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HomeMy WebLinkAboutDrainage Reports - 09/06/2006FRUPERTY OF We'd' COLD S ITI'ILMM City of Ft. Collins ppr ved Ptah s Approved By Ac Dac 9-5 -06 FINAL DRAINAGE AND EROSION CONTROL REPORT FOR KINGDOM HALL OF JEHOVAH'S WITNESS FINAL DRAINAGE AND EROSION CONTROL REPORT FOR KINGDOM HALL OF JEHOVAH'S WITNESS u I 11 ,'. FINAL DRAINAGE AND EROSION CONTROL REPORT FOR KINGDOM HALL OF JEHOVAH'S WITNESS Prepared for: Poudre Valley Congregation KC Johnson 4985 Hogan Drive Fort Collins, CO 80525 Prepared by: North Star Design 700 Automation Drive, Unit I Windsor, Colorado 80550 (970) 686-6939 May 22, 2006 Job Number 242-0I r North Star rl*sa. design, ina May 22, 2006 R Wes Lamarque City of Fort Collins Stormwater 700 Wood Street Fort Collins, CO 80522-0580 RE: Final Drainage & Erosion Control Report for Kingdom Hall of Jehovah's Witness Dear Wes, I am pleased to submit for your review and approval, this Final Drainage and Erosion Control Report for Kingdom Hall of Jehovah's Witness. I hereby certify that this report for the drainage design 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. ' Sinc rely, �0 REG� .S 0O�O� 0 Pgq�FF�� Troy prake ....... .��G\ 4Pa"ciaroPE et , ii 700 Automation Drive, Unit I Windsor, Colorado 80550 970-686-6939 Phone 970-686-1 1 88 Fax TABLE OF CONTENTS - TABLE TABLE OF CONTENTS............................................................................................................... iuit 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...........................................................................................1......3 3.4 Hydraulic Criteria ....... :................................................................................. :.......... 3 4. DRAINAGE FACILITY DESIGN 4.1 General Concept........................................................... :........................................... 3 4.2 Specific Flow Routing.............................................................................................4 4.3 Drainage Summary ...................................................................................................5 5. EROSION CONTROL 5.1 General Concept......................................................................................................5 6. CONCLUSIONS 6.1 Compliance with Standards.......:.............................................................................6 6.2 Drainage Concept.....................................................................................................6 ' 7. REFERENCES....................................................................................................................7 APPENDICES A Vicinity Map B Hydrologic and Hydraulic Computations C Detention Pond Sizing Calculations D Erosion Control Calculations E Figures and Tables iii 1. GENERAL LOCATION AND DESCRIPTION 1.1. Location This site is located on the northeast corner of the intersection of Timberline Road and Kechter Road in Fort Collins. This project is located in the Southwest Quarter of Section 5, Township 6 North, Range 68 West of the Sixth Principal Meridian, in the City of Fort Collins, Larimer County, Colorado. See the location map in Appendix A. The project is bounded on the north and east by existing estate lot residential properties, on the west by existing Timberline Road and on the south by existing Kechter Road. Access to the site will be obtained from Kechter Roadon the south. 1.2. Description of Property The entire project consists of approximately 3.4 acres of land. The site is currently developed with an existing house, driveway, and several outbuildings. There is also an existing irrigation ditch on the site that divides the runoff into two directions. Currently, the site slopes away from the irrigation ditch to the southeast and the northeast at slopes ranging from 1 to 1.5 percent. With this project, the site will be divided into two lots and only the south lot (Lot'1) will be developed at this time. A portion of Lot 2 will be used as a retention pond until the downstream outfall becomes usable. This project will include demolishing the existing structures on site and construction of a church building and a residence with associated parking and drives, as well as construction of the Kechter Road improvements and a portion of the Timberline Road sidewalk. The remainder of the Timberline Road right- of-way improvements will be constructed in the future. S2. DRAINAGE BASINS AND SUB -BASINS 2.1. Major Basin Description 1 The proposed development