual precipitation: 13 to 17 inches Mean annual air temperature: 50 to 54 degrees F Frost-free period: 135 to 160 days Farmland classification: Prime farmland if irrigated Map Unit Composition Nunn and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Nunn Setting Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Pleistocene aged alluvium and/or eolian deposits Typical profile Ap - 0 to 9 inches: clay loam Bt - 9 to 13 inches: clay loam Btk - 13 to 25 inches: clay loam Bk1 - 25 to 38 inches: clay loam Bk2 - 38 to 80 inches: clay loam Properties and qualities Slope: 1 to 3 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum content: 7 percent Maximum salinity: Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm) Sodium adsorption ratio, maximum: 0.5 Available water capacity: High (about 9.9 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: R067BY042CO - Clayey Plains Hydric soil rating: No Custom Soil Resource Report 13 Minor Components Heldt Percent of map unit: 10 percent Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: R067BY042CO - Clayey Plains Hydric soil rating: No Satanta Percent of map unit: 5 percent Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: R067BY002CO - Loamy Plains Hydric soil rating: No Custom Soil Resource Report 14 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 15 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 16 APPENDIX D DRAINAGE EXHIBITS PREVIOUSLY ACCOUNTED FOR AREA IN HTP SITE MASTER PLAN DRAINAGE REPORT FOR PRECISION TECHNOLOGY SITE DRAINING NORTH TO HARMONY COMMONS POND = 0.78 ACRES PREVIOUSLY ACCOUNTED FOR AREA IN HTP SITE MASTER PLAN DRAINAGE REPORT FOR PRECISION TECHNOLOGY SITE DRAINING SOUTH TO POND 110 = 3.90 ACRES 0' 30' 60' SCALE: 1" = 30' 15' PATH: P:\U20015 - PRCS PRECISION TECH II\CADD\IMAGES\DRAINAGE FIGURES\EX DRAINAGE EXHIBIT.DWG DRAWING NAME: EX DRAINAGE EXHIBIT SHEET SIZE: 24x 36 PRECISION TECHNOLOGY EXISTING DRAINAGE CONVEYANCE AREAS EXHIBIT DATE: August 12, 2020 TIME: 8:44:00 AM PREPARED FOR: PRECISION TECHNOLOGY LLC JOB NUMBER: U20015 NOTE: THIS EXHIBIT WAS PREPARED FOR INFORMATION ONLY AND THE ENGINEER PREPARING THESE PLANS WILL NOT BE RESPONSIBLE FOR UNAUTHORIZED USE OF THEM. 1501 ACADEMY COURT, SUITE 203 FORT COLLINS, CO 80524 (970) 530-4044 WWW.UNITEDCIVIL.COM SHEET 1 OF 1 UNITED CIVIL Design Group LLC NORTH PROPOSED AREA FROM PRECISION TECHNOLOGY SITE DRAINING SOUTH TO POND 110 = 4.24 ACRES PROPOSED AREA FROM PRECISION TECHNOLOGY SITE DRAINING NORTH TO HARMONY COMMONS POND = 0.44 ACRES 0' 30' 60' SCALE: 1" = 30' 15' PATH: P:\U20015 - PRCS PRECISION TECH II\CADD\IMAGES\DRAINAGE FIGURES\EX DRAINAGE EXHIBIT.DWG DRAWING NAME: EX DRAINAGE EXHIBIT SHEET SIZE: 24x 36 PRECISION TECHNOLOGY PROPOSED DRAINAGE CONVEYANCE AREAS EXHIBIT DATE: August 12, 2020 TIME: 8:44:00 AM PREPARED FOR: PRECISION TECHNOLOGY LLC JOB NUMBER: U20015 NOTE: THIS EXHIBIT WAS PREPARED FOR INFORMATION ONLY AND THE ENGINEER PREPARING THESE PLANS WILL NOT BE RESPONSIBLE FOR UNAUTHORIZED