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HomeMy WebLinkAboutDrainage Reports - 10/30/2000�r 0P T • OF 'FORT C4,11ILLINS I.JV"-.rrMP ftV*— Day 9 e, 7.31 Aprllrovad Rgport DOWNTOWN TRANSIT CENTER FINAL DRAINAGE & EROSION CONTROL STUDY BEY ON D E N G IN E E R ING DOWNTOWN TRANSIT CENTER FINAL DRAINAGE & EROSION CONTROL STUDY for Aber+L-ihck iArrh #ec#s PX. r 748 Whalers Way Building E, Suite 200 Fort Collins, Colorado 80525 by Nolte Associates, Inc. 1901 Sharp Point Drive, Suite A Fort Collins, Colorado 80525 (970) 221-2400 August 10, 2000 y October 19, 2000 Mr. Basil Hamdan City of Fort Collins Water Utilities - Stormwater 700 Wood Street Fort Collins, Colorado 80522 NO= BEYOND ENGINEERING SUBJECT: Final Drainage and Erosion Control Study for the Downtown Transit Center Dear Mr. Hamdan: We are pleased to submit to you, for your review and approval, this Final Drainage and Erosion Control Study for the Downtown Transit Center. All computations within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria We appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. ' Sincerely, NOLTE ASSOCIATES, Inc. Prepared by: Reviewed by: �•�� ®® C�6l�T�'% 07 I: Storm Gew- EIT Thomas Ochwat, PE ' L o - 4 ' Project Engineer Project Manager ��%.,�'`F,�S�ONA��� Cc: File FC0091 NOLTE ASSOCIATES, INC. 1901 SHARP POINT DRIVE, SUITE A FORT COLLINS, CO 80525 970.221.2400 TEL 970.221.2415 FAX WWW.NOLTE.COM n:\fc0091\documents\drainage\cover letter.doc Final Drainage & Erosion Control Study ' BEYOND ENGINEERING Downtown Transit Center ' TABLE OF CONTENTS ' PAGE 1.0. INTRODUCTION........................................................................................................ 1 ' 1.1 Site Location..................................................................................................... 1 1.2 Existing Site Description................................................................................... 1 1.3 Proposed Project Description............................................................................1 1.4 Previous Reports and Studies............................................................................ 2 2.0 METHODOLOGY.......................................................................................................3 3 2.1 Compliance with Standards............................................................................... 2.2 Analytical Methods........................................................................................... 3 ' 3.0 HISTORIC DRAINAGE CONDITIONS..................................................................... 4 3.1 Major Basin Description.................................................................................... 4 4.0 DEVELOPED DRAINAGE CONDITIONS................................................................. 5 4.1 General Concept............................................................................................... 5 ' 4.2 Basin Descriptions............................................................................................. 5 4.3 Detention Pond Design...................................................................................... 7 4.4 Water Quality.................................................................................................... 7 9 5.0 EROSION CONTROL................................................................................................. 5.1 General Concept............................................................................................... 9 5.2 Specific Details................................................................................................. 9 6.0 CONCLUSIONS........................................................................................................11 6.1 Drainage Concept........................................................................................... 11 REFERENCES........................................................................................................... 12 ' APPENDIX A - Vicinity Map APPENDIX B - Developed Site Hydrology • Developed Flow Calculations • Curb Cut & Inlet Analysis APPENDIX C - Detention Pond Design & Water Quality Design ' • Orifice Sizing & Existing Pipe Capacity APPENDIX D - Erosion Control Calculations ' APPENDIX E - Charts, Tables & Graphs BACK POCKET - Drainage and Erosion Control Plan i N:\FC0091�DowmeDtsWnunage\FcG09lDmgRpLdoe J Final Drainage & Erosion Control Study BEYOND ENGINEERING Downtown Transit Center ' 1.0 INTRODUCTION ' 1.1 Site Location The proposed Downtown Transit Center is located south of Maple Street, north of LaPorte Street and west of Mason Street. More particularly, the Site is located in the northeast 1/4 of Section 11, Township 7 North, Range 69 West of the 6d' Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. ' The site location can be seen in the Appendix. ' 1.2 Existing Site Description The Downtown Transit Center site contains approximately 3.5 acres and currently ' serves as a parking lot. It was designed to temporarily replace the parking that was lost during the construction of the parking garage located to the south of the site. The existing Freight Depot building is also located on this site, as well as a ' back alley. The historic "Anne's Grave" monument is located on the west side of the site. ' Currently, the site's topography generally slopes toward the center of the site, toward four existing area inlets. A gravel base covers the majority of the site. Empire Laboratories prepared a geotechncal engineering report in January 1995 ' for the Storm Drainage Department Office Building, which is the present Downtown Transit Center site. This soil report indicates that on -site subsoil ' consists of sandy lean clay underlain by well -graded gravel with silt, sand, cobbles and boulders. This study indicates the clays and gravels exhibit moderate to high bearing characteristics and non to low swell potential ' 1.3 Proposed Project Description The proposed Downtown Transit Center will operate as a transit station for City of Fort Collins buses (Transfort). A bike shelter is also proposed. Renovations to the existing Freight Depot building as well as the construction of new buildings are proposed for the future. The back alley is to remain unchanged. The proposed ' site can be seen on the drainage plan in the back of this report. 