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Home My WebLink About209 CHERRY STREET - MIXED USE - PDP230006 - SUBMITTAL DOCUMENTS - ROUND 2 - DRAINAGE REPORT PRELIMINARY DRAINAGE AND EROSION CONTROL REPORT LOT 1 PENNY FLATS SUBDIVISION, SECOND REPLAT Prepared for: Tribe Development Company, LLC 244 N. College Ave., Suite 130 Fort Collins, CO 80524 Prepared by: Wilson & Company 4065 St Cloud Drive, Suite 201 Loveland, Colorado 80538 970-834-6364 July 19, 2023 Job Number 22-100-356-00 4065 St. Cloud, Suite.201 Loveland, CO 80538 970-834-6364 phone July 19, 2023 Mr. Wes Lamarque City of Fort Collins Stormwater Engineering 700 Wood Street Fort Collins, CO 80522 RE: Preliminary Drainage and Erosion Control Report for Lot 1 Penny Flats Subdivision, Second Replat Dear Wes, I am pleased to submit for your review and approval, this Preliminary Drainage and Erosion Control Report for Lot 1 Penny Flats Subdivision, Second Replat development. I certify that this report for the drainage design was prepared in accordance with the criteria in the Fort Collins Stormwater Criteria Manual. We are requesting two variances in this report. It is our understanding that the formal variance form will be provided to us by the City later in the review process. City of Fort Collins review comments dated April 4, 2023 have been addressed in this report. I appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. Sincerely, Erika Schneider Michael Oberlander, P.E. Colorado Professional Engineer No. 41777 Colorado Professional Engineer No. 34288 4065 St. Cloud, Suite.201 Loveland, CO 80538 970-834-6364 phone ENGINEER’S CERTIFICATION “I hereby attest that this report for the final drainage design for the Lot 1 Penny Flats Subdivision, Second Replat development was prepared by me or under my direct supervision, in accordance with the provisions of the Fort Collins Stormwater Criteria Manual. I understand that the City of Fort Collins does not and will not assume liability for drainage facilities designed by others.” ____________________________________________ _______________________ Registered Professional Engineer Date Michael Oberlander, PE Registered Professional Engineer State of Colorado No. 34288 For and on behalf of Wilson & Company Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page i Table of Contents 1. GENERAL LOCATION AND DESCRIPTION ................................................................. 1 1.1 Location ........................................................................................................................... 1 1.2 Description of Property and Project............................................................................. 1 1.3 Floodplain Submittal Requirements ............................................................................ 1 2. DRAINAGE BASINS AND SUB-BASINS .......................................................................... 2 2.1 Major Basin Description ................................................................................................ 2 2.2 Sub-basin Description .................................................................................................... 2 3. DRAINAGE DESIGN CRITERIA ....................................................................................... 2 3.1 Regulations ...................................................................................................................... 2 3.2 Directly Connected Impervious Area (DCIA) Discussion .......................................... 2 3.3 Development Criteria Reference and Constraints ...................................................... 3 3.4 Hydrological Criteria ..................................................................................................... 4 3.5 Hydraulic Criteria .......................................................................................................... 6 3.6 Low Impact Development (LID) Conformance .......................................................... 6 3.7 Water Quality (WQ) Treatment Criteria .................................................................... 7 3.8 Detention Requirements ................................................................................................ 7 3.9 Floodplain Regulations Compliance ............................................................................. 7 3.10 Modifications of Criteria ............................................................................................... 8 4. DRAINAGE FACILITY DESIGN ....................................................................................... 8 4.1 General Concept ............................................................................................................. 8 4.2 Specific Details ................................................................................................................ 9 4.3 LID, WQ and Detention .............................................................................................. 10 5. SEDIMENT AND EROSION CONTROL ........................................................................ 11 6. CONCLUSIONS .................................................................................................................. 12 6.1 Compliance with Standards ........................................................................................ 12 6.2 Drainage Concept ......................................................................................................... 12 7. REFERENCES ..................................................................................................................... 12 APPENDIX A VICINITY MAP AND DRAINAGE PLAN....................................................... A APPENDIX B HYDROLOGIC COMPUTATIONS ................................................................... B APPENDIX C HYDRAULIC CALCULATIONS (TO BE COMPLETED AT FINAL)............ C APPENDIX D LID CALCS AND COMMUNICATION RE ON-SITE DETENTION ............. D APPENDIX E SOILS AND FLOODPLAIN INFORMATION .................................................. E Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 1 1. GENERAL LOCATION AND DESCRIPTION 1.1 Location Lot 1 Penny Flats Subdivision, Second Replat is in the Northeast ¼ of Section 11, Township 7 North, Range 69 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. It is in Old Town Fort Collins and is bounded on the north by Cherry Street, on the east by North Mason Street, on the south by Lots 1A and 1B of Penny Flats Subdivision and on the west by City of Fort Collins owned property (Municipal Railway Carbarn). Please refer to the Vicinity Map located in Appendix A. 1.2 Description of Property and Project The lot is 0.87 acres and is currently vacant with no hardscape improvements. The project proposes to develop a multifamily project including 1 story of underground parking and wet and dry utilities. The project will also include extending the enhanced pedestrian alley between Mason Street and Howes Street. The Zone District of the project site is the Downtown District. Offsite flow does not contribute to the site from any direction. According to Natural Resources Conservation Service Web Soil Survey, the soils onsite consist of Paoli fine sandy loam, 0 to 1 percent slopes, Soil Group A. Please refer to Appendix E for the Hydrologic Soil Group – Larimer County Area map that includes this site. 1.3 Floodplain Submittal Requirements The area is designated as Zone X, Area of Minimal Flood Hazard, on FIRM Panel 08069C0979H, dated 5/02/2012 and is therefore not within any FEMA mapped floodplain. The site does not have any adjacent City of Fort Collins local floodplains. A Floodplain Submittal is not required and has not been included with this report. Please refer to Appendix E for the National Flood Hazard Layer FIRMette. Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 2 2. DRAINAGE BASINS AND SUB-BASINS 2.1 Major Basin Description Lot 1 Penny Flats Subdivision, Second Replat is part of the Old Town Basin Master Drainage Plan. The basin is in north-central Fort Collins and is urbanized. All the water from the basin drains to the Poudre River located north of the site. 2.2 Sub-basin Description The property is in the north central part of the Old Town Basin and drains to the storm system in Mason and Cherry. This system releases flow to the Howes Street Outfall Box Culvert and then the Cache la Poudre River. 3. DRAINAGE DESIGN CRITERIA 3.1 Regulations This report was prepared to meet or exceed the “Fort Collins Stormwater Criteria Manual” (FCSCM) specifications. Where applicable, the criteria established in the Mile High Flood District’s (MHFD) “Urban Storm Drainage Criteria Manual” (USDCM), developed by the Denver Regional Council of Governments, has been used. 3.2 Directly Connected Impervious Area (DCIA) Discussion The USDCM recommends a four-step process for receiving water protection that focuses on reducing runoff volumes, treating the water quality capture volume (WQCV), stabilizing drainageways and implementing long-term source controls. The Four Step Process applies to the management of smaller, frequently occurring events. Step 1: Employ Runoff Reduction Practices To reduce runoff peaks, volumes, and pollutant loads from urbanizing areas, implement Low Impact Development (LID) strategies, including Minimizing Directly Connected Impervious Areas (MDCIA). Runoff from the site shall be conveyed to a water quality facility which promotes settlement of particles and will slow the "first flush" from all storms entering the public street and storm sewer system. Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 3 Step 2: Implement BMPs that Provide a Water Quality Capture Volume with Slow Release Runoff from the site shall be conveyed to a water quality facility that will reduce the rate of runoff and promote settlement of particles. Step 3: Stabilize Drainageways Natural Drainageways are subject to bed and bank erosion due to increases in frequency, duration, rate, and volume of runoff during and following development. Because the site will drain to an existing storm system, bank stabilization is unnecessary with this project. Step 4: Implement Site Specific and Other Source Control BMPs The proposed project will control pollutants by encouraging them to settle out in a water quality facility before being released from the site. The proposed project will proactively control pollutants at their source by preventing pollution rather than removing contaminants once they have entered the stormwater system as compared to historic conditions. 3.3 Development Criteria Reference and Constraints The subject property was previously studied in the “Final Drainage and Erosion Control Report for Penny Flats” prepared by Jim Sell Design and dated August 18, 2006. The historic drainage for the site is based on this plan and proposed designs will conform to this plan. All basins in Fort Collins are required to provide LID water quality. This will be discussed in subsequent sections of the report. The stormwater outfall for this site is the existing storm system in Mason and Cherry Streets. The Cache la Poudre River is the ultimate outfall. Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 4 3.4 Hydrological Criteria The City of Fort Collins requires that all drainage system design and construction take into consideration two design storms: the minor storm and the major storm. The “minor storm” is the 2-year storm or the 50th percentile storm event. The “major storm” is the 100-year storm or the one percentile storm event. Runoff computations were prepared for the 2-year minor and 100-year major storm frequencies utilizing the Rational Method. The study was divided into five onsite basins that can be identified on the Drainage Plan in Appendix A. Percentage impervious values were based on proposed land surface types and are specified in the following table from the FCSCM. Table 1. Recommended Percentage Imperviousness Values. The runoff coefficients are based on surface type and specified in the following table from the FCSCM. The site is classified as NRCS Hydrologic Soil Group A. Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 5 Table 2. Surface Type – Runoff Coefficients. The City of Fort Collins requires a Frequency Adjustment Factor for the 100-year Storm Return Period. The following table lists this factor, Cf. Table 3. Frequency Adjustment Factors. The rainfall intensities used in the Rational Method computation of runoff were obtained from the Fort Collins Rainfall IDF Curve contained in the figure below. Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 6 Figure 1. Rainfall IDF Curve – Fort Collins. All hydrological calculations including a summary of the calculated minor and major rainfall event flows are provided in Appendix B. 3.5 Hydraulic Criteria All hydraulic calculations within this report have been prepared in accordance with the FCSCM and/or the USDCM. Final hydraulic calculations will be included in future submittals. 3.6 Low Impact Development (LID) Conformance Integration of LID systems into the drainage design is required for all development projects. The implementation of LID systems requires one of the following two options: 1. 50% of the newly added or modified impervious area must be treated by LID techniques and 25% of new paved (vehicle use) areas must be pervious. 2. 75% of newly added or modified impervious area must be treated by LID techniques. Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 7 The project does not have any surface parking; therefore, the 50% of the newly added or modified impervious area must be treated by LID techniques rule has been implemented by incorporating a sand filter. Please refer to the Existing vs Proposed Impervious Area Exhibit in Appendix D for comparison of the impervious areas. 3.7 Water Quality (WQ) Treatment Criteria Standard WQ treatment (40 hour drain time) is required for all portions of a development site that is not treated through LID systems. Therefore, the development is required to treat 100% of the site’s impervious area for water quality with at least 50% being LID. 3.8 Detention Requirements Typically, on-site detention is required for the runoff volume difference between the 100- year developed inflow rate and the 2-year historic release rate. This lot’s proposed percent imperviousness was determined to be 85%. Because the City’s Master Plan model for this site already shows all of Penny Flats modeled with 90% imperviousness, the City has agreed that there is no need to provide an updated hydrology model run to prove a “beat- the-peak” justification for this site and would allow discharge without detention into the Howes pipe system. A typical “beat the Peak” study would compare the existing model with an undeveloped impervious percentage to the proposed developed imperviousness. In this case, since the model already assumes more impervious than is proposed, a comparison would actually show slightly less flow regardless of time of concentration. The City also emphasized that another pipe cut into the side of the large Howes box will not be allowed. Please refer to Appendix D for correspondence between the City and Wilson & Company regarding the Master Plan modeling of this area. 3.9 Floodplain Regulations Compliance The project is not within any FEMA mapped floodplain. Therefore, a Floodplain Submittal is not required and has not been included with this report. Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 8 3.10 Modifications of Criteria Two Modifications of Criteria will be requested for this project. The first is the modification to the additional 20% of required Water Quality Capture Volume storage for sedimentation accumulation. This requirement was not intended to apply to LID facilities but is not written as such in the FCSCM. Because sand filters should be maintained several times per year and sediment accumulation over time will not be an issue the additional 20% was added to the sand filter capture volume calculations. This is consistent with the method that Mile High Flood District uses to size LID. The second is the modification to the requirement that 100% of the site’s impervious area be treated for water quality. The City has stated that the site is not allowed to drain directly to the box culvert on the west side of the site (no new connections). Because of this, the portion of the site west of the building can only be directed to Cherry Street and cannot be captured for water quality. We request that the City vary this standard to allow 79% of the site to be treated for Water Quality (the entire building) as the remainder of the site is not able to be captured. After preliminary review by the City of the two variance requests, formal submittal will be provided on the Stormwater Alternative Compliance/Variance Application form during final compliance. 4. DRAINAGE FACILITY DESIGN 4.1 General Concept The storm runoff of the proposed development will be conveyed to the existing storm system in Cherry and Mason Streets via sheet flow to existing inlets, roof drains and proposed storm system. 79% of the impervious area of the site will pass through a proposed sand filter water quality treatment system. Details for LID water quality will continue to be developed as the project design progresses. Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 9 4.2 Specific Details A summary of the drainage patterns within each basin is provided in the following paragraphs. Please refer to Appendix A for the drainage plan. Basin A is 0.66 acres and contains the proposed building. This basin will produce 1.8 cfs and 6.6 cfs during the 2-year and 100-year events, respectively. This flow will travel to the Sand Filter located at the southeast corner of the building. The sand filter will be connected to an existing inlet in Mason Street. Basin B is 0.07 acres and is located in the south and southeast corner of the site. It contains the driveway into the parking structure off of Mason and the pedestrian walkway between the proposed building and Penny Flats Subdivision Lot 1A and Lot 1B. This basin drains to the existing storm inlet at design point b in Mason Street and will produce 0.3 cfs and 0.7 cfs during the 2-year and 100-year events, respectively. Basin C 0.03 acres and is located just east of the building. The basin contains concrete walk and a small portion of Mason Street (concrete parallel parking area) and drains north along the curb and gutter of North Mason Street to design point c and then into basin E. This basin will produce 0.1 cfs and 0.3 cfs during the 2-year and 100-year events, respectively. Basin D is 0.33 acres and contains the west and north portions of the development. The basin contains concrete walks and landscaping. The west portion drains to a concrete pan and sidewalk chase that directs flow to Cherry Street. The north portion sheets directly to Cherry Street. Flow is then collected in the large bank of existing inlets at design point d. This basin will produce 0.4 cfs and 2.0 cfs during the 2-year and 100-year events, respectively. Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 10 Basin E is 0.05 acres and contains the curb and sidewalk in the northeast corner of the development (Cherry and Mason Streets). The basin sheets to design point e on Mason Street where flow is collected by a proposed City of Fort Collins curb inlet (Detail D-43). This basin will produce 0.1 cfs and 0.5 cfs during the 2-year and 100-year events, respectively. Any overtopping of this inlet will sheet east and is the current drainage pattern for this basin. 4.3 LID, WQ and Detention The project is required to treat 50% of on-site new impervious area with LID. For this initial submittal, LID treatment has been identified as a sand filter. The LID sand filter will treat 79% of the on-site impervious area (the entire roof area). Appendix D includes preliminary calculations for LID treatment. Table 4. LID Summary Table On-site detention for this site is not required due a “beat-the-peak” philosophy because the Master Plan already assumes the site is 90% impervious and adequate conveyance capacity to the Poudre River is provided. 50% On-Site Treatment by LID Requirement New or Modified Impervious Area 32,194 sf Required Minimum Impervious Area to be Treated 16,097 sf Treatment - Sand Filtration 25,370 sf Total impervious Area Treated 25,370 sf Actual % of Impervious Area On-Site Treated by LID 79 % Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 11 5. SEDIMENT AND EROSION CONTROL The disturbed area is greater than 1 acre and will require a State of Colorado Discharge Permit and City of Fort Collins plan and report. Temporary Sediment and Erosion Control Erosion and sedimentation will be controlled on-site during construction by use of vehicle tracking control pad, concrete washout area, silt fence, rock socks in adjacent existing curb and gutter, inlet protection, sediment control logs in swales, and seeding and mulch. The measures will be designed to limit the overall sediment yield increase due to construction as required by the City of Fort Collins. During grading, the soil will be roughened and furrowed perpendicular to the prevailing winds. During the performance of the work required by these specifications or any operations appurtenant thereto, whether on right-of-way provided by the City or elsewhere, the contractor shall furnish all labor, equipment, materials, and means required to comply with applicable permits. The Contractor shall carry out proper efficient measures wherever and as necessary to reduce dust nuisance, and to prevent dust nuisance that has originated from his operations from damaging crops, orchards, cultivated fields, and dwellings, or causing naissance to persons. The Contractor will be held liable for any damage resulting from dust originating from his operations under these specifications on right-of-way or elsewhere. Wherever construction vehicles access routes or intersect paved public roads, provisions must be made to minimize the transport of sediment by runoff or vehicles tracking onto the paved surface. The contractor will be responsible for clearing mud tracked onto city streets daily. All temporary erosion and sediment control practices must be maintained and repaired as needed to assure continued performance of their intended function. An Erosion Control Report will be submitted during Final Compliance. Lot 1 Penny Flats Subdivision, Second Replat 4065 Saint Cloud Drive; Suite 201, Loveland, CO 80538 phone: 970.834.6364 Page 12 6. CONCLUSIONS 6.1 Compliance with Standards All computations that have been completed within this report are in compliance with the City of Fort Collins Storm Drainage Design Criteria Manual. 6.2 Drainage Concept The proposed drainage concepts presented in this report and on the preliminary construction plans adequately provide for stormwater quantity and quality treatment of proposed impervious areas. Conveyance elements have been designed to pass required flows and to minimize future maintenance. If, at the time of construction, groundwater is encountered, a Colorado Department of Health Construction Dewatering Permit will be required. 7. REFERENCES 1. “Final Drainage and Erosion Control Report for: Penny Flats”, Jim Sell Design, dated August 18, 2006. 2. City of Fort Collins, “Fort Collins Stormwater Criteria Manual”, adopted December 2018. 