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Home My WebLink AboutLINCOLN CORRIDOR HOTEL - PDP - PDP170026 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTLINCOLN HOTEL PRELIMINARY DRAINAGE REPORT PREPARED FOR Lincoln Hotel Fort Collins, Colorado PREPARED BY Olsson Associates 1880 Fall River Drive, Suite 200 Loveland, CO 80538 970.461.7733 Contact: Mike Maurer, PE July, 2017 Olsson Project No. 017-0150 i Table of Contents 1.0 General Location and Description ...................................................................................... 1 1.1 Location ................................................................................................................... 1 1.2 Description of Property ............................................................................................. 1 1.3 Floodplain ................................................................................................................. 1 2.0 Drainage Basin and Sub-Basins ........................................................................................ 1 2.1 Major Basin Description ............................................................................................ 1 2.2 Sub-Basin Description .............................................................................................. 1 3.0 Drainage basin criteria ....................................................................................................... 2 3.1 Development Criteria Reference and Constraints ..................................................... 2 3.2 Hydrological Criteria ................................................................................................. 2 3.3 Hydraulic Criteria ...................................................................................................... 2 3.4 Floodplain Regulations Compliance ......................................................................... 2 3.5 Modifications of Criteria ............................................................................................ 2 4.0 Drainage Facility Design .................................................................................................... 2 4.1 General Concept ...................................................................................................... 2 4.2 Specific Details ......................................................................................................... 3 1. Minimum Required Water Quality Control Volume ................................................ 3 2. Outlet Structure and Spillway ................................................................................ 3 5.0 Conclusions ....................................................................................................................... 4 5.1 Compliance with Standards .................................................................................. 4 5.2 Drainage Concept ................................................................................................. 4 6.0 References ............................................................................................................... 4 List of Tables Table 1: Proposed Basins.��2 Table 2: Detention Pond Parameters..��3 ii List of Appendices Appendix A Hydrologic Calculations A.1 Imperviousness, Time of Concentration, Runoff Calculation Appendix B Hydraulic Calculations B.1 Detention Volume by the Modified FAA Method B.2 Pond Stage Storage Appendix C Referenced Information C.1 Vicinity Map C.2 NRCS Web Soil Survey C.3 FEMA Firm Map C.4 Fort Collins Floodplain map C.5 NOAA Atlas 14 Intensities C.6 Urban Drainage Imperviousness Values C.7 Drainage Basin Map 1.0 GENERAL LOCATION AND DESCRIPTION 1.1 Location The proposed project is located in the southeast quarter of section 12, township 7 north, range 69 west of the 6th P.M. City of Fort Collins, County of Larimer, State of Colorado. The proposed site is bordered on the north by Lincoln Avenue and on the south by the Cache La Poudre River. 