1 N:1FC0091\DocumeWs\dramage\Fc0091DmgRpt.doc I__ NCUM BEYOND ENGINEERING Final Drainage & Erosion Control Study Downtown Transit Center 1.4 Previous Report and Studies Parsons & Associates, Inc. prepared a report entitled, Final Drainage Report for Temporary Parking Lots, for the existing Downtown Transit Center site, in August 1998. The Civic Parking Structure Final Drainage Report, by Parson & Associates in October 1998, also makes reference to the Transit Center site. Both reports refer to the Downtown Transit Center site as Block 22 and they describe the current drainage patterns of the site. 2 N:\FC0091\Documentsldminage\Fc0091DmgRptdoc � NOLTE ' OEYOND ENGINEERING ' 2.0 METHODOLOGY Final Drainage & Erosion Control Study Downtown Transit Center 2.1 Compliance with Standards ' The following Final Drainage & Erosion Control Study was prepared in accordance with the design requirements and procedures set forth in the City of ' Fort Collins Stormwater Drainage Design Criteria and Construction Standards (Revised January 1997) and Urban Storm Drainage Criteria Manual by the Urban ' Drainage and Flood Control District. ' 2.2 Analytical Methods The Rational Method was used to calculate 10- and 100-year developed flows. ' The Rational Method is widely accepted for design problems involving small drainage areas (<160 acres) and short times of concentration. Mathematically, it ' relates peak discharge to the runoff coefficient, rainfall intensity, and drainage area. Runoff coefficients and rainfall intensity data were obtained from the Stormwater ' Drainage Design Criteria and Construction Standards. 1 3 N:\FC0091Moc:uments\&amage\Fc009lDmgRpLdm 1 NCUEE Final Drainage & 1 BEYOND ENG IKE ERING Erosion Control Study Downtown Transit Center 1 3.0 HISTORIC DRAINAGE BASINS 1 3.1 Major Basin Description 1 As seen on the Fort Collins Stormwater Basin Map, the Downtown Transit Center lies within the Old Town Master Drainage Basin Plan. There is no major 1 drainageway through the basin. Runoff travels through streets and several storm sewer systems where it eventually discharges to the Poudre River. 1 Through discussions between the City of Fort Collins Stormwater Department and 1 Nolte Associates, Inc., the Downtown Transit Center site is not required to provide detention. However, the site can not release more runoff than the existing 1 storm sewer system can handle. Therefore detention has been designed for the difference. Water quality is also required. i 1 1 1 1 L i r 4 N:1FC00911DocumeNx\drainage\Fc0091DmgRpt.doc 1 NONE Final Drainage & ' BEYOND ENGINEERING Erosion Control Study Downtown Transit Center ' 4.0 DEVELOPED DRAINAGE CONDITIONS ' 4.1 General Concept ' In general, developed flows from the proposed site will sheet flow in a northwesterly direction to the proposed on -site water quality/detention pond. ' Runoff from portions of the site will continue to flow as it has done historically. ' 4.2 Basin Descriptions Stormwater runoff from Basin 1 (0.40 ac) travels along the curb and gutter on ' Mason Street where it will enter a relocated inlet. Developed flows from Basin 2 (0.22 ac) will travel in the curb and gutter on Mason Street where it will enter a relocated inlet. Flow from Basins 1 and 2 have historically entered existing inlets along Mason Street. The alignment of Mason Street has changed resulting in the relocation of the inlets to the new curb and gutter. The northeast comer of the LaPorte/Mason ' intersection has been improved and the new inlet that will catch flows from Basin 1 has been installed. Basins 5 and 6 (0.08 ac and 0.52 ac, respectively) combine and travel east along ' existing the curb and gutter of LaPorte Street, where it will enter an existing inlet. ' Runoff from Basin 3 (0,17 ac) will flow in curb and gutter along Maple Street ' where it will combine with the developed flows from Basin 4 (0.74 ac). Basin 4 consists mostly of the back of the existing freight depot building, as well as parking ' and asphalt drive. This area has historically drained to the northeast corner of the site and will continue to do so. 5 N:\FC0091ts\drainage\Fc0091DmgRpt.doc 0 [I u 1_1 n NO= BEYOND ENGINEERING Final Drainage & Erosion Control Study Downtown Transit Center Basin 7 (1.38 ac) contains the main portion of the site involving improvements. Developed flows from this basin will travel northwest in curb and gutter to the detention/water quality pond in the northwest corner of the site. 6 N.\FC0091\DomnientsWramge\Fc0091DmgRpLdm I 1 NOFinal Drainage & BEYOND ENGINEERING Erosion Control Study Downtown Transit Center 4.3 Detention Pond Design As previously stated, the proposed development is not required to detain the runoff from the site. The capacity of the 15" pipe the site drains to is 11.45 cfs. The site (Basin 7) has a total flow of 12.93 cfs. The development proposes to release at the 10-yr flow and provide detention for the remainder of flow. The detention pond shown in Basin 7 was sized using the FAA method. According to the calculations, 0.09 ac-ft is required. Additional volume for water quality has also been provided. See appendix for calculations. The release rate, Qlo=4.56 cfs, is based on the 10-yr flow from Basin 7. Emergency overflows from the detention pond will be directed out the north entrance of the site, at an elevation of 4981.86, onto Maple Street. 4.4 Water Quality Criteria outlined in Volume 3 of the Urban Storm Drainage Criteria Manual were used to determine the required Water Quality Capture Volume (WQCV). The water quality storage volume is equal to 120 percent of the WQCV based on a 40- hour drain time. The Urban Storm Drainage Criteria Manual suggests many mechanisms for treating stormwater runoff for water quality enhancement, two of which are sedimentation and straining. Sedimentation, which includes extended detention, allows smaller particles to combine into larger ones and settle. According to Urban Drainage, sedimentation is the primary pollutant removal mechanism for most structural BMP's. Straining is a method that uses grass to filter out pollutants. This happens when sheet flow is directed to flow slowly over 7 N:\FC00911Documents\drainage\Fc0091DmgRpt.dm NJC4XE BEYOND ENGINEERING Final Drainage & Erosion Control Study Downtown Transit Center vegetated areas. The Downtown Transit Center proposes to use a combination of sedimentation and straining as a means of water quality. Due to the size of the site, only a small