lies within the McClellands-Mail Creek Drainage Basin. Detention is required on -site, with a proposed release rate of 0.5 cfs per acre. At this time, there is no conveyance route for the release from the site, so an interim retention iplan is proposed. With this plan, retention will be provided for Lots 1 and 2, as well as r the ultimate Timberline Road street section adjacent to the site. With the retention option the storage volume is double the calculated detention volume with a 0.0 cfs release rate. In the ultimate condition, Basin 1 and the adjacent Timberline Road will be detained in. Pond 1. Lot 2 will be required to provide on -site water quality and detention upon rdevelopment. t2.2. Sub -basin Description The portion of the site that is proposed to be developed at this time currently drains southeast and into the existing roadside ditch along Kechter Road. The runoff then flows east along Kechter Road to Mail Creek. With the proposed development, runoff from Lot 1 will be conveyed to Pond 1 and then north in a storm pipe to Pond 2. Ponds 1 and 2 will act in combination to provide interim retention for the entire site. A concrete box will be installed in the northwest portion of Pond 2 to allow for a pump to be used if the pond does not drain within 72 hours after a storm event has concluded. In the ultimate condition, it is intended that a proposed swale will be constructed on the north side of Lot 2 and connect to an existing concrete channel in Stetson Creek Second Filing. This swale will then convey the water east to the McClellands Basin Drainageway. Refer to Section I4 of this report for a more detailed description of basin routing for this site. 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 "Urban Storm Drainage Criteria Manual" (UDFCD), 2001, developed by the Denver Regional Council of Governments, has been used. r 3.2. Development Criteria Reference and Constraints ' The runoff from this site has been routed to the proposed on -site ponds. In the interim condition, retention with a supplemental pumping system is being provided for Lots 1 and 2. In this interim condition the retention volume is double the calculated 100yr detention volume with a 0.0 cfs release rate. In the ultimate condition, Pond 1 will provide water quality and the 100yr detention volume for Lot 1 and a portion of Timberline with a peak release rate of 1.08 cfs. It is intended that in the future, Pond 1 be routed through Pond 2 I 2 then discharged into the existing drainage swale located in Stetson Creek 2nd Filing, however this drainage scenario shall be further investigated when Lot 2 develops. The developer of lot 2 will be required to provide water quality and detention. It is intended that in the ultimate condition all detained runoff shall be released in the northeast corner of Lot 2. 1 3.3. Hydrologic Criteria Runoff computations were prepared for the 5-year and 10-year minor and 100-year major storm frequencies utilizing the rational method. All hydrologic calculations associated with the basins 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. Interim retention was calculated using the FAA method for detention pond sizing using a 2-hour, 100-year storm with no release rate. The ultimate detention volume for Lot 1 and Timberline Road was calculated using the FAA method for detention pond sizing based on a release rate of 0.5 cfs per acre (1.08 cfs). Ultimate water quality.volume was calculated using the method recommended in the "Urban Storm Drainage Criteria ' Manual". 3.4. Hydraulic Criteria Hydraulic elements have been designed to adequately convey the 100-year storm runoff from this site to the proposed retention/detention ponds. All hydraulic calculations within this report have been prepared in accordance with the City of Fort Collins Drainage Criteria and are included in Appendix B of this report. 4. DRAINAGE FACILITY DESIGN ' 4.1. General Concept In the interim condition, Ponds 1 and 2 will act in combination to provide retention for Lots 1 and 2 and the portion of ultimate Timberline Road section adjacent to Lot 1. A concrete box will be installed in Lot 2 to allow for a pump system if the pond is not naturally drained within 72 hours after a storm event. In the ultimate condition, the 1 3 Irunoff from this site will be collected in the on site curb and gutter and will be conveyed ' to the proposed detention Pond 1 in the southeast comer of the site. Pond 1 will attenuate the runoff to 0.5 cfs per acre (1.08 cfs release) and will discharge the water to the proposed storm pipe system along the east boundary of the site. Pond 1 will also provided ' extended detention for water quality. Refer to Appendix C for all detention pond sizing calculations. No off site flows enter the site from adjacent properties. Flow from offsite is intercepted by Timberline Road on the west, an existing irrigation ditch on the north and Kechter Road on the south. Only a small portion of the landscape area on the south will be released from this site undetained. 