3. Mile High Flood District, “Urban Storm Drainage Criteria Manual”, Volume 1 (revised August 2018), Volume 2 (revised September 2017), and Volume 3 (updated January 2021). A APPENDIX A VICINITY MAP AND DRAINAGE PLAN SITE VICINITY MAP SCALE: 1"=500' LOT 2 PENNY FLATS SUBDIVISION, SECOND REPLAT XXXXXXXXXFO RD RD S SS W S W W S S S 4 9 8 5 498449824 9 8 1 49 8 1 4982 49834984498549814 9 8 2 4983498549844984LOT 9, BLOCK 33 LOT 10, BLOCK 33 LOT 11-14, BLOCK 33 PENNY FLATS, FTC LOT 3 PENNY FLATS SUB LOT 1A PENNY FLATS SUB LOT 1B CHERRY STREET NORTH MASON STREET10' UE, DE, PEPROP 5' DE 4983 49844985 4985 49854 9 8 4 49824982 EX STORM MH RIM=4982.04 INV=4971.47 (E) (48" RCP) INV=4969.84 (W) (48" RCP) EX STORM MH RIM=4985.10 BOTTOM OF BOX=4970.35 EX STORM MH RIM=4981.68 INV=4971.57 (SE) (48" RCP) INV=4971.41 (W) (48" RCP) EX STORM MH RIM=4981.40 EX INV=4972.60 (S) (36" RCP) EX INV=4972.31 (SE) (18" RCP) EX INV=4971.79 (NW) (48" RCP) INV= EX STORM INLET RIM=4981.74 EX INV=4978.11 (N) (18" RCP) EX INV (EST.)=4973.5 (36" RCP) PROP INV=4978.0 (18" HDPE) EX STORM GRATES RIM=4980.61 CONC CULVERT=4973.70 EX STORM GRATE RIM=4980.77 CONC CULVERT=4973.51 EX STORM MH RIM=4983.18 INV=4978.33 (E) (18" RCP) INV=4974.13 (N) (36" RCP) INV=4974.03 (S) (36" RCP) PROPOSED SAND FILTER PROPOSED SW CHASE PROPOSED 2' CONC PAN 4984.67 EX 5'X16' BOX CULVERT (HOWES STREET OUTFALL EX 25' UE, DE, PE EX 100' ROWEX 100' ROWCITY OF FORT COLLINS CURB INLET (DETAIL D-43) CONNECT 15" RCP TO EX MH PROP DEPENNY FLATS SUBTRACT A UE, DE, PEENCLOSURE WALL 8" COURSE AGGREGATE 18" OF SAND FILTER MATERIAL TOP=4980.5 36" PONDING ABOVE SAND FILTER MEDIA 4983.5 18" HDPE OUTLET PIPE INV=4978.5 REQUIRED FLAT SURFACE AREA = 350 SF REQUIRED VOLUME = 933 CF (7,000 GALLONS) 4" DIAMETER PERFORATED PVC UNDERDRAIN 4978.3 BOTTOM SLAB 24" NYLOPLAST OVERFLOW INLET W/ DOME GRATE 4983.5 RIM 4984.5 SPILLWAY NOTCH TOP OF EAST WALL 4985.5 TOP OF WALL SOUTH AND WEST EX MASON STORM INLET RIM=4981.74 EX INV=4978.11 (N) (18" RCP) EX INV (EST.)=4973.5 (36" RCP) PROP INV=4978.0 (18" HDPE) SAND FILTER N.T.S. 20.6 LF 18" HDPE OUTLET PIPE TO MASON STORM INLET TOP OF WALK=4984.67 TOP OF WALK=4983.50 CONC WALK SOUTH OF WALL DRAINAGE PLAN 6 MPO ES ES 22-100-356-00 JULY 19, 20234065 SAINT CLOUD DRIVE, SUITE 201LOVELAND, CO 80538PHONE: 970-834-6364www.wilsonco.comDRAWN BY: CHECKED BY: DATE:DESCRIPTIONDATEPROPERTY OWNERSEALPROJECT NAMEPROJECT NO: DESIGNED BY: SHEET NO: SHEET TITLE REV.BYPRE LI MI N A R Y S U B MI T T A L NOT F O R CON S T R U C TI O N EXISTING MAJOR CONTOUR BASIN COEFFICIENT (100-YR) DRAINAGE BASIN AREA DRAINAGE BASIN NUMBER DESIGN POINT PROPOSED DRAINAGE BASIN DIVIDE LINE FLOW PATH LEGEND EXISTING MINOR CONTOUR PROPOSED MINOR CONTOUR PROPOSED MAJOR CONTOUR TRIBE DEVELOPMENT244 N COLLEGE AVESUITE 130FORT COLLINS, CO 80524LOT 1 PENNY FLATSSUBDIVISION, SECONDREPLAT811 B APPENDIX B HYDROLOGIC COMPUTATIONS Wilson & CompanyDRAINAGE SUMMARY TABLEDesign Tributary Area C (2 & 10) C (100) tc (2 & 10) tc (100) Q(2)tot Q(10)tot Q(100)totSub-basinREMARKSPoint (ac)(min) (min) (cfs) (cfs) (cfs)a A 0.66 0.94 1.00 5.0 5.0 1.8 3.0 6.6 Sand Filterb B 0.07 0.88 1.00 5.0 5.0 0.2 0.3 0.7 Existing inlet on North Mason Streetc C 0.03 0.94 1.00 5.0 5.0 0.1 0.2 0.3 Existing inlet on North Mason Streetd D 0.33 0.50 0.62 5.0 5.0 0.4 0.8 2.0 Existing bank of inlets on Cherry Streete E 0.05 0.78 0.97 5.0 5.0 0.1 0.2 0.5 Cherry Street230216 COFC FLOW (209 CHERRY).xlsB1 Wilson & Company RUNOFF COEFFICIENTS & % IMPERVIOUS LOCATION:209 CHERRY (PENNY FLATS) PROJECT NO:22-100-356 COMPUTATIONS BY:es DATE:2/16/2023 Recommended Runoff Coefficients from Table 3.2-2 of City of Fort Collins Stormwater Criteria Manual Recommended % Impervious from Table 4.1-3 of City of Fort Collins Stormwater Criteria Manual Hydrologic Soil Group Type A Runoff % coefficient Impervious C Asphalt, Concrete: 0.95 100 Rooftop: 0.95 90 Gravel: 0.50 40 Landscape Areas (Flat slope, clay) : 0.20 2 Landscape Areas (Avg slope, clay) : 0.25 2 SUBBASIN TOTAL TOTAL LANDSCAPE RUNOFF % DESIGNATION AREA AREA ROOFTOP ASPHALT, CONCRETE GRAVEL (Flat slope, clay) COEFF. Impervious REMARKS (ac.) (sq.ft) (sq.ft) (sq.ft) (sq.ft) (sq.ft) (C) Existing LOT 0.87 38,042 0 0 38,042 0 0.50 40 OFFSITE (LOT BOUNDARY TO LOD) 0.18 7,808 0 3,189 0 4,619 0.39 42 Total 1.05 45850 0 3189 38042 4619 0.48 40 Proposed LOT 0.87 38,042 28,008 6,767 408 2,859 0.89 85 OFFSITE (LOT BOUNDARY TO LOD) 0.18 7,808 0 5,435 0 2,374 0.72 70 TOTAL 1.05 45850 28008 12202 408 5232 0.86 82 Equations - Calculated C coefficients & % Impervious are area weighted C = S (Ci Ai) / At Ci = runoff coefficient for specific area, Ai Ai = areas of surface with runoff coefficient of Ci n = number of different surfaces to consider At = total area over which C is applicable; the sum of all Ai's 230216 COFC FLOW (209 CHERRY).xls B2 Wilson & Company RUNOFF COEFFICIENTS & % IMPERVIOUS LOCATION:209 CHERRY (PENNY FLATS) PROJECT NO:22-100-356 COMPUTATIONS BY:es DATE:2/23/2023 Recommended Runoff Coefficients from Table 3.2-2 of City of Fort Collins Stormwater Criteria Manual Recommended % Impervious from Table 4.1-3 of City of Fort Collins Stormwater Criteria Manual Hydrologic Soil Group Type A Runoff % coefficient Impervious C Asphalt, Concrete: 0.95 100 Rooftop: 0.95 90 Gravel: 0.50 40 Landscape Areas (Flat slope, clay) : 0.20 2 Landscape Areas (Avg slope, clay) : 0.25 2 SUBBASIN TOTAL TOTAL LANDSCAPE RUNOFF % DESIGNATION AREA AREA ROOFTOP ASPHALT, CONCRETE GRAVEL (Flat slope, clay) COEFF. Impervious REMARKS (ac.) (sq.ft) (sq.ft) (sq.ft) (sq.ft) (sq.ft) (C) A 0.66 28,922 28,008 485 408 21 0.94 89 B 0.07 3,230 0 2,934 0 296 0.88 91 C 0.03 1429 0 1411 0 19 0.94 99 D 0.33 14287 0 5681 0 8,606 0.50 41 E 0.05 2099 0 1613 0 486 0.78 77 Total 1.15 49,967 28,008 12,124 408 9,428 0.80 75 Equations - Calculated C coefficients & % Impervious are