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Home My WebLink AboutMOUNTAIN VIEW COMMUNITY CHURCH - FDP200020 - - DRAINAGE REPORT (2)FINAL DRAINAGE REPORT 1501 ACADEMY CT. STE 203 | FORT COLLINS, CO 80524 | 970-530-4044 | www.unitedcivil.com M OUNTAIN V IEW C OMMUNITY C HURCH A Portion of Tract A Seven Lakes Business Park P.U.D Fort Collins , CO Prepared for: M ountain View Community Church 2330 East Prospect Road Fort Collins , CO 805 2 5 Date: Dec ember 18 , 2020 F INAL D RAINAGE R EPORT M OUNTAIN V IEW C OMMUNITY C HURCH F ORT C OLLINS , CO i U20004_Drainage Report.docx December 18, 2020 City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, Colorado 80521 RE: Mountain View Community Church Improvements Fort Collins, Colorado Project Number: U20004 Dear Staff: United Civil Design Group, LLC. is pleased to submit this Final Drainage Report for the Mountain View Community Church 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. This report was prepared in compliance with technical criteria set forth in 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 Colton Beck, PE Sam Eliason, PE Project Engineer Principal F INAL D RAINAGE R EPORT M OUNTAIN V IEW C OMMUNITY C HURCH F ORT C OLLINS , CO ii U20004_Drainage Report.docx 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 .........................................................................................................................3 A. Major Basin Description ............................................................................................................... 3 B. Sub-Basin Description .................................................................................................................. 3 III. Drainage Design Criteria ....................................................................................................................................3 A. Regulations ................................................................................................................................... 3 B. Directly Connected Impervious Area (DCIA) ................................................................................ 3 C. Hydrological Criteria ..................................................................................................................... 4 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 ...................................................................................................................................................7 VI. Conclusions ........................................................................................................................................................7 A. Compliance with Standards ......................................................................................................... 7 B. Drainage Concept ......................................................................................................................... 7 C. Stormwater Quality ...................................................................................................................... 7 VII. References ......................................................................................................................................................8 APPENDICES APPENDIX A – Hydrology Calculations APPENDIX B – Hydraulic Calculations B.1 – Low Impact Development Calculations B.2 – Water Quality Calculations B.3 – Inlet Sizing Calculations (Reserved for Final Submittal) B.4 – Storm Pipe Calculations (Reserved for Final Submittal) B.5 – Curb Channel Calculations (Reserved for Final Submittal) B.6 – Weir Calculation (Reserved for Final Submittal) APPENDIX C – Referenced Materials APPENDIX D – Drainage Exhibits F INAL D RAINAGE R EPORT M OUNTAIN V IEW C OMMUNITY C HURCH F ORT C OLLINS , CO 1 U20004_Drainage Report.docx I. GENERAL LOCATION AND DESCRIPTION A. LOCATION AND PROJECT DESCRIPTION The Mountain View Community Church site (referred herein as “the site”) exists as a portion of Tract A, Seven Lakes Business Park P.U.D, located in the southwest quarter of Section 17, T7N, R698W of the 6th P.M., City of Fort Collins, Larimer County, Colorado. The property, consisting of approximately 2.90 acres, is located north of East Prospect Road and east of South Timberline Road. The site currently exists as a commercial property with adjacent parking. The proposed Mountain View Community Church modified site improvements are limited to 0.56 acres of disturbed area. The property is bounded by the Spring Creek Trail to the north and west, and commercial properties to the south and east. Stormwater on the site currently drains in several directions away from the existing building, however, all runoff is ultimately collected by storm sewer infrastructure and conveyed to the Cattail Chorus Natural Area ponds to the north or a drainage channel to the east of the site. Ultimately both areas drain to the Cache La Poudre River, which is approximately 2000 feet east of the site. The proposed improvements to the site consist of reconstructing a portion of the building along with associated landscaping, walks, and parking around the perimeter of the building. Additionally, water quality measures are proposed with the reconstruction to improve drainage function and water quality. FIGURE 1: SITE VICINITY MAP This drainage report presents the overall drainage plan for the development. 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. E Prospect Rd F INAL D RAINAGE R EPORT M OUNTAIN V IEW C OMMUNITY C HURCH F ORT C OLLINS , CO 2 U20004_Drainage Report.docx B. DESCRIPTION OF PROPERTY The project site currently exists as a fully developed commercial lot, including concrete and asphalt pavement, sidewalks, rooftop, and landscaping, comprising of an existing imperviousness of 65.3%. In its existing condition, by means of sheet flow, concrete pans, curb and gutter, inlets, and storm sewer, the site ultimately drains off-site to Cattail Chorus Natural Area ponds north the site or to a drainage channel to the east. 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 exists as a commercial development with concrete and asphalt pavement, sidewalk, rooftop, and surrounding grass landscaping. The grass cover is good (ie., heavy or dense cover with nearly all ground surfaces protected by vegetation). Existing Topography – The site slopes in a multitude of directions away from the existing on-site building, however, runoff ultimately drains north to an existing downstream pond associated with the Cattail Chorus Natural Area. Grades – In general, the western portion of the site is sloped westerly and northerly at approximately 1.0% to 5.0%; the southern and eastern portions of the site are sloped easterly and northerly at approximately 1.0% to 5.0%. The northern portion of the side drains northerly off-site. Soil Type - The USDA’s Web Soil Survey shows that the site consists largely of a “Type C” soil, namely Loveland clay loam (0 to 1% slopes). The Web Soil Survey also indicates the site is comprised of Table Mountain loam (0 to 1% slopes), a “Type B” soil. The on-site soils provide moderate infiltration and