4.2. Specific Flow Routing The site has been divided into four basins and a summary of the drainage patterns within each basin is provided in the following paragraphs. Basin 1 (1.56 acres) contains the majority of Lot 1, including all of the proposed building, the parking lot, and Pond 1. The runoff from this basin is conveyed via surface tflow to the southeast corner of the parking lot. The runoff enters the detention pond through curb openings and is detained before being conveyed to Pond 2 via Storm 4. The runoff for Basin 1 is 3.7 cfs for the 10-year storm and 11.2 cfs for the 100-year storm. Basin 2 (0.61 acres) contains the portion of the Timberline Road right-of-way that will be collected in Inlet 1-3. Runoff from this basin will be conveyed via the roadside ditch to Inlet 1-3 and will be piped to Pond 1 via Storm 2. In the ultimate condition, Inlet 1-3 will ' be replaced with a 5' Type R Inlet. The impervious area for this basin has been calculated assuming full build -out of the ultimate street section. Runoff from Basin 2 is 2.5 cfs for the 10-year storm and 6.0 cfs for the 100-year storm. ' Basin 3 (0.74 acres) contains the majority of Lot 2, which is not proposed to be developed at this time. In the interim condition, runoff from this basin will sheet flow to Pond 2 and has been included in the retention calculations for the entire site. In the ultimate condition, Pond 1 will act as a detention pond for Lot 1 and the developers of Lot 2 will be responsible for providing on -site water quality and detention. Basin 4 (0.38 acres) is the portion of the site containing the realigned irrigation ditch, as 4 i ' well as a small amount of landscape area immediately adjacent to the ditch. Runoff from this basin will be conveyed in the ditch through the site and has not been included in the interim retention or ultimate detention calculations for the site. Runoff from Basin 4 is 0.3 cfs for the 10-year storm and 0.7 cfs for the 100-year storm. 4.3. Drainage Summary The City of Fort Collins will be, responsible for maintenance of the existing and proposed storm drainage facilities located within the right-of-way, including Inlet 1-3 and Storm 2. The drainage facilities located outside of the right of way (including the detention pond, outlet structure, and outlet pipe) will be maintained by the owners of the site. 5. EROSION CONTROL i5.1. General Concept This site lies within the Moderate Rainfall and Wind Erodibility Zone per the City of Fort Collins Zone Maps. The potential exists for silt movement from the site and into the existing storm system during construction. Potential also exists for tracking of mud onto existing streets which could then wash into existing storm systems. Silt fence will be provided around the perimeter of the site, a construction entrance will be provided at the exit from the site and wattles will be provided around the outlet pipe and in all swales. During overlot grading, disturbed areas shall be kept in a roughened condition and watered to reduce wind erosion. Detention Pond 1 will be used as a sediment basin during the construction process. The incorporation of these best management practices (BMP's) will reduce the amount of sediment leaving the site during construction. The required performance standard for the site is 76.1%. During construction and after paving, this figure has been exceeded with the use of silt fence, inlet filters, straw bales, ' and a sediment trap. The calculated performance standard for the site, using the standard City of Fort Collins Effectiveness Calculations, is 77.4%. The erosion control escrow amount for the entire site is $9,825 (see Appendix D). 5 I C 1 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 Erosion Control Reference Manual for Construction Sites and the Storm Drainage Design Criteria Manual. 