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HomeMy WebLinkAboutReports - Drainage - 09/26/2025 PRELIMINARY DRAINAGE AND EROSION CONTROL REPORT for BANK OF AMERICA 2413 S. College Avenue Fort Collins, CO 80525 Prepared For: NELSON 906 W McDermott Dr Allen, TX 75013 Contact: Harry Koutsis Prepared By: Langan Engineering and Environmental Services, LLC 300 Union Boulevard, Suite 405 Lakewood, CO 80228 G. Robert Adams, PE, CPESC Professional Engineer License No. 51524 September 26, 2025 Project No. 532045801 TABLE OF CONTENTS SECTION 1: GENERAL LOCATION AND EXISTING SITE INFORMATION…………..………..1 1.1 Site Location…………..…………………...……………………………………1 1.2 Site Description…………………………………………………………………1 1.3 Vicinity Map……………………...………...……………………………………1 1.4 Master Drainage basin Description……………………………………………2 1.5 Floodplain Information………………………………………………………….2 SECTION 2: PROPOSED DRAINAGE DESIGN……………….……...…………………………....3 2.1 Proposed Project Description….………………………..…………………….3 2.2 Impervious Cover and Drainage Plan…..…..…………………………………3 2.3 Runoff Calculations……………………………………….........………………3 SECTION 3: WATER QUALITY & LID IMPLEMENTATION………………………….…………...5 3.1 Water Quality Narrative…………………………………..…………………….5 3.2 Four Step Process………………………..…..…………………………………5 3.3 Water Quality Capture Volume (WQCV) Design……………………………..6 3.4 Water Quality Peak Flow (WQPF) Design……………………………………7 3.5 Best Management Practice (BMP) Selection………………………………...7 SECTION 4: EROSION CONTROL…………………………..………………………….…………...8 4.1 Statement of Compliance……………………………..……………………….8 SECTION 5: CONCLUSION…………………………..………………………….…………………...8 References………………………………………………………………………………………………..9 Appendix…………………………………………………………………………………...….……….10 NRCS Soil Report FEMA FIRM Panel Impervious Coverage Exhibit E-1 Existing Drainage Area Map Proposed Drainage Area Map Drainage Plan LID Exhibit Spring Creek Basin Management Proposed Condition BMP Map City of Fort Collins Master Plan Basin Recommended Improvements Project Development Plan Drainage Report 2413 S. College Avenue Fort Collins, CO 805252 Langan Project No.: 532045801 September 26, 2025 Page 1 of 10 SECTION 1: GENERAL LOCATION & EXISTING SITE INFORMATION 1.1 Site Location The project is situated in the southeastern quarter of section 23, Township 7 North, Range 69 West of the Sixth Principal Meridian, City of Fort Collins, County of Larimer, Colorado. Lot 1, Midtown Commercial Center, recorded in Reception No. 20240039325. 1.2 Site Description The existing development contains a single-story dine-in restaurant, situated in the General Commercial District, currently consisting of mostly asphalt pavement with gravel, sod, and trees for landscaping. Located within the Spring Creek Drainage Basin, the property is predominantly impervious. Presently, rainwater is managed by sheet flow into on-site storm inlets, which then gravity outfall into the existing 24” CMP main within S. College Avenue. Adjacent properties consist of King Soopers supermarket to the South, CSU Shops to the West, GKT University Plaza LLC to the North, and S. College Avenue to the East. 1.3 Vicinity Map Project Development Plan Drainage Report 2413 S. College Avenue Fort Collins, CO 805252 Langan Project No.: 532045801 September 26, 2025 Page 2 of 10 1.4 Master Drainage Basin Description The project site lies within the limits of the Spring Creek drainage basin. Spring Creek, originating from Spring Canyon Dam at Horsetooth Reservoir and flowing to the Poudre River, spans nearly nine square miles in central Fort Collins, Colorado. This primarily residential basin also includes parks, open spaces, and some commercial and industrial areas. In late 2002, the City of Fort Collins revised the floodplain as part of an update to its stormwater master plans, addressing issues such as structural damage, road overtopping, and significant financial losses during severe storms. To mitigate these problems, the City proposed constructing or enlarging detention ponds, reinforcing the Burlington Northern Railroad embankment, stabilizing creek banks, and improving storm sewers, aiming to reduce future flood damage and enhance the basin's resilience. The project site, to Langan’s knowledge, is not within the limits of any currently master planned improvements. Refer to the “Spring Creek Basin Management Proposed Condition BMP Map” and the “City of Fort Collins Master Plan Basin Recommended Improvements” within the Appendix of this report for spatial reference of the project site to the city’s planned mitigation projects. 1.5 Floodplain Information This property is located in an area of minimal flood hazard zone x (areas determined to be outside the 0.2% annual chance floodplain) of the flood insurance rate map for Larimer County, Colorado and incorporated areas, map no. 08069C0987G, dated May 2, 2012, via scaled map location and graphic plotting and/or the national flood hazard layer (NFHL) web map service (WMS) at http://hazards.fema.gov. A copy of the FEMA FIRM panel with the site location marked is included within the Appendix of this report. Project Development Plan Drainage Report 2413 S. College Avenue Fort Collins, CO 805252 Langan Project No.: 532045801 September 26, 2025 Page 3 of 10 SECTION 2: PROPOSED DRAINAGE DESIGN 2.1 Proposed Project Description Bank of America is proposing to redevelop a 1.13-acre lot located at 2413 S. College Ave, Fort Collins, Colorado. The development will contain a traditional financial services building with both walk-in and drive-thru capabilities. The proposed building is 4,240 SF, single-story, with overhead canopy. The proposed site will consist of asphalt pavement, concrete curb and gutter, concrete sidewalks and landscape areas. The new development will utilize storm inlets, catch curb and gutters, and water quality best management practices (BMP) discussed in section 3 to gravity outfall into the existing MS4 system. 2.2 Impervious Cover and Drainage Plan The proposed Bank of America development will direct its drainage into on-site drainage inlets before discharging into the existing drainage system along S. College Ave. A comparative analysis of runoff coefficients and impervious coverage percentages between the existing and proposed conditions indicated that the proposed development does not increase the impervious surface area or runoff value. As a result, the proposed development does not trigger the detention requirements described within the Fort Collins Stormwater Criteria Manual (FCSCM). No stormwater detention is proposed. See “Impervious Coverage Exhibit E-1” within the Appendix for a summary of existing vs. proposed impervious coverage illustrating the overall reduction. The watershed basins for the pre and post developed site are illustrated on the drainage area maps within the Appendix of this report. 