1.2 Description of Property Currently the site consists of an office building, some storage sheds, a workshop, a paved parking lot, and a gravel storage area to the south. The project will require the demolition of the existing structures, the paved parking lot and the gravel storage area. The proposed site is 4.37 acres and will consist of the construction of a hotel building, new parking lot, and detention ponds. Based on the NRCS soil survey the soil present on the site is classified as hydrologic group C. The site currently slopes to the south with an average slope of 1% to the Cache La Poudre River. Changes to the site grading are proposed to ensure proper drainage around the proposed building, and include the construction of connected detention ponds along the south edge of the property. 1.3 Floodplain The site, and its proposed features, are currently located within a FEMA and City of Fort Collins regulatory floodplain. The site is within a FEMA designated flood hazard zone “AE” meaning that the base flood elevation for the site has been determined to be 4946.50 per FEMA Firm Map 08069C0979H dated May 2, 2012. However, the FEMA floodplain is currently under review to revise the boundaries and the proposed building will no longer be within the floodplain. The owner is aware that proceeding before the new floodplain is approved will be at his or her own risk. 2.0 DRAINAGE BASIN AND SUB-BASINS 2.1 Major Basin Description Historically, the site drains to the south into the Cache La Poudre River by overland flow. The site historically discharges at a rate of 1.71 cfs and 7.09 cfs for the 2-year and 100-year storm events historically. The existing drainage patterns for the land surrounding the property will not be impacted and there will be no drainage routed through our site from the surrounding properties. 2.2 Sub-Basin Description Historically, the site drains to the south into the Cache La Poudre River by overland flow. Due to the proposed site grading, the site was divided up into 3 drainage basins. Basin 1 includes the proposed hotel building, the detention ponds, and the majority of the site. This basin drains to the detention ponds located in the south portion of the site. Basin 2 is located in the northwest portion of the site and is the location of the west access drive. This basin drains north onto Lincoln Avenue before the runoff is collected in an existing roadside ditch to the east. 2 | P a g e Basin 3 is located in the northeast portion of the site and is the location of the east access drive. This basin also drains north onto Lincoln Avenue before the runoff is collected in an existing roadside ditch to the east. Basin Q2 (cfs) Q100 (cfs) 1 5.58 23.02 2 0.03 0.16 3 0.08 0.33 Table 1. Proposed Basins 3.0 DRAINAGE BASIN CRITERIA 3.1 Development Criteria Reference and Constraints The design of the proposed drainage system was completed in accordance with the criteria set forth in Colorado Urban Drainage and Flood Control District Manual and the amendments that pertain to Fort Collins. 3.2 Hydrological Criteria Hydrologic calculations have been prepared in accordance with criteria set forth in Colorado Urban Drainage and Flood Control District Manual and the amendments that pertain to Fort Collins. 