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HomeMy WebLinkAboutDrainage Reports - 07/25/2002;nal A r` vad Report D r Date :MZS_ * IyROpERTY OF FORT COLLINS bTUXrM FINAL DRAINAGE AND EROSION CONTROL REPORT WESTCHASE P.U.D. BLOCK 11, LOT 1 POUDRE FIRE AUTHORITY STATION #14 rj` D F, ' FINAL DRAINAGE AND EROSION CONTROL REPORT t WESTCHASE P.U.D. BLOCK 11, LOT 1 POUDRE FIRE AUTHORITY STATION #14 1 . 1 Prepared for: Poudre Fire Authority " 102 Remington Street ' Fort Collins, CO 80526 Prepared by: ' ,r North Star Design, Inc.# ' 700 Automation Drive, Unit I Windsor, Colorado 80550 Ph# (970) 686-6939 ' Fax# (970) 686-1188 May 24, 2002 Job Numb erl14-22"' Y A i j North Star anow design, inc. [I [' May 24, 2002 [I Basil Hamdan l City of Fort Collins Stormwater 700 Wood Street (' Fort Collins, CO 80522-0580 l RE: Final Drainage Report for Westchase P.U.D. Block 11, Lot 1 [' Poudre Fire Authority Station 414 Dear Basil, I am pleased to submit for your review and approval, this Final Drainage & Erosion Control Report for Westchase P.U.D. Block 11, Lot 1, Poudre Fire Authority Station #14. I certify that this report for the drainage design of Poudre Fire Authority Station # 14 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, (' Patri is Kroetch, P. . North Star Design, I It ii 700 Automation Drive, Unit I Windsor, Colorado 80550 970-686-6939 Phone • 970-686-1188 Fax 2. ' GENERAL LOCATION AND DESCRIPTION 1.1 Location This site is located in Block 11 of the Westchase P.U.D. in the Southwest Quarter of Section 8, Township 6 North, Range 69 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 east of Timberline Road, north of Trilby Road and south of Westchase Road. The site is bounded by residential development on the east and north boundaries and by future church site on the south boundary. 1.2 Description of Property The entire project consists of 0.88 acres of land. The land is currently undeveloped and slopes to the southeast at approximately 1.5%. The runoff from the site currently enters the adjacent street and is conveyed to a detention pond. The project will consist of a single structure which will be a fire station with bay doors and associated drives and parking area. The site will access from the existing Westchase Road on the north and a proposed private access on the south that will connect from Timberline Road to Carmichael Street. DRAINAGE BASINS AND SUB -BASINS 2.1 Major Basin Description The proposed development lies within the Fossil Creek Reservoir Drainage Basin. The site is included in the area covered by the Final Drainage Report for Westchase P. U.D..by David Evans and Associates dated December 14, 2000. Portions of this report are included in Appendix E. 2.2 Sub -basin Description This site is included in Basin 71 of the Westchase P.U.D. The site is restricted to the 1 criteria established in the Final Drainage Report for Westchase P. U.D. Detention and water quality are provided for this site in the ponds south and east of this site. The site accepts no runoff from the adjacent streets on the west, north and east and will discharge to Carmichael Street along the eastern boundary of the site. DRAINAGE DESIGN CRITERIA 3.1 Regulations This report was prepared to meet or exceed the "City of Fort