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HomeMy WebLinkAboutDrainage Reports - 09/17/2003 (2)'W k' 'r . t 4 . G�. 5 f � 7 . rL` ."a} ✓ w, k >, � n. k i = Y ' n a r r r d .( Collins A i'{Vt r � r r L. t a ''i} .t: n"4 r� {n S' -ta t.iit <{," 1 i `t ,F l r. �i tT t yr ,vJ"h f, r _.rl' _.� "� ... ,. FINAL ,EROSION CONTROL #' •. � S.G y. t ,t F ` "` + < "• �, � 1 ✓ � T t ,,; ' r •,,,, � h' ; ." � r t r , � CO -.'DO .'..4 y N s rrs U.f i � ,~ ' fsa, �.s �� r! r; � yt. i �"• 1 `,`� i. 1�-� ;T y l -#� t k J � � C a' F f ti { ,; r r',' - 4 'C"' s 1! r 1 r� y vt f (k�F� # � .ri y, ,{ _ Y .�- � s s i r a t ' e ,, y y s'` `te �b tr 4{n rt tt aiJ � s ''�> i its q 1 X >�4 ,i 1 .- r #, F .; a l � j Sa 45� Number 57 —0 1 FINAL DRAINAGE AND EROSION CONTROL REPORT RIVERBEND CONDOMINIUMS Prepared for: HOORAZ, LLC. 1218 West Ash, Suite A Windsor, CO 80550 Prepared by: North Star Design, Inc. 700 Automation Drive, Unit I Windsor, Colorado 80550 Phone: (970) 686-6939 Fax: (970) 686-1188 July 17, 2003 Job Number 157-01 North Star ftwr design, inc. July 17, 2003 ' Basil Hamdan City of Fort Collins Stormwater ' 700 Wood Street Fort Collins, CO 80522-0580 RE: Final Drainage Report for Riverbend Condominiums Dear Basil, ' I am pleased to submit for your review and approval this Final Dr ainage &Erosion Control ' Report for Riverbend Condominiums. I certify that this report for the drainage design of Riverbend Condominiums was prepared in accordance with the criteria in the City of Fort Collins Storm Drainage Manual. ' I appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. Sincerely, eviewe,.�¢��''t'%�cca.; ' Troy D. Spraker, E.I.T. North Star Design, Inc. r 1 ' 700 Automation Drive, Unit I Windsor, Colorado 80550 870-686-6939 Phone a 970-686-1188 Fax TABLE OF CONTENTS TABLE OF CONTENTS ................... 1. GENERAL LOCATION AND DESCRIPTION 1.1 Location...............................................................................................................................1 1.2 Description of Property........................................................................................................1 2. DRAINAGE BASINS AND SUB -BASINS 2.1 Major Basin Description....................................................:................................................. I 2.2 Sub -Basin Description.........................................................................................................2 3. DRAINAGE DESIGN CRITERIA 3.1 Regulations..........................................................................................................................2 3.2 Development Criteria Reference and Constraints................................................................2 3.3 Hydrologic Criteria..............................................................................................................3 3.4 Hydraulic Criteria................................................................................................................3 4. DRAINAGE FACILITY DESIGN 4.1 General Concept.................................................................................................................. 3 4.2 Specific Flow Routing.........................................................................................................3 4.3 Drainage Summary ..............................................................................................................4 4.4 Variance Requests...............................................................................................................4 5. EROSION CONTROL 5.1 General Concept.................................................................................................................. 4 5.2 Specific Details....................................................................................................................5 5.3 Dust Abatement...................................................................................................................5 5.4 Tracking Mud......................................................................................................................5 5.5 Maintenance........................................................................................................................ 5 6. CONCLUSIONS 6.1 Compliance with Standards................................................................................................6 6.2 Drainage Concept................................................................................................................ 6 6.3 Water Quality and Erosion Control Concept.......................................................................6 7. REFERENCES.................................................................................................................................7 APPENDICES A Vicinity Map B Hydrologic Computations C Hydraulic Calculations D Detention and Water Quality Calculations E Figures and Tables iii 1. GENERAL LOCATION AND DESCRIPTION ' 1.1. Location ' . This site is located in a tract of land in the North % of Section 17, Township 7 North, Range 68 West of the Sixth Principal Meridian, in the City of Fort Collins, County of Larimer, State of Colorado. See the location map in Appendix A. ' The project is located south of State Highway 14 and east of Timberline Road. The site is bounded by Countryside Road landscape to the west, an existing business to the north, Erick Street to the east and the Poudre Ponds to the south. ' 1.2. Description of Property ' The entire project consists of 0.99 acres (43,153 sq.ft) of land. The land is currently undeveloped and slopes to the south at approximately 1 %. The site currently drains ' overland to the Poudre Ponds to the south of this site. The project will consist of three structures including one 4 unit building and two 2 unit ' buildings. The site will access Countryside Road on the western boundary of the site. A private cul-de-sac is included in the plans for proper traffic control. The developed site will include'buildings, street and irrigated lawn. 2. DRAINAGE BASINS AND SUB -BASINS 2.1. Major Basin Description ' The development lies within the Poudre River Drainage Basin. The Natural proposed p g ' Resources Department has required that this site detain the 100-yr developed event. This site shall also include water quality treatment before being discharged into the Poudre Ponds at a release rate equal to the 2-yr historic event (0.96 cfs.). This ' requirement has been made by the City of Fort Collins Natural Resources Department, due to the outfall from the site discharging directly into the City Natural Wetlands Area. ' 2.2. Sub -basin Description ' Sub -basins are described thoroughly in Section 4.2. 