3.3 Hydraulic Criteria Hydraulic calculations have been prepared in accordance with the criteria set forth in Colorado Urban Drainage and Flood Control District Manual and the amendments that pertain to Fort Collins. The Colorado Urban Drainage Detention sizing spread sheet v2.34 was used to size the detention pond using the modified FFA method. 3.4 Floodplain Regulations Compliance The site is currently located within a FEMA and City of Fort Collins regulatory floodplain so the project will comply with the safety regulations of chapter 10 of the city of Fort Collins municipal code. The floodplain elevation was determined to be 4956.50, the lowest finished floor elevation was set a foot above that at 4957.50. The foundation will be set as slab-on-grade. As stated previously, the floodplain is currently under review to be revised which will shift the floodplain and the proposed building will no longer be within it. The owner is aware that proceeding before the new floodplain is approved will be at his or her own risk. 3.5 Modifications of Criteria There are no modifications to the criteria for this project. 4.0 DRAINAGE FACILITY DESIGN 4.1 General Concept In the proposed condition, the site will drain to the detention ponds located in the south portion 3 | P a g e of the site. The water will reach the ponds by a combination of sheet flow and gutter flow. The site is 4.37 acres and contains a proposed parking lot, the proposed building, and some landscaped areas. Runoff will flow to the south portion of the parking lot where there is no curb, then proceed to flow south into the proposed detention ponds where the runoff will discharge into the existing storm manhole then into the Cache La Poudre River. 4.2 Specific Details 1. Minimum Required Water Quality Control Volume The minimum required storage volume was determined using Colorado Urban Drainage’s detention volume spreadsheet (UD-Detention v2.34) See Appendix B.1. The WQCV for the site was determined to be 4,657 cubic feet based on the UD-Detention b2.34 spreadsheet. Parameter Value WQCV Required Volume 4,657 cubic feet 2 yr + WQCV Required Volume 8,994 cubic feet 100 yr + WQCV Required Volume 21,607 cubic feet Bottom of Pond 4941.00 Provided WQCV 5,710 cubic feet WQCV WSEL 4943.00 2 yr + WQCV Provided Volume 9,060 cubic feet 2 yr + WQCV WSEL 4943.50 100 yr + WQCV Provided Volume 22,370 cubic feet 100 yr + WQCV WSEL 4944.75 Outlet Structure Invert 4941.00 100 yr Allowable Release Rate 4.37 cfs Spillway Elevation 4944.75 Top of Pond 4945.75 Table 2. Detention Pond Parameters 2. Outlet Structure and Spillway The Outlet structure was designed to hold back the WQCV for 40 hours and to release the 100 year volume at the allowable peak outflow rate of 4.37 cfs. The allowable peak outflow rate was determined using the UD-Detention b2.34 spreadsheet. See Appendix B.1. 4 | P a g e The bike trail to the south of the ponds will serve as the emergency spillway where excess volume will overtop the trail and discharge directly into the Cache La Poudre River. 5.0 CONCLUSIONS 5.1 Compliance with Standards This report has been prepared in accordance with common engineering practices, the criteria set forth in Colorado Urban Drainage and Flood Control District Manual and the amendments that pertain to Fort Collins. 