amount of water quality storage is required. The Downtown Transit Center proposes to employ characteristics of different structural BMP's for basic pollutant removal. The detention/water quality pond on the site is a shallow flat grassy area that allows for stormwater to sheet flow slowly, allowing pollutants to settle out before the runoff leaves the site. The flat grassy area also acts like a grass buffer that promotes filtration, infiltration and settling to reduce runoff pollutants. In addition, the detention/ water quality pond acts like an extended detention basin, allowing small particles to combine and settle. The pond proposes to utilize a water quality structure with an orifice plate to slow the release of runoff from the site, allowing more time for sediment to settle. See appendix and plans for more details. The WQCV is based on the tributary area draining to the detention pond as well as the percentage of the total area that is impervious. The calculated water quality storage volume is 0.041 ac-ft. At elevation 4979.94, 0.041 ac-ft of water quality has been provided for. Calculations can be found in the appendix. The 100-yr WSEL for the 0.09 ac-ft of required storage plus the 0.041 ac-ft of water quality is 4980.74. The proposed detention/water quality pond adequately provides for this amount. 8 N:\FC00911Documents\dmmage\Fc00911hngRp[aloe NOT Final Drainage & BEYOND ENGINEERING Erosion Control Study Downtown Transit Center ' 5.0 EROSION CONTROL ' 5.1 General Concept The Downtown Transit Center site lies within the moderate Rainfall Erodibility ' Zone and the low Wind Erodibility Zone per the City of Fort Collins zone maps. The potential exists for erosion problems during and after construction until the ' disturbed ground is again vegetated. ' The Erosion Control Performance Standard (PS) during construction for this project was computed to be 76.80 per the criteria in the City of Fort Collins ' Erosion Control Reference Manual for Construction Sites. The Effectiveness (EFF) of the proposed erosion control plan was calculated to be 90.35. The ' proposed erosion control methods meet the City of Fort Collins' requirements. Calculations can be found in the appendix. 5.2 Specific Details ' During overlot grading, the detention area will be excavated. This area will act as a sediment trap during construction. A gravel filter will be placed over the outlet ' pipe until sodding is completed. Silt fence will also be installed. After overlot grading has been completed, all disturbed areas not in a roadway area shall have straw hay mulch applied. The areas of the site that are to be paved shall have gravel mulch applied. After the utilities have been installed, the impervious ' areas shall be paved as soon as possible. The pervious areas will have sod installed. The erosion control measures can be seen on the drainage and erosion ' control plan in a pocket in the back of this report. 9 N:\FC0091\Documents\drainage\Fc00911hngRpt.doc ' r%*O� Final Drainage & B E r O N D 6 N GIN E E RING Erosion Control Study Downtown Transit Center ' All construction activities must comply with the State of Colorado permitting process for Stormwater Discharges Associated with Construction Activity. A ' Colorado Department of Health NPDES Permit will be required before any construction grading can begin. C C n t 10 N:\FC0091\Documents\dminage\Fc0091DmgRpLdoc 0 N UB"E Final Drainage & BEYOND ENGINEERING Erosion Control Study Downtown Transit Center 6.0 I 6.1 Drainage Concept The proposed drainage concepts presented in this study and shown on the final drainage plans adequately provide for the conveyance and detention of developed runoff from the proposed development. I N-.TC0091\Do=nentsUamage\Fc0091DmgRpt.doe 11 ' NO� Final Drainage & Erosion Control Study ' BEYOND ENGINEERING Downtown Transit Center ' REFERENCES 1. Storm Drainage Design Criteria and Construction Standards (Criteria), City of Fort Collins, Colorado (Revised January 1997). ' 2. Drainage Criteria Manual (Manual), Urban Drainage and Flood Control District, Wright - McLaughlin Engineers, Denver, Colorado, March 1969. 3. Erosion Control Reference Manual for Construction Sites, City of Fort Collins, Colorado, January 1991. ' 4. Final Drainage Report for Temporary Parking Lots, Parsons & Associates, Inc., Fort Collins, Colorado, August 19, 1998. ' 5. Civic Center Parking Structure Final Drainage Report, Parson & Associates, Inc., Fort Collins, Colorado, (Revised January 1999). ' r F 0 n L 1 1 12 N:1FC0091\DocumeNs\dramage\Fc0091DmgRpLdoc 1 1 1 1 1 1 1 1 APPENDIX A Vicinity Map CHERRY ST. WflL0 S7. MAPLE ST. LAPORTE AVE = W9 UT MOUNTAIN AVE. VICINITY MAP NTS 1 1 1 1 1 1 APPENDIX B Developed Site Hydrology u I I 1 i I i 1 I 1 I I 1 1 I 1 Developed Flow Calculations i FC0091 ' Project Name: Downtown Transit Center Calculated By: asg Runoff Coefficients Cimpmious 0.95 ' CPM;oW 0.25 Percent Percent Impervious Pervious ' Basin Area Area Area Area Composite "C" f2 ac. % % 1 17,405.30 0.40 75.00% 25.00% 0.78 2 9,658.20 0.22 90.00% 10.00% 0.88 3 7,365.43 0.17 90.00% 10.00% 0.88 4 32,163.18 0.74 90.000/. 10.00% 0.88 5 3,568.23 0.08 85.00% 15.00% 0.85 6 1 22,664.62 1 0.52 1 50.00% 1 50.00% 1 0.60 7 1 60,310.72 1 1.38 1 75.00% 1 25.00% 1 0.78 E F Z E- Lr� _T O o pp ul v1 O r h O vl pp O r r M M O� =nroo-000�n Z C:i ^ � v v a F_ c = v�nvrMr—�o iJ L 0o r x x x x x� x x o �a x r V `"'000d000 U C O 0 0 0 0 0 0 0 [z. u U� r oo x x oo �o r � u `�0000000 0 V FO N r 7 00 N o0 a N- r 0 ut M C CO MO G A ttl r,+ C � v V -_ woo—oo,M M N O• �O O �D N Grp _T o— � 0 0— t C n n oo �O O O vt N— z Q o 0 0 0 0 0 0 C a F F_ Z s U U L n0000�nn a o 0 0 o n rn U U c o U N N N N N N N !z. c 00 0o ao 00 �n o 00 O U a F �" oNnaooN oo n 0— c c0 C r0.0 C O lO M_ �z a U � h L O U C z_ L z F y O F V � w RE � h N o0 Q N �O •y 3 n rn n oo M p h L C � C V Q 00 Q 00 Q Q Q o0 Q 00 Q N Q W E • ` r1 N "n — O t�l O U e d o 0,O � E r000•0000 v m z p Uao ao 00 0o vi o ao V r o0 0o 0o w n 0 0 0 0 0 0 o C n h O N n Q 00 N o0 O O C G O C R _G N f�l Q V1 b r C] m� �Q LL - �i Z_ L z O • ` M o0 w � o a a` O U T u C Q y Uh i Lr. O Z y E � v z U b o0 0 0 Q •ud O C C _ b < n h n �E c= EEC O O U iI y S (ll Z d U � N ' )` a c a y U O L+. W C O v Z .Ci z O Y N W C .r E a G. r N V' 00 00 CL n � a c � 000�a�aa� 'n 9: . o;do�o,o:rnd � 5 o— U W W O A o o e 00 F U G U r o 0 0 o y r U o.0000rrn C O] e 00 a A y O N V M C N C .