3. DRAINAGE DESIGN CRITERIA 3.1. Regulations ' This report was prepared to meet or exceed the "City of Fort Collins Storm Drainage Design Criteria Manual" specifications. Where applicable, the criteria established in the 1 "Urban Storm Drainage Criteria Manual" (UDFCD), 1984, developed by the Denver Regional Council of Governments, has been used. ' 3.2. Development Criteria Reference and Constraints The runoff from this site has been routed to conform to existing site constraints. Since ' this is an "established" area, with adjacent streets, natural areas and buildings already constructed, there is little room for varying from existing site conditions. The street and associated drainage systems surrounding the site are existing. The nearest storm system is approximately 150'to the west of this site on Countryside Road, however this site is designed to drain south into a detention pond and release into the Poudre Ponds. As currently proposed, this site will receive off -site flows from the east half of Countryside Road west of the proposed site. The east half of Countryside Road flows to the south and into the proposed detention and water quality pond via a sidewalk culvert and -grassed swale. The west half of Countryside Road flows to the west and into the Poudre Ponds through the existing storm sewer system without being detained. Detention is proposed for this site. The existing site (based on the rainfall criteria adopted by the City of Fort Collins on March 26, 1999) generates 0.96 cfs runoff in the 2-yr storm event; this is the proposed release rate for the detention pond. The site as it is proposed will generate a peak flow of 9.1 cfs in the 100-yr storm event. The site as designed has 63.5% imperviousness area. 3.3. Hydrologic Criteria Runoff computations were prepared for the 2-yr minor and 100-yr major storm frequency utilizing the rational method. All hydrologic calculations are included in Appendix B of this report. Standard Form 8 (SF-8) provides time of concentration calculations for all sub -basins. Standard Form 9 (SF-9) provides a summary of the design flows for all sub -basins and design points associated with this site. K 1 3.4. Hydraulic Criteria ' All hydraulic calculations within this report have been prepared in accordance with the City of Fort Collins Drainage Criteria and are also included in Appendix C of this ' report. ' 4. DRAINAGE FACILITY DESIGN ' 4.1. General Concept The runoff from this site flows east from a high point at the entrance into the cul-de-sac. ' The flow line slopes to the east at approximately 0.5% to a low point. Runoff flow will be collected in an inlet located at the low point and conveyed through a storm pipe along the east side of the building .and into the northeast corner of the proposed ' detention pond. Runoff generated by Countryside Road will flow south to a sidewalk culvert located near the entrance to the natural areas parking and will be conveyed to the proposed detention pond. ' 4.2. Specific Flow Routing A summary of the drainage patterns within each basin is provided in the following ' paragraphs. 'For more specific details see the calculation located in Appendix B of this - report. ' Sub -basin A contains the northeast portion of the site and runoff from this basin flows to the east to a low point located on the east portion of the cul-de-sac. Flow enters a ' Type-3 combination inlet and, is conveyed to the detention pond in a 15" RCP. Sub -basin B contains % of the roof from the two southern buildings and the detention area. The flow is detained and released into the Poudre Ponds at a rate equal to the 2-yr historic storm event. Sub -basin C contains a portion of the site but primarily consists of the east half of P p Y ' Countryside Road from the south edge of the site to the intersection of Countryside Road and Countryside Drive. Runoff from Sub -basin C flows to a low point and is conveyed into the detention pond by a sidewalk culvert. Runoff is discharged into the northwest corner of the proposed detention pond. 1 4.3. Drainage Summary The storm conveyance system is a surface and sub -surface system and has been designed for minimal maintenance. The. storm sewer system and the detention pond ' will be owned and maintained by the homeowners association. 4.4. Variance Requests No variances are being requested at this time. ' 5. EROSION CONTROL ' 5.1. General Concept ' This site lies within the Moderate Rainfall and Wind Erodibility Zone per the City of Fort Collins Zone Maps. A potential exists for silt movement from the site to be transported into the existing ponds located to the south of the site. All erosion control ' measures necessary to minimize sediment transport have been shown on the Erosion Control Plan, included in this report. ' 5.2. Specific Details ' To limit the amount of silt leaving the site, several erosion control measures shall be implemented during construction. Silt fence shall be installed along the southern side of proposed site. Also, a vehicle -tracking pad shall be installed at the entrance off Countryside Road to control the mud being tracked onto the existing pavement. During ' overlot grading, disturbed areas are to be kept in a roughened condition and watered to reduce wind erosion. ' 5.3. Dust Abatement 1 During the performance of the work required by these plans, the contractor shall carry out proper sufficient measures wherever and as necessary to reduce dust nuisance, and to prevent dust nuisance, which has originated from his operations from damaging ' crops, orchards, cultivated fields and dwellings, or causing nuisance to persons. The Contractor will be held liable for any damage resulting from dust originating from his operations under these plans, on right-of-way or elsewhere. a] 1 11 1 5.4. Tracking Mud Wherever construction vehicles access routes_ intersect paved public roads, provisions shall be made to minimize the transport of sediment (mud) by runoff or vehicles tracking onto the paved surface. A stabilized construction entrance is required per the detail shown on the Detail Sheet with base material consisting of 6" coarse aggregate. The contractor will be responsible for clearing tracked mud on a daily basis.. 