5.2 Drainage Concept Developed runoff generated on the proposed site will be directed to the detention ponds located in the south portion of the site. The pond is designed to drain the WQCV in 40 hours and release the 100 year volume at the allowable peak outflow rate of 4.37 cfs. 6.0 References Drainage Criteria Manual, Volumes 1, 2, & 3, Urban Drainage and Flood Control District, Volumes 1 & 2 – Originally Published September 1969, updated January 2016; Volume 3 – Originally Published September 1992, updated November 2010 Fort Collins Amendments to the Urban Drainage and Flood Control District Criteria Manual dated December 2011 5 | P a g e APPENDIX A HYDROLOGIC CALCULATIONS 1880 Fall River Drive Suite 200 Loveland, CO 80538 TEL 970.461.7733 Lincoln Hotel Hydrologic Calcs COMPOSITE PERCENT IMPERVIOUSNESS Paved Building Brick Pavers Landscape 90% 90% 22% 2% (sf) (sf) (sf) (sf) Historic Onsite/Offsite 1 - - - 190,173.00 190,173.00 4.37 2% Developed 1 Building, Parking Lot, Detetnion 50,218.00 34,608.00 4,944.00 98,010.00 187,780.00 4.31 42% 2 West Access Drive 545.00 - - 545.00 0.01 90% 3 East Access Drive 1,254.00 - - 594.00 1,848.00 0.04 62% - - Overall Onsite 52,017.00 34,608.00 4,944.00 98,604.00 190,173.00 4.37 43% Basin Name Basin Description Total Area (ac) Percent Impervio usness Total Area (sf) TIME OF CONCENTRATION CALCULATIONS Total Check Final BASIN L1 S1 C5 Ti L 2 V T2 Tc 10+L/180 Tc (ft) (%) (min) (ft) (f/s) (min) (min) (min) (min) Historic Onsite/Offsite 1 300.0 0.0 0.2 295.5 - - - 295.5 11.67 11.67 Developed 1 60.0 0.0 0.5 57.2 380.0 0.1 100.1 157.3 12.44 12.44 2 20.0 0.0 1.0 7.6 - - - 7.59 10.11 7.59 3 50.0 0.0 0.7 35.9 - - - 35.86 10.28 10.28 OVERLAND FLOW GUTTER FLOW 1 STORM DRAINAGE CALCULATION Type AREA C2 C100 Tc* I2 I 100 Q Q BASIN 2-yr 100-yr (acres) (min) (in/hr) (in/hr) (cfs) (cfs) Historic Onsite/Offsite 1 4.37 0.15 0.19 11.7 2.60 8.60 1.71 7.09 Developed 1 4.31 0.51 0.63 12.4 2.53 8.35 5.58 23.02 2 0.01 0.95 1.19 7.6 3.26 10.77 0.03 0.16 3 0.04 0.69 0.87 10.3 2.74 9.08 0.08 0.33 * If time of concentration was less than 5 minutes, 5 minutes was used. Basin Characteristics Intensities Sub-basin 6 | P a g e APPENDIX B HYDRAULIC CALCULATIONS Project: Basin ID: Design Information (Input): Design Information (Input): Catchment Drainage Imperviousness Ia = 43.00 percent Catchment Drainage Imperviousness I a = 43.00 percent Catchment Drainage Area A = 4.370 acres Catchment Drainage Area A = 4.370 acres Predevelopment NRCS Soil Group Type = C A, B, C, or D Predevelopment NRCS Soil Group Type = C A, B, C, or D Return Period for Detention Control T = 2 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100) Time of Concentration of Watershed Tc = 13 minutes Time of Concentration of Watershed Tc = 13 minutes Allowable Unit Release Rate q = 0.04 cfs/acre Allowable Unit Release Rate q = 1.00 cfs/acre One-hour Precipitation P1 = 0.82 inches One-hour Precipitation P 1 = 2.86 inches Design Rainfall IDF Formula i = C1* P 1/(C2 +Tc)^C 3 Design Rainfall IDF Formula i = C1 * P1/(C 2+Tc )^C3 Coefficient One C1 = 28.50 Coefficient One C 1 = 28.50 Coefficient Two C2 = 10 Coefficient Two C 2 = 10 Coefficient Three C3 = 0.789 Coefficient Three C 3 = 0.789 Determination of Average Outflow from the Basin (Calculated): Determination of Average Outflow from the Basin (Calculated): Runoff Coefficient C = 0.30 Runoff Coefficient C = 0.59 Inflow Peak Runoff Qp-in = 2.58 cfs Inflow Peak Runoff Qp-in = 17.71 cfs Allowable Peak Outflow Rate Qp-out = 0.17 cfs Allowable Peak Outflow Rate Qp-out = 4.37 cfs Mod. FAA Minor Storage Volume = 4,337 cubic feet Mod. FAA Major Storage Volume = 16,950 cubic feet Mod. FAA Minor Storage Volume = 0.100 acre-ft Mod. FAA Major Storage Volume = 0.389 acre-ft 5 <- Enter Rainfall Duration Incremental Increase Value Here (e.g. 5 for 5-Minutes) Rainfall Rainfall Inflow Adjustment Average Outflow Storage Rainfall Rainfall Inflow Adjustment Average Outflow Storage Duration Intensity Volume Factor Outflow Volume Volume Duration Intensity Volume Factor Outflow Volume Volume minutes inches / hr acre-feet "m" cfs acre-feet