Collins Stonn Drainage Design Criteria Manual' specifications. Where applicable, the criteria established in the "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 and the allowable release rate has been routed to conform to existing drainage reports completed that have included this area. The streets and associated drainage systems surrounding the site are existing. There is no storm system adjacent to this site and therefore, the site will discharge directly to the street. The runoff will flow south in Carmichael to an inlet and into a storm system that will cant' the flow to the detention area. Detention is provided for this site in the detention ponds up to a 2-year c value of 0.70 and a 100-year c value of 0.88. The site meets this criteria and therefore will not provide any onsite detention. Runoff from the site was calculated based on the rainfall criteria adopted by the City of Fort Collins on March 26, 1999. Water quality measures will also be provided downstream in the form of extended detention. 3.3 Hydrologic Criteria Runoff computations were prepared for the 2-year minor and 100-year major storm frequency utilizing the rational method. All hydrologic calculations associated with the basins are included in Appendix B of this 2 ' 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. ' 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 B of this report. ' 4. DRAINAGE FACILITY DESIGN ' 4.1 General Concept The runoff from this site is split by the proposed building and will flow east on each side of the building in the parking lots via pans, curb & gutter and concrete channels to Carmichael Street. The flow will be conveyed to the detention pond (SB 91) that was ' sized to accept undetained runoff from this site. 1 4.2 Specific Flow -Routing This site is a portion of Basin 71 in the overall Westchase P.U.D. Basin 71 contains 7.55 acres and is limited to a 2-year c-value of 0.70 and a 100-year c-value of 0.88. A portion of Basin 71 is analyzed with this report and the c-value limitation was applied to the portion analyzed. A summary of the drainage patterns within each basin is provided in the following paragraphs. For more specific details see the calculations located in Appendix B of this report. Basin 1 contains the north portion of the site including the north half of the building, the drive area on the north side of the building, the parking lot on the north side of the building and a portion of the landscaped area. Runoff from this basin flows to the east in pans to a concrete channel and enters Carmichael (Basin 3) through a metal sidewalk culvert. Basin 2 contains the south portion of the site including the south half of the building and parking, drives and landscaping on the south side of the building. and a portion of the drive areas. Runoff from this basin flows to the east in pans and curb to a concrete 3 I ' channel and enters Carmichael (Basin 3) through a metal sidewalk culvert. Basin 3 contains the eastern portion of the site including the west half of Carmichael along the site frontage. This basin accepts runoff from Basins I and 2 and conveys the flow south to an inlet and storm system that conveys the runoff to the detention area discussed above. ' The overall 2 year c-value for Basins 1, 2 and 3 is 0.66 and the overall 100 year c-value is ' 0.83. This meets the criteria set forth in the previous study and no further analysis of the downstream facilities was completed. 