2.3 Runoff Calculations The runoff calculations for this project have been prepared using the rational method. The runoff coefficient values utilized in these calculations are sourced from FCSCM, Chapter 5, Table 3.2.2 ensuring compliance with local regulations and best practices. According to the geotechnical report, and NRCS web soil survey, the site contains clayey soil with an average slope within the 2-7% range or less. The NRCS web soil survey report is included within the Appendix of this report. Composite runoff coefficient calculations for the pre and post developed site are shown in the tables below. As p h a l t , Co n c r e t e , Ro o f t o p Gr a v e l La w n s , Cl a y e y S o i l , Av g S l o p e 2- 7 % 0.95 0.50 0.25 X-01 0.002 0.004 0.014 0.020 0.37 X-02 0.96 0.05 0.03 1.04 0.91 X-03 0.06 0.04 0.10 0.67 X-04 0.28 0.01 0.006 0.30 0.92 X-05 0.33 0.01 0.05 0.39 0.85 X-06 3.25 0.20 1.00 4.45 0.77 0.00 4.89 0.27 1.14 6.30 0.80 PRE-DEVELOPED COMPOSITE RUNOFF COEFFICIENTS Dr a i n a g e A r e a Nu m b e r To t a l A r e s (a c r e s ) Co m p o s i t e R u n o f f Co e f f i c i e n t Project Development Plan Drainage Report 2413 S. College Avenue Fort Collins, CO 805252 Langan Project No.: 532045801 September 26, 2025 Page 4 of 10 In accordance with the FCSCM, Chapter 5, Section 3.3.4, the minimum time of concentration of 5 minutes was utilized in the calculations for all drainage areas to conservatively account for the most intense storm. FSCSM Table 3.4-1 was referenced to determine the rainfall intensity (in/hr) for the 2, 10, and 100-year storms having a duration of 5 minutes. The tables below show the rational method calculations for the project site. As p h a l t , Co n c r e t e , Ro o f t o p Gr a v e l La w n s , Cl a y e y S o i l , Av g S l o p e 2- 7 % 0.95 0.50 0.25 DA-1 0.35 0.06 0.41 0.85 DA-2 0.33 0.01 0.34 0.93 DA-3 0.11 0.03 0.14 0.80 DA-4 0.09 0.01 0.10 0.88 DA-5 0.05 0.05 0.95 R-1 0.13 0.13 0.95 OS-1 0.001 0.003 0.012 0.02 0.34 OS-2 0.06 0.07 0.13 0.57 OS-3 0.51 0.02 0.01 0.54 0.92 OS-4 3.25 0.20 1.00 4.45 0.77 0.00 4.88 0.22 1.20 6.30 0.80 POST-DEVELOPED COMPOSITE RUNOFF COEFFICIENTS Dr a i n a g e A r e a Nu m b e r To t a l A r e s (a c r e s ) Co m p o s i t e R u n o f f Co e f f i c i e n t Drainage Area Designation Drainage Area Runoff Coefficient C*Cf 2,5,10 C*Cf 100 Time of Concentrati on 2-Year Rainfall Intensity (I2) 2-Year Peak Discharge (Q2) 10-Year Rainfall Intensity (I10) 10-Year Peak Discharge (Q10) 100-Year Rainfall Intensity (I100) 100-Year Peak Discharge (Q100) -(ac)"C"Cf = 1.00 Cf = 1.25 (min)(in/hr)(cfs)(in/hr)(cfs)(in/hr)(cfs) X-01 0.02 0.37 0.37 0.46 5 2.85 0.0 4.87 0.0 9.95 0.1 X-02 1.04 0.91 0.91 1.00 5 2.85 2.7 4.87 4.6 9.95 10.3 X-03 0.10 0.67 0.67 0.84 5 2.85 0.2 4.87 0.3 9.95 0.8 X-04 0.30 0.92 0.92 1.00 5 2.85 0.8 4.87 1.3 9.95 2.9 X-05 0.39 0.85 0.85 1.00 5 2.85 1.0 4.87 1.6 9.95 3.9 X-06 4.45 0.77 0.77 0.97 5 2.21 7.6 3.78 13.0 7.72 33.2 Total 6.30 12.2 20.9 51.3 Note: Calculations based on the Rational Method: Q = C*I*A; Intensities and Frequency Adjustment Factors (Cf) taken from Fort Collins Stormwater Criteria Manual PRE-DEVELOPMENT DRAINAGE AREA CALCULATIONS Project Development Plan Drainage Report 2413 S. College Avenue Fort Collins, CO 805252 Langan Project No.: 532045801 September 26, 2025 Page 5 of 10 SECTION 3: WATER QUALITY & LID IMPLEMENTATION 3.1 Water Quality Narrative Per the FCSCM (2018) and Mile High Flood District (MHFD) guidelines, water quality treatment is required to mitigate the qualitative stormwater impacts of the proposed development. The tributary area upstream of the water quality unit totals approximately 50,965.20 square feet, with an estimated 87.9% imperviousness, and will require a water quality treatment capture volume of +/- 1,406 cu ft. and a Water Quality Peak Flow (WQPF) of 1.71 cfs. This flow rate was determined based on the contributing watershed area directed to the underground filtration basin. The stormwater management strategy involves routing runoff to a centralized, below-grade manufactured treatment device (MFD) designed to remove pollutants from stormwater to the greatest extent practical prior to its release into receiving waters. The MFD, more specifically an ADS Stormtech SC-800 chamber system with isolator rows, will include an internal bypass to divert flow exceeding the WQPF. Following treatment, stormwater will be conveyed through an outlet pipe and discharged into the existing public storm sewer system located within South College Avenue. Due to the expansive clays identified on site, the water quality system will include an impermeable liner and underdrain to prevent excessive wetting of the soils to mitigate the effects of soil shrinkage and expansion 3.2 Four Step Process The FCSCM references the “Four Step Process” which the Denver Urban Drainage and Flood Control District (UDFCD) recommends for protection of receiving waters. These steps focus on reducing runoff volumes, treating the water quality peak flow (WQPF), stabilizing streams and implementing long-term source controls. Step 1. Employ Runoff Reduction Practices: Drainage Area Designation Drainage Area Runoff Coefficient C*Cf 2,5,10 C*Cf 100 Time of Concentrati on 2-Year Rainfall Intensity (I2) 2-Year Peak Discharge (Q2) 10-Year Rainfall Intensity (I10) 10-Year Peak Discharge (Q10) 100-Year Rainfall Intensity (I100) 100-Year Peak Discharge (Q100) -(ac)"C"Cf = 1.00 Cf = 1.25 (min)(in/hr)(cfs)(in/hr)(cfs)(in/hr)(cfs) DA-1 0.41 0.85 0.85 1.00 5 2.85 1.0 4.87 1.7 9.95 4.1 DA-2 0.34 0.93 0.93 1.00 5 2.85 0.9 4.87 1.5 9.95 3.4 DA-3 0.14 0.80 0.80 1.00 5 2.85 0.3 4.87 0.5 9.95 1.4 DA-4 0.10 0.88 0.88 1.00 5 2.85 0.3 4.87 0.4 9.95 1.0 DA-5 0.05 0.95 0.95 1.00 5 2.85 0.1 4.87 0.2 9.95 0.5 R-1 0.13 0.95 0.95 1.00 5 2.85 0.4 4.87 0.6 9.95 1.3 OS-1 0.02 0.34 0.34 0.43 5 2.85 0.0 4.87 0.0 9.95 0.1 OS-2 0.13 0.57 0.57 0.72 5 2.85 0.2 4.87 0.4 9.95 0.9 OS-3 0.54 0.92 0.92 1.00 5 2.85 1.4 4.87 2.4 9.95 5.3 OS-4 4.45 0.77 0.77 0.97 10 2.21 7.6 3.78 13.0 7.72 33.2 Total 6.30 12.2 20.8 51.1 Intensities and Frequency Adjustment Factors (Cf) taken from Fort Collins Stormwater Criteria Manual POST-DEVELOPMENT DRAINAGE AREA CALCULATIONS Note: Calculations based on the Rational Method: Q = C*I*A; Project Development Plan Drainage Report 2413 S. College Avenue Fort Collins, CO 805252 Langan Project No.: 532045801 September 26, 2025 Page 6 of 10 The proposed underground water quality treatment measures (i.e. pavers or underground detention system) will partially detain and infiltrate runoff generated during the minor storm events, reducing the peak runoff rate and volumes. Additionally, the water quality treatment measures will capture sediment (i.e. pollutant) laden surface runoff and reduce the pollutant load being discharged offsite. Due to the existing site constraints, the use of Disconnected Impervious Areas is not feasible. Existing drainage patterns will generally match the historic conditions of the developed site. Step 2. Implement BMPs To Treat WQPF: The proposed underground water quality treatment measures will be designed to capture runoff and slow the release of the WQPF through infiltration or an underdrain system controlled by an orifice. Step 3. Stabilize Streams: Compared to the existing developed site, the proposed imperviousness for this project will be reduced by 1%. The reduction in impervious area results in a slight reduction in the release rate for the major and minor storm events. This reduction in conjunction with the proposed underground water quality treatment measure, will ensure that the proposed development does not create an adverse condition downstream in the receiving waters. Step 4. Implement Site Specific and Other Source Control BMPs: The proposed project will develop an Erosion and Sediment Control Report or plan that identifies the initial, interim, and final BMPs required to construct the site. Materials, trash collection, etc. will be protected via an approved BMP and located as far away from the storm sewer or streams as possible. Stormwater facilities for this site will generally be placed below grade and will not be in conflict with publicly available spaces. 3.3 Water Quality Capture Volume (WQCV) Design Design methodologies shown within Chapter 7, Water Quality, were used to determine the required WQCV. The WQCV is calculated as a function of imperviousness and BMP drain time using the following equation: 𝑊𝑄𝐶𝑉=𝑎(0.91𝑖3 −1.19𝑖2 +0.78𝑖) a = 0.8 (12-hr drain time) Proposed 𝐼 = 82.53% WQCV = 0.27579 inches Once the WQCV in watershed inches is found, the required BMP volume in acre-feet can be calculated as follows: 𝑉=(𝑊𝑄𝐶𝑉 12 )𝐴× 1.2 V = required volume, acre-ft WQCV = Water Quality Capture Volume, watershed inches A = Tributary catchment area upstream, acres (Site area = 1.17 ac) 1.2 = to account for the additional 20% of required storage for sedimentation accumulation Project Development Plan Drainage Report 2413 S. College Avenue Fort Collins, CO 805252 Langan Project No.: 532045801 September 26, 2025 Page 7 of 10 V = 0.032 acre-ft (1,405.57cu ft) The project site’s required WQCV is 1,406 cu ft. 3.4 Water Quality Peak Flow (WQPF) Design Design methodologies shown within Volume 1, Chapter 6, Water Quality Event and Water Quality Peak Flow Rate, were used to determine the required WQPF. The WQPF is calculated as a function of imperviousness, time of concentration and rainfall intensity using 0.6 inches for the 1-hour point rainfall depth. Equation 5-1 – Rainfall Intensity 𝐼= 28.5 𝑃1 (10 +𝑇𝑑)0.786 I = Rainfall intensity (inches per hour) P1 = 0.6 inches (1-hour point rainfall depth) Td = 5 minutes (Storm Duration minimum) I = 2.035 in/hr Table 6-5 Runoff Coefficients Equations Based on NRCS HSG and Storm Return Period 𝐶= 0.834𝐼1.122 C = Runoff Coefficient I = 0.879 (Weighted imperviousness of catchment expressed as a decimal) C = 0.72 Rational Formula 𝑄= 𝐶𝐼𝐴 Q = Peak rate of runoff (cfs) C = 0.72 (Runoff Coefficient) I = 2.035 in/hr (Rainfall intensity) A = 1.17 Acres (Watershed area contributing to Underground Filtration Basin) Q = 1.71 cfs The proposed water quality unit will be sized to effectively treat runoff generated by the Water Quality Protection Flow (WQPF), ensuring compliance with water quality requirements. In addition to filtration, the system will be designed to accommodate high-flow conditions by incorporating a bypass mechanism capable of conveying the peak flow rate associated with the 100-year storm event. 3.5 Best Management Practice (BMP) Selection Surface BMP’s are infeasible due to spatial constraints. The redevelopment site will utilize a proprietary underground filtration basin in lieu of common BMP’s such as permeable pavers or bioretention. The underground filtration basin will capture 100% of the required WQCV and major storm events will bypass the water quality chamber and outfall into the MS4 system. See the LID Exhibit within the Appendix of this report for proposed location of the underground system. Project Development Plan Drainage Report 2413 S. College Avenue Fort Collins, CO 805252 Langan Project No.: 532045801 September 26, 2025 Page 8 of 10 SECTION 4: EROSION CONTROL 4.1 Statement of Compliance Compliance with Erosion Control Criteria and all Erosion Control Materials will be provided with the Final Drainage Report. SECTION 5: CONCLUSION The comprehensive analysis presented in this report demonstrates that the proposed drainage and water quality management meets and exceeds the regulatory standards set forth by the City of Fort Collins, CO. Through the implementation of engineering solutions and sustainable practices, the proposed stormwater management effectively addresses potential water runoff and pollution concerns, ensuring the protection and enhancement of local water resources. The proactive measures outlined will not only mitigate flood risks but also contribute to the long- term health of the ecosystem. Given the thoroughness of the design and its alignment with the city's environmental goals, we strongly recommend the approval of this development. Project Development Plan Drainage Report 2413 S. College Avenue Fort Collins, CO 805252 Langan Project No.: 532045801 September 26, 2025 Page 9 of 10 References Fort Collins Stormwater Criteria Manual, December 2018 Web Soil Survey, Natural Resources Conservation Service, United States Department of Agriculture, Available at http://websoilsurvey.nrcs.usda.gov, accessed April 2025 Mile High Flood District (MHFD) Drainage Criteria Manual, Volumes 1, 2, and 3, Latest Revisions. Federal Emergency Management Agency (FEMA), Flood Insurance Rate Map (FIRM), City of Fort Collins, Larimer County, Colorado and