acre-feet minutes inches / hr acre-feet "m" cfs acre-feet acre-feet (input) (output) (output) (output) (output) (output) (output) (input) (output) (output) (output) (output) (output) (output) 0 0.00 0.000 0.00 0.00 0.000 0.000 0 0.00 0.000 0.00 0.00 0.000 0.000 5 2.76 0.025 1.00 0.17 0.001 0.024 5 9.62 0.171 1.00 4.37 0.030 0.141 10 2.20 0.040 1.00 0.17 0.002 0.037 10 7.67 0.272 1.00 4.37 0.060 0.212 15 1.84 0.050 0.93 0.16 0.003 0.047 15 6.43 0.343 0.93 4.08 0.084 0.258 20 1.60 0.058 0.83 0.14 0.004 0.054 20 5.57 0.396 0.83 3.61 0.099 0.296 25 1.41 0.064 0.76 0.13 0.005 0.059 25 4.93 0.438 0.76 3.32 0.114 0.323 30 1.27 0.069 0.72 0.13 0.005 0.064 30 4.44 0.473 0.72 3.13 0.129 0.343 35 1.16 0.073 0.69 0.12 0.006 0.068 35 4.04 0.503 0.69 3.00 0.144 0.358 40 1.07 0.077 0.66 0.12 0.006 0.071 40 3.72 0.529 0.66 2.90 0.160 0.369 45 0.99 0.080 0.64 0.11 0.007 0.073 45 3.45 0.552 0.64 2.82 0.175 0.377 50 0.92 0.083 0.63 0.11 0.008 0.076 50 3.22 0.572 0.63 2.75 0.190 0.383 55 0.87 0.086 0.62 0.11 0.008 0.078 55 3.03 0.591 0.62 2.70 0.205 0.386 60 0.82 0.089 0.61 0.11 0.009 0.080 60 2.85 0.608 0.61 2.66 0.220 0.388 65 0.77 0.091 0.60 0.10 0.009 0.082 65 2.70 0.624 0.60 2.62 0.235 0.389 70 0.74 0.093 0.59 0.10 0.010 0.083 70 2.57 0.639 0.59 2.59 0.250 0.389 75 0.70 0.095 0.59 0.10 0.011 0.084 75 2.45 0.652 0.59 2.56 0.265 0.387 80 0.67 0.097 0.58 0.10 0.011 0.086 80 2.34 0.665 0.58 2.54 0.280 0.385 85 0.64 0.099 0.58 0.10 0.012 0.087 85 2.24 0.677 0.58 2.52 0.295 0.382 90 0.62 0.100 0.57 0.10 0.012 0.088 90 2.15 0.688 0.57 2.50 0.310 0.378 95 0.59 0.102 0.57 0.10 0.013 0.089 95 2.07 0.699 0.57 2.48 0.325 0.374 100 0.57 0.103 0.57 0.10 0.014 0.090 100 2.00 0.709 0.57 2.47 0.340 0.369 105 0.55 0.105 0.56 0.10 0.014 0.091 105 1.93 0.719 0.56 2.46 0.355 0.364 110 0.53 0.106 0.56 0.10 0.015 0.091 110 1.87 0.729 0.56 2.44 0.370 0.358 115 0.52 0.108 0.56 0.10 0.015 0.092 115 1.81 0.738 0.56 2.43 0.385 0.352 Project: Basin ID: Design Information (Input): Width of Basin Bottom, W = ft Right Triangle OR� Length of Basin Bottom, L = ft Isosceles Triangle OR� Dam Side-slope (H:V), Zd = ft/ft Rectangle OR� Circle / Ellipse OR� Irregular X (Use Overide values in cells G32:G52) MINOR MAJOR Storage Requirement from Sheet 'Modified FAA': 0.10 0.39 acre-ft. Stage-Storage Relationship: Storage Requirement from Sheet 'Hydrograph': acre-ft. Storage Requirement from Sheet 'Full-Spectrum': acre-ft. Labels Water Side Basin Basin Surface Surface Volume Surface Volume Target Volumes for WQCV, Minor, Surface Slope Width at Length at Area at Area at Below Area at Below for WQCV, Minor, & Major Storage Elevation (H:V) Stage Stage Stage Stage Stage Stage Stage & Major Storage Stages ft ft/ft ft ft ft2 ft2 User ft3 acres acre-ft Volumes (input) (input) Below El. (output) (output) (output) Overide (output) (output) (output) (for goal seek) 0.00 (input) 0 0.000 0.000 0.50 0.00 0.00 900 225 0.021 0.005 1.00 0.00 0.00 3,000 1,200 0.069 0.028 1.50 0.00 0.00 4,500 3,075 0.103 0.071 WQCV 2.00 0.00 0.00 6,000 5,700 0.138 0.131 0.107 2 YR 2.50 0.00 0.00 7,500 9,075 0.172 0.208 0.207 3.00 0.00 0.00 10,000 13,450 0.230 0.309 100 YR+WQCV 3.50 0.00 0.00 12,100 18,975 0.278 0.436 0.496 4.00 0.00 0.00 15,000 25,750 0.344 0.591 4.50 0.00 0.00 18,500 34,125 0.425 0.783 STAGE-STORAGE SIZING FOR DETENTION BASINS Lincoln Hotel Check Basin Shape UD-Detention_v2.34.xls, Basin 7/13/2017, 12:47 PM 7 | P a g e APPENDIX C REFERENCED INFORMATION TEL 970.431.7733 Loveland, CO 80538 Suite 160 5285 McWhinney Boulevard R &XVWRP6RLO5HVRXUFH5HSRUW 6RLO0DS 1 : 1 : 1 : 1 : 1 0DSSURMHFWLRQ:HE0HUFDWRU&RUQHUFRRUGLQDWHV:*6(GJHWLFV870=RQH1:*6 )HHW 0HWHUV 0DS6FDOHLISULQWHGRQ$SRUWUDLW [ 