5.5. Maintenance All temporary and permanent erosion and sediment control practices must be maintained and repaired as needed to assure continued performance of their intended function. Silt fences will require periodic replacement. Maintenance is the responsibility of the contractor. 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 construction plans adequately provide for the detention and transmission of developed on -site runoff to the Poudre Ponds. The impact of the development of this site on existing downstream facilities has been minimized by the use of detention and water quality ponds. Detention is provided to meet Fort Collins Natural Resources Department requirements. If, at the time of construction, groundwater is encountered, a Colorado Department of Health Construction Dewatering Permit would be required. 6.3. Erosion Control Concept Since the site is less than 5.0 acres, a NPDES permit is not required. During construction, erosion control shall be maintained to minimize erosion on this site and transport of silt downstream. 1 1 7. REFERENCES ' 1. City of Fort Collins, "Storm Drainage Criteria Manual", (SDCM), dated March, 1986. ' 2. Urban Drainage and Flood Control District, "Urban Storm Drainage Criteria Manual", Volumes 1 and 2, dated March, 1969, and Volume 3 dated September, 1992. 1 1 1 6 APPENDIX A VICINITY MAP A PROJECT SITE BENCHMARK: NORTHWEST CORNER OF SECTION 17-T7N-R68W FOUND 3-1/4" ALUMINUM CAP IN MONUMENT BOX MARKED IS 17497" PROPERTY DESCRIPTION: A TRACT OF LAND IN THE N. 1 /2 OF SECTION 17, TOWNSHIP 7 NORTH, RANGE 68 WEST OF THE 6TH P.M., COUNTY OF LARIMER, STATE OF COLORADO. SHEET 1 OF 1 DATE: 03/28/03 RIVERBEND %North Star SCALE: 1 " = 300' design, inc. CONDOMINIUMS 700 Automation Drive, Unit I DRAWN BY: TD S VICINITY MAP Windsor, Colorado 80550 Fxnso688839 JOB NO.: 157-01 Phone: i 1 APPENDIX B i HYDROLOGIC COMPUTATIONS 1 1 i 1 i i 1 1 U H W o J O � Cl?00 Cl? a ; O O O O i O U 0 LL N N N N Z LLJ � O O O O O U W LL Q U 17 o 0 Q cl W � 0 0 0 Q<Z Q J O LL rn rn rn rn z W O o 0 0 0 U U) LL :) O O < > _ V M N 0 0 0 W o Q a J. Q W to V* M M O ¢ O O O Z 2 O o ~Q N Q Z Q m U = Q U m o a W of O a LL fO 2 O U U - I- CO WO co WW c`�o a a cn O Q W 00 w Q o J J Q W M M LLJ Q O J Fa- O Z LL Q N O Z LL W U o'Q Z V O U N LL. O CWC G 0 p 'U) U N 0i >C Z > z U � W A a a WvFi �� xo 5. o � A NFzen C1 OCR z�Fw O�EQ.,F F U U W Urn pqF A OU h A N Y� Q � w U R' U O _N Ci LL' O ` Q �Um .. 0 Y N W N N N O U N O yO N to u � O J E N toii LL J W a W N tD r0 to O N N zz Q S rn U ct tDoO to O C C 7 O O O O a W a O O O O tD 'Al n Vn O a 0 O W ~ _ In o 0 N m N lW J r Z _ c E UD ID M N M tD (D C 0 O O O O U) N N N N « am^ O D O O c N N O R J z g �wm U 0 0 0 0 W > 0 J m m to tD a W U A M m 0 0 Z � . y U N A V M M Q=° 000 z� Z—p m Q m U U w LL 0 U O z Ae to Q m U = m U Z m y Q Q m Q C N a w 1 tn N z c� UrA w A x� w E"I N �oozzM w o� O Q owo]e .aAUv�A to Y Q f LU J Z E� ui co 0 LL O C <7 m O a Z Ev �o of v2 N a II 10 O « 0 W Y J U N W _ N I I o 0 2 m « N O 04 Uto u � LL J m nrn a0 CO INn. W 2 42 rn U � ct mom In O c c a o00 c� 0 C W mQ c o o o O O O O LU ~ J L W J F Z 0 0 0 0 O o N O O O O cn N N e N L ' c O 0 O O J 0 U rn v o CU 0 0 o lu o_ mmm ID �w U r m m c f.� o00 0 Z F.. U (V wi N m Ci C) c7 Q 0 0 0000 Z (7 Fn 5 Q m U U o a C 0 z ; Q Q co O Z fd U m a N C 0 a W y a c Z i z W o W U WO cn a >- 0 N0 W = Q W z Q J a z gO O Q c �z o>=, z c) O�Fo FZ�Fi O W O p d a AUrn N C O to O Y U QU � O LU N_ w O ',1: O O O m O L OR N O O � V� G� C N N N fh M E ui r- nCO r-M00 o M U U.- o00 0 co U ti cq M coo 0 U Q ca In C ch Cl) O o O LL LL O z C U ca rn to _ s U O Mn Q 0CL U m Q Z a W W W U W 0 U)a >-o (1)O W aw zg J 0z 20 0 O U) 0 v 0 0 U Ya�i a 0 o > w a>i � o a U L lA � C7 m L N N C m W W O U C O rh 1 O LA co co 00 II to O U r-N QOi '7 CO UU� �ClCO co Lo U 0 0 0 0 Q U U') V c7 Cl) 000 LL LL 0 z C m rn a Q CO U U U w 0 a 0 N o a ¢aoU 0 U m Q X 0 [1 APPENDIX C HYRAULIC CALCULATIONS 0 11 C 1 -------------------------------------- -------------------------------- UDINLET: INLET HYDRAULICS AND SIZING DEVELOPED -BY CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD ----------------------------------------------------------------------------- N DATE 10-23-2002 AT TIME 12:15:17 ** PROJECT TITLE: Riverbend ' *** GRATE INLET HYDRAULICS AND SIZING: I INLET ID NUMBER: 1 INLET HYDRAULICS: IN A SUMP. GIVEN INLET DESIGN INFORMATION: - -9- 5 So) - z INLET GRATE WIDTH (ft) = 2.38 N Gew A� INLET GRATE LENGTH INLET GRATE TYPE (ft)= =Type 2.38 16 Grate Inlet �iePrrc iaiG1 NUMBER OF GRATES = 1.00 SUMP DEPTH ON GRATE )= F� Ae GRATE OPENING AREA RATIO M 0.55 �T�o►�o.Q IS THE INLET GRATE NEXT TO A CURB ?-- YES Note: Sump is the additional depth to flow depth. �h oV GQ. STREET GEOMETRIES: IN LG� STREET LONGITUDINAL SLOPE (%) = 1.00 STREET CROSS SLOPE (%) = 2.00 STREET MANNING N = 0.016 GUTTER DEPRESSION (inch)= 1.50 GUTTER WIDTH (ft) = 2.00 STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 12.25 GUTTER FLOW DEPTH (ft) = 0.37 FLOW VELOCITY ON STREET (fps)= 3.07 FLOW CROSS SECTION AREA (sq ft)= 1.65 GRATE CLOGGING FACTOR (%) = 50.00 G CURB OPENNING CLOGGING FACTOR(%)= 10.00 INLET INTERCEPTION CAPACITY: FOR 1 GRATE INLETS: DESIGN DISCHARGE (cfs)= 5.10 IDEAL GRATE INLET CAPACITY (cfs)= 10.46 BY FAA HEC-12 METHOD: FLOW INTERCEPTED (cfs)= CARRY-OVER FLOW (cfs)= 0.00 BY DENVER UDFCD METHOD: G� Q FLOW INTERCEPTED (cfs)= CARRY-OVER FLOW (Cfs)= 0.00 1 r - I Scenario: Storm A DET POND 1 1 1 i 1 CL 1 1 1 1 &2 C-Z Title: Riverbend Project Engineer: Troy Spraker ' u:\157-01 riverbend\drainage\storm cad\storma.stm North Star Design, Inc. StormCAD v4.1.1 [4.20141 03/27/03 09:29:57 AM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 E N J O 3=v � 0 ' m rn C3 o do rn C 2- 0 O E rn m Cl) o N > v O ' C C � 3. O E M cu N = D) d ' 3 O `O � O y O aU v E LO Ci �a E O CL Cl O N � IC m .