4.3 Drainage Summary The storm conveyance system is a surface and sub -surface system and has been designed ' for minimal maintenance. The proposed storm sewer system (outlet structure and pans) and the detention pond will be owned and maintained by the property owners. The existing storm system shall be maintained by the City of Fort Collins or other responsible parties. 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. 5.2 Specific Details To limit the amount of silt leaving the site, several erosion control measures shall be ' 4 1 1 1 6. 1 implemented during construction. Silt fence shall be installed along the southern and eastern sides of proposed site. Also, vehicle -tracking pads shall be installed at the three entrances to the site 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 During the performance of the work required by these plans, the contractor shall carry out proper efficient 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. 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. CONCLUSIONS 6.1 Compliance with Standards All computations that have been completed within this report are in compliance with the 5 I 1 0 1 7. 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 transmission of developed on -site runoff to the storm system in Carmichael and to the detention area downstream. The impact of the development of this site on downstream facilities has been accounted for in the previous drainage report for the overall Westchase P.U.D. Imperviousness of the site was restricted to meet the criteria set forth in the Final Drainage Report for Westchase P. U.D. 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. REFERENCES 1. City of Fort Collins, "Storm Drainage Criteria Manual", (SDCM), dated March, 1986. 2. The Final Drainage Report for Westchase P. U.D..by David Evans and Associates dated December 14, 2000. 3. Urban Drainage and Flood Control District, "Urban Storm Drainage Criteria Manual", Volumes 1 and 2, dated March, 1969, and Volume 3 dated September, 1992. 6 APPENDIX A 141"MolvadOw A \ C � F 5s BA EE 0 Y pa � Z t � m CS W COUNTY ROAD No. 36 t s t m� Ooy=o 0 U xQ Z p 0 _0 .a �a O REE FOS {Z s R x T O J V s l^. 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'03/11/02 FlowMaster v5.15 06:24:38 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 11 1 1 1 1 0 1 Sidewalk Culvert at DP 2 Worksheet for Rectangular Channel Project Description Project File e:\haestad\fmw\pfal4.fm2 Worksheet Sidewalk Culvert 2 Flow Element Rectangular Channel Method Manning's Formula Solve For Channel Depth Input Data Mannings Coefficient 0.013 Channel Slope 0.70 % Bottom Width 2.00 ft Discharge 3.57 cfs Results Depth 0.42 ft Flow Area 0.84 ft' Wetted Perimeter 2.84 ft Top Width 2.00 ft Critical Depth 0.46 ft Critical Slope 0.005287 ft/ft Velocity 4.25 fus Velocity Head 0.28 ft Specific Energy 0.70 ft Froude Number 1.15 Flow is supercritical. '03/11/02 FlowMaster v5.15 06:24:59 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 1 t 1 1 1 APPENDIX C EROSION CONTROL CALCULATIONS le � � � � � � � � � ) &§) ka 00 )20 gjf #�k \ < & \ (2 (j SE ) aaa S oq \ �-- 7 z 0 § ][ §]] § 2 } ){ o00 $ ■2 000 § k S §kk 21:61 � ■ ] � wk S\ 5 w � mM )/ �2 au .