USE OF THEM. 1501 ACADEMY COURT, SUITE 203 FORT COLLINS, CO 80524 (970) 530-4044 WWW.UNITEDCIVIL.COM SHEET 1 OF 1 UNITED CIVIL Design Group LLC NORTH RD RD RD RD RD RD RD RD RD OVF OVF OVF OVF OVF OVF OVF OVF RD OVF RD OVF RD OVF A1.6 0.50 0.95 1.00 A1.5 0.46 0.95 1.00 A1.4 0.45 0.95 1.00 A1.3 0.47 0.95 1.00 A1.2 0.06 0.95 1.00 A1.1 0.06 0.95 1.00 C1.1 0.04 0.95 1.00 C1.2 0.06 0.95 1.00 C1.3 0.13 0.95 1.00 C1.4 0.10 0.95 1.00 C1.5 0.06 0.95 1.00 C1.6 0.06 0.95 1.00 A4 0.09 0.95 1.00 A3 0.17 0.86 1.00 A2 0.12 0.87 1.00 A1 0.29 0.25 0.31 E1 0.11 0.52 0.66 F1 0.08 0.25 0.31 F2 0.38 0.66 0.83 B2 0.53 0.83 1.00 B1 0.04 0.25 0.31 C1 0.59 0.47 0.58 D1 0.09 0.44 0.55 LOT 2 HARMONY TECHNOLOGY PARK FIFTH FILING LOT 1 HARMONY TECHNOLOGY PARK FOURTH FILING PORTION OF LOT 2 HARMONY TECHNOLOGY PARK SECOND FILING TRACT A HARMONY TECHNOLOGY PARK SIXTH FILING LOT 1 HARMONY TECHNOLOGY PARK FIFTH FILING PRECISION DRIVE PROPOSED BUILDIING FFE = 4916.50 EXISTING STORM SEWER LOT LINE LOT LINE LOT LINE LOT LINE POND OUTLET STRUCTURE POND OUTLET STRUCTURE BIORETENTION POND A BIORETENTION POND B DRAINAGE SWALE 1.5' SPILL C&G 1.5' CATCH C&G 1.5' SPILL C&G 1.5' CATCH C&G ROOF DRAIN LINE (SEE SHEET XXX) STORM LINE 1 (SEE SHEET XXX) 1.5' SPILL C&G 1.5' CATCH C&G CURB CUT CURB CUT ROOF DRAIN LINE (SEE SHEET XXX) TRENCH DRAIN STORM LINE 1 (SEE SHEET XXX) EXISTING BIORETENTION POND 9' UTILITY EASEMENT 30' UTILITY & DRAINAGE EASEMENT 45' UTILITY & DRAINAGE EASEMENT DRAINAGE EASEMENT 24' EMERGENCY ACCESS EASEMENT 24' EMERGENCY ACCESS EASEMENT DRAINAGE EASEMENT DRAINAGE EASEMENT CURB CUT 64' ROW PRECISION TECHNOLOGY LLC 8/12/2020 U20015 1" = 30' 1" = N/A PRECISION TECHNOLOGY NORTH 8/11/2020 3:25:21 PM P:\U20015 - PRCS PRECISION TECH II\CADD\CP\C5.00 - DRAINAGE PLAN.DWG C5.00 - DRAINAGE PLAN SME NKS C5.00 8 DRAINAGE PLAN 0 30' 60' SCALE: 1" = 30' 15' PREPARED FOR: JOB NUMBER SHEET NUMBER OF SHEETS DATE SUBMITTED: The engineer preparing these plans will not be responsible for, or liable for, unauthorized changes to or uses of these plans. All changes to the plans must be in writing and must be approved by the preparer of these plans. NO. BY DATE CAUTION REVISIONS: VERTICAL: HORIZONTAL: SCALE PRELIMINARY PLANS NOT FOR CONSTRUCTION 1501 Academy Ct. Ste. 203 Fort Collins, CO 80524 (970) 530-4044 www.unitedcivil.com Civil Engineering & Consulting PROJ. MGR: DRAWING NAME: PATH: DATE: TIME: DESIGNER: UNITED CIVIL Design Group LLC 8 X.XX XX.X X.XX X BASIN DESIGNATION BASIN AREA (ACRE) 5 - YR RUNOFF COEFF. 100 - YR RUNOFF COEFF. DESIGN POINT FLOW DIRECTION DP D1 LEGEND 1. EXISTING UNDERGROUND AND OVERHEAD PUBLIC AND PRIVATE UTILITIES AS SHOWN ARE INDICATED ACCORDING TO THE BEST INFORMATION AVAILABLE TO THE ENGINEER. 2. VEGETATIVE SWALES, BIOSWALES, AND THE BIORETENTION PONDS SHALL BE MAINTAINED BY THE PROPERTY OWNER AND FOLLOW APPLICABLE STANDARD OPERATING PROCEDURES AS SHOWN IN DEVELOPMENT AGREEMENT. 