`T' Cl) Q� Nci, UO N. Q 'a a>� N C0 w LLU� 30 O a) N w O TLL d' O E O U O O t N C v O n N J C 0 O ' t N fn C N C o E U m Z (n N a m J a 1 m O O a N r Cl) m r m a �o c Q 0 E N � 0 d p = O o c? 0 CLo't I- 06 o worn p rn� a)NN E LL (n O O co O N � O OSr! CD • � Q E E J i2 Cn O Ln O Ln 00 r- � �o O O O O C C Cl C '� It It It G O (0 O W O u? O In O CO LO Ln It. 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JDOJ(nfC� ;F r Y O O a N r � � m > r co 2�a u > c_ Q m c W E _o N "o EL` 10 10 Lh LO 1n M a N Q co O 0 0 U ci :3 c d o� d 0 �o o� Z� Y 0 m n Cl) ca cu C 0 0 E E 0 E 0 m �Q dN c N M o CD > p CO iR o n ciU)N C-% Countryside - Sidewalk Culvert Worksheet for Rectangular Channel Project Description ' Countryside Road - Sidewalk Culvert Worksheet Flow Element Rectangular Channel Method Manning's Formula ' Solve For Channel Depth Input Data 0.013 Mannings Coefficient Slope 1.00 % Bottom Width 4.00 ft ' Discharge 3.50 cfs Results Depth 0.22 ft ' Flow Area 0.9 ft2 Wetted Perimeter 4.45 ft . Top Width Critical Depth 4.00 ft 0.29 ft Critical Slope 0.45 % Velocity 3.92 ft/s Velocity Head 0.24 ft ' Specific Energy 0.46 ft Froude Number 1.46 Flow Type Supercritical Project Engineer: North Star Design, Inc ...\drainage\flowmaster\sidewalk.fm2 North Star Design, Inc FlowMaster v6.1 [614o] 3/27/2003 9:24 AM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 Page 1 c- �. 3/27/2003 Riprap Calculations for Pipe Outlets LOCATION: RIVERBEND PROJECT NO: 157-01 COMPUTATIONS BY: TDS SUBMITTED BY: North Star Design DATE: 3/27/2003 From Urban Strom Drainage Criterial Manual, March 1969 (Referenced figures are attached at the end of this section) Q = discharge, cfs D = diameter of circular conduit, ft W = width of rectangular conduit, ft H = height of rectangular conduit, ft Yt = tailwater depth, ft At = required area of flow at allowable velocity, ft2 V = allowable non -eroding velocity in the downstream channel, ft/s = 7.0 ft/s for erosion resistant soils = 5.5 ft/s for erosive soils Outlet Structure 15" RCP - Storm Sewer A Q = 0.96 cfs D = 15 in = 1.25 ft Yt = - 0.25 ft V = 5.5 ft/s Q/D1.5 = 0.7 Yt / D = 0.2 From Figure 5-7, use Type L for a distance 3D downstream, L = From Table 5-1, d50 = 9 in From Fig. 5-6. Riprap depth from outlet to dist. U2 = 18.0 in Riprap depth from U2 13.5 in Width of riprap (extend to height of culvert) = 3.75 ft Q/D2.5 = 0.5 From Fig. 5-9, Expansion factor, 1/(2 tan 0) = 2.25 At = Q/V = 0.17 ft2 L = (1/(2 tan 0))*(At/Yt - W) _ -1.24 ft Use L = 3.75 ft Use W = 3H = 3.75 ft 3.75 ft Riprap.xls Page 1 of 1 3/27/2003 Riprap Calculations for Pipe Outlets LOCATION: RIVERBEND PROJECT NO: .157-01 COMPUTATIONS BY: TDS SUBMITTED BY: North Star Design DATE: 3/27/2003 From Urban Strom Drainage Criterial Manual, March 1969 (Referenced figures are attached at the end of this section) Q = discharge, cfs D = diameter of circular conduit, ft W = width of rectangular conduit, ft H = height of rectangular conduit, ft Yt = tailwater depth, ft At= required area of flow at allowable velocity, ft2 V = allowable non -eroding velocity in the downstream channel, ft/s = 7.0 ft/s for erosion resistant soils = 5.5 ft/s for erosive soils Outlet Structure 15" RCP - Strom Sewer B Q = 5.0 cfs D = 15 in = 1.25 ft Yt = 0.5 ft V = 5.5 ft/s Q/D'.5 = 3.6 Yt / D = 0.4 From Figure 5-7, use Type L for a distance 3D downstream, L = From Table 5-1, d50 = 9 in From Fig. 5-6. Riprap depth from outlet to dist. U2 = 18.0 in Riprap depth from L/2 13.5 in Width of riprap (extend to height of culvert) = 3.75 ft Q/D2.s = 2.9 From Fig. 5-9, Expansion factor, 1/(2 tan 0) = 6.75 At = QN = 0.91 ft2 L = (1/(2 tan 0))*(At/Yt - W) = 3.84 ft Use L = 4 ft Use W = 3H = 3.75 ft 3.75 ft Riprap.xls Page 1 of 1 C-/O. 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 APPENDIX D DETENTION AND WATER QUALITY CALCULATIONS D DETENTION MINIMUM DETENTION VOLUME REQUIRED FAA METHOD ' (100-YEAR) LOCATION: RIVERBEND PROJECT NO: 157-01 COMPUTATIONS BY: TDS SUBMITTED BY: NORTH STAR DESIGN DATE: 3/27/2003 Equations: ' Qp = CIA Vi=TCIA=TQD Vo=QPoT S=Vi -Vo Rainfall intensity from City of Fort Collins IDF Curve i A trib. To pond = 1.33 . C (100) = 0.88 Developed C A = 1.17 QPo = 0.76 1 acre acre cfs Storm Duration, T (min) Rainfall Intensity, I (in/hr) Qo (cfs) Vol. In Vi (ft) Vol. Out Vo (ft) Storage S (ft) Storage S (ac-ft) 5 9.95 11.6 3494 228 3266 0.075 10 7.72 9.0 5421 456 4965 0.114 20 5.60 6.6 7865. 912 6953 0.160 30 4.52 5.3 9522 1368 8154 0.187 40 3.74 4.4 10506 1824 8682 0.199 50 3.23 3.8 11341 2280 9061 0.208 60 2.86 - 3.3 12050 2736 9314 0.214 70 2.60 3.0 12781 3192 9589 0.220 80 2.40 2.8 13483 3648 9835 0.226 90 2.20 2.6 13904 4104 9800 0.225 100 2.05 2.4 14396 4560 9836 0.226 110 1.95 2.3 15063 5016 10047 0.231 . 120 1.80 2.1 15168 5472 9696 0.223 ' 10047 Required Storage Volume: ft3 1 0.231 acre-ft 1 J ' Page 1 2 3/27/2003 REQUIRED WATER QUALITY VOLUME LOCATION: Riverbend ITEM: Water Quality Pond Sizing COMPUTATIONS BY: TDS SUBMITTED BY: North Star Design, Inc DATE: 3/27/2003 From Urban Strom Drainage Criterial Manual, March 1969 (Referenced figures are attached in Appendix) Use 40-hour brim -full volume drain time for extended detention basin Water Quality Capture Volume = WQCV = (required storage/12)"(tributary drainage area) MAJOR BASIN Trib. area (ac) % Imperv. Req. Storage (in. of runoff) from Fig. 5-1 WQCV (ac-ft) DWQ (ft) req. vol WQCV •1.2 (ac-ft) req. area/row (in 2/row) from Fig. 5-3 POND 1.33 63.5 0.25 0.028 1.39 0.033 0.15 WQ outlet sizing for pond 1 From Figure 5, for 7/16 in. hole diameter Area of hole = 0.15 in # of columns = 1 Area provided/row = 0.15 in Area Required/row = 0.15 in Use 1 columns of 7116" diam holes WQVOL.xls D-z d �1 i O , Cf :3 (n o > z o � c U C U O w A O O O G. mma�icu y c A z H a a)M CD +� cn M x o � C E L a t C? c a N + O' -00 N �A CO o zzM +> -aa a a d cn > 3 z0 ozHw a � w oao�a .aaUcn O �, O CDO M In r M N y6 ? N O O O O O r Cl N O > ... 0000000 C N N O O C C U a) O CN O 0 N a) > :d O O O cu cu U (6 N �C%.