= c rWz, oro aro z =- z — E,., U a o 0 W E O O U .T. e � c ¢ H t V V` V 1O W W z F U a A moo V o - — i ¢ U O O A C n C1 � M oGD C T O O I Curb Cut and Inlet Analysis 'J 1 h u 1 1 I 1 I 1 11 Downtown Transit Center FC0091 8' Curb Cut Q=C*L*han L= 8 Weir Coefficient C = 3.367 Coefficient for Cippoletti Weir (See Appendix) h = observed head above weir crest at a point where water surface beyond beginning of draw down, ft. Sta. Elev. 0.0 1.5 1.0 1.5 3.0 1.0 11.0 1.0 13.0 1.5 14.0 1.5 Elev Discharge (ft) (cfs) 1.0 0.0 1.1 0.9 1.2 2.4 1.3 4.4 1.4 6.8 1.5 9.5 -4— Max. Discharge @ 6 inch for a 8' Curb Cut 6: 4 � J4 I� 8 , Q10 (Basin 7) — 4.56 cfs A 8' curb cut will allow the minor storm flow to pass through. In a major storm event, flows will overtop the curb and enter the detention pond directly to the north. i June 27,2000 N:\FC0091\Documents\drainage\[curbcut.xls]8' curbcut Nolte Associates, Inc. ---------- ------------------------------------------------------- UDINLET: INLET HYDARULICS AND SIZING DEVELOPED BY CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD ------------------------------------------------------------------------------ SER::.................................................. N DATE 06-27-2000 AT TIME 08:03:25 ** PROJECT TITLE: DOWNTOWN TRANSIT CENTER *** CURB OPENING INLET HYDRAULICS AND SIZING• bP � E INLET ID NUMBER: 1 �` 0 "660n Laeo rfe rn INLET HYDRAULICS: IN A SUMP. GIVEN INLET DESIGN INFORMATION: ' GIVEN CURB OPENING LENGTH (ft)= 10.00 HEIGHT OF CURB OPENING (in)= 6.00 INCLINED THROAT ANGLE (degree)= 45.00 LATERAL WIDTH OF DEPRESSION (ft)= 2.00 ' SUMP DEPTH (ft)= 0.00 Note: The sump depth is additional depth to flow depth. STREET GEOMETRIES: STREET LONGITUDINAL SLOPE (o) 0.50 ' STREET CROSS SLOPE (o) 2.00 STREET MANNING N _ 0.016 GUTTER DEPRESSION (inch)= 2.00 ' GUTTER WIDTH (ft) = 2.00 STREET FLOW HYDRAULICS: ' WATER SPREAD ON STREET (ft) = 12.44 GUTTER FLOW DEPTH (ft) = 0.42 FLOW VELOCITY ON STREET (fps)= 2.23 FLOW CROSS SECTION AREA (sq ft)= 1.71. GRATE CLOGGING FACTOR (o)= 50.00 CURB OPENNING CLOGGING FACTOR(%)= 15.00 ' INLET INTERCEPTION CAPACITY: IDEAL INTERCEPTION CAPACITY (cfs)= 8.38 BY FAA HEC-12 METHOD: DESIGN FLOW (cfs)= 3.79 FLOW INTERCEPTED (cfs)= 3.79 CARRY-OVER FLOW (cfs)= 0.00 BY DENVER UDFCD METHOD: DESIGN FLOW (cfs)= 3.79 ' FLOW INTERCEPTED (cfs)= 3.79 CARRY-OVER FLOW (cfs)= 0.00 f ____________________________ UDINLET: INLET HYDARULICS AND SIZING DEVELOPED BY ' CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD - ----------------------------------------------------------------------------- ER : . 1 DATE 06-27-2000 AT TIME 08:03:55 11 C * PROJECT TITLE: DOWNTOWN TRANSIT CENTER *** CURB OPENING INLET HYDRAULICS AND SIZING: INLET ID NUMBER: 2 SE corne+- GP P-k4fu rWla_-on (r1{2(SeCfte�r INLET HYDRAULICS: ON A GRADE. GIVEN INLET DESIGN INFORMATION: GIVEN CURB OPENING LENGTH (ft)= REQUIRED CURB OPENING LENGTH (ft)= IDEAL CURB OPENNING EFFICIENCY = ACTURAL CURB OPENNING EFFICIENCY = STREET GEOMETRIES: STREET LONGITUDINAL SLOPE (%) = STREET CROSS SLOPE (%) = STREET MANNING N = GUTTER DEPRESSION (inch)= GUTTER WIDTH (ft) _ STREET FLOW HYDRAULICS: - �piQlC e e SC ISi t r� irl lsLf 0,1�.i� 51 13R Incest 5.00U QIi(�Y�Meilf 9.84 0.72 O� I- �QC.xYI 0.61 0.50 2.00 0.016 2.00 2.00 WATER SPREAD ON STREET (ft) = 9.59 GUTTER FLOW DEPTH (ft) = 0.36 FLOW VELOCITY ON STREET (fps)= 2.02 FLOW CROSS SECTION AREA (sq ft)= 1.09 GRATE CLOGGING FACTOR (%)= 50.00 CURB OPENNING CLOGGING FACTOR(%)= 20.00 INLET INTERCEPTION CAPACITY: IDEAL INTERCEPTION CAPACITY (cfs)= 1.59 ' BY FAA HEC-12 METHOD: DESIGN FLOW (cfs)= FLOW INTERCEPTED (cfs)= CARRY-OVER FLOW BY DENVER UDFCD METHOD: DESIGN FLOW (cfs)= (cfs)= FLOW INTERCEPTED (cfs)= CARRY-OVER FLOW (cfs)= 2.21 1.35 0.86 2.21 1.28 0.93 1 1 1 1 1 1 1 1 1 1 i APPENDIX C Detention Pond Design Water Quality Design __________________________________________________ DETENTION POND SIZING BY FAA METHOD Developed by Civil Eng. Dept., U. of Colorado Supported by Denver Metro Cities/Counties Pool Fund Study Denver Urban Drainage and Flood Control District, Colorado ------------------------------------------------------------------------------ USER=.. ........................................... ' EXECUTED ON 06-20-2000 AT TIME 14:57:17 ' PROJECT TITLE: TRANSIT CENTER - FC0091 **** DRAINAGE BASIN DESCRIPTION BASIN ID NUMBER = 7.00 BASIN AREA (acre)= 1.38 E-dGSlvl'} RUNOFF COEF = 0.97 ***** DESIGN RAINFALL STATISTICS DESIGN RETURN PERIOD (YEARS) = 100.00 ' INTENSITY(IN/HR)-DURATION(MIN) TABLE IS GIVEN DURATION 5 10 20 30 40 50 60 80 100 120 150 180 ' 7.7 INTENSITY 9.9 5.6 4.5 3.7 3.2 2.9 2.4 2.1 1.8 1.4 1.2 POND OUTFLOW CHARACTERISTICS: MAXIMUM ALLOWABLE RELEASE RATE = 4.56 CFS f- ItD See Rc�{io�ai r Me�4 OUTFLOW ADJUSTMENT FACTOR = 1 AVERAGE RELEASE RATE = 4.56 CFS AVERAGE RELEASE RATE = MAXIMUM RELEASE RATE * ADJUSTMENT FACTOR. 1 ***** COMPUTATION OF POND SIZE ----------------------------------------------------- RAINFALL RAINFALL INFLOW OUTFLOW REQUIRED DURATION INTENSITY VOLUME VOLUME STORAGE MINUTE INCH/HR ACRE -FT ACRE -FT ----------------------------------------------------- ACRE -FT 0.00 0.00 0.00 0.00 0.00 5.00 9.95 0.09 0.03 0.06 10.00 7.72 0.14 0.06 0.08 15.00 6.66 0.19 0.09 0.09 20.00 5.60 0.21 0.13 0.08 25.00 5.06 0.24 0.16 0.08 30.00 4.52 0.25 0.19 0.06 35.00 4.13 0.27 0.22 0.05 ' 40.00 3.74 0.28 0.25 0.03 45.00 3.49 0.29 0.28 0.01 7 ----------------- THE REQUIRED POND SIZE = 9. 151586E-02 ACRE -FT F--- THE RAINFALL DURATION FOR THE ABOVE POND STORAGE= 15 MINUTES Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility Sheet 1 of 3 Designer: Company: Date: Project: Location: 1. Basin Storage Volume la = 75.00 % A) Tributary Area's Imperviousness Ratio (i = la/ 100) i = 0.75 B) Contributing Watershed Area (Area) Area = 1.38 acres C) Water Quality Capture Volume (WQCV) WQCV = ' 0.307 watershed inches (WQCV =1.0' (0.91 ' 13 - 1.19' IZ + 0.78' 1)) D) Design Volume: Vol = (WQCV / 12) ' Area ' 1.2 Vol = 0041 'acre-feet 2. Outlet Works A) Outlet Type (Check One) X Orifice Plate Perforated Riser Pipe Other: B) Depth at Outlet Above Lowest Perforation (H) H = 1.09 feet C) Required Maximum Outlet Area per Row, (A,) A. = 0:27 = . square inches D) Perforation Dimensions (enter one only): i) Circular Perforation Diameter OR D = 0.5670 inches, OR ii) 2" Height Rectangular Perforation Width W = inches E) Number of Columns (nc, See Table 6a-1 For Maximum) nc = ]"_ number