area weighted C = S (Ci Ai) / At Ci = runoff coefficient for specific area, Ai Ai = areas of surface with runoff coefficient of Ci n = number of different surfaces to consider At = total area over which C is applicable; the sum of all Ai's 230216 COFC FLOW (209 CHERRY).xls B3 Wilson & Company STANDARD FORM SF-2 TIME OF CONCENTRATION - 2 and 10 YR LOCATION: 209 CHERRY (PENNY FLATS) PROJECT NO: 22-100-356 COMPUTATIONS BY: es DATE: 2/16/2023 2 and 10-yr storm Cf = 1.00 from Table RO-12 of City of Fort Collins Stormwater Code, Volume I SUB-BASIN INITIAL /OVERLAND TRAVEL TIME / GUTTER OR CHANNEL FLOW tc CHECK FINAL REMARKS DATA TIME (ti) (tt)(URBANIZED BASIN) tc DESIGN SUBBASIN(s) Area C Length Slope ti Length Slope n Vel. tt tc = Total L tc=(l/180)+10 PONIT (ac) (ft) (%) (min) (ft) (%) Manning (ft/s) (min) ti + tt (ft) (min) (min) (1) (2) (3) (4) (5) (6) (7) (8) rough. (9) (10) (11) (12) (13) (14) a A 0.66 0.94 5 2.0 0.5 200 2.0 0.012 3.8 0.9 1.4 205 11.1 5.0 b B 0.07 0.88 5 2.0 0.7 200 2.0 0.012 3.8 0.9 1.6 205 11.1 5.0 c C 0.03 0.94 5 2.0 0.5 200 2.0 0.012 3.8 0.9 1.4 205 11.1 5.0 d D 0.33 0.50 5 2.0 2.0 200 2.0 0.012 3.8 0.9 2.9 205 11.1 5.0 e E 0.05 0.78 5 2.0 1.1 200 2.0 0.012 3.8 0.9 2.0 205 11.1 5.0 EQUATIONS:Overland Flow Length tc = ti + tt Equation 5-3 L=200' Max in developed areas L=500' Max in undeveloped areas ti = [1.87 (1.1 - CCf ) L0.5 ] / S Equation 3.3-2 tt = L/(V*60)Equation 5-5 V=1.49/n * R^2/3*S^1/2 Equation 5-4 final tc = minimum of ti + tt and urbanized basin check min. tc = 5 min. due to limits of IDF curves 230216 COFC FLOW (209 CHERRY).xls B4 Wilson & Company STANDARD FORM SF-2 TIME OF CONCENTRATION - 100 YR LOCATION: 209 CHERRY (PENNY FLATS) PROJECT NO: 22-100-356 COMPUTATIONS BY: es DATE: 2/16/2023 100-yr storm Cf = 1.25 from Table RO-12 of City of Fort Collins Stormwater Code, Volume I SUB-BASIN INITIAL /OVERLAND TRAVEL TIME / GUTTER OR CHANNEL FLOW tc CHECK FINAL REMARKS DATA TIME (ti)(tt)(URBANIZED BASIN) tc DESIGN SUBBASIN(s) Area C C*Cf Length Slope ti Length Slope n Vel. tt tc = Total L tc=(l/180)+10 PONIT (ac)(ft) (%) (min) (ft) (%) Manning (ft/s) (min) ti + tt (ft) (min) (min) (1) (2) (3) (4) (5) (6) (7) (8) rough. (9) (10) (11) (12) (13) (14) a A 0.66 0.94 1.00 5 2.0 0.3 200 2.0 0.012 3.8 0.9 1.2 205 11.1 5.0 b B 0.07 0.88 1.00 5 2.0 0.3 200 2.0 0.012 3.8 0.9 1.2 205 11.1 5.0 c C 0.03 0.94 1.00 5 2.0 0.3 200 2.0 0.012 3.8 0.9 1.2 205 11.1 5.0 d D 0.33 0.50 0.62 5 2.0 1.6 200 2.0 0.012 3.8 0.9 2.5 205 11.1 5.0 e E 0.05 0.78 0.97 5 2.0 0.4 200 2.0 0.012 3.8 0.9 1.3 205 11.1 5.0 EQUATIONS:Overland Flow Length tc = ti + tt Equation 5-3 L=200' Max in developed areas L=500' Max in undeveloped areas ti = [1.87 (1.1 - CCf ) L0.5 ] / S Equation 3.3-2 tt = L/(V*60)Equation 5-5 V=1.49/n * R^2/3*S^1/2 Equation 5-4 final tc = minimum of ti + tt and urbanized basin check min. tc = 5 min. due to limits of IDF curves 230216 COFC FLOW (209 CHERRY).xls B5 Wilson & Company RATIONAL METHOD PEAK RUNOFF (City of Fort Collins, 2-Yr Storm) LOCATION: 209 CHERRY (PENNY FLATS) PROJECT NO: 22-100-356 COMPUTATIONS BY: es DATE: 2/16/2023 2 yr storm, Cf = 1.00 DIRECT RUNOFF CARRY OVER TOTAL REMARKS Design Tributary A C Cf tc i Q (2) from Q (2) Q(2)tot Sub-basin Design Point (ac) (min) (in/hr) (cfs) Point (cfs) (cfs) a A 0.66 0.94 5.0 2.85 1.8 1.8 b B 0.07 0.88 6.0 2.66 0.2 0.2 c C 0.03 0.94 7.0 2.53 0.1 0.1 d D 0.33 0.50 8.0 2.42 0.4 0.4 e E 0.05 0.78 9.0 2.32 0.1 0.1 Q = Cf C iA Q = peak discharge (cfs) C = runoff coefficient Cf = frequency adjustment factor i = rainfall intensity (in/hr) from City of Fort Collins IDF curve A = drainage area (acres)i = 24.221 / (10+ tc)0.7968 230216 COFC FLOW (209 CHERRY).xls B6 Wilson & Company RATIONAL METHOD PEAK RUNOFF (City of Fort Collins, 10-Yr Storm) LOCATION: 209 CHERRY (PENNY FLATS) PROJECT NO: 22-100-356 COMPUTATIONS BY: es DATE: 2/16/2023 10 yr storm, Cf = 1.00 DIRECT RUNOFF CARRY OVER TOTAL REMARKS Design Tributary A C Cf tc i Q (10) from Q (10) Q(10)tot Sub-basin Design Point (ac) (min) (in/hr) (cfs) Point (cfs) (cfs) a A 0.66 0.94 5.0 4.87 3.0 3.0 b B 0.07 0.88 5.0 4.87 0.3 0.3 c C 0.03 0.94 5.0 4.87 0.2 0.2 d D 0.33 0.50 5.0 4.87 0.8 0.8 e E 0.05 0.78 5.0 4.87 0.2 0.2 Q = Cf C iA Q = peak discharge (cfs) C = runoff coefficient Cf = frequency adjustment factor i = rainfall intensity (in/hr) from City of Fort Collins IDF curve A = drainage area (acres)i = 41.44 / (10+ tc)0.7974 230216 COFC FLOW (209 CHERRY).xls B7 Wilson & Company RATIONAL METHOD PEAK RUNOFF (City of Fort Collins, 100-Yr Storm) LOCATION: 209 CHERRY (PENNY FLATS) PROJECT NO: 22-100-356 COMPUTATIONS BY: es DATE: 2/16/2023 100 yr storm, Cf = 1.25 DIRECT RUNOFF CARRY OVER TOTAL REMARKS Des. Area A C Cf tc i Q (100) from Q (100) Q(100)tot Design Point Design. (ac) (min) (in/hr) (cfs) Point (cfs) (cfs) a A 0.66 1.00 5.0 9.95 6.6 6.6 b B 0.07 1.00 5.0 9.95 0.7 0.7 c C 0.03 1.00 5.0 9.95 0.3 0.3 d D 0.33 0.62 5.0 9.95 2.0 2.0 e E 0.05 0.97 5.0 9.95 0.5 0.5 Q = C iA Q = peak discharge (cfs) C = runoff coefficient i = rainfall intensity (in/hr) from City of Fort Collins IDF curve A = drainage area (acres)i = 84.682 / (10+ tc)0.7975 230216 COFC FLOW (209 CHERRY).xls B8 City of Fort Collins Stormwater Criteria Manual B9 City of Fort Collins Stormwater Criteria Manual B10 C APPENDIX C HYDRAULIC CALCULATIONS (TO BE COMPLETED AT FINAL) D APPENDIX D LID CALCULATION AND COMMUNICATION REGARDING ON-SITE DETENTION CHERRY STREET NORTH MASON STREETPENNY FLATS SUBTRACT AIIIIIIIIIIIIIIIIIIIIIIIIXXI I I I I I I I I I I I IIIIIIIIIIII IIIIII IIIIII IIIIII IIIII IIIIIII IIIIII IIIIII SS W W W S S S CHERRY STREET NORTH MASON STREETPENNY FLATS SUBTRACT AXXSS W W W S S S IMPERVIOUS AREA EXHIBIT 1 MPO ES MPO 22-100-356-004065 SAINT CLOUD DRIVE, SUITE 201LOVELAND, CO 80538PHONE: 970-834-6364www.wilsonco.comDRAWN BY: CHECKED BY: DATE:DESCRIPTIONDATEPROPERTY OWNERSEALPROJECT NAMEPROJECT