� O 000 C)O CV cm tocoO M N co H� v r N CD r r CpON JID O ti to r:O ON r o h M T M N v cu fO CO M cl) r N p .i o N 01 N CO ) Q -- N M V' LO COD �novooaoo M o w o 0 1- o cm 4 6 6 o ti ti O Cn CD O 0 o 0 O 0 m 0 O 0 O 0 o �! d 'It It v � O O O O CA V V w � w w N N C-) CD M I-- C") N M CDM � m CO o N CN o N N o o o m C C u u E E ? 11 a > > 75 k 0 0 > w ) X_0 fu T d o N (u c d D-3 Detention Pond Outlet Sizing (100 yr event) LOCATION: RIVERBEND CONDMINIUMS PROJECT NO: 157-01 COMPUTATIONS BY: TDS DATE: 3/27/2003 Submerged Orifice Outlet: release rate is described by the orifice equation, Q. = C.A. sqrt( 2g(h-Eo)) where . Qo = orifice outflow (cfs) Co = orifice discharge coefficient g = gravitational acceleration = 32.2 ft/s A, = effective area of the orifice (W) Eo = geometric center elevation of the orifice (ft) h = water surface elevation (ft) Allowable Release Rate Allowable Release = 0.96 cfs Proposed Detention Pond -100yr RELEASE RATE Qo = 0.96 cfs outlet pipe dia = D = 15.0 in Invert elev. = 4904.25 ft Eo = 4904.44 ft h = 4907.78 ft - 100 yr WSEL Co = 0.61 solve for effective area of orifice using the orifice equation Ao = 0.107 ft` 15.5 in' orifice dia. = d = 4.44 in Check orifice discharge coefficient using Figure 5-21 (Hydraulic Engineering) d/ D = 0.30 kinematic viscosity, v = 1.22E-05 ft2/s Reynolds no. = Red = 4Q/(7Edv) = 2,71E+05 Co = (K in figure) = 0.61 check Use d = 4.5 in Ao = 0.110 ftZ = 15.90 in Qmax = 0.99 cfs D-Y Riverbend Emergency Overflow Spillway Sizing LOCATION: Riverbend PROJECT NO: 157-01 COMPUTATIONS BY: TDS SUBMITTED BY:. North Star Design DATE: 3/27/2003 Equation for flow over weir Q = CLH311 where C = weir coefficient = 3.1 H = overflow height L = length of the weir toD of berm H 4 splll elevation .� L -� p 140 yr WSEO_ Spillways will be designed with 0.5 ft flow depth, thus H = 0.5 ft Size the spillway assuming that the pond outlet is completely clogged. Detention Pond Q (100) = 9.10 cfs Spill elev = 4907.80 ft 100 yr WSEL = 4907.78 ft Min top of berm elev.= 4908.30 ft Weir length required: L = 8.30 ft Use L= 10.0 ft v = 1.48 ft/s APPENDIX E FIGURES AND TABLES E No Text City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (5 minutes - 30 minutes) Figure 3-1a Duration (minutes) 2-year Intensity in/hr 10-year Intensity in/hr 100-year Intensity in/hr 5.00. 2.85 4.87 9.95 6.00 2.67 4.56 9.31 7.00 2.52 4.31 8.80 8.00 2.40 4.10 8.38 9.00 2.30 3.93 10.00 2.21 3.78 7.72 11.00 2.13 3.63 7.42 12.00 2.05 3.50 7.16 13.00 1.98 3.39 6.92 14.00 1.92 3.29 6.71 15.00 1.87 3.19 6.52 16.00 1.81 3.08 6.30 17.00 1.75 2.99 6.10 18.00 1.70 2.90 5.92 19.00 1.65 2.82 5.75 20.00 1.61 2.74 5.60 21.00 1.56 2.67 5.46 22.00 1.53 2.61 5.32 23.00 1.49 2.55 5.20 24.00 1.46 2.49 5.09 25.00 1.43 2.44 4.98 26.00 1.40 2.39 4.87 27.00 1.37 2.34 4.78 28.00 1.34 2.29 4.69 29.00 1.32 2.25 4.60 30.00 1.30 2.21 4.52 r- . .. _-, r- 1 1 1 1 1 1 1 F 1 1 1 1 1 1 1 City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (31 minutes - 60 minutes) Figure 3-1 b Duration (minutes) 2-year Intensity in/hr 10-year Intensity in/hr 100-year Intensity in/hr 31.00 1.27 2.16 4.42 32.00 1.24 2.12 4.33 33.00 1.22 2.08 4.24 34.00 1.19 2.04 4.16 35.00 1.17 2.00 4.08 36.00 1.15 1.96 4.01 37.00 1.13 1.93 3.93 38.00 1.11 1.89 3.87 39.00 1.09 1.86 3.80 40.00 1.07 1.83 3.74 41.00 1.05 1.80 3.68 42.00 1.04 1.77 3.62 43.00 1.02 1.74 3.56 44.00 1.01 1.72 3.51 45.00 0.99 1.69 3.46 46.00 0.98 1.67 3.41 47.00 0.96 1.64 3.36 48.00 0.95 1.62 3.31 49.00 0.94 1.60 3.27 50.00 0.92 1.58 3.23 51.00 0.91 1.56 3.18 52.00 - 0.90 1.54 3.14 53.00 -- 0.89 1.52 3.10 54.00 0.88 1.50 3.07 55.00 0.87 1.48 3.03 56.00 0.86 1.47 2.99 57.00 0.85 1.45 2.96 58.00 0.84 1.43 2.92 59.00 0.83 1.42 2.89 60.00 0.82 1.40 2.86 C_ 2 3.1.6 Runoff Coefficients ' The runoff coefficients to be used with the Rational Method referred to in Section 32 -. "Analysis Methodology" can be determined based on either zoning classifications or the types of surfaces on the drainage area. Table 3-2 lists the runoff coefficients for the various types of zoning along with the zoning definitions. Table 3-3 lists coefficients for the different kinds of surfaces. Since the Land Development Guidance System for Fort Collins allows land development to occur which may vary the zoning requirements and produce runoff coeffi- cients different from those specified .in Table 3-2, the runoff coefficients should not be based ' solely on the zoning classifications. The Composite Runoff Coefficient shall be calculated using the following formula: C = (rC;A;)/At Where C = Composite Runoff Coefficient C; = Runoff Coefficient for specific area A; ' A; = Area of surface with runoff coefficient of Ci n = Number of different surfaces to be considered At = Total area over which C is applicable; the sum of all A;'s is equal to At Table 3-2 RATIONAL METHOD RUNOFF COEFFICIENTS FOR ZONING CLASSIFICATIONS ' Description of Area or Zoning Coeffxient Business: BP, BL........................................................................................ 0.85 ' Business: BG, HB, C.................................................................................. 0.95 Industrial: IL, IP.......................................................................................... 0.85 Industrial: IG............................................................................................... 0.95 Residential: RE, RLP ................. Residential: RL, ML, RP .......................................... ........:.......................... 0.50 Residential: RLM, RMP....................................---...:................................... 0.60 Residential: RM, MM............................................... ....................:.............. 0.65 Residential: RH.................................................................................... ... 0.70 Parks, Cemeteries................................................................. ................... 0.25 ' Playgrounds ^ RailroadYard Areas................................................................................... 0.40 UnimprovedAreas...................................................................................... 