F) Actual Design Outlet Area per Row (A,) Ao = 0.25 . _ square inches G) Number of Rows (nr) nr = 3 `"- number H) Total Outlet Area (At) At = '•` 083' 3 square inches 3. Trash Rack A) Needed Open Area: A, = 0.5' (Figure 7 Value)kt B) Type of Outlet Opening (Check One) C) For 2", or Smaller, Round Opening (Ref.: Figure 6a): i) Width of Trash Rack and Concrete Opening (Wwnc) from Table 6a-1 ii) Height of Trash Rack Screen (HTR) At = 30 square inches x < 2" Diameter Round 2" High Rectangular Other: W.nc = 3 _ inches HTR = 37 inches ' w quality.xls, EDB Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility Sheet 2 of 3 Designer: Company: Date: Project: Location: iii) Type of Screen (Based on Depth H), Describe if "Other" x S.S. #93 VEE Wire (US Filter) Other: iv) Screen Opening Slot Dimension, Describe if "Other' X 0.139" (US Filter) Other: v) Spacing of Support Rod (D.C.) 0.75 inches Type and Size of Support Rod (Ref.: Table 6a-2) #156 VEE vi) Type and Size of Holding Frame (Ref.: Table 6a-2) 3/8 in. x 1.0 in. flat bar D) For 2" High Rectangular Opening (Refer to Figure 6b): 1) Width of Rectangular Opening (W) W = inches ii) Width of Perforated Plate Opening (Wmnc = W + 12") Wmnc = inches iii) Width of Trashrack Opening (Wop,ro„g) from Table 6b-1 W,pen;ny = inches iv) Height of Trash Rack Screen (HTR) HTR = inches v) Type of Screen (based on depth H) (Describe if "Other") KlempTm KPP Series Aluminum Other: vi) Cross -bar Spacing (Based on Table 6b-1, KlempTm KPP inches Grating). Describe if "Other" ' Other: vii) Minimum Bearing Bar Size (KlempTM Series, Table 6b-2) (Based on depth of WQCV surcharge) 4. Detention Basin length to width ratio (L/W) 5 Pre -sedimentation Forebay Basin - Enter design values A) Volume (5 to 10% of the Design Volume in 1 D) acre-feet B) Surface Area acres C) Connector Pipe Diameter inches (Size to drain this volume in 5-minutes under inlet control) D) Paved/Hard Bottom and Sides ves/no w quality.xls, EDB 1 1 1 1 1 Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility Sheet 3 of 3 Designer: Company: Date: Project: Location: 6. Two -Stage Design A) Top Stage (Dwo = 2' Minimum) Dwo = feet Storage= acre-feet B) Bottom Stage (DBs = Dwo+ 1.5' Minimum, D o+ 3.0' Maximum, DBs = feet Storage = 5% to 15% of Total WQCV) Storage= acre-feet Surf. Area= acres C) Micro Pool (Minimum Depth = the Larger of Depth= feet 0.5' Top Stage Depth or 2.5 Feet) Storage= acre-feet Surf. Area= acres D) Total Volume: Vol,ot = Storage from 5A + 6A + 6B Voltot = acre-feet Must be > Design Volume in 1 D 7. Basin Side Slopes (Z, horizontal distance per unit vertical) Z = (horizontal/vertical) Minimum Z = 4, Flatter Preferred 8. Dam Embankment Side Slopes (Z, horizontal distance Z = (horizontal/vertical) per unit vertical) Minimum Z = 4, Flatter Preferred 9. Vegetation (Check the method or describe "Other") Native Grass Irrigated Turf Grass Other: Notes: w_quality.xls, EDB ' Downtown Transit Center FC0091 Detention Pond Rating Curve tElevation area (ft2) area (ac) Storage (ac-ft) Cum. Storage (ac-ft) ' 4978.75 0.00 0.00 0.00 0.00 4979 663.75 0.02 0.00 '0.00 4980 3385.56 0.08 0.04 0.04 4981 7067.36 0.16 0.12 0.16 Interpolate the water surface elevation for the 1.00-yr storage in detention pond. ' Required Storage W.S. ' (ac-ft) Elevation 100-yr WSEL (W.Q. only) = 0.041 4979.94 ' 100-yr WSEL (storage & W.Q.) = 0.131 4980.74 t 1 - ' June 27, 2000 N:\FC0091 \Documents\drainage\[storage2.xls]STORAGE I ' Orifice Sizing Existing Pipe Capacity 1 Fi 1 I 1 I 1 I Downtown Transit Center August 10. 2000 Orifice Plate Sizing W.S. n n d Q=Cd*A*(2 *gx(h+k*d/2)).s Qallowable — 4.56 cfS WSEL = 4980.74 Inv. = 4978.75 Q = discharge through outlet (allowed) _ Cd = discharge coefficient of the orifice = A = area of the orifice opening = g = acceleration due to gravity = h = water depth above the invert of the orifice = h = WSEL - (Inv. + (d/2)) k = -1.0 for vertical orifice = d = diameter (or its equivalent) of the orifice = d= Qcalculated = 4.56 cfs ** Using an 13.75 in. orifice plate, a Q =4.56 cfs is released NA\FC009I \Documents\drainage\[orifice.xls]Vertical 4.56 0.60 1.03 32.20 1.42 -1.00 13.75 in 1.15 ft FC0091 UNIVERSITY OF COLORADO AT DENVER Continuing Engineering Education Best Management Practices Six W�ednesdays - O:JQDII - iZ:30vin �ana; ar lSee:ng Canter 1,:amond rill Office Co**=ziex 2460 -W. 26th Ave., Bldg. 1 1 :_,--: actor-. Ban R. ,bo�as, ' James C ., Guc7 Ph.D., F.I�c. I ird 1 1 1 1 r 1 1 1 1 1 1 1 Reservoir OutletD si n = ORIFICE & SLUICE d Vertical ®© Datum Bask Equation: h=h(t)-E Horizontal Cd 2 h�. +k d �- g 2. in -which, Q discharge through. outlet Ca discharge coefficient of the orifice area of the orifice opening g acceleration due to gravity, h = water depth above the invert of the orifice k = 4.0 for vertical and; +1.0 for horizontal orifice L� = diameter (nr itq enmvalerit) nfthP nrifire 1 t I� 1 66 Chapter 6 — FlowMaster Theory Triangu/ar and Trapezoidal Weir The discharge over a triangular or trapezoidal weir is: 6.5 Figure 6.23 Orifice Flow (schematic) Q = CLH3/z (6.64) Where: Q = Discharge over the weir (m'/s, cfs) C = Weir coefficient L = Weir length (m, ft) H = Head above the weir crest (m, ft) Model these weirs by using the Generic Weir in FlowMaster, entering the appropriate coefficient. The weir coefficient is a function of the upstream head and the shape of the weir. Orifice Flow H 77 Forfree Outfall, measure H from centroid mmmm The orifice equation is defined as: Q = CA 2gH Where: Q = Flow (m'/s, cfs) C = Orifice coefficient A = Flow area (m', ft) g = Gravitational acceleration (m/s-, ft/s') H = Head (m, ft) (6.65) ' Orifice Coefficients Although these coefficients vary with shape, size, and head depth, an average C coefficient of 0.60 is often used for storm water orifice openings. A list of orifice ' coefficients for various heads and sizes of circular, square, rectangular, and triangular shapes can be found in the Handbook of Hvdraulics, by Brater et Al. (see References). i Downtown Transit Center - Pipe Capacity Worksheet for Circular Channel Project Description Project File n:\fc0091\documents\drainage\outlet.fm2 Worksheet Outlet Pipe Flow Element Circular Channel Method Manning's Formula Solve For Full Flow Capacity Input Data Mannings Coefficient 0.013 Channel Slope 0.031400 ft/ft SkOpC Diameter 15.00 in -iflq � of P�pt Results Depth 1.25 ft Discharge 11.45 cfs-�►Cc�paCCh� of exas,� p,nC Flow Area 1.23 ft2 Wetted Perimeter 3.93 ft Top Width 0.00 ft Critical Depth 1.21 ft Percent Full 100.00 Critical Slope 0.027571 ft/ft Velocity 9.33 ft/s Velocity Head 1.35 ft Specific Energy FULL ft Froude Number FULL Maximum Discharge 12.31 cfs Full Flow Capacity 11.45 cfs Full Flow Slope 0.031400 ft/ft , Moc v uckvtoc site. (Oan not I!?)