are suitable for development. Utilities – The following dry utility lines run along the south side of the site: gas, electric, cable TV, fiber optic. Water mains are also present on the south side of the site within West Prospect Road. A recently constructed sanitary sewer service exists at the northwest portion of the site. Drainage Features and Storm Sewer – An off-site pond exists north of the site. On-site and off-site storm sewer infrastructure conveys runoff to the mentioned downstream pond. C. FLOODPLAINS The existing site is within the Spring Creek Floodplain which is a FEMA designated 100- year floodplain and floodway. In addition, the existing site and building is located within the Spring Creek moderate risk floodplain. The FEMA FIRM Panel # is 08069C0983H effective 5/2/2012. A Letter of Map Amendment (LOMA) Determination Document #19-08- 0473A dated 3/27/2019 removed the building from the 100-year floodplain. The current FEMA FIRM Map along with the LOMA is included in the appendix. The proposed building will be used as a place of Worship. The proposed improvements will comply with Chapter 10 of the Municipal Code. FIGURE 2: FLOODPLAIN MAP Existing Building F INAL D RAINAGE R EPORT M OUNTAIN V IEW C OMMUNITY C HURCH F ORT C OLLINS , CO 3 U20004_Drainage Report.docx II. DRAINAGE BASINS AND SUB-BASINS A. MAJOR BASIN DESCRIPTION The existing site is located within both the Spring Creek and Cache La Poudre River master drainage basins. The northern portion of the site drains downstream within the Spring Creek Basin, while the southern portion of the site drains east, ultimately conveyed to the Cache La Poudre River. No known master planning improvements are associated with or adjacent to the site. B. SUB-BASIN DESCRIPTION The site, along with the rest of Tract A, is included within the Seven Lakes Business Park P.U.D completed by Parsons & Associates in January 1982. A Site Drainage and Grading Plan associated with this P.U.D is included in the Appendix . A drainage report could not be located. The approved P.U.D provides context for how the overall Tract A portion of the Seven Lakes Business Park was designed to drain and is somewhat similar to existing drainage patterns. The site exists within Basins A3 and B of the mentioned Site Drainage and Grading Plan. Basin A3 drains north within the Spring Creek drainage basin; Basin B drains south and east within the Cache La Poudre drainage basin. More recent drainage reports and letters related to the Seven Lakes Business Park are recorded with the City of Fort Collins, however, documents specifically related to this site are not recorded. III. DRAINAGE DESIGN CRITERIA A. REGULATIONS The design criteria for this study are directly from the City of Fort Collins Storm Drainage Design Crit eria 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) The “Four Step Process” that is recommended in Volume 3 of the USDCM in selecting structural BMPs for 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 bioretention facilities and vegetated buffers to increase the 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 bioretention facilities. Step 3 – Stabilize Drainageways The site is adjacent to Spring Creek and the use of LID will help slow runoff from the site and benefit the stabilization of the Spring Creek drainageway. In addition, this project will pay stormwater development and stormwater utility fees which the City uses, in part, to maintain the stability of the City drainageway systems. 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 redevelopment of the existing site will include multiple site specific and source controls, including: • Dedicated maintenance personnel providing landscape maintenance and snow and ice management. F INAL D RAINAGE R EPORT M OUNTAIN V IEW C OMMUNITY C HURCH F ORT C OLLINS , CO 4 U20004_Drainage Report.docx 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 condi tions. 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 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 existing design points via swales, concrete pans, 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 swales and bioretention ponds, 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 A variance was approved for storm water quality requirements. The site was unable to meet City of Fort Collins stormwater requirements due to existing site constraints further documented in the approved variance included with Appendix C. IV. DRAINAGE FACILITY DESIGN A. GENERAL CONCEPT Developed runoff is designed to largely maintain existing drainage patterns. Existing conveyance methods include sheet flow, concrete pans, curb and gutter, inlets, and storm sewer that ultimately drain runoff off -site to Cattail Chorus Natural Area ponds north the site. Runoff that drains off-site to the east is ultimately conveyed to the Cache La Poudre River by means of existing storm sewer infrastructure and drainage swales related to Tract B and Tract C of the Seven Lakes Business Park. Per City standards, stormwater detention is not being provided because the increase in impervious surfaces is less than 1,000 square-feet. Per City standards, water quality and low impact development (LID) is being proposed with project to mitigate the impervious areas that are being modified with the development. This includes a proposed bioretention pond on the north side of the building and a new storm drain system that conveys runoff to the vegetative buffer on the west side of the property. B. SPECIFIC DETAILS Hydrology Site improvements include an increase of approximately 601-sf of additional impervious area relative to existing conditions. Due to the minimal impacts related to the site’s overall imperviousness (i.e. less than 1,000 sf), the proposed improvements are not expected to negatively impact the existing nearby hydraulic features. The table on the following page summarizes the hydrologic impact associated with the proposed site improvements relative to existing conditions . Refer to the drainage exhibits and hydrology calculations attached for additional information. F INAL D RAINAGE R EPORT M OUNTAIN V IEW C OMMUNITY C HURCH F ORT C OLLINS , CO 5 U20004_Drainage Report.docx MVCC Site Existing Proposed Overall Area (acre) 2.90 2.90 *Roof (sf) 36,667 37,606 *Asphalt (sf) 36,862 34,709 *Concrete (sf) 13,123 14,482 *Gravel (sf) - 536 *Landscape (sf) 39,608 38,927 % Imperviousness 66.4% 66.6% Composite C2 0.73 0.73 Composite C100 0.91 0.92 TABLE 1 - HYDROLOGIC SUMMARY For purposes of Low Impact Development (LID) calculations, hydrology calculations related to the “modified” site area (limite d to 0.56 acres of site modifications) are included in Appendix B. On-site Basins The following basins provide drainage delineations for the site in its improved condition . Note that basin designations are not bound by property lines; the site receives additional off-site runoff in its existing 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 B Sub-basins B1-B2 represent on-site and off-site drainage basins where runoff is captured and conveyed to an on-site vegetative buffer area. These basins consist of