0$3/(*(1' 0$3,1)250$7,21 $UHDRI,QWHUHVW $2, $UHDRI,QWHUHVW $2, 6RLOV 6RLO0DS8QLW3RO\JRQV 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8QLWHG6WDWHV'HSDUWPHQWRI$JULFXOWXUH6RLO&RQVHUYDWLRQ6HUYLFH/DQG FDSDELOLW\FODVVLILFDWLRQ86'HSDUWPHQWRI$JULFXOWXUH+DQGERRNKWWS ZZZQUFVXVGDJRY,QWHUQHW)6(B'2&80(176QUFVSBSGI &XVWRP6RLO5HVRXUFH5HSRUW 4,514 752.3 FCMaps This map is a user generated static output from the City of Fort Collins FCMaps Internet mapping site and is for reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. City of Fort Collins - GIS 572.0 1: WGS_1984_Web_Mercator_Auxiliary_Sphere 0 286.00 572.0 Feet Notes Legend 3,430 FEMA Floodplain FEMA High Risk - Floodway FEMA High Risk - 100 Year FEMA Moderate Risk - 100 / 500 Year FEMA Map Panel City Floodplains City High Risk - Floodway City High Risk - 100 Year City Moderate Risk - 100 Year City Limits Project Site NOAA Atlas 14, Volume 8, Version 2 Location name: Fort Collins, Colorado, USA* Latitude: 40.5764°, Longitude: -105.0859° Elevation: 5005.09 ft** * source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin NOAA, National Weather Service, Silver Spring, Maryland PF_tabular | PF_graphical | Maps_&_aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour) 1 Duration Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 5-min 3.24 (2.59-3.96) 3.79 (3.04-4.63) 4.98 (3.97-6.11) 6.23 (4.94-7.69) 8.36 (6.56-11.2) 10.3 (7.80-13.8) 12.5 (9.10-17.2) 15.1 (10.4-21.2) 18.9 (12.4-27.2) 22.1 (14.0-31.8) 10-min 2.37 (1.90-2.90) 2.77 (2.23-3.40) 3.64 (2.91-4.48) 4.57 (3.62-5.63) 6.12 (4.81-8.19) 7.55 (5.71-10.1) 9.18 (6.65-12.6) 11.0 (7.62-15.5) 13.8 (9.10-19.9) 16.2 (10.2-23.3) 15-min Runoff Chapter 6 6-8 Urban Drainage and Flood Control District January 2016 Urban Storm Drainage Criteria Manual Volume 1 Table 6-3. Recommended percentage imperviousness values Land Use or Percentage Imperviousness Surface Characteristics (%) Business: Downtown Areas 95 Suburban Areas 75 Residential: Single-family 2.5 acres or larger 12 0.75 – 2.5 acres 20 0.25 – 0.75 acres 30 0.25 acres or less 45 Apartments 75 Industrial: Light areas 80 Heavy areas 90 Parks, cemeteries 10 Playgrounds 25 Schools 55 Railroad yard areas 50 Undeveloped Areas: Historic flow analysis 2 Greenbelts, agricultural 2 Off-site flow analysis (when land use not defined) 45 Streets: Paved 100 Gravel (packed) 40 Drive and walks 90 Roofs 90 Lawns, sandy soil 2 Lawns, clayey soil 2 BASIN 2 529± SF 0.012± AC BASIN 3 1848± SF 0.042± AC BASIN 1 187967± SF 4.315± AC LEGEND EXISTING PROPOSED PROPERTY LINE FLOWLINE BACK OF CURB EASEMENT SETBACK LINE MAJOR CONTOURS MINOR CONTOURS STORM SEWER SPOT ELEVATION FLOW ARROW FINISH FLOOR ELEVATION HIGH POINT LOW POINT GRADE BREAK FFE HP LP INVERTED CROWN SIDEWALK SW FLOWLINE FL STORM MANHOLE GRATE INLET WATER LINE SANITARY SEWER MATCH EXISTING GRADE MEG BOTTOM OF WALL BOW TOP OF POND TOP BENCHMARK BASIS OF BEARING BASIN PARAMETERS REVISIONS NO. REV. DATE REVISIONS DESCRIPTION project no.: approved by: checked by: drawn by: drawing no.: QA/QC by: date: SHEET TEL 970.461.7733 www.olssonassociates.com 5285 McWhinney Boulevard, Suite 160 Loveland, CO 80538 OLSSON ASSOCIATES ASSUMES NO RESPONSIBILITY FOR EXISTING UTILITY LOCATIONS (HORIZONTAL OR VERTICAL). THE EXISTING UTILITIES SHOWN ON THIS DRAWING HAVE BEEN PLOTTED FROM THE BEST AVAILABLE INFORMATION. IT IS HOWEVER THE RESPONSIBILITY OF THE CONTRACTOR TO FIELD VERIFY THE LOCATION OF ALL UTILITIES PRIOR TO THE COMMENCEMENT OF ANY CONSTRUCTION ACTIVITIES. NOTE THIS DOCUMENT HAS BEEN RELEASED BY OLSSON ASSOCIATES ONLY FOR REVIEW BY REGULATORY AGENCIES AND OTHER PROFESSIONALS, AND IS SUBJECT TO CHANGE. THIS DOCUMENT IS NOT TO BE USED