(6(ft5A 02/15/00 03:45:07 PM 1 - 1 1 i 1 1 1 APPENDIX D Erosion Control Calculations RAINFALL PERFORMANCE STANDARD EVALUATION PROJECT: Downtown Transit Center STANDARD FORM A COMPLETED BY: ASG June 27, 2000 DEVELOPED SUB -BASIN ERODIBILITY ZONE Asb (ac) Lsb (ft) Ssb N Lb (ft) Sb N PS N 1 LOW/MODERATE* 0.40 395.00 0.59 2 LOW/MODERATE* 0.22 221.00 0.73 3 LOW/MODERATE* 0.17 144.00 1.19 4 LOW/MODERATE* 0.74 516.00 0.21 5 LOW/MODERATE* 0.08 27.00 2.00 6 LOW/MODERATE* 0.52 214.00 0.43 7 LOW/MODERATE* 1.38 415.00 0.70 TOTAL 3.51 370.11 0.60 76.80 * - LOW WIND ERODIBILITY ZONE & MODERATE RAINFALL ERODIBILITY ZONE Lb = sum(AiLi)/(sum(Ai) _ (0.4*395+ ... +1.38*415)/3.51 = 370.11 Sb = sum(AiSi)/(sum(Ai) _ (0.4*0.59+ ... +1.38*0.7)/3.51 = 0.60 PS (during construction) = 76.80 (from Table 8-A) PS (after construction) = 76.8/0.85 = 90.35 N:\F00091 \Documents\drainagegerosion.xls]performance Nolte Associates, Inc. EFFECTIVENESS CALCULATIONS DURING CONSTRUCTION PROJECT: Downtown Transit Center STANDARD FORM B COMPLETED BY: ASG June 27, 2000 EROSION CONTROL METHOD C-FACTOR VALUE P-FACTOR VALUE COMMENTS BARE SOIL 1 1.00 0.90 GRAVEL MULCH 2 O.05 1.00 STRAW -HAY MULCH 3 0.06 1.00 ESTABLISHED GRASS COVER 4 0.35 1.00 PAVEMENT 1 5 0.01 1 1.00 SUB BASIN PS N AREA (ac) SITE 76.80 3.51 SUB BASIN SUB AREA AREA (ac) PRACTICE C'A P'A REMARKS 1 PERVIOUS 0.10 4 0.04 0.10 ESTABLISHED GRASS COVER 1 IMPERVIOUS 0.30 5 0.00 0.30 PAVEMENT 2 PERVIOUS 0.02 4 0.01 0.02 ESTABLISHED GRASS COVER 2 IMPERVIOUS 0.20 5 0.00 0.20 PAVEMENT 3 PERVIOUS 0.02 3 0.00 0.02 STRAW -HAY MULCH 3 IMPERVIOUS 0.15 2 0.01 0.15 GRAVEL MULCH 4 PERVIOUS 0.07 4 0.03 0.07 ESTABLISHED GRASS COVER 4 IMPERVIOUS 0.67 5 0.01 0.67 PAVEMENT 5 PERVIOUS 0.01 3 0.00 0.01 STRAW -HAY MULCH 5 IMPERVIOUS 0.07 2 0.00 0.07 GRAVEL MULCH 6 PERVIOUS 0.27 3 0.02 0.27 STRAW -HAY MULCH 6 IMPERVIOUS 0.25 2 0.01 0.25 GRAVEL MULCH 7 PERVIOUS 0.34 3 0.02 0.34 STRAW -HAY MULCH 7 IMPERVIOUS 1.04 2 0.05 1.04 GRAVEL MULCH Cnet = (0.1'0.35+ ... +1.04'0.05)/(0.1+,.,+1.04) = 0.06 Pnet = (0.1'1+ ... +1.04'1)/(0.1+,,,+1.04) = 1.00 EFF = (1-C`P)100 = (1-0.06.1)100 = 94 > 76.80 (PS) N:\FC0091\Documents\drainage\[erosion.xls]DURING I EFFECTIVENESS CALCULATIONS AFTER CONSTRUCTION ' PROJECT: Downtown Transit Center STANDARD FORM B COMPLETED BY: ASG June 27, 2000 1 EROSION CONTROL METHOD C-FACTOR VALUE P-FACTOR VALUE COMMENT BARE SOIL 1 1.00 0.90 GRAVEL MULCH 2 O.05 1.00 STRAW -HAY MULCH 3 0.06 1.00 ESTABLISHED GRASS COVER 4 0.35 1.00 ' PAVEMENT 1 5 1 0.01 1 1.00 SUB BASIN PS N AREA (ac) SITE 90.35 3.51 SUB BASIN SUB AREA AREA (ac) PRACTICE C*A P*A REMARKS 1 PERVIOUS 0.10 4 0.04 0.10 ESTABLISHED GRASS COVER 1 IMPERVIOUS 0.30 5 0.00 0.30 PAVEMENT 2 PERVIOUS 0.02 4 0.01 0.02 ESTABLISHED GRASS COVER 2 IMPERVIOUS 0.20 5 0.00 0.20 PAVEMENT 3 PERVIOUS 0.02 4 0.01 0.02 ESTABLISHED GRASS COVER 3 IMPERVIOUS 0.15 2 0.00 0.15 PAVEMENT 4 PERVIOUS 0.07 5 0.03 0.07 ESTABLISHED GRASS COVER 4 IMPERVIOUS 0.67 2 0.01 0.67 PAVEMENT 5 PERVIOUS 0.01 4 0.00 0.01 ESTABLISHED GRASS COVER 5 IMPERVIOUS 0.07 2 0.00 0.07 PAVEMENT 6 PERVIOUS 0.27 4 0.09 0.27 ESTABLISHED GRASS COVER 6 IMPERVIOUS 0.25 2 0.00 0.25 PAVEMENT 7 PERVIOUS 0.34 4 0.12 0.34 ESTABLISHED GRASS COVER 7 IMPERVIOUS 1.04 2 0.01 1.04 PAVEMENT ' Cnet = (0.1*0.35+ ... +1.04*0.05)/(0.1+...+1.04) = 0.09 ' Pnet = (0.1*1+ ... +1.04*1)/(0.1+...+1.04) = 1.00 EFF = (1-C*P)l00 = (1-0.09*1)100 = 91 t> 90.35 (PS) N:\F00091 \Documents\drainage\[erosion.xls]after Nolte Associates, Inc. EROSION CONTROL CONSTRUCTION SEQUENCE PROJECT: Downtown Transit Center COMPLETED BY: ASG Sequence for 2000 only. Indicate by use of a bar line or symbols when erosion control measures will be installed. Major modifications to an approved schedule may require submitting a new schedule for approval by the City Engineer. STANDARD FORM B June 27, 2000 Year Month 2000 O N D 2001 J F M A M J J A S Overlot Grading Wind Erosion Control Soil Roughening Perimeter Barrier Additional Barriers Vegetative Methods Soil Sealant Other Rainfall Erosion Control Structural: Sediment Trap/Basin Inlet Filters Straw Barriers Silt Fence Barriers Sand Bags Bare Soil Preparation Contour Furrows Terracing Asphalt/Concrete Paving Other Vegetative: Permanent Seed Planting Mulching/Sealant Temporary Seed Planting Sod Installation N etting s/Mats/Blankets Other STRUCTURES: INSTALLED BY VEGETATION/MULCHING CONTRACTOR DATE SUBMITTED MAINTAINED BY APPROVED BY CITY OF FORT COLLINS 1 N:\FC0091\Documents\drainageqerosion.xlslconstruction Nolte Associates, Inc. 1 I I ' Rainfall Intensity -Duration -Frequency Table Figure 3-1 a 1 Duration (minutes) 2-year Intensity in/hr 5-year Intensity . in/hr 10-year Intensity in/hr 25-year Intensity (in/hr 50-year Intensity in/hr 100-year Intensity in/hr 5.00 2.85 3.97 4.87 6.30 7.90 9.95 10.00 2.21 3.08 3.78 4.89 6.13 7.72 15.00 1.87 2.60 3.19 4.13 5.18 6.52 20.00 1.61 2.23 2.74 3.54 4.44 5.60 25.00 1.43 1.98 2.44 3.15 3.95 4.98 30.00 1.30 1.80 2.21 2.86 3.59 4.52 35.00 1.17 1.63 2.00 2.58 3.24 4.08 40.00 1.07 1.49 1.83 2.37 2.97 3.74 45.00 0.99 1.38 1.69 2.19 2.74 3.46 50.00 0.92 1.29 1.58 2.04 .2.56 3.23 55.00 0.87 1.21 1.48 1.92 2.40 3.03 60.00 0.82 1.14 1.40 1.81 2.27 2.86 65.00 0.77 1.07 1.32 1.72 2.16 2.72 70.00 0.73 1.02 1.25 1.64 2.06 2.59 75.00 0.69 0.97 1.19 1.57 1.97 2.48 80.00 0.66 0.92 1.14 1.50 1.89 2.38 85.00 0.63 0.88 1.09 1,44 1.82 2.29 90.00 0.61 0.84 1.05 1.39 1.75 2.21 95.00 0.58 0.81 1.01 1.34 1.69 2.13 100,00 0.56 0.78 0.97 1.30 1.64 2.06 105.00 0.54 0.75 0.94 1.26 1.59 2.00 110.00 0.52 0.73 0.91 1.22 1.54 1.94 115.00 0.51 0.70 0.88 1.19 1.50 1.89 120.00 0.49 0.68 1 0.86 -�1.16 1.46 1.84 4" DRAINAGE CRITERIA MANUAL 50 30 f- 20 z W 0 cc ul a 10 z w 0. 0 5 ul cc 3 .0 0 2 Cr w Q 3 1 RUNOFF WAIN 'I III�II��IID' Him �iMIFAWAWAIJIiMM�NEMEI� 1 -.5 - 1 .2 .3 .5 1 2 3 5 .10 20 VELOCITY IN FEET . PER SECOND FIGURE 3-2. ESTIMATE OF AVERAGE FLOW VELOCITY FOR i USE WITH THE RATIONAL FORMULA. *MOST FREQUENTLY OCCURRING "UNDEVELOPED" LAND SURFACES IN THE DENVER REGION. REFERENCE: "Urban. Hydrology For Small Watersheds" Technical Release No. 55. USDA, SCS Jan. 1975. 