3. SEE GRADING PLANS (SHEET C4.00) FOR MORE DETAIL ON POND AND SITE GRADING. NOTES CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: APPROVED: DRAINAGE SUMMARY POND SUMMARY LOW IMPACT DEVELOPMENT TREATMENT SUMMARY Pond A Pond B LID WQCV REQUIRED 2,541 CF 494 CF LID WQCV PROVIDED 2,610 CF 648 CF BOTTOM OF POND ELEVATION 4,908.50 4,911.00 LID WQCV WATER SURFACE ELEVATION 4,909.50 4,912.00 TOP OF POND ELEVATION 4,910.50 4,912.50 Proposed Basins Basin Area %I C2 C100 Q2 Q100 (acre) (cfs) (cfs) A1 0.27 2% 0.25 0.31 0.18 0.79 A2 0.12 86% 0.87 1.00 0.30 1.20 A3 0.17 86% 0.86 1.00 0.42 1.70 A4 0.09 90% 0.95 1.00 0.25 0.90 A1.1 0.06 90% 0.95 1.00 0.17 0.64 A1.2 0.06 90% 0.95 1.00 0.16 0.58 A1.3 0.47 90% 0.95 1.00 1.26 4.63 A1.4 0.45 90% 0.95 1.00 1.21 4.43 A1.5 0.46 90% 0.95 1.00 1.23 4.53 A1.6 0.50 90% 0.95 1.00 1.34 4.93 A Total 2.64 81% 0.87 1.00 6.52 24.35 B1 0.06 2% 0.25 0.31 0.05 0.20 B2 0.53 81% 0.83 1.00 1.16 5.24 B Total 0.59 73% 0.76 0.95 1.21 5.44 C1 0.59 29% 0.47 0.58 0.55 2.48 C1.1 0.04 90% 0.95 1.00 0.12 0.43 C1.2 0.06 90% 0.95 1.00 0.16 0.57 C1.3 0.13 90% 0.95 1.00 0.34 1.24 C1.4 0.10 90% 0.95 1.00 0.28 1.01 C1.5 0.06 90% 0.95 1.00 0.15 0.57 C1.6 0.06 90% 0.95 1.00 0.15 0.56 C Total 1.03 55% 0.67 0.84 1.74 6.86 D1 0.09 26% 0.44 0.55 0.12 0.50 E1 0.11 37% 0.52 0.66 0.17 0.73 F1 0.08 2% 0.25 0.31 0.06 0.26 F2 0.30 77% 0.78 0.98 0.66 2.88 F Total 0.38 60% 0.66 0.83 0.72 3.15 Proposed Total 4.85 71% 0.78 0.98 10.47 41.03 Basin Proposed Impervious Area (sf) LID Treatment Area Treated (sf) % of Site Treated (%) A1 237 Bioretention Pond A 237 0% A2 4,529 Bioretention Pond A 4,529 3% A3 6,422 Bioretention Pond A 6,422 4% A4 3,564 Bioretention Pond A 3,564 2% A1.1 2,529 Bioretention Pond A 2,529 2% A1.2 2,276 Bioretention Pond A 2,276 2% A1.3 18,234 Bioretention Pond A 18,234 12% A1.4 17,468 Bioretention Pond A 17,468 12% A1.5 17,868 Bioretention Pond A 17,868 12% A1.6 19,432 Bioretention Pond A 19,432 13% A Total 92,558 Bioretention Pond A 92,558 62% B1 56 Bioretention Pond B 56 0% B2 18,658 Bioretention Pond B 18,658 13% B Total 18,714 Bioretention Pond B 18,714 13% C1 7,588 None 0 0% C1.1 1,675 None 0 0% C1.2 2,257 None 0 0% C1.3 4,905 None 0 0% C1.4 3,986 None 0 0% C1.5 2,236 None 0 0% C1.6 2,211 None 0 0% C Total 24,859 None 0 0% D1 1,030 None 0 0% E1 1,769 None 0 0% F1 73 None 0 0% F2 9,880 None 0 0% F Total 9,953 None 0 0% Total Site 148,882 111,271 75% accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 15, Jun 9, 2020 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 11, 2018—Aug 12, 2018 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 10 The proposed impervious area treated through this bioretention pond includes proposed concrete and asphalt paving areas in Basin B. Approximately 648-cf of volume in the bioretention pond, with up to one foot of depth, is designed specifically for water quality. This volume slightly exceeds the required WQCV for Basin B (494-cf). This pond is located at the northeast corner of the site and provides up to one foot of depth specifically for bioretention