Incorporated Areas, Map Number 08069C0987G, May 2, 2012 “Spring Creek || Utilities.” Spring Creek - City of Fort Collins, www.fcgov.com/utilities/what-we- do/stormwater/drainage-basins/spring-creek-basin. Accessed 24 Apr. 2025. Project Development Plan Drainage Report 2413 S. College Avenue Fort Collins, CO 805252 Langan Project No.: 532045801 September 26, 2025 Page 10 of 10 Appendix Supporting Documents 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 Bank of America, 2413 S College Ave, Fort Collins, CO 80525 Natural Resources Conservation Service April 24, 2025 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 5 6 Custom Soil Resource Report Soil Map 44 8 9 3 5 0 44 8 9 3 6 0 44 8 9 3 7 0 44 8 9 3 8 0 44 8 9 3 9 0 44 8 9 4 0 0 44 8 9 4 1 0 44 8 9 4 2 0 44 8 9 4 3 0 44 8 9 4 4 0 44 8 9 4 5 0 44 8 9 3 5 0 44 8 9 3 6 0 44 8 9 3 7 0 44 8 9 3 8 0 44 8 9 3 9 0 44 8 9 4 0 0 44 8 9 4 1 0 44 8 9 4 2 0 44 8 9 4 3 0 44 8 9 4 4 0 44 8 9 4 5 0 493400 493410 493420 493430 493440 493450 493460 493470 493400 493410 493420 493430 493440 493450 493460 493470 40° 33' 20'' N 10 5 ° 4 ' 4 0 ' ' W 40° 33' 20'' N 10 5 ° 4 ' 3 7 ' ' W 40° 33' 17'' N 10 5 ° 4 ' 4 0 ' ' W 40° 33' 17'' N 10 5 ° 4 ' 3 7 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 25 50 100 150 Feet 0 5 10 20 30 Meters Map Scale: 1:524 if printed on A portrait (8.5" x 11") 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 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 19, Aug 29, 2024 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 2, 2021—Aug 25, 2021 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 7 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 73 Nunn clay loam, 0 to 1 percent slopes 1.3 100.0% Totals for Area of Interest 1.3 100.0% 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 8 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 9 Larimer County Area, Colorado 73—Nunn clay loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: 2tlng Elevation: 4,100 to 5,700 feet Mean annual precipitation: 14 to 15 inches Mean annual air temperature: 48 to 52 degrees F Frost-free period: 135 to 152 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 6 inches: clay loam Bt1 - 6 to 10 inches: clay loam Bt2 - 10 to 26 inches: clay loam Btk - 26 to 31 inches: clay loam Bk1 - 31 to 47 inches: loam Bk2 - 47 to 80 inches: loam Properties and qualities Slope:0 to 1 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 (0.1 to 1.0 mmhos/cm) Sodium adsorption ratio, maximum:0.5 Available water supply, 0 to 60 inches: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: C Ecological site: R067BY042CO - Clayey Plains Hydric soil rating: No Custom Soil Resource Report 10 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 Wages 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 11 SITE LOCATION PROPOSED BANK OF AMERICA (REFER TO ARCH PLANS) ONE-STORY ±4,240 SF CG (GENERAL COMMERCIAL) FFE = 5021.75 VANNO PARKING 31' EMERGENCY ACCESS & PRIVATE DRAINAGE EASEMENT FH %1.2 5019 5018 501 9 50 2 1 50 2 1 5021 5020 502 1 50 2 1 502 0 502 0 5021 5020 501 9 5020 5019 5021 5021 5021 % 2.0 TY P . % 8. 3 3MA X % 2.0MAX 50 1 9 % 5.0 MA X 502 0 20' D R A I N A G E EASE M E N T (REC E P T I O N N O . 20240 0 3 9 3 2 5 ) 20' PEDESTRIAN ACCESS & UTILITY EASEMENT (RECEPTION NO. 20240039325) 11' PUBLIC R.O.W. (RECEPTION NO. 20240039325) SOUTH COLLEGE SHOPS(STUCCO SIGN) 20 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T BO O K 1 9 4 6 , P A G E 7 5 7 26' UTILITY EASEMENT (RECEPTION NO. 20240039325) 8" WIDE BLOCK 8" WIDE BLOCK 8.5' 8.9' 8.7' 9.0' 3.4' 15 ' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) 24' PUBLIC R.O.W. (RECEPTION NO. 20230035995) 30' PUBLIC ACCESS EASEMENT (RECEPTION NO. 20230035995) 20' UTILITY EASEMENT (RECEPTION NO. 20230035995) 37' UTILITY EASEMENT (RECEPTION NO. 20240039325) 24' RECIPROCAL EASEMENT AGREEMENT TO DILLON COMPANIES LLC (RECEPTION NO. 20230020881) 20' UTILITY EASEMENT (RECEPTION NO. 20230020879) 23' PEDESTRIAN ACCESS EASEMENT (RECEPTION NO. 98073456) 17.5' EMERGENCY ACCESS EASEMENT & ACCESS EASEMENT (RECEPTION NO. 20240039325) 22' UTILITY EASEMENT (RECEPTION NO. 20240039325) 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) 15' PSC UTILITY EASEMENT (BOOK 1946, PAGE 757) 30' DRAINAGE EASEMENT (RECEPTION NO. 20110028622) 15' UTILITY EASEMENT (BOOK 1462, PAGE 890) 5' UTILITY EASEMENT (RECEPTION NO. 98073456) 30' SANITARY SEWER EASEMENT (RECEPTION NO. 98073456) 0.7'x1.8' COLUMN 0.7'x1.7' COLUMN 0.7'x1.7' COLUMN CUT-OFF PIPE W/ELECTRICAL BOX TREE STUMP GROUND LIGHT 31 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T (R E C E P T I O N N O . 2 0 2 4 0 0 3 9 3 2 5 ) 15 ' B I C Y C L E P E D E S T R I A N AC C E S S E A S E M E N T (R E C E P T I O N N O . 9 8 0 7 3 4 5 6 ) 9' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) RAMPRAMP RAMP RA M P RA M P RAMP BENCH 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) CONCRETE SIDEWALK 6' U T I L I T Y E A S E M E N T BO O K 1 4 5 1 , P A G E 7 0 1 6' U T I L I T Y E A S E M E N T (B O O K 1 4 6 2 , P A G E 8 9 0 ) 5.0' 20' UTILITY EASEMENT (RECEPTION NO. 770323) 32.0' 15.0' 37' UTILITY EASEMENT (RECEPTION NO. 20240039325) 49 ' 27.0' 5.0' 32.0' 5.0'21.0' 26.0' 502 1 5019 50 1 9 5019 5018 5019 5018 5019 5019 5021 50 2 1 50 2 2 502 2 5022 5022 5021 502 2 50 2 2 50 2 1 5023 5020 50 2 0 50 2 0 50 2 0 50 2 0 50 2 0 5020 5025 50 2 5 5019 ST ST WEIR SIZE EXISTING PUBLIC 30" RCP @ ±0.45% PROPOSED ADS STORMTECH SC-800 CHAMBER SYSTEM WITH ISOLATOR ROWS, IMPERMEABLE LINER, AND UNDERDRAIN EXISTING CMP @ ±0.40% PROPOSED CURB INLET TO FILTRATION BASIN PROPOSED GRATE INLET TO FILTRATION BASIN PROPOSED CURB INLET TO FILTRATION BASIN PROPOSED STORM MANHOLE TO EXISTING PUBLIC 30" RCP EXISTING STORM GRATE TO BE CONVERTED TO MANHOLE AND OFFSITE TRIBUTARY AREA TO BYPASS THE PROPOSED FILTRATION BASIN PROPOSED CURB INLET TO FILTRATION BASIN PROPOSED CURB INLET TO BYPASS Date Description No. Revisions © 2 0 2 5 L a n g a n www.langan.com 300 Union Boulevard, Suite 405 Lakewood, CO 80228 T: 303.262.2000 Langan Engineering and Environmental Services, LLC GRAPHIC SCALE FEET04020 1" = 20' LEGEND PROPOSED STORM LINE PROPOSED STORM CENTERLINE PROPOSED CURB INLET WQ/LID SUMMARY TRIBUTARY CATCHMENT AREA UPSTREAM 1.17 AC WQCV REQUIRED 1,406 cu ft WQCV PROVIDED 1,450 cu ft FH 20' DR A I N A G E EASE M E N T (REC E P T I O N N O . 