roofs, concrete and asphalt paving, and landscaping. Sub-basin B1 largely consists of a parking lot, and Basin B2 consists solely of roof area. Runoff within sub-basin B1 is conveyed to the vegetative buffer via pans, curb and storm sewer infrastructure, while runoff within sub-basin B2 is conveyed to the vegetative buffer via roof drains/storm sewer. The storm sewer and inlets are designed to convey the 2-year storm to the vegetative buffer area. In a major storm event larger than the 2-year storm event, stormwater will continue northeast along the asphalt path toward the Spring Creek trail. Basin C Sub-basin C1 is an on-site basin that consists of modified roof area. Similar to existing conditions, runoff is conveyed to the access drive immediately south of the existing building. This runoff drains east to an existing, off -site inlet, and ultimately to the Cache La Poudre River. Stormwater Quality Stormwater quality is required to be provided for the total new or modified impervious area on the site. The scope of the MVCC site improvements do not include extensive parking lot work. City s taff determined that the permeable paver requirement does not apply to this project. The project is required to provide a minimum of 50% LID treatment, for all new or modified impervious areas, using any approved LID method. The remaining 50% can be trea ted with LID or ‘standard’ water quality methods. A variance was approved to provide less than the required stormwater quality due to the existing site constraints. See Appendix C for approved variance. F INAL D RAINAGE R EPORT M OUNTAIN V IEW C OMMUNITY C HURCH F ORT C OLLINS , CO 6 U20004_Drainage Report.docx WATER QUALITY REQUIRED: TOTAL NEW OR MODIFIED IMPERVIOUS AREA = 18,850 SF REQUIRED LID WQ TREATMENT = 9,425 SF (50% MIN) WATER QUALITY PROVIDED: VEGETATIVE BUFFER (LID WQ) FOR BASINS B1 & B2 = 11,198 SF (limited to 1:1 run-on ratio) TOTAL IMPERVIOUS AREA TREATED = 11,198 SF (Approved Variance) I. Vegetated Buffer A vegetated buffer with an approximate area of 11,198-sf is utilized for water quality purposes with the site improvements. This buffer treats basins B1 and B2 (see drainage plan attached) which has a total impervious area of 29,332 sf. However, the water quality approved for LID credit is limited to the size of the vegetative buffer per City standards. This buffer is designed to improve stormwater runoff quality by straining sediment and promoting infiltration. To distribute the concentrated flows of this buffer, an 84 lf level spreader is being provided downstream of the concentrated flows. Refer to Appendix B for Grass Buffer calculations and minimum length of the level spreader. 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 additi on to more standard treatment techniques. The scope of the MVCC site improvements do not include extensive parking lot disturbance or construction. City of Fort Collins staff determined that the permeable paver requirement does not apply to this project. The project is required to provide a minimum 50% LID treatment, for all new or modified impervious area, using any approved LID method. The remaining 50% can be treated with LID or standard water quality methods. The following measures are implemented with this proposed development: I. Vegetative Buffer A vegetated buffer with an approximate area of 11,198-sf is utilized for water quality purposes with the site improvements. The inclusion of the vegetative buffer measures support that more than 50% of the modified site area requiring the use of LID treatment is provided with the site improvements. Refer to Appendix B for calculations. Detention Detention is not being provided with the redevelopment of the site because the net increase in impervious surfaces is less than 1,000 square-feet. 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. F INAL D RAINAGE R EPORT M OUNTAIN V IEW C OMMUNITY C HURCH F ORT C OLLINS , CO 7 U20004_Drainage Report.docx Storm Sewer There are multiple storm sewers, roof drains and underdrains for the bioretention ponds proposed with the site improvements. All storm sewers will be private and are typically sized to accommodate the flows from the 100-year storm event. Storm system B is only sized to accommodate the flows from the 2-year storm event although all pipe upstream of the Type C inlet is also able to accommodate the 100-year storm event. Hydraulic computations of these systems are included in Appendix B. Inlets There are multiple inlets proposed with the site improvements. Inlets are utilized to support the proposed site modifications in addition to existing site drainage insufficiencies . A Type 13 inlet associated with Basin B1 is proposed with site improvements. Due to existing site constraints and the desire to only capture minor flows for water quality purposes, this inlet is limited to capturing 1.5-cfs – additional runoff related to Basin B1 will continue to drain downstream in accordance with existing drainage patterns. Other proposed inlets are designed to convey the 100-year storm event. Hydraulic computations of these systems are included in Appendix B. V. EROSION CONTROL Erosion control, both temporary and permanent, is a vital part of any development project. For this project, the site disturbance is less than 1 acre; therefore, a CDPHE Stormwater Management Plan (SWMP) is not required. However, comprehensive erosion control measures are included with the site improvements. Refer to the Utility Plans for additional information. 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. • 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. 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 in an effective, safe manner. No negative impacts are anticipated to the City of Fort Collins Master Drainage Plan or to downstream properties or infrastructure due to the proposed improvements. C. STORMWATER QUALITY A vegetated buffer is being provided to meet some of the water quality needs of the site. An approved variance is included in Appendix C due to an inability to meet all City of Fort Collins water quality requirements. F INAL D RAINAGE R EPORT M OUNTAIN V IEW C OMMUNITY C HURCH F ORT C OLLINS , CO 8 U20004_Drainage Report.docx 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. Site Drainage and Grading Plan, Parsons & Associates, Fort Collins, Colorado, last revised 8/5/1985. 