( � ) JS��, \}\ \ 7 �\\ �UU 7 4 /00 /a§ 0 -0d) §EQ q G% ] 0 w s± ]aa©® ®2§ w ,;; /7 4a«S« P. LU North Star Design 700 Automation Drive, Unit 1 Windsor, CO 80550 EFFECTIVENESS CALCULATIONS PROJECT: POUDRE FIRE AUTHORITY STATION #14 STANDARD FORM B COMPLETED BY: PPK DATE: 1I-Mar-02 EROSION CONTROL C-FACTOR P-FACTOR METHOD VALUE VALUE COMMENT BARE SOIL 1.00 1.00 SMOOTH CONDITION ROUGHENED GROUND 1.00 0.90 ROADS/WALKS/BLDG 0.01 1.00 GRAVEL FILTERS 1.00 0.80 PLACED AT OUTLET SILT FENCE 1.00 0.50 STRAW MULCH 0.06 1.00 ESTABLISHED GRASS 0.08 1.00 FROM FIGURE 8-A STRAW BARRIERS 1.00 0.80 EFF = (1-C*P)*100 MAJOR SUB BASIN AREA EROSION CONTROL METHODS BASIN BASIN (Ac) 1 0.40 ROADS/WALKSBLDG 0.28 Ac. ROUGHENED OR, 0.00 Ac. GRAVEL FILTER 0.00 STRAW BARRIER 0.12 Ac. NET C-FACTOR 0.31 NET P-FACTOR 0.94 EFF = (I-C*P)* 100 = 71.1% 2 0.45 ROADS/WALKSBLDG 0.29 Ac. ESTABLISHED GRASS 0.00 Ac. ROUGHENED OR. 0.00 Ac. SILT FENCE 0.16 Ac. STRAW BARRIERS 0.00 Ac. NET C-FACTOR 0.36 NET P-FACTOR 0.82 EFF = (1-C*P)*100 = 70.2% 3 0.19 ROADS/WALKSBLDG 0.11 Ac. ESTABLISHED GRASS 0.00 Ac. ROUGHENED OR. 0.00 Ac. SILT FENCE 0.08 Ac. STRAW BARRIERS 0.00 Ac. NET C-FACTOR 0.43 NET P-FACTOR 0.79 EFF = (1-C*P)* 100 = 66.3% TOTAL AREA = 1.04 ac TOTAL EFF = 69.9% _ (94.0%*29.77 ac. + .. +99.6%*0.40 ac)ll . 14 ac REQUIRED PS = 74.6% Since 69.9% < 74.6%, the proposed plan does not meet the performance standard ' Erosion.xls 1 of 1 North Star Design, Inc. 700 Automation Drive, Unit I Windsor, CO 80550 CONSTRUCTION SEQUENCE STANDARD FORM C PROJECT: POUDRE FIRE AUTHORITY STATION #14 SEQUENCE FOR 2002 ONLY COMPLETED BY: PPK DATE: 11-Mar-02 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. 2002 MONTH J F M A M J J A S O N Demolition Grading Wind Erosion Control: Soil Roughing 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 ettings/Mats/Blankets Other BUILDING CONSTRUCTION STRUCTURES: INSTALLED BY: CONTRACTOR MAINTAINED BY: DEVELOPER VEGETATION/MULCHING CONTRACTOR: TO BE DETERMINED BY BID DATE SUBMITTED: APPROVED BY CITY OF FORT COLLINS ON: Page 1 North Star Design, Inc. 700 Automation Drive, Unit I Windsor, CO 80550 EROSION CONTROL COST ESTIMATE Project: POUDRE FIRE AUTHORITY STATION #14 Prepared by: PPK ITEM IQUANTITY JUNIT COST/UNIT TOTAL COST Silt Fence 420 LF $3 $1,260 Straw Bale Barrier 0 EA $150 $0 Gravel Inlet Filter 0 EA $150 $0 Construction Entrance 3 EA $550 $1,650 Subtotal Contingency(50%) Total $2,910 $1,455 $4,365 CITY RESEEDING COST Reseed/Mulch 0.88 ACRE $615 $541 Subtotal Contingency (50%) Total $541 $271 $812 EROSION CONTROL ESCROW AMOUNT $4,365 Page 1 I1 "D1\1 11 ►:is 11 FIGURES AND TABLES c No Text I 1 11 L1 1 1 R-M-P Medum Density Planned Residential District — designation for medium density areas 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-tut 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-famiy 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 light 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 fight 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 feet 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 ciassifications, refer to the Code of the City of Fort Collins, Chapters 99 and 118. Table 3-3 RATIONAL METHOD RUNOFF COEFFICIENTS FOR COMPOSITE ANALYSIS Characterof Surtaoe Runoff Coetfi Streets, Parking Lots, Drives: Asphalt..» .................... ».................... ».................. ...... _..................... 