20240 0 3 9 3 2 5 ) HANDICAP PARKING SIGNS 20' PEDESTRIAN ACCESS & UTILITY EASEMENT (RECEPTION NO. 20240039325) 11' PUBLIC R.O.W. (RECEPTION NO. 20240039325) SOUTH COLLEGE SHOPS(STUCCO SIGN) DUMPSTER 20 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T BO O K 1 9 4 6 , P A G E 7 5 7 8.5' 8.9' 8.7' 9.0' 3.4' BRICK WALL 1" WIDE STUCCO WALL 15 ' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) 24' PUBLIC R.O.W. (RECEPTION NO. 20230035995) 30' PUBLIC ACCESS EASEMENT (RECEPTION NO. 20230035995) INCA CUSTOMER PARKING ONLY SIGNS 24' RECIPROCAL EASEMENT AGREEMENT TO DILLON COMPANIES LLC (RECEPTION NO. 20230020881) 17.5' EMERGENCY ACCESS EASEMENT & ACCESS EASEMENT (RECEPTION NO. 20240039325) 22' UTILITY EASEMENT (RECEPTION NO. 20240039325) 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) 15' PSC UTILITY EASEMENT (BOOK 1946, PAGE 757) 30' DRAINAGE EASEMENT (RECEPTION NO. 20110028622) 15' UTILITY EASEMENT (BOOK 1462, PAGE 890) 5' UTILITY EASEMENT (RECEPTION NO. 98073456) (RECEPTION NO. 98073456) 1.7'x1.7' COLUMN 1.7'x1.7' COLUMN 1.7'x1.7' COLUMN 1.7'x1.7' COLUMN 1.7'x1.7' COLUMN 1.7'x1.7' COLUMN CUT-OFF PIPE W/ELECTRICAL BOX TREE STUMP GROUND LIGHT 31 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T (R E C E P T I O N N O . 2 0 2 4 0 0 3 9 3 2 5 ) 9' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) RAMPRAMP RAMP RA M P RA M P HANDICAP RAMP RAMP BENCH BIKE RACK 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) CONCRETE SIDEWALK GRAVEL GRAVEL BUILDING FOOTPRINT AT GROUND LEVEL BUILDING EAVE/OVERHANG 6' U T I L I T Y E A S E M E N T BO O K 1 4 5 1 , P A G E 7 0 1 5.0' (RECEPTION NO. 770323) 32.0' 15.0' 37' UTILITY EASEMENT (RECEPTION NO. 20240039325) 49 ' 27.0' 5.0' 32.0' 5.0'21.0' 26.0' 502 1 5019 50 1 9 5019 5018 5019 5018 5019 5019 5021 50 2 1 50 2 2 502 2 5022 5022 5021 502 2 50 2 2 50 2 1 5023 5020 50 2 0 50 2 0 50 2 0 50 2 0 50 2 0 5020 5025 50 2 5 5019 31' EMERGENCY ACCESS & PRIVATE DRAINAGE EASEMENT 20' DR A I N A G E EASE M E N T (REC E P T I O N N O . 20240 0 3 9 3 2 5 ) HANDICAP PARKING SIGNS 20' PEDESTRIAN ACCESS & UTILITY EASEMENT (RECEPTION NO. 20240039325) 11' PUBLIC R.O.W. (RECEPTION NO. 20240039325) SOUTH COLLEGE SHOPS(STUCCO SIGN) DUMPSTER 20 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T BO O K 1 9 4 6 , P A G E 7 5 7 8.5' 8.9' 8.7' 9.0' 3.4' BRICK WALL 1" WIDE STUCCO WALL 15 ' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) 24' PUBLIC R.O.W. (RECEPTION NO. 20230035995) 30' PUBLIC ACCESS EASEMENT (RECEPTION NO. 20230035995) INCA CUSTOMER PARKING ONLY SIGNS 24' RECIPROCAL EASEMENT AGREEMENT TO DILLON COMPANIES LLC (RECEPTION NO. 20230020881) 17.5' EMERGENCY ACCESS EASEMENT & ACCESS EASEMENT (RECEPTION NO. 20240039325) 22' UTILITY EASEMENT (RECEPTION NO. 20240039325) 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) 15' PSC UTILITY EASEMENT (BOOK 1946, PAGE 757) 30' DRAINAGE EASEMENT (RECEPTION NO. 20110028622) 15' UTILITY EASEMENT (BOOK 1462, PAGE 890) 5' UTILITY EASEMENT (RECEPTION NO. 98073456) (RECEPTION NO. 98073456) 1.7'x1.7' COLUMN 1.7'x1.7' COLUMN 1.7'x1.7' COLUMN 1.7'x1.7' COLUMN 1.7'x1.7' COLUMN 1.7'x1.7' COLUMN CUT-OFF PIPE W/ELECTRICAL BOX TREE STUMP GROUND LIGHT 31 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T (R E C E P T I O N N O . 2 0 2 4 0 0 3 9 3 2 5 ) 9' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) RAMPRAMP RAMP RA M P RA M P HANDICAP RAMP RAMP BENCH BIKE RACK 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) CONCRETE SIDEWALK GRAVEL GRAVEL BUILDING FOOTPRINT AT GROUND LEVEL BUILDING EAVE/OVERHANG 6' U T I L I T Y E A S E M E N T BO O K 1 4 5 1 , P A G E 7 0 1 5.0' (RECEPTION NO. 770323) 32.0' 15.0' 37' UTILITY EASEMENT (RECEPTION NO. 20240039325) 49 ' 27.0' 5.0' 32.0' 5.0'21.0' 26.0' 502 1 5019 50 1 9 5019 5018 5019 5018 5019 5019 5021 50 2 1 50 2 2 502 2 5022 5022 5021 502 2 50 2 2 50 2 1 5023 5020 50 2 0 50 2 0 50 2 0 50 2 0 50 2 0 5020 5025 50 2 5 5019 FH 20' D R A I N A G E EASE M E N T (REC E P T I O N N O . 20240 0 3 9 3 2 5 ) 20' PEDESTRIAN ACCESS & UTILITY EASEMENT (RECEPTION NO. 20240039325) 11' PUBLIC R.O.W. (RECEPTION NO. 20240039325) SOUTH COLLEGE SHOPS(STUCCO SIGN) 20 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T BO O K 1 9 4 6 , P A G E 7 5 7 8.5' 8.9' 8.7' 9.0' 3.4' 15 ' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) 24' PUBLIC R.O.W. (RECEPTION NO. 20230035995) 30' PUBLIC ACCESS EASEMENT (RECEPTION NO. 20230035995) 24' RECIPROCAL EASEMENT AGREEMENT TO DILLON COMPANIES LLC (RECEPTION NO. 20230020881) 23' PEDESTRIAN ACCESS EASEMENT (RECEPTION NO. 98073456) 17.5' EMERGENCY ACCESS EASEMENT & ACCESS EASEMENT (RECEPTION NO. 20240039325) 22' UTILITY EASEMENT (RECEPTION NO. 20240039325) 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) 15' PSC UTILITY EASEMENT (BOOK 1946, PAGE 757) 30' DRAINAGE EASEMENT (RECEPTION NO. 20110028622) 15' UTILITY EASEMENT (BOOK 1462, PAGE 890) 5' UTILITY EASEMENT (RECEPTION NO. 98073456) 30' SANITARY SEWER EASEMENT (RECEPTION NO. 98073456) 0.7'x1.8' COLUMN 0.7'x1.7' COLUMN 0.7'x1.7' COLUMN CUT-OFF PIPE W/ELECTRICAL BOX TREE STUMP GROUND LIGHT 31 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T (R E C E P T I O N N O . 2 0 2 4 0 0 3 9 3 2 5 ) 9' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) RAMPRAMP RAMP RA M P RA M P RAMP BENCH 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) CONCRETE SIDEWALK 6' U T I L I T Y E A S E M E N T BO O K 1 4 5 1 , P A G E 7 0 1 5.0' 20' UTILITY EASEMENT (RECEPTION NO. 770323) 32.0' 15.0' 37' UTILITY EASEMENT (RECEPTION NO. 20240039325) 49 ' 27.0' 5.0' 32.0' 5.0'21.0' 26.0' 502 1 5019 50 1 9 5019 5018 5019 5018 5019 5019 5021 50 2 1 50 2 2 502 2 5022 5022 5021 502 2 50 2 2 50 2 1 5023 5020 50 2 0 50 2 0 50 2 0 50 2 0 50 2 0 5020 5025 50 2 5 5019 PROPOSED BANK OF AMERICA (REFER TO ARCH PLANS) ONE-STORY ±4,240 SF CG (GENERAL COMMERCIAL) FFE = 5021.75 4 12 VAN LANE 1BYPASS DO NOT ENTER 4 6 NO PARKING 31' EMERGENCY ACCESS & PRIVATE DRAINAGE EASEMENT 20' D R A I N A G E EASE M E N T (REC E P T I O N N O . 20240 0 3 9 3 2 5 ) 20' PEDESTRIAN ACCESS & UTILITY EASEMENT (RECEPTION NO. 20240039325) 11' PUBLIC R.O.W. (RECEPTION NO. 20240039325) SOUTH COLLEGE SHOPS(STUCCO SIGN) 20 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T BO O K 1 9 4 6 , P A G E 7 5 7 8.5' 8.9' 8.7' 9.0' 3.4' 15 ' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) 24' PUBLIC R.O.W. (RECEPTION NO. 20230035995) 30' PUBLIC ACCESS EASEMENT (RECEPTION NO. 20230035995) 24' RECIPROCAL EASEMENT AGREEMENT TO DILLON COMPANIES LLC (RECEPTION NO. 20230020881) 23' PEDESTRIAN ACCESS EASEMENT (RECEPTION NO. 98073456) 17.5' EMERGENCY ACCESS EASEMENT & ACCESS EASEMENT (RECEPTION NO. 20240039325) 22' UTILITY EASEMENT (RECEPTION NO. 20240039325) 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) 15' PSC UTILITY EASEMENT (BOOK 1946, PAGE 757) 30' DRAINAGE EASEMENT (RECEPTION NO. 20110028622) 15' UTILITY EASEMENT (BOOK 1462, PAGE 890) 5' UTILITY EASEMENT (RECEPTION NO. 98073456) 30' SANITARY SEWER EASEMENT (RECEPTION NO. 98073456) 0.7'x1.8' COLUMN 0.7'x1.7' COLUMN 0.7'x1.7' COLUMN CUT-OFF PIPE W/ELECTRICAL BOX TREE STUMP GROUND LIGHT 31 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T (R E C E P T I O N N O . 