FOR CONSTRUCTION. CALL 811 SEVENTY-TWO HOURS PRIOR TO DIGGING, GRADING OR EXCAVATING FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES DRAINAGE BASIN MAP R FORT COLLINS, CO 2017 07-14-2017 017-0150 LINCOLN HOTEL MM C_DRN_0170150.dwg MM CH C7 PRELIMINARY DESIGN PLANS CH NOTES 1.92 (1.54-2.36) 2.26 (1.81-2.76) 2.96 (2.36-3.64) 3.71 (2.94-4.58) 4.98 (3.91-6.66) 6.14 (4.64-8.24) 7.46 (5.41-10.2) 8.98 (6.20-12.6) 11.2 (7.40-16.2) 13.1 (8.31-18.9) 30-min 1.23 (0.990-1.51) 1.44 (1.16-1.77) 1.90 (1.52-2.33) 2.38 (1.89-2.94) 3.20 (2.52-4.29) 3.96 (2.99-5.31) 4.81 (3.49-6.61) 5.80 (4.00-8.16) 7.26 (4.78-10.5) 8.50 (5.38-12.2) 60-min 0.756 (0.607-0.924) 0.880 (0.705-1.08) 1.16 (0.926-1.42) 1.47 (1.16-1.81) 1.99 (1.57-2.69) 2.49 (1.88-3.35) 3.05 (2.22-4.20) 3.70 (2.56-5.23) 4.68 (3.09-6.77) 5.51 (3.49-7.93) 2-hr 0.448 (0.361-0.542) 0.518 (0.418-0.628) 0.684 (0.550-0.832) 0.869 (0.694-1.06) 1.19 (0.950-1.60) 1.50 (1.14-2.00) 1.85 (1.35-2.53) 2.25 (1.57-3.16) 2.87 (1.91-4.12) 3.39 (2.17-4.84) 3-hr 0.331 (0.268-0.398) 0.381 (0.308-0.458) 0.500 (0.403-0.604) 0.637 (0.509-0.773) 0.878 (0.704-1.17) 1.11 (0.850-1.48) 1.37 (1.01-1.87) 1.68 (1.18-2.35) 2.15 (1.44-3.08) 2.54 (1.64-3.62) 6-hr 0.199 (0.162-0.236) 0.228 (0.185-0.271) 0.297 (0.240-0.355) 0.374 (0.301-0.449) 0.511 (0.411-0.674) 0.640 (0.495-0.845) 0.789 (0.586-1.07) 0.962 (0.682-1.33) 1.22 (0.828-1.74) 1.45 (0.939-2.05) 12-hr 0.118 (0.097-0.139) 0.137 (0.112-0.161) 0.176 (0.144-0.209) 0.218 (0.177-0.259) 0.289 (0.232-0.372) 0.353 (0.274-0.458) 0.427 (0.318-0.567) 0.510 (0.364-0.698) 0.635 (0.434-0.894) 0.740 (0.486-1.04) 24-hr 0.072 (0.059-0.083) 0.083 (0.068-0.096) 0.105 (0.086-0.122) 0.127 (0.103-0.149) 0.164 (0.132-0.208) 0.197 (0.154-0.252) 0.234 (0.176-0.308) 0.277 (0.199-0.374) 0.339 (0.233-0.472) 0.391 (0.260-0.547) 2-day 0.041 (0.034-0.047) 0.048 (0.040-0.056) 0.062 (0.051-0.072) 0.076 (0.062-0.088) 0.096 (0.077-0.118) 0.113 (0.088-0.142) 0.132 (0.099-0.170) 0.152 (0.110-0.203) 0.182 (0.126-0.250) 0.206 (0.138-0.286) 3-day 0.029 (0.024-0.034) 0.035 (0.029-0.040) 0.045 (0.037-0.051) 0.054 (0.044-0.062) 0.068 (0.054-0.083) 0.079 (0.062-0.099) 0.092 (0.070-0.118) 0.106 (0.077-0.141) 0.126 (0.088-0.173) 0.142 (0.096-0.197) 4-day 0.023 (0.019-0.027) 0.028 (0.023-0.031) 0.035 (0.029-0.040) 0.042 (0.035-0.049) 0.053 (0.043-0.065) 0.062 (0.049-0.077) 0.072 (0.054-0.092) 0.082 (0.060-0.109) 0.098 (0.068-0.133) 0.110 (0.075-0.152) 7-day 0.015 (0.013-0.017) 0.018 (0.015-0.020) 0.023 (0.019-0.026) 0.027 (0.023-0.031) 0.034 (0.027-0.041) 0.039 (0.031-0.048) 0.045 (0.034-0.057) 0.051 (0.038-0.067) 0.060 (0.042-0.082) 0.067 (0.046-0.092) 10-day 0.012 (0.010-0.013) 0.014 (0.012-0.016) 0.018 (0.015-0.020) 0.021 (0.017-0.024) 0.026 (0.021-0.031) 0.030 (0.023-0.036) 0.034 (0.026-0.042) 0.038 (0.028-0.050) 0.044 (0.031-0.060) 0.049 (0.034-0.067) 20-day 0.008 (0.006-0.009) 0.009 (0.007-0.010) 0.011 (0.009-0.012) 0.013 (0.011-0.014) 0.015 (0.012-0.018) 0.017 (0.014-0.021) 0.019 (0.015-0.024) 0.021 (0.016-0.027) 0.024 (0.017-0.032) 0.027 (0.019-0.036) 30-day 0.006 (0.005-0.007) 0.007 (0.006-0.008) 0.008 (0.007-0.009) 0.010 (0.008-0.011) 0.011 (0.009-0.013) 0.013 (0.010-0.015) 0.014 (0.011-0.017) 0.016 (0.012-0.020) 0.018 (0.013-0.023) 0.019 (0.013-0.026) 45-day 0.005 (0.004-0.005) 0.006 (0.005-0.006) 0.007 (0.006-0.007) 0.008 (0.006-0.008) 0.009 (0.007-0.010) 0.010 (0.008-0.012) 0.011 (0.008-0.013) 0.012 (0.009-0.015) 0.013 (0.009-0.017) 0.014 (0.010-0.019) 60-day 0.004 (0.003-0.004) 0.005 (0.004-0.005) 0.006 (0.005-0.006) 0.007 (0.006-0.007) 0.008 (0.006-0.009) 0.008 (0.007-0.010) 0.009 (0.007-0.011) 0.010 (0.007-0.012) 0.011 (0.008-0.014) 0.012 (0.008-0.016) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top