0.95 Concrete.............. _..»................... ................................... ................... 0.95 Gravel........................ ................. .... »..... _......................................... 0.50 Roofs........................................... .......... ................. ...... .... ......... ............ 0.95 Lawns, Sandy Soil: Flat<2% ............ »» »._....__:........»......................._.._.............. 0.10 Average2 to 71/6 .... .................................................. .... ... ...-------------- 0.15 Steep>T/o.......................................................................................... 020 Lawns, Heavy Soil: Flat<20k................................. ........................... _.............................. 020 Average2 to 7%,.................................................................................. 025 Steep>7'/e.......................................................................................... 0.35 MAY Is" 3-4 DESIGN CRITERIA ' Table 8B C-FacWra and P-Factors for Evaluating EFF Values. Treatment C-Factor P-Factor BARE SOIL Packedand smooth ................................................................ 1.00 Freshly disked 1.00 ...................................................................... 1.00 Rough irregular surface 0.90 ........................................................... 1,00 0.90 SEDIMENT BASIN/TRAP ................................................................. 1.00 0.50111 ' STRAW BALE BARRIER, GRAVEL FILTER, SAND BAG 1.00 ........................ 0.80 SILT FENCE BARRIER ..................................................................... 1.00 ASPHALT/CONCRETE PAVEMENT 0.50 ................................................... 0.01 1.00 ESTABLISHED DRY LAND (NATIVE) GRASS .......................... See Fig. 8-A SODGRASS 1.00 ............................................................ ..................... 0.01 1.00 TEMPORARY VEGETATION/COVER CROPS ....................................0.45°1 1.00 HYDRAULIC MULCH @ 2 TONS/ACRE ........................................... 0.10°" 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 /40 to 1 1 /20 and applied at a rate of at least 135 tons/acre.............. 0.05 1.00 HAY OR STRAW DRY MULCH ' After olanti. ora_ss seedp apply mulch at a rate of 2 tons/acre (minimum) and adequately anchor, tack or cramp material into the soil. ' Slone M 1 to 05. .............................................................................0.06 6 to 10 1.00 ............................................................................. 0.06 11 to 15 1.00 ' ................................................................. ........ 0.07 16 to 20 "" 1.00 21 to 25....................:...................................... ............ 0.14 25 to 33 """ 1.00 NOTE: Use of other C-Factor or P-FactDr values s-Vorted in this table must be (1) Must be constructed as the fast step in overlot ' grading. (2) Assumes planting by dates identified in Table 11-4, thus dry or hydraulic mulches are not mgt*W. 13) Hydraulic mulches shag be used only between March 15 and May 15 unless irrigated. 