2 0 2 4 0 0 3 9 3 2 5 ) 9' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) RAMPRAMP RAMP RA M P RA M P RAMP BENCH 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) CONCRETE SIDEWALK 6' U T I L I T Y E A S E M E N T BO O K 1 4 5 1 , P A G E 7 0 1 5.0' 20' UTILITY EASEMENT (RECEPTION NO. 770323) 32.0' 15.0' 37' UTILITY EASEMENT (RECEPTION NO. 20240039325) 49 ' 27.0' 5.0' 32.0' 5.0'21.0' 26.0' 502 1 5019 50 1 9 5019 5018 5019 5018 5019 5019 5021 50 2 1 50 2 2 502 2 5022 5022 5021 502 2 50 2 2 50 2 1 5023 5020 50 2 0 50 2 0 50 2 0 50 2 0 50 2 0 5020 5025 50 2 5 5019 Date Description No. Revisions © 2 0 2 5 L a n g a n www.langan.com 300 Union Boulevard, Suite 405 Lakewood, CO 80228 T: 303.262.2000 Langan Engineering and Environmental Services, LLC GRAPHIC SCALE FEET04020 1" = 20' THESE PLANS ARE SUBJECT TO REVIEW & APPROVAL BY JURISDICTIONAL ENTITIES. Know what's below. before you dig.Call R LEGEND IMPERVIOUS SURFACE IMPERVIOUS COVERAGE Total Area 49,360 SF Existing Condition 40,758 SF (82.57%) Proposed Condition 40,739 SF (82.53%) *Proposed condition removes 19 SF of impervious area EXISTING PROPOSED FH CUT-OFF PIPE W/ELECTRICAL BOX 502 1 5019 50 1 9 5019 5018 5019 5018 5019 5019 5021 50 2 1 50 2 2 502 2 5022 5022 5021 502 2 50 2 2 50 2 1 5023 5020 50 2 0 50 2 0 50 2 0 50 2 0 50 2 0 5020 5025 50 2 5 5019 5022 5021 5020 5019 5019 5018 5022 5022 502 3 50 2 2 50 2 1 50 2 0 50 1 9 50 1 8 5022 502 2 5023 5024 502 3 502 4 5025 502 550 2 6 50 2 7 50 2 5 50 2 6 50 2 3 50 2 2 5021 5023 50 2 6 50 2 5 50 2 7 50 2 6 50 2 6 50 2 7 50 2 2 50 2 1 502 4 5021 5022 X-02 1.04 10.3 X-03 0.10 0.8 X-05 0.39 3.9 X-04 0.30 2.9 X-01 0.02 0.1 X-06 4.45 33.2 CONSERVATIVE ASSUMPTION OF UPSTREAM STORMWATER FLOW. UPSTREAM INFORMATION OBTAINED THROUGH OFFSITE LIDAR DATA AND CITY OF FORT COLLINS GIS INFORMATION. Date Description No. Revisions © 2 0 2 5 L a n g a n www.langan.com 300 Union Boulevard, Suite 405 Lakewood, CO 80228 T: 303.262.2000 Langan Engineering and Environmental Services, LLC GRAPHIC SCALE FEET010050 1" = 50' THESE PLANS ARE SUBJECT TO REVIEW & APPROVAL BY JURISDICTIONAL ENTITIES. Know what's below. before you dig.Call R LEGEND ACRES BASIN NAME 100 YR FLOW (CFS) DRAINAGE BASIN DRAINAGE AREA EXISTING FLOW ARROW X-00 1.00 5.00 PRE-DEVELOPMENT DRAINAGE AREA CALCULATIONS Drainage Area Designation Drainage Area Runoff Coefficient C*Cf 2,5,10 C*Cf 100 Time of Concentration 2-Year Rainfall Intensity (I2) 2-Year Peak Discharge (Q2) 10-Year Rainfall Intensity (I10) 10-Year Peak Discharge (Q10) 100-Year Rainfall Intensity (I100) 100-Year Peak Discharge (Q100) -(ac)"C"Cf = 1.00 Cf = 1.25 (min)(in/hr)(cfs)(in/hr)(cfs)(in/hr)(cfs) X-01 0.02 0.37 0.37 0.46 5 2.85 0.0 4.87 0.0 9.95 0.1 X-02 1.04 0.91 0.91 1.00 5 2.85 2.7 4.87 4.6 9.95 10.3 X-03 0.10 0.67 0.67 0.84 5 2.85 0.2 4.87 0.3 9.95 0.8 X-04 0.30 0.92 0.92 1.00 5 2.85 0.8 4.87 1.3 9.95 2.9 X-05 0.39 0.85 0.85 1.00 5 2.85 1.0 4.87 1.6 9.95 3.9 X-06 4.45 0.77 0.77 0.97 5 2.21 7.6 3.78 13.0 7.72 33.2 Total 6.30 12.2 20.9 51.3 Note: Calculations based on the Rational Method: Q = C*I*A; Intensities and Frequency Adjustment Factors (Cf) taken from Fort Collins Stormwater Criteria Manual FH TP 5020.70 ±ME TC 5019.30TC ±ME TP 5018.80TP ±ME TC 5018.95 ±ME TP 5018.55 ±ME TP 5018.50 ±ME TP 5021.60 ±ME TC 5021.60 ±ME TP 5021.10 ±ME TC 5020.61 TC 5020.11 ±ME TP 5020.58±ME TP 5021.05 ±ME TP 5021.25 TC 5021.20 TP 5020.70 TC 5021.10 TP 5020.60 TC 5020.75 TP 5020.25 ±ME TC 5019.10 ±ME TP 5018.60 ±ME TP 5018.60 TC 5019.00 TP 5018.50 TP 5020.60 TC 5020.70 TP 5020.20 TC 5021.40 TP 5020.90 TC 5021.00 TP 5020.50 FF 5021.75 TP 5021.70 FG 5021.60 FG 5021.60 TP 5020.25 FF 5021.75 TP 5021.50 TP 5021.70 FG 5021.60 TC 5021.55 TP 5021.05 TC 5021.50 TP 5021.00 TP 5020.50 ±ME TP 5022.00 ±ME TP 5022.00 ±ME TP 5021.00 ±ME TC 5020.66 ±ME TP 5020.16 ±ME TP 5018.35 TC 5021.95 TP 5021.45 TP 5021.45 TP 5021.40 TP 5020.95 TP 5020.90 TC 5021.65 TP 5021.15 TC 5021.65 TP 5021.15 TC 5021.40 TP 5020.90 TP 5020.50 TC 5021.40 TP 5020.90 TC 5020.55 TP 5020.05 TC 5021.00 TP 5020.50 TP 5020.75 TP 5021.20 TP 5020.60 TP 5021.30 ±ME TP 5021.77 ±ME TP 5021.65 TP 5020.45 TP 5020.90 TP 5021.05 TP 5021.15 5021.05TP ±ME TP 5020.51 ±ME TP 5020.18 ±ME TC 5020.18 ±ME TP 5019.68 TP 5021.40 TC 5021.95 TP 5021.45 TP 5020.50 ±ME TP 5018.51 ±ME TP 5018.56 TC 5019.25 TP 5018.75 FG 5020.36 EX FG 5021.49 TP 5021.40 TP 5021.25 TP 5021.35 TP 5021.60 EX FG 5021.01 EX FG 5020.21 TP 5021.26 TP 5020.25 EX TP 5020.75 TC 5021.88 TP 5021.56 TI 5018.60 TP 5019.05 TP 5019.10 EX FG 5019.10 TC 5021.30 TP 5020.80 TP 5020.50 TP 5020.90 TC 5019.40 TP 5018.90 TP 5020.80 TC 5021.30 TP 5020.80 TP 5021.05 FG 5021.70 TP 5020.75 FG 5021.60 TC 5021.45 TP 5020.95 TP 5020.50 %1.2 TI 5020.00 TC 5020.60 TP 5020.10 TI 5019.85 TI 5020.00 5019 5018 501 9 50 2 1 50 2 1 5021 5020 502 1 TC 5021.15 TP 5020.65 50 2 1 502 0 502 0 5021 5020 501 9 5020 5019 5021 5021 5021 FG 5021.13 TI 5020.45 %2.0 TY P . ±ME TP 5018.35 % 8.3 3MA X % 2.0MAX TP 5021.55 50 1 9 % 5.0 MA X EX TP 5018.68 EX TP 5018.80 502 0 TP 5017.90 ST ST PROPOSED BANK OF AMERICA (REFER TO ARCH PLANS) ONE-STORY ±4,240 SF CG (GENERAL COMMERCIAL) FFE = 5021.75 LANE 1BYPASS DO NOT ENTER 31' EMERGENCY ACCESS & PRIVATE DRAINAGE EASEMENT SOUTH COLLEGE SHOPS(STUCCO SIGN) 8" WIDE BLOCK 8" WIDE BLOCK 8.5' 8.9' 8.7' 9.0' 3.4' NORTHWEST CORNER OF MIDTOWN GARDENS MARKETPLACE 0.7'x1.8' COLUMN 0.7'x1.7' COLUMN 0.7'x1.7' COLUMN CUT-OFF PIPE W/ELECTRICAL BOX TREE STUMP GROUND LIGHT RAMPRAMP RAMP RA M P RA M P RAMP BENCH CONCRETE SIDEWALK 5.0' 32.0' 15.0' 49 ' 27.0' 5.0' 32.0' 5.0'21.0' 26.0' 502 1 5019 50 1 9 5019 5018 5019 5018 5019 5019 5021 50 2 1 50 2 2 502 2 5022 5022 5021 502 2 50 2 2 50 2 1 5023 5020 50 2 0 50 2 0 50 2 0 50 2 0 50 2 0 5020 5025 50 2 5 5019 5022 5021 5020 5019 5019 5018 5022 5022 502 3 50 2 2 50 2 1 50 2 0 50 1 9 50 1 8 5022 502 2 5023 5024 502 3 502 4 5025 502 550 2 6 50 2 7 50 2 5 50 2 6 50 2 3 50 2 2 5021 5023 50 2 6 50 2 5 50 2 7 50 2 6 50 2 6 50 2 7 