Precipitation Frequency Data Server Page 1 of 4 https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.5764&lon=-105.0859&da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&XVWRP6RLO5HVRXUFH5HSRUW VKHHW 6RLO0DSPD\QRWEHYDOLGDWWKLVVFDOH 120 0.50 0.109 0.55 0.10 0.016 0.093 120 1.75 0.746 0.55 2.42 0.400 0.346 125 0.49 0.110 0.55 0.10 0.017 0.093 125 1.70 0.755 0.55 2.41 0.415 0.339 130 0.47 0.111 0.55 0.10 0.017 0.094 130 1.65 0.763 0.55 2.40 0.430 0.332 135 0.46 0.112 0.55 0.10 0.018 0.094 135 1.61 0.770 0.55 2.40 0.445 0.325 140 0.45 0.113 0.55 0.10 0.018 0.095 140 1.56 0.778 0.55 2.39 0.460 0.317 145 0.44 0.114 0.54 0.10 0.019 0.095 145 1.52 0.785 0.54 2.38 0.476 0.309 150 0.43 0.115 0.54 0.09 0.020 0.096 150 1.49 0.792 0.54 2.37 0.491 0.301 155 0.42 0.116 0.54 0.09 0.020 0.096 155 1.45 0.799 0.54 2.37 0.506 0.293 160 0.41 0.117 0.54 0.09 0.021 0.097 160 1.42 0.805 0.54 2.36 0.521 0.285 165 0.40 0.118 0.54 0.09 0.021 0.097 165 1.39 0.812 0.54 2.36 0.536 0.276 170 0.39 0.119 0.54 0.09 0.022 0.097 170 1.35 0.818 0.54 2.35 0.551 0.267 175 0.38 0.120 0.54 0.09 0.023 0.097 175 1.33 0.824 0.54 2.35 0.566 0.258 180 0.37 0.121 0.54 0.09 0.023 0.098 180 1.30 0.830 0.54 2.34 0.581 0.249 185 0.36 0.122 0.54 0.09 0.024 0.098 185 1.27 0.835 0.54 2.34 0.596 0.240 190 0.36 0.123 0.53 0.09 0.024 0.098 190 1.25 0.841 0.53 2.33 0.611 0.230 195 0.35 0.123 0.53 0.09 0.025 0.098 195 1.22 0.847 0.53 2.33 0.626 0.221 200 0.34 0.124 0.53 0.09 0.026 0.099 200 1.20 0.852 0.53 2.33 0.641 0.211 205 0.34 0.125 0.53 0.09 0.026 0.099 205 1.18 0.857 0.53 2.32 0.656 0.201 210 0.33 0.126 0.53 0.09 0.027 0.099 210 1.16 0.862 0.53 2.32 0.671 0.191 215 0.33 0.126 0.53 0.09 0.027 0.099 215 1.14 0.867 0.53 2.32 0.686 0.181 220 0.32 0.127 0.53 0.09 0.028 0.099 220 1.12 0.872 0.53 2.31 0.701 0.171 225 0.31 0.128 0.53 0.09 0.029 0.099 225 1.10 0.877 0.53 2.31 0.716 0.161 230 0.31 0.129 0.53 0.09 0.029 0.099 230 1.08 0.882 0.53 2.31 0.731 0.150 235 0.30 0.129 0.53 0.09 0.030 0.099 235 1.06 0.886 0.53 2.31 0.746 0.140 240 0.30 0.130 0.53 0.09 0.030 0.099 240 1.05 0.891 0.53 2.30 0.761 0.129 245 0.30 0.131 0.53 0.09 0.031 0.099 245 1.03 0.895 0.53 2.30 0.776 0.119 250 0.29 0.131 0.53 0.09 0.032 0.100 250 1.01 0.900 0.53 2.30 0.792 0.108 255 0.29 0.132 0.53 0.09 0.032 0.100 255 1.00 0.904 0.53 2.30 0.807 0.097 260 0.28 0.132 0.53 0.09 0.033 0.100 260 0.98 0.908 0.53 2.29 0.822 0.087 265 0.28 0.133 0.52 0.09 0.033 0.100 265 0.97 0.912 0.52 2.29 0.837 0.076 270 0.27 0.134 0.52 0.09 0.034 0.100 270 0.96 0.917 0.52 2.29 0.852 0.065 275 0.27 0.134 0.52 0.09 0.035 0.100 275 0.94 0.921 0.52 2.29 0.867 0.054 280 0.27 0.135 0.52 0.09 0.035 0.100 280 0.93 0.925 0.52 2.29 0.882 0.043 285 0.26 0.135 0.52 0.09 0.036 0.099 285 0.92 0.928 0.52 2.28 0.897 0.032 290 0.26 0.136 0.52 0.09 0.036 0.099 290 0.91 0.932 0.52 2.28 0.912 0.020 295 0.26 0.136 0.52 0.09 0.037 0.099 295 0.89 0.936 0.52 2.28 0.927 0.009 300 0.25 0.137 0.52 0.09 0.038 0.099 300 0.88 0.940 0.52 2.28 0.942 -0.002 Mod. FAA Minor Storage Volume (cubic ft.) = 4,337 Mod. FAA Major Storage Volume (cubic ft.) = 16,950 Mod. FAA Minor Storage Volume (acre-ft.) = 0.0996 Mod. FAA Major Storage Volume (acre-ft.) = 0.3891 Determination of MAJOR Detention Volume Using Modified FAA Method (For catchments less than 160 acres only. For larger catchments, use hydrograph routing method) (NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended) UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013 Determination of MINOR Detention Volume Using Modified FAA Method DETENTION VOLUME BY THE MODIFIED FAA METHOD Lincoln Hotel UD-Detention_v2.34.xls, Modified FAA 7/13/2017, 12:46 PM