4. Natural Resources Conservation Service Web Soil Survey at: websoilsurvey.nrcs.usda.gov/app 5. Flood Insurance Rate Map, FEMA, Panel 08069C0983H, https://hazards.fema.gov/femaportal/ 6. Stormwater Discharges Associated with Construction Activity, Stormwater Management Plan Preparation Guides, State of Colorado, www.colorado.com A PPENDIX A H YDROLOGY C ALCULATIONS RUNOFF COEFFICIENTS AND % IMPERVIOUS Mountain View Community Church, Fort Collins, CO Basin Design Pt. Total Total Roof (1)Asphalt Concrete(1)Gravel(1)Lawns(10(3)Composite Effective C2 C100 %I = 90% %I = 100% %I = 100% %I =40% %I=2% Imperviousness Impervious C=0.95 C=0.95 C=0.95 C=0.50 C=0.25 Areas acres sf sf sf sf sf sf (%) sf EX-Site Existing Site 2.90 126,260 36,667 36,862 13,123 39,608 66.4%83,777 0.73 0.91 Basin Design Pt. Total Total Roof (1)Asphalt Concrete(1)Gravel(1)Lawns(10(3)Composite Effective C2 C100 acres sf %I = 90% %I = 100% %I = 100% %I =40% %I=2% Imperviousness Impervious C=0.95 C=0.95 C=0.95 C=0.50 C=0.25 Areas sf sf sf sf sf (%) sf PR-MA Modified Area 0.56 24,441 8,949 1,216 8,471 536 5,269 73.9%0.79 0.99 PR-Site Proposed Site 2.90 126,260 37,606 34,709 14,482 536 38,927 66.6%84,029 0.73 0.92 B1 B1 0.60 26,000 20,750 2,150 3,100 88.3% 0.87 1.00 B2 B2 0.15 6,432 6,432 - 90.0% 0.95 1.00 C1 C1 0.16 6,927 6,927 - 90.0% 0.95 1.00 939 (2,153) 1,359 536 (681) 0.2% 252 Less than 1,000 sf (no detention req'd) 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% Difference between Proposed and Existing Site Composite Runoff Coefficients (2)Areas Existing Basins Proposed Basins Areas Composite Runoff Coefficients (2) Date: 12/18/2020 C:\United Civil Dropbox\Projects\U20004 - Mountain View Community Church\Reports\Drainage\Calculations\U20004-Drain Calcs.xlsm RATIONAL METHOD PEAK RUNOFF Mountain View Community Church, Fort Collins, CO Basin Design Pt. Area Final acre tc (6)C2 C100 I2 I100 Q2 Q100 min in/hr in/hr cfs cfs B1 B1 0.60 5.0 0.87 1.00 2.85 9.95 1.47 5.94 B2 B2 0.15 5.0 0.95 1.00 2.85 9.95 0.40 1.47 C1 C1 0.16 5.0 0.95 1.00 2.85 9.95 0.43 1.58 Notes: 2 year runoff rate Basins B1 and B2 used for calculating level spreader length. Proposed Basins Runoff Coefficients Rainfall Intensity Peak Discharge Date: 12/18/2020 C:\United Civil Dropbox\Projects\U20004 - Mountain View Community Church\Reports\Drainage\Calculations\U20004-Drain Calcs.xlsm A PPENDIX B H YDRAULIC C ALCULATIONS WATER QUALITY - LOW IMPACT DEVELOPMENT Mountain View Community Church, Fort Collins, CO Water Quality & LID Requirements Basin Area Area Roof Asphalt Concrete Gravel (sf) (acres)(sf) (sf) (sf) (sf) PR-MA 24,441 0.561 8,949 1,216 8,471 536 Total New or Modified Impervious Area for Water Quality Treatment*18850 sf 50% to be treated by LID WQ 9425 sf *Impervious Areas calculated based on all of the new or modified asphalt, concrete, and roof areas and 40% of new or modified gravel areas LID - Vegetative Buffer Water Quality Provided Basin Area Area Roof Asphalt Concrete Gravel (sf)(acres)(sf) (sf) (sf) (sf) B1 26,000 0.597 0 20,750 2,150 0 B2 6,432 0.148 6,432 0 0 0 Impervious Area to Vegetative Buffer 29332 sf #REF! LID Water Quality limited to Vegetative Buffer Area 11198 sf Total Water Quality Provided Total Impervious Areas Treated 11198 sf (variance approved for not meeting requirements) Date: 12/18/2020 C:\United Civil Dropbox\Projects\U20004 - Mountain View Community Church\Reports\Drainage\Calculations\U20004-Drain Calcs.xlsm Sheet 1 of 1 Designer: Company: Date: Project: Location: 1. Design Discharge A) 2-Year Peak Flow Rate of the Area Draining to the Grass Buffer Q2 =2.0 cfs 2.Minimum Width of Grass Buffer WG =40 ft 3.Length of Grass Buffer (14' or greater recommended)LG =45 ft 4.Buffer Slope (in the direction of flow, not to exceed 0.1 ft / ft)SG =0.010 ft / ft 5. Flow Characteristics (sheet or concentrated) A) Does runoff flow into the grass buffer across the entire width of the buffer? B) Watershed Flow Length FL=ft C) Interface Slope (normal to flow)SI=ft / ft D) Type of Flow CONCENTRATED FLOW Sheet Flow: FL * SI <1 Concentrated Flow: FL * SI > 1 6. Flow Distribution for Concentrated Flows 7 Soil Preparation (Describe soil amendment) 8 Vegetation (Check the type used or describe "Other") 9. Irrigation (*Select None if existing buffer area has 80% vegetation AND will not be disturbed during construction.) 10. Outflow Collection (Check the type used or describe "Other") Notes: Continues to sheet flow to Spring Creek Fort Collins, CO Design Procedure Form: Grass Buffer (GB) Sam Eliason United Civil Design Group Mountain View Community Church August 19, 2020 UD-BMP (Version 3.07, March 2018) Existing Xeric Turf Grass Irrigated Turf Grass Other (Explain): Choose One Choose One Grass Swale Street Gutter Storm Sewer Inlet Other (Explain): None (sheet flow) Slotted Curbing Level Spreader Choose One Other (Explain): Choose One Yes No Choose One Permanent None* Temporary UD-BMP_v3.07 (2).xlsm, GB 8/19/2020, 5:47 PM IINLETCAPACITY Mountain View CommunityChurch, FortCollins, CO INLETID:Type C Governing Equations: Inlet capacity equation at low flows (weir calculation): Where: P = 2(L + W) H = depth of water above the flowline Inlet capacity equation at higher flows (orifice calculation): Where: A = open area of the inlet grate H = depth of water above the centroid of the cross-sectional area (A) InputParameters: Grate:Type C Wier Perimeter:12.0 Open Area of Grate (ft2):4.5 Grate Centroid Elevation (ft):4906.45 Allowable Capacity:50% Depth vs. Flow: Depth Elevation Shallow Orifice Actual Above Inlet Weir Flow Flow Flow (ft)(ft)(cfs)(cfs)(cfs) 0.00 4906.45 0.00 0.00 0.00 0.05 4906.50 0.20 2.70 0.20 0.10 4906.55 0.57 3.82 0.57 0.15 4906.60 1.05 4.68 1.05 0.20 4906.65 1.61 5.41 1.61 0.25 4906.70 2.25 6.05 2.25 <----Maximum Depth 0.30 4906.75 2.96 6.62 2.96 0.35 4906.80 3.73 7.15 3.73 0.40 4906.85 4.55 7.65 4.55 0.45 4906.90 5.43 8.11 5.43 0.50 4906.95 6.36 8.55 6.36 5.10.3 HPQ= 5.0)2(67.0 gHAQ= Date: 11/18/2020 E:\United Civil Dropbox\Projects\U20004 - Mountain View Community Church\Reports\Drainage\Calculations\U20004-Drain Calcs.xlsm A PPENDIX C R EFERENCED M ATERIALS Stormwater Alternative Compliance/Variance Application City of Fort Collins Water Utilities Engineering Section A: Engineer/Owner Information Engineer Name____________________________________________Phone___________________________ Street Address_____________________________________________________________________________ City__________________________________________State________________________Zip_____________ Owner Name______________________________________________Phone___________________________ Street Address_____________________________________________________________________________ City__________________________________________State________________________Zip_____________ Section C: Alternative Compliance/Variance Information Section B: Proposed Project Information Legal description and/or address of property____________________________________________________ Project Name______________________________________________________________________________ Project/Application Number from Development Review (i.e. FDP123456)__________________________ Description of Project_______________________________________________________________________ __________________________________________________________________________________________ Existing Use (check one): ☐ residential ☐ non-residential ☐ mixed-use ☐ vacant ground Proposed Use (check one): ☐ residential ☐ non-residential ☐ mixed-use ☐ other____________________ If non-residential or mixed use, describe in detail_______________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ State the requirement from which alternative compliance/variance is sought. (Please include applicable Drainage Criteria Manual volume, chapter and section.) What hardship prevents this site from meeting the requirement? What alternative is proposed for the