50 2 2 50 2 1 502 4 5021 5022 DA-1 0.41 4.1 OS-2 0.13 0.9 DA-3 0.14 1.4 DA-4 0.10 1.0 OS-1 0.02 0.1 OS-3 0.54 5.3 DA-2 0.34 3.4 R-1 0.13 1.3 DA-5 0.05 .5OS-4 4.45 33.2 Date Description No. Revisions © 2 0 2 5 L a n g a n www.langan.com 300 Union Boulevard, Suite 405 Lakewood, CO 80228 T: 303.262.2000 Langan Engineering and Environmental Services, LLC GRAPHIC SCALE FEET010050 1" = 50' THESE PLANS ARE SUBJECT TO REVIEW & APPROVAL BY JURISDICTIONAL ENTITIES. Know what's below. before you dig.Call R LEGEND ACRES BASIN NAME 100 YR FLOW (CFS) DRAINAGE BASIN DRAINAGE AREA PROPOSED FLOW ARROW DA-00 1.00 5.00 POST-DEVELOPMENT DRAINAGE AREA CALCULATIONS Drainage Area Designation Drainage Area Runoff Coefficient C*Cf 2,5,10 C*Cf 100 Time of Concentration 2-Year Rainfall Intensity (I2) 2-Year Peak Discharge (Q2) 10-Year Rainfall Intensity (I10) 10-Year Peak Discharge (Q10) 100-Year Rainfall Intensity (I100) 100-Year Peak Discharge (Q100) -(ac)"C"Cf = 1.00 Cf = 1.25 (min)(in/hr)(cfs)(in/hr)(cfs)(in/hr)(cfs) DA-1 0.41 0.85 0.85 1.00 5 2.85 1.0 4.87 1.7 9.95 4.1 DA-2 0.34 0.93 0.93 1.00 5 2.85 0.9 4.87 1.5 9.95 3.4 DA-3 0.14 0.80 0.80 1.00 5 2.85 0.3 4.87 0.5 9.95 1.4 DA-4 0.10 0.88 0.88 1.00 5 2.85 0.3 4.87 0.4 9.95 1.0 DA-5 0.05 0.95 0.95 1.00 5 2.85 0.1 4.87 0.2 9.95 0.5 R-1 0.13 0.95 0.95 1.00 5 2.85 0.4 4.87 0.6 9.95 1.3 OS-1 0.02 0.34 0.34 0.43 5 2.85 0.0 4.87 0.0 9.95 0.1 OS-2 0.13 0.57 0.57 0.72 5 2.85 0.2 4.87 0.4 9.95 0.9 OS-3 0.54 0.92 0.92 1.00 5 2.85 1.4 4.87 2.4 9.95 5.3 OS-4 4.45 0.77 0.77 0.97 10 2.21 7.6 3.78 13.0 7.72 33.2 Total 6.30 12.2 20.8 51.1 Note: Calculations based on the Rational Method: Q = C*I*A; Intensities and Frequency Adjustment Factors (Cf) taken from Fort Collins Stormwater Criteria Manual FH %1.2 5019 5018 501 9 50 2 1 50 2 1 5021 5020 502 1 50 2 1 502 0 502 0 5021 5020 501 9 5020 5019 5021 5021 5021 % 2.0 TY P . % 8. 3 3MA X % 2.0MAX 50 1 9 % 5.0 MA X 502 0 PROPOSED BANK OF AMERICA (REFER TO ARCH PLANS) ONE-STORY ±4,240 SF CG (GENERAL COMMERCIAL) FFE = 5021.75 VANNO PARKING 31' EMERGENCY ACCESS & PRIVATE DRAINAGE EASEMENT 20' D R A I N A G E EASE M E N T (REC E P T I O N N O . 20240 0 3 9 3 2 5 ) 20' PEDESTRIAN ACCESS & UTILITY EASEMENT (RECEPTION NO. 20240039325) 11' PUBLIC R.O.W. (RECEPTION NO. 20240039325) SOUTH COLLEGE SHOPS(STUCCO SIGN) 20 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T BO O K 1 9 4 6 , P A G E 7 5 7 26' UTILITY EASEMENT (RECEPTION NO. 20240039325) 15 ' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) 24' PUBLIC R.O.W. (RECEPTION NO. 20230035995) 30' PUBLIC ACCESS EASEMENT (RECEPTION NO. 20230035995) 20' UTILITY EASEMENT 37' UTILITY EASEMENT (RECEPTION NO. 20240039325) 24' RECIPROCAL EASEMENT AGREEMENT TO DILLON COMPANIES LLC (RECEPTION NO. 20230020881) 20' UTILITY EASEMENT (RECEPTION NO. 20230020879) 23' PEDESTRIAN ACCESS EASEMENT (RECEPTION NO. 98073456) 17.5' EMERGENCY ACCESS EASEMENT & ACCESS EASEMENT (RECEPTION NO. 20240039325) 22' UTILITY EASEMENT (RECEPTION NO. 20240039325) 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) 15' PSC UTILITY EASEMENT (BOOK 1946, PAGE 757) 30' DRAINAGE EASEMENT (RECEPTION NO. 20110028622) 15' UTILITY EASEMENT (BOOK 1462, PAGE 890) 5' UTILITY EASEMENT (RECEPTION NO. 98073456) 30' SANITARY SEWER EASEMENT (RECEPTION NO. 98073456) TREE STUMP 31 ' E M E R G E N C Y AC C E S S E A S E M E N T & A C C E S S E A S E M E N T (R E C E P T I O N N O . 2 0 2 4 0 0 3 9 3 2 5 ) 15 ' B I C Y C L E P E D E S T R I A N AC C E S S E A S E M E N T (R E C E P T I O N N O . 9 8 0 7 3 4 5 6 ) 9' U T I L I T Y E A S E M E N T (R E C E P T I O N N O . 2 0 2 3 0 0 3 5 9 9 5 ) RAMP BENCH 6' UTILITY EASEMENT (BOOK 1462, PAGE 890) 6' U T I L I T Y E A S E M E N T BO O K 1 4 5 1 , P A G E 7 0 1 6' U T I L I T Y E A S E M E N T (B O O K 1 4 6 2 , P A G E 8 9 0 ) 20' UTILITY EASEMENT (RECEPTION NO. 770323) 37' UTILITY EASEMENT (RECEPTION NO. 20240039325) 502 1 5019 50 1 9 5019 5018 5019 5018 5019 5019 5021 50 2 1 50 2 2 502 2 5022 5022 5021 502 2 50 2 2 50 2 1 5023 5020 50 2 0 50 2 0 50 2 0 50 2 0 50 2 0 5020 5025 50 2 5 5019 SEE DETAIL OF THIS INLET AND EXISTING PUBLIC STORM INFRASTRUCTURE TO THE LEFT, THIS SHEET EXISTING PUBLIC 30" RCP @ ±0.45% EXISTING PUBLIC 15" RCP @ ±0.45% EXISTING 24" CMP @ ±0.40% STA. 1+73.79 ~ STRM-2 INSTALL SINGLE CURB INLET (REF. DETAIL D-43) RIM = 5019.85 FL 12" = 5016.21 FL 15" = 5015.96 STA. 1+54.21 ~ STRM-1 INSTALL STRM MANHOLE RIM = 5019.00 FL 30" = 5013.16 FL 30" = 5013.16 FL 12" = 5013.16 FL 18" = 5013.16 STA. 0+00.00 ~ STRM-1 INSTALL STRM MANHOLE RIM = MATCH EXISTING FINISH GRADE FL 30" = 5011.11 STA. 0+00.00 ~ LAT-2.2 CONNECT TO SC-800 CHAMBER FL 12" = 5014.94 STA. 0+00.00 ~ STRM-2 CONNECT TO SC-800 CHAMBER FL 18" = 5014.19 STA. 0+29.52 ~ LAT-2.1 CONNECT TO SC-800 CHAMBER FL 18" = 5013.50 STA. 3+85.64 ~ STRM-1 REMOVE EXISTING GRATED LID AND REPLACE WITH ENCLOSED LID RIM = 5020.70 FL 30" = 5016.19 STA. 2+63.66 ~ STRM-2 INSTALL SINGLE CURB INLET (REF. DETAIL D-43) RIM = 5020.00 FL 12" = 5017.00 STA. 0+23.54 ~ LAT-2.2 INSTALL SINGLE CURB INLET (REF. DETAIL D-43) RIM = 5017.90 FL 12" = 5015.40 STA. 0+27.83 ~ LAT-1.1 INSTALL SINGLE CURB INLET (REF. DETAIL D-43) RIM = 5018.60 FL 12" = 5015.60 STA. 1+52.33 ~ STRM-2 INSTALL SINGLE CURB INLET (REF. DETAIL D-43) RIM = 5020.00 FL 15" = 5015.77 FL 15" = 5015.77 STA. 0+46.92 ~ STRM-2 INSTALL SINGLE CURB INLET (REF. DETAIL D-43) RIM = 5020.45 FL 15" = 5014.85 FL 18" = 5014.60 FL 6" = 5015.60 30 " H P S T O R M 2 3 1 . 4 3 L F @ 1 . 3 1 % 30" HP ST O R M 1 5 4 . 2 1 L F @ 1 . 3 3 % 12" HP STORM 27.83 LF @ 8.77% 18" HP STORM 29.52 LF @ 1.15% 12" HP STORM 23.54 LF @ 1.95% 12" HP S T O R M 8 9 . 8 7 L F @ 0 . 8 8 % 15" HP STORM 21.46 LF @ 0.88% 18 " H P S T O R M 4 6 . 9 2 L F @ 0 . 8 8 % 15 " H P S T O R M 1 0 5 . 4 0 L F @ 0 . 