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Lr) Lo tC r� r� ram= cc cc co COO i I JC I N N M MMMMMMMMMMMMM MC9MC")MCCC C C I C i vI i C co C C co co co co Cco coq coco co co cc Cco co coco= C C co I C I O 1 tC U')COVI IT Ln t: Ln tO to tC tp tC co= co Cl. CT 1 G 1 1 C r C I N N M M M M M M M M M c ncn ") M P') M M m m ff) ) M M CV) 1 Z 1 t CJ C," CCJ Coco co co co co co cc co cc co co 117co co co OD co co Co t G 1 1 Ln LC. ~.--1 U') r�co0c I N N M co M C CCC C to Ln LLI%0 tp%D r\}� 1 LLJ 1 M 1 .-. N N N N M M M M M M M M M M M M M M M M M M Cl) M C') I C co C co co co co co coco cococo co coco coco qco co co co co I Z t O I M N t0 Co C:1 C.--i N N M M M C CC C C Ctt) M) W) LA tC%C t0t0 1 C �% G •"� �•+•--r .-t N N NNN N N NN N N N N N N N NN N N N 1 C)t 1 C= cc Co co cc co= co Co co co coco co C) co co co coco= co co t L 1 Lr7 t Lr') O C CN MCt')tCf�ct m01omc;%010000 C O t L:1 t N 1 0'1 C O .-+ .� .•n .� .r ..., ..-t .-r .r .-, ..,..-. ..r .-• rrr N N N N N N I C I I r� cc co C co co co co CC co Co co co q Co coco+ gcogtqC co cc I I 1 I O I.0 LL) O M Ln tD Co co CN'000N NN NM M MM en I 1 , I N 1 CDC % O O O O C O O .-t .-, r+ .-+ .-1 .•..-..--, .-+ IOCocoClcocococz cococogCC)gqcococDcoCCC) 1 Lr, Is Co LVNNMMM M M 1 I tO co co Im m CT C) C1 tT C1 CT O 0 C 0000000 CCO 00 I r� co qco co co co co co co Co co Co i 1 1 I O 1 t0 fM N C7 M C C Ln Ln Ln tf) t0 tC LO tC r` r\ t0 tC %D I I ..•1 I c%0r.-r�,r�P,co coCCggqqqcococo=cocogqoJCcoco i r\ r\ n f\ r� r\ r` f\ f\ 1 1 1 1 Ln 1 01O Ctpr\C74"in r\ r\ to to tO Ln CCM M N NtTbC.•N 01 tp I 1 O I O CV N N N NNN NN N N NN NNN NN N.-r\r\.--t ..r ..y O O L 1 1 ram^ ranf\f\nf\^r�nr�nr�f\f\r�nr�t\^f 131--^ 1 CO C O O O C 00000 C 0OOCO00000000 1 I CD cm 1 00 C O O O O O O O O O O O O O O C O O O O C G OO 1 1 Lr_Wv I MC Ln to r� co Ct0 CJ(n< t7 tD r\ Qc106nCD LL7= Ln CD 1 J 1 ..-t .+ .--� .•..r .-+ rr rr .r .-r N N C9 M C Q Ln I TABLE 5.1 ' APPENDIX E ' EXCERPTS FROM PREVIOUS REPORTS 1 1 E p FINAL DRAINAGE REPORT FOR WESTCHASE P.C.D. At The northeast Corner of Trilby Road and Timberline Road Larimer Count},, Colorado Prepared for: Marcus S. Palkowitsh Willowood Corporation 760 Whalers Way, Suite B-102 Fort Collins, Colorado 80525 (970) 204-4070 January 11, 2000 Rev: June 6.2000 Rev: August 18, 2000 Rev. November 3, 2000 Rev. December 14, 2000 Project Number: MSPP 0000-0002 Prepared by: Roy L. Vestal, P.E. David Evans and Associates, Inc. 777 South Wadsworth Boulevard Building 3, Suite 100 Lakewood, CO 80226 DAVID EVANS AND ASSOCIATES, .ice ����:ite�T•L�i�±ii 1 1 1 1 1 1 1 1 STANDARD FORM SF-2 TIME OF CONCENTRATION LOCATION. watwse SuDOwtaw CALCULATED By taw CHECKED BY. RLV DATE: It-0ac-0D SUB -BASIN DATA INITIAL,'OVERLANO TIME 4 TRAVEL TIME pl Ic p -p IC CHECK LL1A6ANIZEDSASIH51 SUB -BASIN L SA N L DESIG. (11 C 2 C'G' C1 C1100 AREA AC ] LENGTHI Ft a SLOPE % 5 I. Mn (8) UENGTHI Ft (7 SLOPE % 8 VEL FPS 9 4 Mn 10 TOTAL Ft (11 1,=(UISO)-10 Min 12 FINAL Min t3 (ROUTING) Mn 14 I] 053. 