site? Attach separate sheet if necessary Attach separate sheet if necessary United Civil Design Group, LLC 970-530-4044 19 Old Town Square #238 Fort Collins CO 80524 Mountain View Community Church 970-490-2262 328 Remington Street Fort Collins CO 80524 Mountain View Community Church FDP200020 A Portion of Tract A, Seven Lake Business Park PUD 2330 E. Prospect Rd, Fort Collins, Co 80525 Redevelopment of a portion of the existing commercial building and site to a church facility. ● ●Place of Worship Alternative Compliance to Chapter 8, Section 6 Low Impact Development, 6.1 Vegetative Buffer -See attached sheet -See attached sheet Mountain View Community Church Alternative Compliance/Variance Application Supplemental Sheet What hardship prevents this site from meeting the requirement? This is an existing developed site that has many constraints that make development of more typical LID types such as permeable pavement, bioretention, sand filters, and underground filtration very difficult to include with this development. These constraints include the following: x Existing large trees with large root zones that restrict construction area of LID. x No storm sewer or shallow storm sewer that restrict the locations of LID with an underdrain. x Adjacent Spring Creek trail, Natural Area pond and buffer, wetlands, and floodway that all limit the location of construction in proximity to those natural features. x Constructing a new storm outlet pipe into a City of Fort Collins Natural Area is an arduous process that requires that all other alternatives be exhausted. This alternative was looked at early in the process. x There is limited space north of the building in the only location with an existing viable storm sewer outlet. This location has steep side slopes that would require a large wall to construct a bioretention facility and the outlet pipe is still near existing large trees. What alternative is proposed for the site? A vegetative buffer to meet standard water quality and LID requirements is being proposed. This is an existing well-established native grass area on the northwest portion of the site that we are proposing to utilize as a vegetative buffer. We are redirecting the runoff from almost 30,000 square feet of pavement and roof areas to drain across this vegetative buffer. We believe this truly meets the intent of Low Impact Development and the Key LID techniques listed in Ch. 7, Section 2 because it “Conserves Existing Amenities”, “Minimizes Impacts”, and “Minimizes Directly Connected Impervious Areas”. A vegetative buffer is allowed within Section 6.7 to meet the water quality and LID requirements. However, we cannot meet all the Standard Design Criteria for Vegetative Buffers shown in Figure 6.7-1 including minimum cross slope of 2%, soil amendments, 1:1 run-on ratio, and soil types. By City of Fort Collins requirements, the site is required to provide stormwater quality treatment for 18,850 square feet of impervious area. The 1:1 ratio requirement limits the amount of treated area to the area of the vegetative buffer which is approximately 11,200 square feet as measured in the direction of the stormwater flow from the level spreader. 11/10/2020 11/10/20 11/18/2020 12/07/2020 The site constraints for this site make the addition of LID facilities, that fully meet the City's requirements, close to impossible. This site is not being completely redeveloped which significantly limits the options for location of new LID facilities. The project has triggered LID requirements through "modified impervious areas," due to the reconstruction of a portion of the existing building and adjacent patios and sidewalk. Staff agrees with the justification presented here and thinks the proposed vegetated buffer and level spreader will provided high quality treatment for the runoff from the parking lot. Staff thinks that this trade-off is acceptable even through the project is not able to quantitatively meet the LID and Water quality requirements. USGS The National Map: Orthoimagery. Data refreshed April, 2019. National Flood H azard Layer FIR Mette 0 500 1,000 1,500 2,000250Feet Ü105°2'22.10"W 40°34'20.14"N 105°1'44.65"W 40°33'52.81"N SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOODHAZARD AREAS Without Base Flood Elevation (BFE)Zone A, V, A99With BFE or Depth Zone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areasof 1% annual chance flood with averagedepth less than one foot or with drainageareas of less than one square mile Zone X Future Conditions 1% AnnualChance Flood Hazard Zone XArea with Reduced Flood Risk due toLevee. See Notes.Zone X Area with Flood Risk due to Levee Zone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood Hazard Zone D Channel, Culvert, or Storm SewerLevee, Dike, or Floodwall Cross Sections with 1% Annual Chance17.5 Water Surface ElevationCoastal Transect Coastal Transect BaselineProfile BaselineHydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of StudyJurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from theauthoritative NFHL web services provided by FEMA. This mapwas exported on 2/5/2020 at 10:10:59 PM and does notreflect changes or amendments subsequent to this date andtime. The NFHL and effective information may change orbecome superseded by new data over time. This map image is void if the one or more of the following mapelements do not appear: basemap imagery, flood zone labels,legend, scale bar, map creation date, community identifiers,FIRM panel number, and FIRM effective date. Map images forunmapped and unmodernized areas cannot be used forregulatory purposes. Legend OTHER AREAS OFFLOOD HAZARD OTHER AREAS GENERALSTRUCTURES OTHERFEATURES MAP PANELS 8 1:6,000 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. LAG 4908.7' 4 9 0 9 490449064907490 8 49104907 4913 49074911 4907490649074909 49 1 0 49034904 4904 4906491049134906490449104910490649094905 4907 4909 49054912 49054907491 1 49054903 49074905 4905490449044911 4904491349054910490 4 49094903 4904 490449104906 4903 49084905 490849064906 4903 490749 0 5 4906490749044905 4911 49094908 49054907 49104908 49054 9 0 6 4905 4906 49074904 4908490449 0 1 49044906 4904 490549054905 4903490549064904 4905 4909490649094911490649134912 490649064903 4 9 0 4 49064905 4911 49064911 4907 4903 4 9 1 0 4913 490649104904490949114905 49074908 49094908 4912491249044903 4906 4904 4905 49104909 4907490749114902 49064907 4904490349094910 49104906 490649054904 4903 490549044906 4906 4904 4908 4910 4 9 0 3 490449054903 4908 4913 4 9 0 9 4903 4907 4905 4904 4910491 04904 49 0 4 4907 4910 4908 4903 4908 4912 4904 4903 49094909 491049074908 4 9 0 6 4906 490949094904 49104905 49 0 4 4903490849084910 490849004911 49 0 6 4910 49044904 4 9 0 9 4909 4905 4908490949084903 49014909 49074905 49094905 49024911 4910 49034910 4903 4904 49084910 49094903 4909 49094908 4909 4907 49044905 49034906 4906 4907 49064905 4904 4905 49054907 490849074905 4906 4901 49044902 49044903 ¯ 0 125 250 375 50062.5 Feet Revised Floodplain Ground Contours Spring Creek Profile Flooding Extents Base Flood Elevations Spring Creek Cross Sections Parcels Fort Collins Buildings Lowest Adjacent