5-1-84 URBAN DRAINAGE & FLOOD CONTROL DISTRICT DRCOG Figure 1. Peak Flow Adjustment Factor For FAA Method 0.4 0.75 0.2. 0.6 Opo/Qpi RaUo . 11 Oude Desim • Wcim. PaCc I Reservoir Outlet Design -WEIRS: 71 L 1.0 h=h(t)-Ew OI I Rectangular Triangular Cippoletti Ew ' h (t) . DATUM Broad Crested Weir: STORM DRAINAGE DESIGN AND TECHNICAL CRITERIAI TABLE 1401 WEIR FLOW COEFFICIENT'S SHAPE Sharp Crested Projection Ratio (H/P = 0.4) Projection Ratio (H/P = 2.0) Broad Crested W/Sharp U/S Corner W/Rounded U/S Corner Triangular Section A) Vertical U/S Slope 1:1 D/S Slope 4:1 D/S Slope 10:1 D/S Slope B) 1:1 U/S Slope 1:1 D/S Slope 3:1 D/S Slope Trapezoidal Section 1:1 U/S.Slope, 2:1.D/S Slope 2:1 U/S Slope, 2:1 D/S Slope Road Crossings Gravel Paved 17 V COEFFICIENT COMMENTS SCHEMATIC _ HTI t - 8n 3.4 H< 1.0 �`- 4.0 H> 1.0 P U/S D/3 2.6 Minimum Value '° Vr 3.1 Critical Depth 3.8 H>0.7 it 3.2 H> 0.7 � = 2.9 H>0.7 3.8 H>0.5 3.5 N >0.5 U/S D/s 3.4 H> 1.0 H 3.4 H>1.0 U/S D/S 3.0 H>1.0 3.1 H>1.0 !l��nlnn� n�nn n�n■!n ■ r�nn� inn ■n■■n �nn■!nn!!!nn u u u .. u u •a u ' x••c[ a su•.[••[wc[ � ADJUSTMENT FOR TAILWATER Date: NOV 1984 Rev: REFERENCE: Book Company, King & 1963 Brater, - Design Handbook of Small of Hydraulics, McGraw Hill Dams, -Bureau of Reclam.,1977 0 0 a 0 U 1:03 z H a 0 U W 0 G4 as Go P4 40 0 �, EG E N w U ,►, MARCH 1991 o. o+ oI Ol o O' c mit In mmmmm 0 o+mmm000000 _ o -W; 1; to m tc tn* ui In ocl, mmmmmmmmmm o m 0, of of o, o, o+ rn rn rn of o+ o 0 0 o V• V• v V• V' a IT v v Vv V• v In In In M 00 CO CO m m m m m m m m m m m m o r000OOOD+o+rnO+o,rnrno,otrnotrnototo+o, o V V V•aV vvV�rvvV a�rV V avaa N CQ ODm mCOmmmmmmmmmmmmmmm 0 or1VIntOtOtDtOrrnnnnnrnnrnmmmmmm o 44-we v-0va-WO .� mo,mc00000mm000000000000mmmmmmmmmmmm O mc.1r,V InlnlnwD Oww%DtDrnnrnrrrnnmmm •. • • • • • ••' 4 Y Y 01 Y Y • •- 1 • • •= • • .' • M V• IT V' V• V V' V' v V V' V' V• V' V' V' v V V' "T W V' V' V' V V' mmmmco00mcoco000OmCID mmmmmmmmmmmmm 0 t0 O N M V' V' In In In In tD w t0 tD t0 t0 t0 w t0 %0 r r- r r n n m M V' V' V' V' V' V• V" V' V' V' V' V' V' 4V' V' V' 4V' V' V' V' V' V' 4 m m m m m m m m m m m m m m m m m m m m m m m CO m m O V' 01 rl N M M V' V" V' V'- In In m m In In In In In t0 tD t0 t0 W t0 r- m m m m m m m m m m m m m m m m m m m Or CO m m m m CO O 0%0m0r4••1NNmmmm V' W V' w V' ow -w V'InInInIn%0%0 l0. 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CO CO CO CO CO CO CO CO CO CO In rl r1_ In r, m O 0 ri N N M M M .0 V' V'' or V' In 0, In %OL %0 t0 r n M' rl N NN N M M M M M M M M M !'9 M M M M M M M M M M M m m m m m m m m m m m m m m m W m m m m m m m m m m O" f'1 N%0 m'' ON O H N N M M M V' V' V' V' V' V' In In In In tD t0 t0 t0 M" O.-fHf-IrlNNNNNNNNN(NI NNNNNNNNNNN mmmmmmmmmmmmmmmmmmmmmmmmmm In In In 01 N M- V' In tO r ti r• m m m Ot 0% 01 Ot 0% 01 0 O O O O 0 N 0% O O ri H rl r1 rl rl rl rl ri H H ri '4 H H r♦ rl-N N N N N N nCOaommmmmmmmmmmmmmmmmmmmmmm O V"In 0 MIn tO CO CO 0% 000 rl ri ri rl N N N N M M M M MM . . Y .. .. .: . .. N . . .' ... . .. ,.. .. .. . .. .. . .. . S. com0000000r1rlHHf-4Hr-4Hrlrlrl."1HHrlHH nr00mmmmm000Ocommmmmmmmmmmmmmm In OD N m rr .0 In r r m 0% c% 0 0 r4 rl rl rl rl N N N M M M M M rl t0 m' m 01 01 01 01 01 01 01 01 0 C; c; c 0 0 0 0 0 0 0 0 0 nnnrnrnnrnrmmmmmmmmmmmmmmm O tOMO V n010•-1NMM V'V In InlnlntOtOtOtOrntDtDtO r♦ V tOc�nrrCOmmmCDCOCOmmmmmmmm.mmmmm rrrnrnr-rrnr-rnrnrnrnrrrnnnr. In 01O V WNW W rnnt0.WWM VW M M N Cq Ch %0 Wri01.t0' 8NNNNNNN4NNNNN4NNNN14r1-4rIr100 O nrrrrrrnrnrnrnrnrrrnrrrrrr x_ 00000000000000000000000000 CE9 E 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ZW H M V'MtDrm010HNM V'Int0rm010InOInOInO', . W•• riHHHHHrIHHHNNMMV V'0 CRITERIA 9-4 DESIGN Table 86 C-Factors and P-Factors for Evaluating EFF Values. Treatment C-Factor P-Factor BARE SOIL Packedand smooth................................................................ 1.00 1.00 Freshlydisked........................................................................ 1.00 0.90 Roughirregular surface........................................................... 1.00 0.90 SEDIMENT BASIN/TRAP "' STRAW BALE BARRIER, GRAVEL FILTER, SAND BAG ........................ 1.00 0.80 SILTFENCE BARRIER ............................................... I..................... 1.00 0.50 ASPHALT/CONCRETE PAVEMENT ................................................... 0.01 1.00 ESTABLISHED DRY LAND (NATIVE) GRASS .......................... See Fig. 8-A 1.00 SODGRASS................................................................................. 0.01 1.00 TEMPORARY VEGETATION/COVER CROPS....................................0.45(2) 1.00 HYDRAULIC MULCH @ 2 TONS/ACRE........................................... 0.1013' 1.00 SOIL SEALANT...............................:....................................0.01-0.60(•1 1.00 EROSION CONTROL MATS/BLANKETS............................................ 0.10 1.00 GRAVEL MULCH Mulch shall consist of gravel having a diameter of approximately 1 /4' to, 1.1 /2' and applied at.a rate of at least 135 tons/acre.............. 0.05 1.00 HAY OR. STRAW DRY MULCH -- After olantino crass seedapply mulch at rate of 2 tons/acre (minimum) and adequately anchor, tack or crimp material into -the soil" Slone: l%) 1 to 05...............................................:......................:......0.06 1.00 6 to 10............................................................................. 0.06 1.00 11- to 15.............................................................................0.07 1.00 16 to 20.............................................................................0.11- 1.00 21' to 25..........................:...................................................0.14 1.00 25 to 33.............................................................................0.17' 1.00 > 33....................................................:..................... 0.20 1.00 NOTE Use of other C-Factor or P-Factor values reported in this table must be substantiated by documentation. (1) Must: be constructed as the first step in overlot grading. (2) Assumes planting by dates identified in Table 11-4, thus dry or hydraulic mulches are not required. (3) Hydraulic mulches shall be used only between March 15 and May 15 unless irrigated. (4) Value used must be substantiated by documentation. M I Table 8-13 C-Factors and P-Factors for Evaluating EFF Values (continued from previous page). 