8 8 % 6" HDPE 32.70 LF @ 6.58% ST ST WEIR SIZE STA. 0+32.70 ~ LAT-2.0 CONNECT TO ROOF DRAIN (REF MEP PLANS) FL 6" OUT = 5017.75 PROPOSED ADS STORMTECH SC-800 CHAMBER SYSTEM WITH IMPERMEABLE LINER AND UNDERDRAIN REF SHEETS 8 & 9 FOR DETAILS 0+00 0+28 0+0 0 0+3 0 0+00 1+00 2+ 0 0 3+ 0 0 3+ 8 6 0+ 0 0 1+ 0 0 2+00 2+64 0+00 0+33 0+ 0 0 0+ 2 4 Date Description No. Revisions © 2 0 2 5 L a n g a n www.langan.com 300 Union Boulevard, Suite 405 Lakewood, CO 80228 T: 303.262.2000 Langan Engineering and Environmental Services, LLC GRAPHIC SCALE FEET04020 1" = 20' ** NOTICE TO CONTRACTORS - TOPOGRAPHIC SURVEY ** TOPOGRAPHIC INFORMATION TAKEN FROM A TOPOGRAPHIC SURVEY PERFORMED BY LANGAN ENGINEERING AND ENVIRONMENTAL SERVICES, LLC.. THE CONTRACTOR SHALL NOTIFY THE ENGINEER IMMEDIATELY, IN WRITING, OF ANY DISCREPANCIES OR OMISSIONS TO THE TOPOGRAPHIC INFORMATION. THE CONTRACTOR(S) SHALL BE RESPONSIBLE FOR CONFIRMING THE LOCATION (HORIZONTAL/VERTICAL) OF ANY BURIED CABLES, CONDUITS, PIPES, AND STRUCTURES (STORM SEWER, SANITARY SEWER, WATER, GAS, TELEVISION, TELEPHONE, ETC.) WHICH IMPACT THE CONSTRUCTION SITE. THE CONTRACTOR(S) SHALL NOTIFY THE OWNER AND ENGINEER IF ANY DISCREPANCIES ARE FOUND BETWEEN THE ACTUAL CONDITIONS VERSUS THE DATA CONTAINED IN THE CONSTRUCTION PLANS. ANY COSTS INCURRED AS THE RESULT OF NOT CONFIRMING THE ACTUAL LOCATION (HORIZONTAL/VERTICAL) OF SAID CABLES, CONDUITS, PIPES, AND STRUCTURES SHALL BE BORNE BY THE CONTRACTOR. ADDITIONALLY, THE CONTRACTOR(S) SHALL NOTIFY THE OWNER AND ENGINEER IF ANY ERRORS OR DISCREPANCIES ARE FOUND ON THE CONSTRUCTION DOCUMENTS (PS&E), WHICH NEGATIVELY IMPACT THE PROJECT. THE ENGINEER AND OWNER SHALL BE INDEMNIFIED OF PROBLEMS AND/OR COST WHICH MAY RESULT FROM CONTRACTOR'S FAILURE TO NOTIFY ENGINEER AND OWNER. THESE PLANS ARE SUBJECT TO REVIEW & APPROVAL BY JURISDICTIONAL ENTITIES. THE CONTRACTOR IS SPECIFICALLY CAUTIONED THAT THE LOCATION AND/OR ELEVATION OF ANY EXISTING UTILITIES AS SHOWN ON THESE PLANS ARE BASED ON RECORDS OF THE VARIOUS UTILITY COMPANIES, THE GOVERNING MUNICIPALITY, AND WHERE POSSIBLE, MEASUREMENTS TAKEN IN THE FIELD. THE INFORMATION PROVIDED IS NOT TO BE RELIED ON AS BEING EXACT OR COMPLETE. THE CONTRACTOR MUST CALL THE APPROPRIATE UTILITY COMPANY AT LEAST 48 HOURS BEFORE ANY EXCAVATION TO REQUEST EXACT FIELD LOCATION OF UTILITIES. IT SHALL BE THE RESPONSIBILITY OF THE CONTRACTOR TO RELOCATE ALL EXISTING UTILITIES WHICH CONFLICT WITH THE PROPOSED IMPROVEMENTS SHOWN ON THESE PLANS. **NOTICE TO CONTRACTORS - UTILITIES** !!!CAUTION!!! EXISTING OVERHEAD & UNDERGROUND UTILITIES IN THE VICINITY. VERIFY LOCATION OF EXISTING UNDERGROUND UTILITIES BY VACUUM EXCAVATION OR OTHER POTHOLING TECHNIQUES. Know what's below. before you dig.Call R LEGEND PROPOSED STORM LINE PROPOSED STORM CENTERLINE PROPOSED CURB INLET FL FLOWLINE TI TOP OF INLET REMOVE EXISTING 24" CMP IMAGE ABOVE SOURCED FROM THE "EXTENSION OF K-MART PLAZA" PLANS SEALED BY PHILLIP I. ROBINSON 04/15/1974 100-YEAR RATIONAL METHOD STORM SEWER CALCULATIONS Line ID Upstream Station Downstream Station Pipe Length Pipe Slope Drainage Area Designation Incremental Drainage Area Cumulative Drainage Area Runoff Coefficient Incremental Cumulative Time at Inlet Time in Pipe Cumulative Time Rainfall Intensity Peak Flow Pipe Material Pipe Capacity Pipe Diameter Friction Slope Hydraulic Gradient Velocity In Velocity Out V1^2/2g V2^2/2g Upstream Junction Type Loss Coefficient Velocity Head Loss Upstream Invert Elev. Downstream Invert Elev. Comments Upstream Downstream --- (ft)(ft/ft)-(ac)(ac)"C""CA""CA"(min)(min)(min)(in/hr)(cfs)-(cfs)(in)(ft/ft)--(ft/sec)(ft/sec)(ft)(ft)-"Kj"(ft)(ft)(ft) STRM-1 3+85.64 1+54.21 231.43 0.0133 OS-4 4.45 4.45 0.97 4.30 4.30 10.00 0.57 10.57 7.72 33.2 HP Storm 51.2 30 0.0056 5017.78 5016.49 0.00 6.76 0.00 0.71 Begin Line 1.25 0.89 5016.24 5013.16 1+54.21 0+00.00 154.21 0.0133 DA-(1-5), R-1, OS-3 1.71 6.16 1.00 1.71 6.001875 10.57 0.27 10.84 7.72 46.3 HP Storm 51.2 30 0.0109 5015.29 5013.61 6.76 9.44 0.71 1.38 MH with 90 Lateral 0.25 1.21 5013.16 5011.11 LAT-1.1 0+27.83 0+00.00 27.83 0.0877 OS-3 0.54 0.54 1.00 0.54 0.54 5.00 0.07 5.07 9.95 5.3 HP Storm 11.4 12 0.0190 5017.02 5016.49 0.00 6.78 0.00 0.71 Begin Line 1.25 0.89 5015.60 5013.16 STRM-2 2+63.66 1+73.79 89.87 0.0088 DA-3 0.14 0.14 1.00 0.14 0.14 5.00 0.84 5.84 9.95 1.4 HP Storm 3.6 12 0.0013 5017.44 5017.26 0.00 1.77 0.00 0.05 Begin Line 1.25 0.10 5017.00 5016.21 1+73.79 1+52.33 21.46 0.0088 DA-2 0.34 0.48 1.00 0.34 0.48 5.84 0.09 5.94 9.95 4.8 HP Storm 6.5 15 0.0047 5017.05 5016.95 1.77 3.89 0.05 0.24 Inlet 0.50 0.21 5015.96 5015.77 1+52.33 0+46.92 105.41 0.0088 DA-4 0.10 0.58 1.00 0.10 0.58 5.94 0.37 6.31 9.95 5.8 HP Storm 6.5 15 0.0068 5016.73 5016.01 3.89 4.70 0.24 0.34 Inlet 0.50 0.23 5015.77 5014.85 0+46.92 0+00.00 46.92 0.0088 DA-5,R-1 0.18 0.76 1.00 0.18 0.76 6.31 0.18 6.49 9.95 7.6 HP Storm 10.6 18 0.0044 5015.90 5015.69 4.70 4.28 0.34 0.28 Inlet 0.50 0.11 5014.60 5014.19 LAT-2.0 0+32.70 0+00.00 32.70 0.0658 R-1 0.13 0.13 1.00 0.13 0.13 5.00 0.08 5.08 9.95 1.3 HDPE 1.7 6 0.0380 5018.08 5015.18 0.00 6.59 0.00 0.67 Begin Line 1.25 0.84 5017.75 5015.60 LAT-2.1 0+29.52 0+00.00 29.52 0.0115 DA-1,DA-2,DA-3,DA-4,DA-5,R-1 1.17 1.17 1.00 1.17 1.17 5.00 0.07 5.07 9.95 11.6 HP Storm 12.2 18 0.0105 5016.80 5016.49 0.00 6.59 0.00 0.67 Begin Line 1.25 0.84 5013.50 5013.16 LAT-2.2 0+23.54 0+00.00 23.54 0.0195 DA-1 0.41 0.41 1.00 0.41 0.41 5.00 0.08 5.08 9.95 4.1 HP Storm 5.4 12 0.0112 5017.41 5017.15 0.00 5.19 0.00 0.42 Begin Line 1.25 0.52 5015.40 5014.94 .0 2,500 5,0001,250 Feet SPRING CREEK BASIN MANAGEMENT PROPOSED CONDITION BMP MAP Ov e r l a n d T r a i l Co l l e g e A v e Co l l e g e A v e Harmony Rd Horsetooth Rd Prospect Rd Prospect Rd Sh e i l d s S t Taft Hill Rd Taft Hill Rd Sheilds St Drake Rd Lem ay Ave Timberline Rd Colorado State University Lemay Ave Parkwood Lake !( !( !(!(!( !( !( Union Pacific RR Burlington Northern RR Burlington Northern RR Warren Lake Horsetooth Reservoir College Lake Lake Sherwood Spring Canyon Park Pond (Optional) • Retrofit Existing Pond To Accomodate Water Quality Volume Kensington Pond • Retrofit Existing Pond To Accomodate Water Quality Volume Proposed CSU Ropes Pond • Construct Pond To Accomodate Water Quality Volume Proposed Edora Pond • Construct Pond To Accomodate Water Quality Volume CSU Vet Hospital Pond • Retrofit Existing Pond To Accomodate Water Quality Volume Woodwest Detention Pond • Construct Proprietary Mechanical BMP At Pond Outlet. Wagon Wheel Pond (Optional) • Retrofit Existing Pond To Accomodate Water Quality Volume Rossborough Park Pond • Install Water Quality Outlet To Accomodate Water Quality Volume Proposed Taft and Horsetooth Pond • Construct Pond To Accomodate Water Quality Volume Proposed Centre Ave Pond • Construct Pond To Accomodate Water Quality Volume !( !( #### !( ## ## ## ## ## ## ## Proposed Stream Restoration and Habitat Improvements Legend ##Proposed Water Quality Pond Proposed BMP Basin Type Flood Control Only Water Quality Only WQ Not Evaluated Water Drains Into Irrigation System Undeveloped Area Flood Control and Water Quality Proprietary Mechanical BMP!( Proposed Improvement Spring Creek Basin Proposed Stream Restoration and Habitat Improvements SITE LOCATION SITE LOCATION