Ground Flood Zones . AE, AE,FLOODWAY X,0.2 PCT ANNUAL CHANCE FLOOD HAZARD Legend:LOMA for 2330 E Prospect Rd LAG 4908.7'4908490949104907 4 9 0 94909 49084908SPRING CREEKCROSS SECTION 1335 Federal Emergency Management Agency Washington, D.C. 20472 Date: Case No.: 19-08-0473A LOMAPage 1 of 5 March 27, 2019 COMMUNITY AND MAP PANEL INFORMATION LEGAL PROPERTY DESCRIPTION DETERMINATION APPROXIMATE LATITUDE & LONGITUDE OF PROPERTY: 40.568580, -105.034568 SOURCE OF LAT & LONG: GOOGLE EARTH DATUM: NAD 83 FLOODING SOURCE: SPRING CREEK AFFECTED MAP PANEL COMMUNITY CITY OF FORT COLLINS, LARIMER COUNTY, COLORADO 08069C0983HNUMBER: DATE: 5/2/2012 COMMUNITY NO: 080102 A portion of Tract A, Seven Lakes Business Park P.U.D, as described in the Special Warranty Deed recorded as Document No. 20060013344, in the Office of the Clerk and Recorder, Larimer County, Colorado LETTER OF MAP AMENDMENT DETERMINATION DOCUMENT (REMOVAL) LOT STREETSUBDIVISIONBLOCK/ SECTION FLOOD ZONE OUTCOME WHAT IS REMOVED FROM THE SFHA LOWEST LOT ELEVATION (NAVD 88) LOWEST ADJACENT GRADE ELEVATION (NAVD 88) 1% ANNUAL CHANCE FLOOD ELEVATION (NAVD 88) --4908.7 feet--X (unshaded) Structure2330 East Prospect Road Seven Lakes Business Park P.U.D. --Tract A -- Special Flood Hazard Area (SFHA) - The SFHA is an area that would be inundated by the flood having a 1-percent chance of being equaled or exceeded in any given year (base flood). ADDITIONAL CONSIDERATIONS (Please refer to the appropriate section on Attachment 1 for the additional considerations listed below.) PORTIONS REMAIN IN THE SFHA/FLOODWAY eLOMA DETERMINATION This document provides the Federal Emergency Management Agency's determination regarding a request for a Letter of Map Amendment for the property described above. Using the information submitted and the effective National Flood Insurance Program (NFIP) map, we have determined that the structure(s) on the property(ies) is/are not located in the SFHA, an area inundated by the flood having a 1-percent chance of being equaled or exceeded in any given year (base flood). This document amends the effective NFIP map to remove the subject property from the SFHA located on the effective NFIP map; therefore, the Federal mandatory flood insurance requirement does not apply. However, the lender has the option to continue the flood insurance requirement to protect its financial risk on the loan. A Preferred Risk Policy (PRP) is available for buildings located outside the SFHA. Information about the PRP and how one can apply is enclosed. This determination is based on the flood data presently available. If there are any errors on this eLOMA Determination Letter that cause FEMA to rescind and /or nullify the determination the property owner should consult the Licensed Professional that submitted this eLOMA. The enclosed documents provide additional information regarding this determination. If you have any questions about this document, please contact the FEMA Map Assistance Center toll free at (877) 336-2627 (877-FEMA MAP) or by letter addressed to the Federal Emergency Management Agency, Attn: North Wind Resource Partners (NWRP) eLOMA Coordinator, 3601 Eisenhower Avenue, Alexandria, VA 22304-4605, Fax: 703-751-7415. Luis V. Rodriguez, P.E., Director Engineering and Modeling Division Federal Insurance and Mitigation Administration eLOMA LETTER OF MAP AMENDMENT DETERMINATION DOCUMENT (REMOVAL) ATTACHMENT 1 (ADDITIONAL CONSIDERATIONS) Date: Case No : 19-08-0473A LOMAPage 2 of 5 3/27/2019 Federal Emergency Management Agency Washington, D.C. 20472 Structure Removal: The following considerations may or may not apply to the determination for your Structure: PORTIONS OF THE PROPERTY REMAIN IN THE SFHA and/or FLOODWAY - Portions of this property, but not the subject of the Determination document, may remain in the Special Flood Hazard Area (SFHA) and/or the regulatory floodway for the flooding source indicated on the Determination Document. The NFIP regulatory floodway is the area that must remain unobstructed in order to prevent unacceptable increases in base flood elevations. Therefore, no construction may take place in an NFIP regulatory floodway that may cause an increase in the base flood elevation. Therefore, any future construction or substantial improvement on the property remains subject to Federal, State /Commonwealth, and local regulations for floodplain management. The NFIP regulatory floodway is provided to the community as a tool to regulate floodplain development. Modifications to the NFIP regulatory floodway must be accepted by both the Federal Emergency Management Agency (FEMA) and the community involved. Appropriate community actions are defined in Paragraph 60.3(d) of the NFIP regulations. Any proposed revision to the NFIP regulatory floodway must be submitted to FEMA by community officials. The community should contact either the Regional Director (for those communities in Regions I -IV, and VI-X), or the Regional Engineer (for those communities in Region V) for guidance on the data which must be submitted for a revision to the NFIP regulatory floodway. Contact information for each regional office can be obtained by calling the FEMA Map Assistance Center toll free at (877) 336-2627 (877-FEMA MAP) or from our web site at https://www.fema.gov/regional-contact-information STUDY UNDERWAY - This determination is based on the flood data presently available. However, the Federal Emergency Management Agency may be currently revising the National Flood Insurance Program (NFIP) map for the community. New flood data could be generated that may affect this property. If a new NFIP map is issued it will supersede this determination. The Federal requirement for the purchase of flood insurance will then be based on the newly revised NFIP map. EXTRATERRITORIAL JURISDICTION - The subject of the determination is shown on the National Flood Insurance Program map and may be located in an Extraterritorial Jurisdiction area for the community indicated on the Determination Document. This attachment provides additional information regarding this request. If you have any questions about this attachment, please contact the FEMA Map Assistance Center toll free at (877) 336-2627 (877-FEMA MAP) or by letter addressed to the Federal Emergency Management Agency, Attn: North Wind Resource Partners (NWRP) eLOMA Coordinator, NWRP eLOMA Coordinator, 3601 Eisenhower Ave., Alexandria, VA 22304-6439, Fax: 703-751-7415 Luis V. Rodriguez, P.E., Director Engineering and Modeling Division Federal Insurance and Mitigation Administration eLOMA LETTER OF MAP AMENDMENT DETERMINATION DOCUMENT (REMOVAL) ATTACHMENT 1 (ADDITIONAL CONSIDERATIONS) Date: Case No : 19-08-0473A LOMAPage 3 of 5 3/27/2019 Federal Emergency Management Agency Washington, D.C. 20472 GREAT LAKES - The Federal Emergency Management Agency (FEMA) has based this determination on elevation data which is published in the current Flood Insurance Study for the community. However, the elevations established in the U .S. Army Corps of Engineers (USACE) reports on the Great Lakes are the best available data known to us. If in the future there are any subsequent