0.20 Zoning Definitions R-E Estate Residential District — a low density residential area primadly in outlying ' areas with a minimum lot area of 9,000 square feet. R-L Low Density Residential District — low density residential areas located throughout the City with a minimum lot area of 6,000 square feet ' R-M Medium Density Residential District — both low and medium density residential areas with a minimum lot area of 6,000 square feet for one -family or two-family dwellings and 9,000 square feet for a multiple family dwelling. ' R-H High Density Residential District —high density residential areas with a minimum lot area of 6,000 square feet for one -family or two-family dwellings, 9,000 square feet for a multiple family dwelling, and 12,000 square feet for other specified uses. ' R-P Planned Residential District — designation of areas planned as a unit (PUD) to pro- vide a variation in use and building placements with a minimum lot area of 6,000 square feet ' R-L-P Low Density Planned Residential District— areas planned as a unit (PUD) to permit variations in use, density and building placements, with a minumum lot area of 6,000 square feet I MAY IN4 3-3 DESIGN CRfrERIA ,.— ._. W Li 1 IMAY 19" R-M-P Medium Density Planned Residential District — designation for medium density area planned as a unit (PUD) to provide a variation in use and building placements with a minimum lot area of 6,000 square feet. R-L-iM Low Density Multiple Family District— areas containing low density multiple family units or any other use in the R-L District with a minimum lot area of 6,000 square feet for one -family or two-family dwellings and 9,000 square feet for multiple -family dwellings. M-L Low Density Mobile Home District — designation for areas for mobile home parks containing independent mobile homes not exceeding 6 units per acre. M-M Medium Density Mobile, Home District — designation for. areas of mobile home parks containing independent mobile homes not exceeding 12 units per acre. B-G General Business District — district designation for downtown business areas, including a variety of permitted uses, with minimum lot areas equal to 112 of the total floor area of the building. B-P Planned Business District — designates areas planned as unit developments to provide business services while protecting the surrounding residential areas with minumum lot areas the same as R-M. H-B Highway Business District — designates an area of automobile -orientated busi- nesses with a minimum lot area equal to 1 /2 of the total floor area of the building. B-L Limited Business District — designates areas for neighborhood convenience centers, including a variety of community uses with minimum lot areas equal to two times the total floor area of the building. C Commercial District —designates areas of commercial, service and storage areas. i-L Limited Industrial District —designates areas of tight industrial uses with a minimum area of lot equal to two times the total floor area of the building not to be less than 20,000 square feet I-P Industrial Park District —designates light industrial park areas containing controlled industrial uses with minimum lot areas equal to two times the total floor area of the building not to be less than 20,000 square feel I-G General Industrial District — designates areas of major industrial development. T Transition District — designates areas which are in a transitional stage with regard to ultimate development For current and more explicit definitions of land uses and zoning classifications, refer to the Code of the City of Fort Collins, Chapters 99 and 118. Table 3-3 RATIONAL METHOD RUNOFF COEFFICIENTS FOR COMPOSITE ANALYSIS Character of surface Runoff coefficient Streets, Parking Lots, Drives: Asphalt................................................................_............................ 0.95 .. Concrete.............._......................................................_................. 0.95 Gravel................................................................................................. 0.50 Roofs.......................................................................................................... 0.95 Lawns, Sandy Soil: Flat<20/9............................................................................................. 0.10 Average2 to 7%.................................................................................. 0.15 Steep >70/6.......................................................................................... 0 .20 Lawns, Heavy Soil: Flat<20/6............................................................................................. Average2 to 7%.......................................................................... .... Steep>7'/6.......................................................................................... 3-4 020 0.25 0.35 DESIGN CRITERIA 3.1.7 Time of Concentration ' In order to use the Rainfall Intensity Duration Curve, the time of concentration must be known. This can be determined either by the following equation or the 'Overland Time of Flow Curves" from the Urban Storm Drainage Criteria. Manual, included in this report (See Figure 3-2). Tc=1.87 1.1 —CC W`2 S ' Where Tc =Time of Concentration, minutes S = Slope of Basin, % C = Rational Method Runoff Coefficient 0 = Length of Basin, feet Cr = Frequency Adjustment Factor Time of concentration calculations should reflect channel and storm sewer velocities as well ' as overland flow times. 3.1.8 Adjustment for Infrequent Storms The preceding variables are based on the initial storm, that is, the two to ten year storms. For storms with higher intensities an' adjustment of the runoff coefficient is required because of the lessening amount of infiltration, depression retention, and other losses that have a proportionally smaller effect on storm runoff. ' These frequency adjustment factors are found in Table 3-4. Table 3-4 RATIONAL METHOD FREQUENCY ADJUSTMENT FACTORS Storm Return Period FrequencyFactor ct 2to 10 1.00 11 to 25 1.10 �. 