NO: DESIGNED BY: SHEET NO: SHEET TITLE REV.BYPRE LI MI N A R Y S U B MI T T A L NOT F O R CON S T R U C TI O N EXISTING PROPOSED SURFACE AREA (SF)% IMPERVIOUS IMPERVIOUS AREA (SF) ROOF 0 90 0 CONCRETE/ASPHALT 0 100 0 GRAVEL 38042 40 15217 LANDSCAPE 0 2 0 TOTAL 38042 15217 SURFACE AREA (SF)% IMPERVIOUS IMPERVIOUS AREA (SF) ROOF 28008 90 25207 CONCRETE/ASPHALT 6767 100 6767 GRAVEL 408 40 163 LANDSCAPE 2859 2 57 TOTAL 38042 32194 TRIBE DEVELOPMENT244 N COLLEGE AVESUITE 130FORT COLLINS, CO 80524LOT 1 PENNY FLATSSUBDIVISION, SECONDREPLATJULY 12, 2023 New or Modified Impervious Area 32,194 sf Required Minimum Impervious Area to be Treated 24,146 sf Treatment - Sand Filtration 25,370 sf Total impervious Area Treated 25,370 sf Actual % of Impervious Area On-Site Treated by LID 79 % 75% On-Site Treatment by LID Requirement LID Table D2 Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =100.0 % (100% if all paved and roofed areas upstream of sand filter) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 1.000 C) Water Quality Capture Volume (WQCV) Based on 12-hour Drain Time WQCV = 0.40 watershed inches WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including sand filter area)Area = 28,008 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =934 cu ft VWQCV = WQCV / 12 * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth DWQCV =3.0 ft B) Sand Filter Side Slopes (Horizontal distance per unit vertical, Z = 0.00 ft / ft 4:1 or flatter preferred). Use "0" if sand filter has vertical walls. C) Minimum Filter Area (Flat Surface Area)AMin =350 sq ft D) Actual Filter Area AActual =350 sq ft E) Volume Provided VT =1050 cu ft 3. Filter Material 4. Underdrain System A) Are underdrains provided?1 B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =cu ft iii) Orifice Diameter, 3/8" Minimum DO = in 209 CHERRY ST. Fort Collins Design Procedure Form: Sand Filter (SF) ES WILSON & CO March 2, 2023 UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" CDOT Class B or C Filter Material Other (Explain): YES NO UD-BMP_v3.07.xlsm, SF 3/2/2023, 1:11 PM D3 Sheet 2 of 2 Designer: Company: Date: Project: Location: 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is an impermeable liner provided due to proximity of structures or groundwater contamination? PROVIDE A 30 MIL (MIN) PVC GEOMEMBRANE PER TABLE SF-4 WITH SEPARATOR FABRIC (PER TABLE SF-3) ABOVE IT. PROVIDE SEPARATOR FABRIC BELOW THE GEOMEMBRANE AS WELL IF SUBGRADE IS ANGULAR OR COULD OTHERWISE PUNCTURE THE GEOMEMBRANE. 6. Inlet / Outlet Works A) Describe the type of energy dissipation at inlet points and means of conveying flows in excess of the WQCV through the outlet Notes: Design Procedure Form: Sand Filter (SF) ES WILSON & CO March 2, 2023 209 CHERRY ST. Fort Collins Choose One YES NO UD-BMP_v3.07.xlsm, SF 3/2/2023, 1:11 PM D4 1 Schneider, Erika From:Matt Simpson <masimpson@fcgov.com> Sent:Thursday, February 23, 2023 9:04 AM To:Oberlander, Michael Cc:Schneider, Erika Subject:RE: 209 Cherry St - Building Section with Box Culvert Hi Mike, Based on this information, there is no need to provide an updated hydrology model run – and would allow you to discharge w/o detention into the Howes pipe system. With the note (again) that we do not want another pipe cut into the side of the large Howes box. Thanks, Matt Matt Simpson, PE, CFM Water Utility Development Review Engineer City of Fort Collins 970-416-2754 office From: Oberlander, Michael <Michael.Oberlander@wilsonco.com> Sent: Monday, February 20, 2023 4:16 PM To: Matt Simpson <masimpson@fcgov.com> Cc: Schneider, Erika <Erika.Schneider@wilsonco.com> Subject: [EXTERNAL] RE: 209 Cherry St - Building Section with Box Culvert Matt- The concept review comments state that we need to show that we beat the peak for the site to not require detention (we will have more than the 5000 SF of new hard surface). Dan had a copy of the model from ICON and it shows all of Penny Flats (including the lot we are looking at) and the impervious percentage in the model is 90% already. He thinks they modeled gravel lots as 90% as a rule. How do we proceed – we effectively wouldn’t be changing the model. Do we need to run the model “corrected effective” with this block at maybe 70% to 80% that it is today, or are we covered since it is already right about where we will be? Thanks- If we do need to re-run anything, please provide files. Mike Michael P. Oberlander, PE Operations Manager, Northern Colorado | Wilson & Company, Inc., Engineers & Architects | 970 834 6365 (direct) | 970 631 2671 (cell) From: Matt Simpson <masimpson@fcgov.com> Sent: Friday, February 3, 2023 4:39 PM To: Oberlander, Michael <Michael.Oberlander@wilsonco.com> Subject: RE: 209 Cherry St - Building Section with Box Culvert Hi Mike, D5 2 For Sand Filters in parking garages, you can see the following projects: · The Standard (blocked in behind a wall… LOL… don’t go see this one..) · Confluence · Union on Elizabeth. · District at Campus West To find plans for these, you will need to go to Engineering Link and search for them by name. https://records.fcgov.com/EngineeringLink/Welcome.aspx?dbid=0&repo=FortCollins Thanks, Matt Matt Simpson, PE, CFM Water Utility Development Review Engineer City of Fort Collins 970-416-2754 office From: Oberlander, Michael <Michael.Oberlander@wilsonco.com> Sent: Wednesday, February 1, 2023 12:19 PM To: Matt Simpson <masimpson@fcgov.com> Subject: [EXTERNAL] RE: 209 Cherry St - Building Section with Box Culvert Thanks Matt – hopefully the City doesn’t ask for more than 10 feet since that was what was in the concept review comments. Very much appreciate your help. One thing (and I’ve been a little scattered). Did you give me a project name for a sand filter in a parking structure? I think you said Dan had one like that (that wasn’t encased in concrete)! I’d just like to see the approach – there