05J i15 1001 3,01 74 430 29 34 2.1 9.5 530 12.9 95 9 18 066 0.86 056 50 2.0 46 320 2.9 341 16 6.2 370 12.1 6.2 6 15 O SS 058 243 75 07 9, 6 770 0.5 t d 9 2 18.8 845 14 7 147 19 16 0,56 056 2.10 130 1.5 100 710 05 14 8.5 iBd B40 147 .147 15 13 0.58 0.58 1.29 80 19 TO 3401 0.5 14 4.0 11.1 420 12.3 it 1 23 14 069 069 089 60 1.7 50 1 270 0.5 1.4 3.2 8.2 330 11.8 82 18 28 0.15 0 15 10.90 300 0.6 1 36.5 1 1000 0.6 0.6 303 66.8 1300 17.2 172 I8 29 0.15 015 4.50 300 0.6 36.5 1 1000 1.2 0.8 • 22.2 58.7 1300 17.2 172 18 27 0.65 065 11.20 300 0.6 173 800 1.4 17 78 25 1 1100 16.1 161 17 28 0.65 065 5.40 300 0.6 17.3 1100 0.8 0.8 33.3 %d 1 1400 178 179 16 25 0,55 065 5,90 300 1.2 13.7 1020 1.2 0.8 22.7 36A 1320 .17.1 17.3 41 0.17 1 0,17 9.20 300 3.3 20.2 1215 IA 1.7 1 t.9 32.1 1515 18.4 1841 41 N' 1 . _ ' ,«< ., i".. .: r±ni. 13.9 1 ., N, 830 w1a;,, x 1.3 ....w'" 23 ,.,:. SO '�M1. s: W' 19.9 Awi;: t. 1 1130 'rx:.`:.r.0 . ,w 16.3 -,. Lv 2 163 R. ;�v. 44t. 16 24 0.41 041 9.00 300 4.2 23 0.49 049 2.23 1101 0.9 12.4 B50 1.3 2.3 4.7 17.1 760 14.2 14.2 16 22 0.49 0.49 2.26 1401 0.7 15A 380 2.2 3.01 2.1 172 520 12.9 12.9 20 21 0.51 0.5t 1.70 110 0.9 12.0 430 2.2 3.0 2.4 14.4 540 1&0 13.0 20 20 0.51 051 3.90 lool 1.0 11.01 940 I.1 2A 7.5 IS'S 1040 15.8 15.8 24 19 054 054 4.37 250 2.6 12.0 9901 IA 2 1 7.9 19.9 1240 16 9 16.9 24 .:A. 11 54 `+n ..:'.x41 0.18 0.33 ,. , .' 018 0.33 4 xrr I4 1 364 1.58 2x F 30 300 im a 25.0 T 2.7 _a07iIi 3.2 ISO MA •. 971 100 1.1 OA 15 1.5 10.6 1.1 140 19.1 1001 400 Ila 12.2 14.0 12.2 55a 10 53 0.51 0 51 2.43 140 C3 8.0 020 1.8 2.6 4.0 12.0 760 14.2 12A 14 52 068 0.68 1.17 50 2.0 4.4 710 1.8 2.6 4.6 9.0 760 14.2 9.0 14 47 0.50 050 453 50 4A 50 awl 14 2.4 5.8 10.8 880 14.9 10.8 20 48 059 ON 219 10 2.0 24 960 14 2.4 6 7 9 1 970 f5,4 9.1 20 r r x;. 4f 39 0.56 056 2.11 70 2.9 60! 620 071.8 85 t2.4 690 U.8 12.4 20r 51 077 0 n 0 >d 20 1.0 2 8 265 t 8 2 6 17 e 5 285 11.6 45 21 .x. --.- ... 4 x jtliY.vhlx`^l •.s'Iy,:: :'. en vu rx+'!kxm ,ay4 „4„TM: kr4 Wrt .f kl Pxx ;;4 43 055 0,55 410 115 4.3 6.8 720 1.5 25 48 11.6 835 14.8 lie 12 44 0.71 0.71 120 20 2.5 2.4 11 690 15 2.5 4.6 7.0 710 13.9 45 0.52 0.52 6.70 135 4.4 77 1020 V3 2.3 7.4 15A 1155 16.4 148 0,66 066 t 12 SO 1.0 3.8 900 1.3 2.3 6.5 12.3 950 113 f .I.'/W,N 075 r �h. ;+"r1 075 .:.YY N71. 1.05 .'.Ax $uip 20 AMyN 2.0 2 3 1000 1.8 i'?E: s:'!X 2.7 iFUA+''CY:`42 6.2 J11 8.5 1020 15 7 40 055 -N . 035 n i91 2 74 ^$• 190 32 9A 570 1 3 i 3 4.1 13 8 760 14.2 1 >9 ... 021 OSt _ -ra4 d'd 2.92 250 ,:.. 4.0 t6.8 'S 210 :. OS r •Yr a.!i 0.5 1 !4 .. 70 6 . 23.6 < N+I.w 4x x I 460 12.6 12.6 27 35 0.46 0,48 2.26 150 15 12.8 ]00 0.9 t 9 2.6 154 450 t2.5 f2.5 27 0 11 1 1 1 1 1 1 1 0 H 1 soma now." NORM --oolmmemos _- ----- -molm ---Noma@ MY&M MEMO 8�?.�. 3^s"5"`u --_--_ ZM=�i� ".'aka'="�w—"-"°mw. 'ai�''�fm:76 ---------------- ©���'i��®�®®���®®gym I CALCULATED BY: AJR DATE: I14Ose-00 CHECKED BY: RLV 1 1 STANOMIO FORM ssa STORM DRAINAGE SYSTEM DEMON (RATIONAL METHOD PROCEDURE) 0 LOCATION: WestWx Subdivism (08 7) DESIGN STORM: CALCULATED SY: AJR STANDARD FORM SF-3 LOCATION: DATE: l I4)vca0 WOMIl o Subdww n (OB J) CHECKED BY: RLV STORM ORAWAOE SYSTEM DESIGN (RATIONAL METHOD PROCEDURE) DESIGN STORM: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 W Z J Ir W m I— ' I I WESTCHASE ROAD A D450.65 I', m fl DRAINAGF CIIMMARY TART F Bill I lip. 0 The City of Fort Collins Storrrwater Utility erosion control Inspector must be notified at lease 