1 Treatment. C-Factor P-Factor 1 CONTOUR FURROWED SURFACE Must be maintained throughout the construction period, otherwise P-Factor = 1.00. Maximum length refers to the down slope length. Basin Maximum 1 Slope Length M (feet) 1 to 000..........................................................................1.00 3 to 5 00..........................................................................1.00 0.60 0.50 1 2 6 to 8 00. .1.00 0.50 9 to 12 120..........................................................................1.00 0.60 1 .1.00 13 to 16 60. 0..........................................................................1.00 17 to 20 0.0 0.80 > 20 50 . . 1.00 0.90 1 TERRACING Must contain 10-year runoff volumes, without overflowing, as determined by applicable hydrologic methods, otherwise P-Factor = 1.00. 1 Basin - Slope M ii. to: 2..................................................................................... 1.00 0.12 3 to 8..................................................................................... 1.00 0.10 9 to. _ .12...................................................................... 1.00 0.12 1 ........................................................... 1.00 0.14 17 to- 20.....................................................................................1.00 0.16 > 20...................................................................................... 1.00 0.18 1 1 1 1] 1 1 7 1 1 NOTE- Use of other C-Factor or P-Factor values reported in this table must be subsmndated by documentation. 1 MARCH 1991 8-7 DESIGN CRITERIA Figure 8-A ESTABLISHED GRASS AND C-FACTORS FORT COLLINS, COLORADO 0.35 0.30 0.25 0 0.20. Ei• o - 4 0.15 0.10 0.05 0.00 0 20 40 60 80 100 ESTABLIZED GRASS GROUND COVER W MARCH 1991 8-8 DESIGN CRITERIA 11 I�EN 11 � J l� M1F e li4an LT6F-- BAY At e rL 1�rmit SMARNMRAFFIRS N11RIB1E YMVS•AE' 'H^�• flfLeil. R �YCiR3':,- i2Y? 1 Gii:ll�IS :161R[ MAY II ;I1� _ 'I,�FIR o ;Y 0 .+ysp&�s_ Y-f7F+�Ya€�,;j:.1.� 4:L. IF ®®: e m 9s. it a ,�AS Y. IT- 77 0.s�i�Lrl�r.rl�i.i�ru.i�irdlr.`�.�rEiriwl.ia I�l�i�sL j MI :I BAD To MRS UNI D o EROSION .AE:P N07LS T. THE OTY OF FORT COLLINS STORIMMATER UTILITY EROSION CONTROL INSPECTOR MUST BE N07MED WEREGN M�W MADRID EVIDENT AT LEAST 24 HOURS PRIM TO ANY CONSTRUCTON ON THE 97 0 2 ALL REQUIRED PAMBETER SALT FORCING SHAUL BE INSTALLED PRIOR TO ANY LAND-DISTUREING ACTIVITY (RADIOPHONE, STARTING. GAMBLING, ETC)ALL ITHELL REQUIRED EROSION CONTROL MEASURES SAIMLL INDICATE By USE OF A BAR LINE OR SYNABOLS WEN MOSION CONTAX MEASURES BILL K BE INSTALLED AT ME APPROPRIATE TME IN THE CONSTIF SEQUENCE AS INI IN ME MALM MODIFICATIMS A AN UPPROAD SCHEMILE MAY REQUIRE %BIDDING A MEN � FOR APPROWD PROECT SCHEDULE. CONSTRUCI PLANS, AND ITROPHON COWLROL REPORT APPROVAL By ME CITY DONALD;! WATER QUALITY/DETENTION POND SUMMARY REWIRED DEMNTON VOLUME - ON AC -FT REWIRED WATER QUALITY VOLUME - 0.041 AI TOTAL REWIRED VOLUME - 0.131 AC -FT PROMOEO VOLUME - 0.16 AC -FT RELEASE RATE (III FLOW) - 4.55 CITE OUSEL - 4980.14 DRAINAGE SUMMARY CHART OR BASKS AREA AC 010(OFF DIED (ORE) 1 1 0140 1.39 3.79 2 2 0.22 0.95 2.21 3 3 0.17 0.72 1,68 N M 0.74 2.08 7,12 5 5 ON 0.34 0.82 a 6 0.52 1.52 3.88 7 1 1.35 4.55 12.93 ROUTED FLOWS 8 5.8 0.a0 1.85 2.30 A SA 0.91 3M 4.42 3. PPE -DISTURBANCE VEGETATON SHALL BE PROTECTED AND RETAINED WHEREVER POSSIBLE. FORMAL OR E SNRBANCE OF ERASING VEGETATION SMALL BE LIMITED TO THE AREA REQUIRED FOR IMMEDIATE CONSTRUCTON OPERATIONS, AND FOR THE SHORTEST PRACTICAL MERGE oq TIME, ALL SOLE EXPOSED DURING LAND DISTURBING ACTIVITY (STRIPPING, GRADING. UIDITY INSTALLATIONS, STOCKPILING, FALLING. ETC) SI BE KEPT IN A ROUGHENED CONDITION BY RIPPING M BIDDING ALONG LAND COMMUNE UNTIL MULCH. YP4TATON. OR OTHER PERMANENT EROSION CONTROL IS INSTALLED. NO SOILS IN AREAS OUTSIDE PROJECT STREET RIGHTS -OF SHALL REMAIN EXPOSED BY LAND -DISTURBING ACTIVITY FOR MORE THAN THIRTY (NI) OAK BEFORE MWMED TEMPORARY M PERMANENT EROSION CONTROL ED. SEED/MULM• LANDSCAPING. ETC.) IS INSTALMID, UNLESS OTHERWISE APPROVED BY THE SMISMATER UTUTY. 5, ME PROPERTY WALL BE WAINEG AND MAINTAINED AT ALL TIMES DURING CONSTRUCTION ACFi SO AS TO PREVENT MND-CAUSED EROSION. ALL LAND dSNRBING ACDNDES SHALL BE IMMEDIATELY DIiCONTNUED WEN FUSTSE DUST IMPACTS ADJACENT PROPERTIES, AS DETERMINED BY THE CITY OF FORT COLLINS ENGINEERING DEPARTMENT 6, ALL TEMPORARY (STRUCTURAL) EROSION CONTROL MEASURES SHALL BE INSPECTED AND REPAIRED M RECONSTRUCTED AS NECESSARY AFTER EACH RUNOFF EVENT IN ORDER TO ASSURE CONTINUED PERFORMANCE CP MDR INTENDED FUNCTION. ALL RETAINED SO MENTS, PARTICULARLY THOSE M DRAG ROADWAY SURFACES. SHALL BE BEHOVED AND OPPOSED b IN A MANNER AND LOCATION RD AS NOT TO CAUSE THEIR RELEASE INTO ANY DRAINAOEWAY. S NO SOL STCCNPBE SHALL EXCEED TEN (10) FEET IN HEIGHT. ALL SOL STOCKPILES SHALL BE PROTECTED FROM SEDIMENT TRANSPORT BY SURFACE SOLDIERING, WATERING, AND PERIMETER 41 FENCING. ANY SON. STOCKPILE REMAINING AFTER 30 DAYS SHALL BE SEEDED AND MULCHED. B CITY ORDNANCE PROHIBITS ME BACKING, DRONING, W DEPOSTNG 7 SOILS M ANY OTHER MATERIAL MiJ STY SBEETS BY OR FROM ANY VEHICLE. ANY INADVERTENT DEPOSITED MATERIAL SHALL BE CLEANED IMMEDIATELY BY ME CONTRACT , B' ME DETENTON AREA SHALL ACT AS A SEDIMENT BAP DURING CONSTRUCTION. ME POND TOLL BE EXCAVATED FIRST DURING MERWT GRADING. A GRAVEL FILFER ALL BE PLACED OVER ME OUTLET PARS UNTIL SODDING IS COMPLETED. AAR oYEFF SPAI Mx0 ERo51MNa SOL REACHING PERIMETER S AGDITWALERS VEGETATIVE aos SON. SEALA OTHER IMPALL IMWT10.STRUCTURAL SEGMENT BASININLET FILTESWAN BARSILT FENCEIERSSAND BAGS BARE SOL RATONCONTOUR FSTERRACING ASPHALT/ ETE PANNE OTHER VEGETAINT PERMANENT SEED PLANING uLCHINc SEALANT MANOR, Y SEED PLANING SCE INSTAI NETINGS/ MATS/ MARKETS OTHER City of Fort Collins, Colorado UTRITY PLAN APPROVAL CHEERED BY: CACKED BY CHECKED By B III M CKgED BY: LEGEND x BASIN DE4pATW p,X 2 YEAR COEFFICIENTS NEW AREA TOO YEAR COEFFICIENTS INSUMMONS BASIN BOUNDARY ® DESIGN PANT PROPOSED SAIRM MAN MANHOLE ® PROPOSED STORM DRAIN PIPE 0 PROPOSED SIERRA DRAIN NLET - EXISTING ICONTOUR -- EXISTING 5' CMTWR s::. PROPOSED P CONIFER a:b PROPOSED IF CONTOUR ---- SILT FENCE EF:ETKM • DAAS b 1 a'RCP STgW 6ENER SMALL BE INSPECTED BY STY OR FORT COLLINS DG PROBE A 1'-TRW W Z wz ()O N F-Oz Fri �Q z Q=-i <0 ~ LIJ F- zQ0 3:z0 OQ �010� zC) 0 0 N PRDaCf FN091 DATE 10/I6 /[ OgaTS MSG, NF •a YONO EN a N a B a 1 N0 190151UMIN T INT DRIVE, SUM A FORT COLLINS,� NS, CO. W525 97"0.221.2101) TEL 970.221.24I5 FAX W W W.NOLW.WM 9 a¢rs