26 to 50 120 ' S1 to 100 125 Note: The product of C times C, shah not exceed 1.00 ' 32 Analysis Methodology . The methods presented in this section will be instituted for use in the determination and/or verification of runoff at specific design points in the drainage system. These methods are (1), the Rational Method and (2) the Colorado Urban Hydrograph Procedure (CUHP). Other computer methods, such as ' SWMM, STORM, and HEC-1 are allowable if results are not radically different than these two. Where applicable, drainage systems proposed for construction should provide the minimum protection as determined by the methodology so mentioned above. ' 3.2.1 Rational Method For drainage basins of 200 acres or less, the runoff may be calculated by the Rational Method, which is essentially the following equation: Q = C,CLk Where Q =Flow Quantity, cfs A = Total Area of Basin, acres ' Ct = Storm Frequency Adjustment Factor (See Section 3.1.8) C = Runoff Coefficient (See Section 3.1.6) 1 = Rainfall Intensity, inches per hour (See Section 3.1.4) ' 3Z2 Colorado Urban Hydrogmaph Procedure For basins larger than 200 acres, the design storm runoff should be analyzed by deriving synthetic unit hydrographs. It is recommended that the Colorado Urban Hydrograph Procedure be used for such anaiysis. This procedure is detailed in the Urban Storm Drainage Criteria Manual, Volume 1, Section 4. ' MAY 1984 3-5 DESIGN CRITFUA S F' "�n mossessumn pf■■fff■� ff■■■■■■■� ■■ 11V .moss /■o■I ff •r � �ff.�■ ■ ■ •■ �'/■ it �■ w .fff as .moor.. ..f. �I/■I/fit/t�■%■�■■ tf.r4", Na'/■■�■■ 'Arl■r./■■:1 ■■!■■t��■ I/f Afflfl fff•■fff'. /.f►fff'/fl f'/:fff■rf /f/ff�fft r.f:■fff.A. frff.'soot �.■.�.�.. /■■soot! i■■�■� iit■ 1■t"/■/Il ■■/I'a ffrff■Ift f■osfoN iffufr.ffl .f•f..Nf s•.ffrofft ■•.�ffffff Ilan■I■■tl ►■�■■>•�■� ■■%■■■tr■�■■■Oi■ �■f•�ffffl� ff■ff.If. If I.■■■■I/1 ■■�■I/ff■ 1�1ff■fffrffl�/Nf i '/ff■►Iffl ■■rI■fl�f ■■■II■ffl ■//■■>!ff■ IS.INfff/ /f��ffff� II/■■■■■!r ■■:■■t■!M fASfff:fa i..ifal� dllfl not o..r. 1 wI ... .. _.. .. ., .... ...... ..... .«era .... .. t.t I t': tia ri:. 1 ' Basically, a unit hydrograph is that hydrograph which corresponds to 1.0 inch of direct runoff from the tributary area resulting from a unit storm. The unit hydrograph reflects the physic - graphic features of the subject basin such as area, shape, street pattern, channel capactities, and street and land slopes. 3.2.2.1 Infiltration Table 3-5 gives' those values for depression and detention effects on runoff. As the 1 storm progresses, the amount of infiltration will decrease because depressions become filled and soil becomes saturated. Table 3-6 gives the infiltration rates to be used with CUHP. Test determined infiltration rates may also be used. 1 Table 3-5 TYPICAL DEPRESSION AND DETENTION FOR VARIOUS LAND COVERS (All Values in Inches) 1 (For Use with CUHP Only) Land Cover Depression & Detention fn.) Impervious: 1 Large Paved Areas0.1 .................................... Roofs —Flat .................0.1 Roofs— Sloped........................................................ 0.1 1 Pervious: Lawn Grass............................................................... 0.5 Wooded Area and Open Fields ................................. 0.4 1 Table 3-6 INFILTRATION RATES (For Use With CUHP Only) - 2nd Half Hour Storm Requm y 1 st Hatf Hour To End Or storm 2 to 5 yr. return ................. 3/4 inch/hr. 112 inch/hr. 10 to 100 yr. return ........... 112 inch/hr. 112 inch'hr. 3.2-2.2 Pervious — Impervious Area 1 In order to determine percentages of impervious land cover for a given land use or zoning, Table 3-7 shall be utilized. Table 3-7 LAND USE VERSUS PERCENT OF IMPERVIOUSNESS (For Use With CUHP Only) Land Use or zoning t Percent Pervious Percent h wavious Business: 1 BG, BL, BP, HB, C, IL, IG, lP ............... 10 Residential: 90 1 RH, RMP .............................................. RM, RP, MM........................................ 55 RM, RMP, RE, RLM, ML ..................... 60 Parks, Greenbelts, etc ........................ ..... 90 60 45 40 10 t See Tabie 3-2 for zon ft de&jdom 1 1 MAY 1984 3-7 DESIGN CRtTERtA Heavy Duty �otal Weight 460 Pounds R 3501 R .-,',-In 64,for Roll, Type:.Curb Heavy Duty 1 Total Weight 540 Pounds L 301 a 1 28"7 29 I I— 31 27— AQ� N EENAH n DRAINAGE CRITERIA MANUAL (V. 3) . I$] 0.- o c ' `o N m L U ' m L N s roe-a.di $ 3 o.zs 0 0." m m o: 0.' 9-1-1992 UDFCD STORMWATER OUALITY MANAQEMIVT- xten P-Ho ed Detention r Drai I time Basi (Dry) IMP- 0 10 20 30 40 s0 60 70 80 90 100 Percent Impervious Area in TributA ry Watershed Source: Urbanos, Guo, Tucker (1989) Note: Watershed inches of runoff shag apply to the entire watershed tributary to the BMP Facility. FIGURE 5-1. WATER QUALITY CAPTURE VOLUME (WQCV) -if - 1;'1 ' DRAINAGE CRITERIA MANUAL(V. 3) ( 10.0 6" 4.0 ' 2.0 ' 1.0 ' 0.6C 0.4C U lb COC C > 0.2C m 7 n. U 0.1C O %✓Q Va I 0.04 0.033 ' 0.02 ' 0.01 STRUCTURAL BMPs PAF EXAMPLE: DW(:) = 4.5 ft Required Area per _==�_ m P ZVA, viemlj 020 PA KSOLUTION: I mwfiw,�A ONE i W, Val ZRAR, FAIN PAr 11 For PAr Pj jrA 1J�i■�I�■I , FOA 11 Ar I ®r, rj molm 0.02 0.04 / 0.06 0.1 0.20 1.0 2.0 4.0 6.0 2� d 7o-- co- OAequired Are�per Row (in. Soume: Douglas County Storm Drainage and Tac n ntena, 19 - FIGURE 5-3. WATER QUALITY OUTLET SIZING: DRY EXTENDED DETENTION BASIN WITH A 40-HOUR DRAIN TIME OF THE CAPTURE VOLUME Rev.3-1-1994 FCD UD F"— I A Orifice Plate Perforation Sizing Circular Perforation Sizing y Chart may be applied to orifice plate or vertical pipe outlet. Hole Did (in) Hole Dia (in) Min. Sc (in) Area per.Row (sq in) n=1 n=2 n=3 1/4 0.250 1 0.05 0.10 0.15 5/16 0.313 2 0.08 0.15 0.23 3/8 0.375 2 1 0.22 0.3. 7/16 0.438 2 0.15 0.30 0.45 1 /2 0.500 2 0.20 0.39 0.59 9/16 0.563 3 0.25 0.50 0.75 5/8 0.625 3 0.31 0.61 0.92 11 /16 0.688 3 0.37 0.74 1.11 3/4 0.750 3 0.44 0.88 1.33 7/8 0.875 3 0.60 1.20 1.80 1 1.000 4 0.79 1.57 2.36 1 1 /8 1.125 4 0.99 1.99 2.98 1 1/4 1.250 4 1.23 2.45 3.68 1 3/8 1,375 4 1.48 2.97 4.45 1 1 /2 1.500 4 1.77 3.53 5.30 1 5 8 1.625 4 2.07 4.15 6.22 1 3 4 1.750 4 2.41 4.81 7.22 1 7 8 1.875 4 2.76 5.52 1 8.28 2 2.000 4 3.14 6.28 9.42 n = Number of columns of perforations Minimum steel plate thickness 1/4 5/16 3/8 " Rectangular Perforation Sizing. Only one column of rectangular perforations allowed. Rectangular Height = 2 inches Rectangular Width (inches) = Req:::red Area per Row (sq in) 2" N Urban Drainage and Flood Control District 5e^ced rrrcJ S c P«Ta►J Rectangular IMin. Steel Hole Width IThickriess 5" 1/4 1 6„ 1/4 ,. 