24 hours prior to any construction on this site. Au real perimeter silt fencing shall be Installed prior to any land disturbing activity (stockpiling, stripping, grading, etc.). All other required erosion control measures shall be installed at the appropriate time 'n the construction sequence as indicated the approved project schedule construction plans and erosion control report. Pro -disturbance vegetation shall be protected and retained wherever possible . Removal or disturbance of existing vegetation shall be limited to the area required for immediate construction operations and for the shortest practical period of time. All sous exposed during land disturbing activity (stripping. grading, utility Installations. stockpiling, filling, etc.) shall be kept F a roughened condition by ripping or do no piano land contours until mulch, vegetation or other permanent erosion Control Is ,. soils In are outside project street rights of way shall remain exposed b, activity for more than thirty (30) days before required temporary or perm. control Hugseed/mulch, landscaping etc.) is installed, unless otherwise of - Stormwoter utility. The property shall be woutered and maintained at all times during construction activities so as to prevent w nd xd erosion All and disturbing activities shall be immediately discontinued when fug!ve dust Impacts adjacent properties determined by the City of Fort Collins Engineering Department. Alt temporary (StructuM) erosion control measures shall he inspected and repaired or reconstrull as ne<eegry Offer each runoff event in Order t0 pe6ure continued performance of their intended function. All retained sediments. particularly those on Foxed roadway surfaces, shall be removed and disposed Of In a manner and location s0 as not to cause their lease Into any drainagency. No s 'I Stockpile shall exceed t (10) feet in height All sail stockpileshall be protected from sediment transport by surface roughening. watering and perimeter sit fencing, Any Sol stockpile remaining after 30 do" shall be seeded and mulched. City Ordinance prohibits the corking, dropping depositing f soils or any other material ontoCity streets by or from any vehicle. Any inadvertent deposited material shall be cleaned immediately by the contractor DESIGN POINT DESIG. 'ES' AREA ACRES C2 C100 To (2) MIN Tc (i MIN a (2) CFS 0 (100) CFS 1 1 0.40 OJO O.BT 6.0 5.0 0.)5 S.aB 2 2 0.45 0.65 1 0.62 6.5 5.2 080 1 3.57 3 3 0.19 0.58 1 073 5.0 &0 0.31 1.36 LEGEND osICN POINT N BASIN CRITERIA 0.60 0.4 RUNOFF COEFFICIENT AREA IN ACRES FLOW DIRECTION nommom BASIN BOUNDARY EX ST NG PIPES EXISTING 1CONTOUR EXISTING 5' CONTOUR PROPOSED 1' CONTOUR 4910— PROPOSED 5' CONTOUR —)E j( SILT FENCE OCONSTRUCTION ENTRANCE Oeslissesselike EROSION BALES Ec m 20 40 SCALE 1 = 20' CALL H TILiTY NGTI-ICATIDN Cif of Fort Collins, Colorado Er,Tra 0. . ., -aA- Y 1-800.922.1987 UTILITY PLAN APPROVAL APPROVED. siei yJJ Ili- oeaC City En9esroAw or An�o�xa <NSAS UnILT1Ei _ CHECKED By _ stann.aW Utility PRELIMINARY CHECKED BY: _ NOT FOR CONSINUL110N paKs A kcrentinn MARCH 12. 2002 CHECKED By Trarcc En9inwer CHECKED BY: _ 6 n 0 N s Y 0 Z ry y II n — a C y P 3 p O X oI a UO J OHa J Q W m F 4 — coZ t= a 0 J e o 2 . a F d Q W W z (n CE O Q LL = Z UWo W w �a SHEET 5 5 OF 114-22