map revisions to the National Flood Insurance Program map and the USACE reports remain the best available data known, FEMA will use those elevations for any such revisions. Further, be advised that the elevations on the Flood Insurance Rate Map (FIRM) may only reflect the Stillwater elevation for the lake and may not account for the effects of wind driven waves or wave run-up. On-site conditions such as wind speed, wind direction, fetch distance, water depth and the slope of the beach or bluff may result in significant increases to the base flood elevation. Therefore, it is strongly recommended that the requestor be aware of these circumstances and, if warranted, evaluate the effects of wind driven waves along the shoreline of the property. STATE AND LOCAL CONSIDERATIONS - Please note that this document does not override or supersede any State or local procedural or substantive provisions which may apply to floodplain management requirements associated with amendments to State or local floodplain zoning ordinances, maps, or State or local procedures adopted under the National Flood Insurance Program. COASTAL BARRIER RESOURCE SYSTEM - Based upon information provided to FEMA by the U .S. Fish and Wildlife Service (USFWS), the subject property may be within a System Unit or an Otherwise Protected Area (OPA) of the John H. Chafee Coastal Barrier Resource System (CBRS). Federal flood insurance is generally not available within the CBRS for new construction or substantial improvements occurring after the flood insurance prohibition date (which is generally tied to the date that the area was first established as either a System Unit or OPA, but may differ in some cases). Other federal expenditures and financial assistance (including certain types of disaster assistance) are also restricted within System Units of the CBRS. The USFWS is the authoritative source for information regarding the CBRS. Additional information, including the CBRS Mapper, can be found on the USFWS website at: https://www.fws.gov/cbra. This attachment provides additional information regarding this request. If you have any questions about this attachment, please contact the FEMA Map Assistance Center toll free at (877) 336-2627 (877-FEMA MAP) or by letter addressed to the Federal Emergency Management Agency, Attn: North Wind Resource Partners (NWRP) eLOMA Coordinator, NWRP eLOMA Coordinator, 3601 Eisenhower Ave., Alexandria, VA 22304-6439, Fax: 703-751-7415 Luis V. Rodriguez, P.E., Director Engineering and Modeling Division Federal Insurance and Mitigation Administration eLOMA 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 Mountain View Community Church Natural Resources Conservation Service March 23, 2020 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................11 Map Unit Descriptions.........................................................................................11 Larimer County Area, Colorado......................................................................13 42—Gravel pits............................................................................................13 64—Loveland clay loam, 0 to 1 percent slopes...........................................13 105—Table Mountain loam, 0 to 1 percent slopes......................................15 References............................................................................................................17 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report 6 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 7 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. 8 9 Custom Soil Resource Report Soil Map 4490790449081044908304490850449087044908904490910449093044907904490810449083044908504490870449089044909104490930496950 496970 496990 497010 497030 497050 497070 497090 497110 497130 497150 497170 497190 496950 496970 496990 497010 497030 497050 497070 497090 497110 497130 497150 497170 497190 40° 34' 9'' N 105° 2' 10'' W40° 34' 9'' N105° 1' 59'' W40° 34' 4'' N 105° 2' 10'' W40° 34' 4'' N 105° 1' 59'' WN 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: 1:1,140 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 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 14, Sep 13, 2019 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 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 42 Gravel pits 0.5 9.2% 64 Loveland clay loam, 0 to 1 percent slopes 3.9 72.8% 105 Table Mountain loam, 0 to 1 percent slopes 1.0 18.0% Totals for Area of Interest 5.3 100.0% 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 Custom Soil Resource Report 11 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. 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 42—Gravel pits Map Unit Composition Gravel pits: 95 percent Minor components: 5 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Gravel Pits Setting Parent material: Gravel pits Typical profile H1 - 0 to 6 inches: extremely gravelly sand H2 - 6 to 60 inches: extremely gravelly sand, extremely gravelly coarse sand, very gravelly coarse sand H2 - 6 to 60 inches: H2 - 6 to 60 inches: Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 8s Hydrologic Soil Group: A Hydric soil rating: No Minor Components Aquents Percent of map unit: 5 percent Landform: Marshes Hydric soil rating: Yes 64—Loveland clay loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: jpx9 Elevation: 4,800 to 5,500 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 135 to 150 days Farmland classification: Prime farmland if irrigated Map Unit Composition Loveland and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Custom Soil Resource Report 13 Description of Loveland Setting Landform: Flood plains, stream terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile H1 - 0 to 15 inches: clay loam H2 - 15 to 32 inches: clay loam, silty clay loam, loam H2 - 15 to 32 inches: very gravelly sand, gravelly sand, gravelly coarse sand H2 - 15 to 32 inches: H3 - 32 to 60 inches: H3 - 32 to 60 inches: H3 - 32 to 60 inches: Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.60 in/hr) Depth to water table: About 18 to 36 inches Frequency of flooding: Occasional Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Very slightly saline to slightly saline (2.0 to 4.0 mmhos/cm) Available water storage in profile: Very high (about 16.7 inches) Interpretive groups Land capability classification (irrigated): 3w Land capability classification (nonirrigated): 3w Hydrologic Soil Group: C Hydric soil rating: No Minor Components Aquolls Percent of map unit: 5 percent Landform: Swales Hydric soil rating: Yes Poudre Percent of map unit: 5 percent Hydric soil rating: No Custom Soil Resource Report 14 105—Table Mountain loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: jpty Elevation: 4,800 to 5,600 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 135 to 150 days Farmland classification: Prime farmland if irrigated Map Unit Composition Table mountain and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Table Mountain Setting Landform: Flood plains, stream terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile H1 - 0 to 36 inches: loam H2 - 36 to 60 