7" 5/32 " 8" 5/16 g" 11 /32 " 10" 3/8 „ Figure 5 WOCV Outlet Orifice Perforation Sizing Drainage Criteria Manual (V.3) Re: V}-Outlet etciadwq T We > O A 41 O W p O W 4-3 k O o b 4-4 41 C� � al ce U) � b O . �l rC c)� O H W 4J. _. O r— - I 'Z S Closed Conduit Flow Red 1 2 i d , K 10, 101 104 105 10" 0 S 102 1W 1047=7. ��/Rey4QS «T rrdv ,« S P[e� 5�m Figure S-21 Flow coefficient K and Re,/K versus the 1, 1 1 1 J 1 1 1 1� 1 DRAINAGE CRITERIA MANUAL 11-15-82 URBAN DRAINAGES FLOOD CONTROL DISTRICT RIPRAP 7--IS DRAINAGE CRITERIA MANUAL 1 tt � RIPRAP NEENEENWAAM NONE►AFAAFE No INN No 0 WAF'A' - mpg 0- .10 111 low Gam/ �iQi� 0 2 4 Y /D 6 8 1.0 _ t ' Use Do instead of D whenever flow is supercritical in the barrel. **Use Type L for a distance of 31) downstream. FIGURE 5-7. RIPRAP EROSION PROTECTION AT CIRCULAR CONDUIT OUTLET. ' 11-15-82 URBAN DRAINAGE 8 FLOOD CONTROL DISTRICT F--- I i.o 1 1 1 1 1 1� 1 1 1 1 1 1 1 1� 1 DRAINAGE CRITERIA MANUAL N 0 � 4 z 0 U) z a x 2 w 1 0 A = Expansion Angle rAd PAN E Ar Emmm'' IfAAW'Aw- RFMENEM 0 .1 .2 .3 .4 .5 .6 .7 .8 TAILWATER DEPTH / CONDUIT HEIGHT, Y t / D RIPRAP FIGURE 5-9. EXPANSION FACTOR FOR CIRCULAR CONDUITS 11-15-82 URBAN DRAINAGE 9 FLOOD CONTROL DISTRICT 1 -7 133UIS I 0 V) �d ?. r =Y Ev ■mmo■m■ ■oo■mu■ ■mmmmmm moommom FEDERAL EMERGENCY MANAGEMENT AGENCY FLOOD PROFILES KEWSED TO I"IMER COUNTY, CO (UNINCORPORATED AREAS) CACHE LA POUDRE LPA DEC ..2 i 9c. BASIN LuDCWNroYATE all I % I LINTS FOR BASN C 20 10 0 20 40 SCALE, V of 20' ■ LEGEND - TCH 1 � �ac DESIGN PONT nN BE�e. 411410.50 C___--- \ ¢gym too x -- BASIN CRITERIA O 0 CT 2 / ` \ x x • 2YR RUNOFF COEFFICIENT U Cq 12 DorrrV7 AREA IN ACRES 1� C E a, FLOW DIRECTION C q r E 15a . n 1 BASIN BOUNDARY ati79 S ISTNG PIPES C====Z3 EXISTNC INLET AND PIPE 1 buildin I \ pPd\ I® PROPOSED INLET AND PIPE 21 FLARED END SECTION allies 1 \III PROPOSED INLET LOCATION E 1 1 l \ EXISTING 5' CONTOUR / "__-------- ..- EXISTING 1' CONTOUR o — �•010, PROPOSED 5' CONTOUR i x SF PROPOSED 1' CONTOUR r ,RHEA DINBn, DRAMA¢ • O —j(X— SILT PENCE 1 11p000 /... —.., yy ACCESS FA T _ _ _ (DETAIL SHEET 9) 1 \ ; � • ... � z INLET (DETAIL OSHEET 9) z 1 ,I / — 1 — /\ \ O ® CONSTRUCTION ENTRANCE G pQ(DETAIL SHEET 8) MUST + w \ 1 M 1 A1[OEATMLL 1 \ O �` EROSION BALES p An iC 1 9�/xF.E�TT (DETAIL SHEET B) T ` � LaC.AN MTxxI ar � PROPERTY LINE CQf O sl a' a sT— — — — — — — — — — — EASEMENT LINE n a. 0.580. IP ______________________ BUILDING ENVELOPE J day9.M tDA — — — BUFFER ZONE d EMSTMe zTaiMiiMfi' / E —.. - --... —... — .• p Ir oer 11 -" - a \ V. be City air Fort Caere Siam vow, utility •woo.. cwtm mWe site must / U 0.,''} I s/• e• notified M ..« v ours wlw m am.wnm m A•.ue. PRIVATE' DRIVE Mlj AN .eaa,ed perimeter silt rwa.v she be metalled purr to any Tom 0 -Ell, -■,III A /' C r dW mA90e Nr •me ampmB roam ere A osier m W� /II ri I __ — p r«ulrea fiber, c tmu measures Na be mtri at the o prol \ ... — ... —... & time a theacmer,mm sera nna was as noodles m thhe approvM protect n a \ LOCo rx on p control ron VnuPre aNNNanae vw•tatam Ian cbe brotwba and maned where IN.AIESIDET! NL�«�me rwlr.Oara low ieti of «I„<nQ� •�atMuvuaanesrwmlMl«i o an o 7 1 1 1 wt«t prod m .. /- I AN .oI• emosea duringland eN remo aeuatr eptrap rev. BraenB amny I e reram b t An d g ter) «an co tour m a ra veer.., ] \ I I I I sa Will e raffi or the, 9 m,mmtt ekIng Ammul, calnd is Is iu .am No Me in • of project .beet ,puts b vov MOII'remain •apoue by land Askant B oil air for more than tnxtr(.SD) Ad" before real Btu 1� IIItwrwrmr w Permanmt w«km rwrm (.ever sera/maw, Iakuha v. t *to) Is mnaied. 11w otn•nI« Optimal by the Sturm Netw utBlty B I Tas tr soak be rFwed and maintained at al tines during w 0.12 W I B Ly i co,st ial no as to prema ! wind-oau•oa waxer All and I aTNawstarMan g 0« sealam e . katxr dlstl,. . w Ago" dust IWM Impacts 0apcmt prm mm. nee er the City of Fort opera MO fiflaul Wall be irl and nearly! or ng D k lewwuwD woman tuba Ir Sr child Intended turbid, of m blared cause Aerder to :emand ho cup rof 1those .�.mu..t worm I d„ 00owa m eere we eto �yb a n y ,Do' eu1RR ZOIc •, I _ _ _ _ _ _ _.. _ _ _ _ _�_ = � a .. � o pro nogwox w q - s W Na «l sb6te• No evil«a ren (10) met n y sunk AI wl sing. • N 9da � SE'Adr Naalk e. ld parts xpn .ere emt . Any a er tormils remains m swig Ana bbe seeded r rmemg. Anr .on «xtp • r•mannv area — — — —� �,./pRCfGn g JD dap .no ale ...aa ma mu mere. z T 9cTu� coy aemwc. pwnE I. A• w«mv. arwP rev sir dap« t ng or «N. air Q xnrvRAL MEAs 1 1 STAL Carl MTER AT WIy1Tr PIXA TRACT A O mr other matwld onto Ctr st.«A ey or bun mr acnae. Mr a PARKING LOT IEpfTMp 1 1 M£i aRlxc CdrS1RI1cnM. tLOyr XM6 •9D].]e TO Mf pAyL / Faal«r`snr fro«itM matwla snau e. Osier, lmm•alawr er u• J EMS+MO 91Wa SEKA pq�glY E6. �L tta rec u +r PIP / UN M p• R•N to the LANDSCAPE PLAN rw ««/mulch mature to be used F tlI O 1 Mpnl • O• \ \ MUN•a was of m• Nmurtl N«. I. s o z . _ .. — .. — .. — . ' _ gmxaDhsmroww`.rroycArE,Dvae¢ Rl�u e" WAY _ ~ — 3 / — / / - a O W Ln J O \ gMiere — T, I Fan rRGF.as / W EMs1NG s+pM EMSTMC TRII / XK-`_— _ X% X% ' qJ TOP OF Ill+ \ \ / Users a toot /—____.________________ CC W � C_ — \ —� — mwacs — �_— NPMIXUFLEV- wmao / __ __ 20 10 0 20 a.I U' -� _ tFLDLEn PMDR ID l_ ` — —� — ��` _— _ �--- — — _z r% MPRM MSVLIAIIMI. �� �— —A906 _ _ _ —_-- SALE, V = 20' Q --_ �___� / -- —�-----------___----- _ City of Fort Collins, Colorado --_ UTILITY PLAN APPROVAL — --- .—_ �.— �•�����.� APPROVED: L�p1MDtN�EapD�MOpa-4r--J / Primer oI G9M«Nq We TO pgtdmq�TDIFE ,l/ / DER DCAVATE DETENnw FORD BY V wrA1D CHECKED BY: SHEET CA6TM1 M TO BE USED AS A SEINYENT TRAPALL �MT SHALL BE Simm.vtw DIVA Date TO FM511ED DRACE PMpf t0 CFUTIFIa nIXIOMED AND D Mrd1aT r CALL UTILITY NOTIFICATION CHECKED BY. CENTER OF COLORADO] Polo a R«rearm Date Rom) 1-800-922-1987 CHECKED BY: Twmr nqm«r Data 1.1e }f QUL 2 BUSINESS DAYS IN ADYMCE CHECKED BY 5 OF 10 OIO IB DEFOR THE DIrMIfi.D 4�POF MDPSEp YC�D Natural Rarourws Dats 00 5 DRAINAGE SUMMARY TABLE DESw POINT APEA DESIGN. AREA AL'RES e9 CIBB To (2) W Tog JI A A 0AT 0AT am 'a B B 0A3 D.N 0•] ].I B.• c c D.N am 1.00 ].] 5.1 DETENTION POND SUMMARY mpna REtTwpeD D9v Ail n DETExnax PRouom om9 Acre NCO M wD/.]B MA% flNEAg gAIE 0.B6 fi5 CHECKED BY: Data Job No. 15%-Ol