are so many utilities on all sides of this site (not just the box culvert side), that I think we are going to have to think “within”. Michael P. Oberlander, PE Operations Manager, Northern Colorado | Wilson & Company, Inc., Engineers & Architects | 970 834 6365 (direct) | 970 631 2671 (cell) From: Matt Simpson <masimpson@fcgov.com> Sent: Wednesday, February 1, 2023 12:06 PM To: Mary Taylor <mtaylor@russellmillsstudios.com>; Oberlander, Michael <Michael.Oberlander@wilsonco.com> Cc: Nathan Starck <nstarck@russellmillsstudios.com>; Don Bernholtz <don@vfla.com>; Chris Aronson <Chris@vfla.com>; Will Lindsey <wlindsey@fcgov.com>; Brandy Bethurem Harras <BBethuremHarras@fcgov.com> Subject: RE: 209 Cherry St - Building Section with Box Culvert Hi Mary, Mike and team, FYI, I ran both of these exhibits by my manager, Heidi Hansen, and she wants to take more time to evaluate this situation. It will most likely involve a discussion with senior utilities leadership (above Ken Sampley). With that said, I do not think the requested 5-feet of separation from the existing concrete storm box pipe will be agreed to. Probably 10- feet at best – but maybe more. We will be running these conversations internally, so stay tuned for further follow up. Sorry this is not the news you were hoping for. Feel free to check back with me though in about a week. Thanks, Matt Matt Simpson, PE, CFM Water Utility Development Review Engineer D6 3 City of Fort Collins 970-416-2754 office From: Matt Simpson Sent: Thursday, January 26, 2023 1:09 PM To: Mary Taylor <mtaylor@russellmillsstudios.com> Cc: Nathan Starck <nstarck@russellmillsstudios.com>; Don Bernholtz <don@vfla.com>; Oberlander, Michael <Michael.Oberlander@wilsonco.com>; Chris Aronson <Chris@vfla.com> Subject: RE: [EXTERNAL] 209 Cherry St - Building Section with Box Culvert Hi Mary and team, Thank you for sending this over. My workload is heavy at the moment. I will need 1-2 weeks to get back with you. Feel free to follow up at the end of next week. Thanks, Matt Matt Simpson, PE, CFM Water Utility Development Review Engineer City of Fort Collins 970-416-2754 office From: Mary Taylor <mtaylor@russellmillsstudios.com> Sent: Tuesday, January 24, 2023 3:08 PM To: Matt Simpson <masimpson@fcgov.com> Cc: Nathan Starck <nstarck@russellmillsstudios.com>; Don Bernholtz <don@vfla.com>; Oberlander, Michael <Michael.Oberlander@wilsonco.com>; Chris Aronson <Chris@vfla.com> Subject: [EXTERNAL] 209 Cherry St - Building Section with Box Culvert Hi Matt, Thanks for your time last week. Please see the attached PDF that includes our proposed section showing the box culvert and building location. We are still working on the streetscape and landscape items (for example, no seatwalls), but this should be what you are looking for in terms of the box culvert. Let us know what you think. Thanks and have a great rest of the week-- Mary Mary Taylor, RLA, ASLA Senior Landscape Architect mtaylor@russellmillsstudios.com | www.russellmillsstudios.com M: 636.675.4122 | O: 970.484.8855 D7 D8 3 Dan Evans, PE, CFM Stormwater Practice Lead, Northern Colorado Wilson & Company, Inc., Engineers & Architects 4065 Saint Cloud Drive, Suite 201 | Loveland, CO 80538 970 834 6371 (direct) | 970 420 1134 (cell) wilsonco.com D9 E APPENDIX E SOILS AND FLOODPLAIN INFORMATION Hydrologic Soil Group—Larimer County Area, Colorado (209 Cherry Street) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 1/16/2023 Page 1 of 44493410449342044934304493440449345044934604493470449348044934104493420449343044934404493450449346044934704493480493230493240493250493260493270493280493290493300493310493320493330 493230 493240 493250 493260 493270 493280 493290 493300 493310 493320 493330 40° 35' 31'' N 105° 4' 48'' W40° 35' 31'' N105° 4' 43'' W40° 35' 29'' N 105° 4' 48'' W40° 35' 29'' N 105° 4' 43'' WN 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: 1:516 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. E1 E1 MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available 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 17, Sep 7, 2022 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. Hydrologic Soil Group—Larimer County Area, Colorado (209 Cherry Street) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 1/16/2023 Page 2 of 4 E2 E2 Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 81 Paoli fine sandy loam, 0 to 1 percent slopes A 0.9 100.0% Totals for Area of Interest 0.9 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Hydrologic Soil Group—Larimer County Area, Colorado 209 Cherry Street Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 1/16/2023 Page 3 of 4 E3 Tie-break Rule: Higher Hydrologic Soil Group—Larimer County Area, Colorado 209 Cherry Street Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 1/16/2023 Page 4 of 4 E4 National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V, A99 With BFE or DepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mileZone X Future Conditions 1% Annual Chance Flood HazardZone X Area with Reduced Flood Risk due to Levee. See Notes.Zone X Area with Flood Risk due to LeveeZone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood HazardZone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction 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 the authoritative NFHL web services provided by FEMA. This map was exported on 1/16/2023 at 10:55 AM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements 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 for unmapped and unmodernized areas cannot be used for regulatory purposes. Legend OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 8 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. 1:6,000 105°5'3"W 40°35'45"N 105°4'26"W 40°35'18"N Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020 E5 SITE E5 4065 St. Cloud, Suite.201 Loveland, CO 80538 970-834-6364 phone