inches: loam, clay loam, silt loam H2 - 36 to 60 inches: H2 - 36 to 60 inches: Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 5.0 Available water storage in profile: Very high (about 18.0 inches) Interpretive groups Land capability classification (irrigated): 1 Land capability classification (nonirrigated): 3c Hydrologic Soil Group: B Custom Soil Resource Report 15 Ecological site: Overflow (R049XY036CO) Hydric soil rating: No Minor Components Caruso Percent of map unit: 7 percent Hydric soil rating: No Fluvaquentic haplustolls Percent of map unit: 4 percent Landform: Terraces Hydric soil rating: Yes Paoli Percent of map unit: 4 percent Hydric soil rating: No Custom Soil Resource Report 16 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 17 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 18 This unofficial copy was downloaded on Dec-04-2019 from the City of Fort Collins Public Records Website: http://citydocs.fcgov.com For additional information or an official copy, please contact Engineering Office 281 North College Fort Collins, CO 80521 USA A PPENDIX D D RAINAGE E XHIBITS MOUNTAIN VIEW COMMUNITYCHURCH BUILDINGLEGENDBUILDING/ROOF AREAASPHALTCONCRETEPROPERTYBOUNDARYLIMITS OF MODIFIEDIMPERVIOUS AREA (TYP)LIMITS OF MODIFIEDIMPERVIOUS AREA (TYP)LIMITS OF MODIFIEDIMPERVIOUS AREA (TYP)LIMITS OF MODIFIEDIMPERVIOUS AREA (BASEDON PHASE 2 ADDITION)LIMITS OF MODIFIEDIMPERVIOUS AREA (TYP)PATH:0'50'100'SCALE: 1" = 50'25'E:\UNITED CIVIL DROPBOX\PROJECTS\U20004 - MOUNTAIN VIEW COMMUNITY CHURCH\CADD\ET\EXISTING IMPERVIOUS EXHIBIT.DWG EXISTING IMPERVIOUS EXHIBITDRAWING NAME:SHEET SIZE: 11 x 17 MOUNTAIN VIEW COMMUNITY CHURCHEXISTING IMPERVIOUS AREAS EXHIBITDATE:July 28, 2020PREPARED FOR:MOUNTAIN VIEW COMMUNITY CHURCHJOB NUMBER:U20004NOTE: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.COMSHEETOF12UNITED CIVILDesign GroupLLCNORTH BASINAREASCOMPOSITEEFFECTIVECOMPOSITE FRUNOFF COEFFICIENTSTOTALTOTALROOFASPHALTCONCRETEGRAVELLAWNSIMPERVIOUSNESSIMPERVIOUS%I = 0%%I = 100%%I = 0%%I =0%%I=2%(%I)AREASC2C100(ACRES)sfsfsfsfsfsfEX-SITE2.90126,26036,66736,86213,12339,60866.4%83,7770.730.91 231WWSMOUNTAIN VIEW COMMUNITYCHURCH BUILDINGLEGENDBUILDING/ROOF AREAASPHALTCONCRETEPROPERTYBOUNDARYGRAVELLIMITS OF MODIFIEDIMPERVIOUS AREA (TYP)LIMITS OF MODIFIEDIMPERVIOUS AREA (TYP)LIMITS OF MODIFIEDIMPERVIOUS AREA (TYP)LIMITS OF MODIFIEDIMPERVIOUS AREA (BASEDON PHASE 2 ADDITION)LIMITS OF MODIFIEDIMPERVIOUS AREA (TYP)PATH:0'50'100'SCALE: 1" = 50'25'E:\UNITED CIVIL DROPBOX\PROJECTS\U20004 - MOUNTAIN VIEW COMMUNITY CHURCH\CADD\ET\PROPOSED IMPERVIOUS EXHIBIT.DWG PROPOSED IMPERVIOUS EXHIBITDRAWING NAME:SHEET SIZE: 11 x 17 MOUNTAIN VIEW COMMUNITY CHURCHPROPOSED IMPERVIOUS AREAS EXHIBITDATE:July 28, 2020PREPARED FOR:MOUNTAIN VIEW COMMUNITY CHURCHJOB NUMBER:U20004NOTE: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.COMSHEETOF22UNITED CIVILDesign GroupLLCNORTH BASINAREASCOMPOSITEEFFECTIVECOMPOSITE FRUNOFF COEFFICIENTSTOTALTOTALROOFASPHALTCONCRETEGRAVELLAWNSIMPERVIOUSNESSIMPERVIOUS%I = 0%%I = 100%%I = 0%%I =0%%I=2%(%I)AREASC2C100(ACRES)sfsfsfsfsfsfPR-SITE2.90126,26037,60634,70914,482 53638,92766.6%84,0290.730.92 2 4 3 12 1 331222124323211 211 23112212211223 1121231 12232233 2 222 21 1 22 1 2 1212311134908490749064904SPRING CREEKCROSS SECTION 1335GM2310 E PROSPECT RDOWNER: C AND C HOLDINGS LLCOWNER: GATEWAY MEDICAL SERVICES LLCEXISTING BUILDINGLOT LINE (TYP)LIMITS OF 100-YEAR FLOODPLAIN100-YEAR FLOODPLAIN(BUILDING REMOVED FROM FLOODPLAIN PERLOMA CASE NO. 19-08-0473A DATED 3/27/2019)EXISTING EDGE OF PONDEXISTING LIMITS OF WETLANDSLIMITS OF FLOODWAYEXISTING 12" CMPEXISTING 8" ADSROOF DRAINB20.150.951.00B10.600.871.00DPB2DPB1C10.160.951.002330 E PROSPECT RDOWNER: MOUNTAIN VIEW COMMUNITY CHURCHBASINS LINES SHOWN BASEDON PHASE 2 ROOF DESIGN(NOT SIGNIFICANTLYDIFFERENT THAN PHASE 1)82 LF - LEVEL SPREADER TO DISTRIBUTESTORMWATER FLOW TO VEGETATIVE BUFFERSTORM LINE BSTORM LINE C(PHASE 1 ONLY)SPRING CREEK TRAILTYPE C INLETEXISTING PONDCATTAIL CHORUSNATURAL AREASTORM LINE BDPC1OWNER: SEVEN LAKESBUSINESS PARK ASSNSPRING CREEKVEGETATIVE BUFFER (APPROX. 4,412 SF)44'EXISTING CREEK BANK9'OUTLET B1502 S TIMBERLINE RDOWNER: POUDRE SCHOOLDISTRICT R-1DRAIN BASINW/12" SUMPVEGETATIVE BUFFER (APPROX. 6,786 SF)3.102.402.454.19 3.974.094.524.804.784.41 4.274.28MODERATE RISK FLOODPLAINSTORM INLET(PHASE 1 ONLY)2290 E PROSPECT ROADOWNER: DDNH COMMERCIAL INCSTORM CULVERTCANOPY DRAINNATURAL HABITAT BUFFER ZONENATURAL HABITAT BUFFER ZONEMOUNTAIN VIEW COMMUNITY CHURCH 12/18/2020U200041" = 20'1" = N/AMOUNTAIN VIEW COMMUNITY CHURCH NORTH 12/18/2020 1:31:33 PMC:\UNITED CIVIL DROPBOX\PROJECTS\U20004 - MOUNTAIN VIEW COMMUNITY CHURCH\CADD\CP\C5.00 - DRAINAGE PLAN.DWGC5.00 - DRAINAGE PLAN SME JRS C5.0016DRAINAGE PLAN020'40'SCALE: 1" = 20'10'PREPARED FOR:JOB NUMBERSHEET NUMBERSHEETSOFDATE SUBMITTED:VERTICAL:HORIZONTAL:SCALEFINAL REVIEWP L A N S NO T FO R CO N S T R U C T IO N PROJ. MGR:DRAWING NAME:PATH:DESIGNER:DATE:TIME:CIVIL ENGINEERING & CONSULTINGUNITED CIVILDesign Group19 OLD TOWN SQUARE #238FORT COLLINS, CO 80524(970) 530-4044www.unitedcivil.comThe 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 CAUTIONREVISIONS:12X.XXX.XXXX.XXBASIN DESIGNATIONBASIN AREA (ACRE)5 - YR RUNOFF COEFF.100 - YR RUNOFF COEFF.DESIGN POINTFLOW DIRECTIONDPD1LEGENDNOTES1.ONSITE DETENTION NOT REQUIRED SINCE INCREASE INIMPERVIOUS AREA IS LESS THAN 1000 SQUARE FEET.2.ONSITE WATER QUALITY AND LID PROVIDED BASED ONMODIFIED IMPERVIOUS AREA FOR PHASE 1 AND PHASE 2INCLUDING THE NEW SANCTUARY IMPROVEMENTS.CHECKED BY:CHECKED BY:CHECKED BY:CHECKED BY:CHECKED BY:APPROVED:FLOODPLAIN NOTES1.PORTIONS OF THIS PROJECT ARE LOCATED WITHIN THEFEMA REGULATED 100-YEAR SPRING CREEK FLOODPLAINAND FLOODWAY. THIS PROPERTY IS ALSO LOCATEDWITHIN THE SPRING CREEK MODERATE RISK FLOODPLAINAND IS SUBJECT TO THE REQUIREMENTS OF CHAPTER 10OF THE CITY CODE.2.ALL DEVELOPMENT (CURB & GUTTER, PAVEMENT, GRADING,FILL, PARKING LOTS, UTILITIES, LANDSCAPING, ETC.) WITHINTHE FEMA REGULATORY FLOODPLAIN MUST BE PRECEDEDBY AN APPROVED FLOODPLAIN USE PERMIT ANDAPPLICABLE FEES.3.A NO RISE CERTIFICATION IS REQUIRED PRIOR TOPERFORMING ANY WORK WITHIN THE FLOODWAY (I.E. CURBCUT, CURB & GUTTER, UTILITY WORK, LANDSCAPING, ETC.)4.ALL SPOT ELEVATIONS AND BASE FLOOD ELEVATIONS ASSHOWN ON THIS DRAWING ARE PER VERTICAL CONTROLDATUM NAVD 88.5.NO STORAGE OF MATERIAL OR EQUIPMENT MAY OCCUR ATANY TIME IN THE FLOODWAY BEFORE, DURING OR AFTERCONSTRUCTION.6.ANY ITEMS LOCATED IN THE FLOODWAY THAT CAN FLOAT(E.G. PICNIC TABLE, BIKE RACKS, ETC.) MUST BEANCHORED.7.FLOODWAY MUST BE SURVEYED AND STAKED IN THE FIELDPRIOR TO COMMENCING ANY SITE WORK.8.ALL FENCING IN THE FLOODWAY SHALL BE BREAK-AWAYAND TETHERED INCLUDING ANY CONSTRUCTION FENCING.WATER QUALITY SUMMARYWATER QUALITY REQUIREMENT:TOTAL NEW OR MODIFIED IMPERVIOUS AREA = 18,850 SFREQUIRED LID WQ TREATMENT = 9,425 SF (50% MIN.)WATER QUALITY PROVIDED:PAVED AREAS IN BASINS B1 & B2 DRAINING TO VEGETATIVEBUFFER = 29,332 SFVEGETATIVE BUFFER (LID CREDIT) IS LIMITED TO THE SIZE OFTHE VEGETATIVE BUFFER = 11,198 SFDOES NOT MEET CITY OF FORT COLLINS REQUIREMENTS.VARIANCE APPROVED FOR WATER QUALITY REQUIREMENTS.DRAINAGE BASIN SUMMARY TABLE