1 J 1 II u 1 6.2. Drainage Concept The proposed drainage concepts presented in this report and on the construction. plans adequately provide for the collection and conveyance of runoff from the 100-year storm to the detention area. Conveyance systems have been sized and will convey the required flows to the pond as required. Storm drainage facilities located within the right-of-way, including Inlet 1-3 and Storm 2 will be owned and maintained by the City of Fort Collins. The proposed on -site storm sewer system will be a privately owned and maintained. If, at the time of construction, groundwater is encountered, a Colorado Department of Health Construction.Dewatering Permit would be required. 6 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. 3. McClellands Creek Master Drainage Plan Update by ICON Engineering, Inc. dated November 30, 2000. APPENDIX A VICINITY MAP r rr 1- 1 1 A i No Text I I 11 i I 1_1 I i I I I 11 r 1 I I r �.� - Y I w' i it I �L I t" I �; I ;lI i t. �sprl� taa , i t; 11 I I = : I I I n ai 1w 11mo� Ave L, L :� 1.d fPIpRY a r� MQI sFt! p1O L6t Q pppl sWT MD s1r eta IRRI /m p1O M QiA1 iAt01 del / IOp pllp smal n last 10 ACbI s v® tAvt a7meA . AURSO101�(AV to al RIRor 0007C0p Comm IIOelIT RAC AI6'A M A0O noR l¢mal. MT rim Do I �� ` r4 s' r atlTla I INS - ptana 1' OOr1am wv tae1r Oanas I Wl / S O11Y i r- l i I I i M 1 I op m ) i I iR0lOAi ) I ! 1 - =` IS I If x L... - i J I a�I1e� CALL UIL)1Y 1tY1s1a111011 *8OO 9221987! 9 e reu I;slltm OAK M c L C Io 9 0 R� M MIBF K wouvou D vpYA aM116 1 C a o 0 O 5 B • • at CD 8 IL 30 15 0 JO w -r. �■1 SCNE 1' - JO' O\ - ! j INTERIM RETENTION POND SLAAMARY i KTOW F0UaM REOIIIW 1256 Ar, M. i I woA®imc / 71AC, FT. \ r am Poo 2 Yalllrt FRWA m 1 0.704 Ar- Ff li ; moo TOTAL VQUAIE PRUM p I 1 100 YR HIM 140037 1 11T'`� ✓✓ !v� .,ram t I �: pales Rt7ApMr . , plop pla /OM7aIWlMI)MAW=WV AAl 001111 aL MR, a l OgIGGIOI � I i 0 m 1. lw Ielbl wlM l:leeeAb M w eetW r Yal bell•Aa u{) �e sns b eve eal.veca.. � r al. 1 N egla Vbmllls ri w OaaaaM 1sW9 M w mmra b a1 bN N area al0llYp ee1111b (rtlaiL sYasYL emp 1ealea bepbl M M i:e1r� M r gtYloh bm w w�W.Ya wWba a y� Iseaea ms..lr . r webA pe►a .abaa....Y.s1ra rlasa � ..am wwa egsl, S a N d ar• arM es:sbsalw w De.aeb M M bNb:rts Ir paaM by W asevay w-r..ro..+rM Ylsml r raI" �av •rr e m :vrr:m. rti bas etminl r OwmlOb M ae a webbaY w roe as :esltim0 m banes a•OV mr pw Itbela L v:rpeY.e.e .evetalle M Y rutalsa by lalrw plsaa sacral• Ide0 s dram a ummll alrab: M w w b w b.v��e.♦ra a m::ra maYaam, wrleea N Y. r asbp sreeoea Mlr r L N er ao)s.II asM 1M abplr -MY 16�m9 rR) trtr♦Rsa = rteeORlL >OIO M M w 1p m a m::Vy� gMlfm lI Mm0 w lYm� Oe.V laa eastmea Iw l.ma, bvpevlti b enb spleblel bats. ebea Me an m.er.a Rs r m aw .aal. veM a,w eRPm-ear-oar M :� asps by ' Y.r wM:s .elver a .a. wa. s+nr.(sM Yta lrsa es♦da! 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(alKl Iwaae mr / . �}tlLw6 `_ {a wss qwv ♦eeeewAa P. aw m ad'pul aaa O (%I ( Alba d r.may. � Y O LOT 1 DETENTION POND SUMMARY (a oep merl.b. v eaaa O Cr (ULTIMATE CONDITION) IL CspaYb m w aa♦ wry eb.st bead mnM neea Y aaad b awl Y rra a .w. vlab r wbleb rr lelrlallet aulbe I..ara .. rler:r p W aeraa.a saw M r avtirr:ly. Q O Z W ILIMTE COMM 909 paw AC F(. 11TYAIE Yalat R AQ R o Im Y01IM PR0AMD ♦ AQ". 100 YR NIF1 MAX RIIrAsp RATE 1A0 cn DRAINAGE SUMMARY TABLE O[WI AIQ11 ARF/1 CIO C 700 Ta IO a" To 100 0111110 O 10 0 1 Cars) 1 1 lie 0.06 Gs2 10.71 7.0 1 A7 --r 112 2 1 La 1 Maloa a a74 am alp I,I u • 0]s OM C 25 11.7 1 n.7 I 0.0 1 0.1 Y Z Q City of Fort Gallia. Como& p UTILITY PLAN APPROVAL SHEET cA1Ea® er oar a ar+aab vlly or avxm eY flbtsaatb. 111mb or C1ca(ra eT: rut. a Rassad ovu 6 OF 20 CWO= sr_ O.se Olamep or Job Na 242-01 ortmm „� i r I I I I 11 r1 I APPENDIX B HYDROLOGIC AND HYDRAULIC COMPUTATIONS u x Lnc000 00 r. CO 00 N N h N 0; V 00 e 0 r O 4 kn 00 O O �o to W .. 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U q a ir U N z w d a (Z) ' v o 0 0 N N M M M v 3 ^= O E ZZ, M M N O w p o vl �o M 00 O 0 O 0 O 0 �.] z E o 00 U O N N N W v a a oq n(IR 00 H G O O N N N a L v O 7 0 O O 00 �^ F N WL O CDO O r V oo O O O a F V^ N O h h 01 M 00 O N N 00 ll z U II o--oo 00 U m 00 Cq d v 0 0 0 N N d p �O V] ¢ M ^-- N M 7 N N d CZ7 -- + V ai Ca vF Aa v7 n �o L J ^ � 3 t w U ° U II II II c E m c � so 00 ` c o 0 E U N `o 0 ¢ v 0 o c z�3 u e° o o U Q d o b „a as°a°� W C4 f-°FF� 5�5 d 'u m ca �, V � .d. C Hr F a w y a 0 v WQ5 U ,« V1 Vl M 14O O a v M NOO vi �° 00 r� 00 7 �o V �O Oo M V1 �D V1 v M V M M M M 0 aj = �q W Cl N r F U o 0 0 0 0 0 U N N In M c A orb " 0 O R 0 w 0 a A W O y, 0 o v a O N F � 3 O N ti x p � O � N � N M w % O ti N C O b U O .. N C F' p� a ;J 00 w U U G Fy F E0 � N 00 �o Fa � s w a v o a g U A 0 00 �o O+ l� c1 rn a. � V N 7 �O 8 (m oo •� o F t0. .. �a aj $ 0000 O N N o0 U 9 q Q p V _ O c L` o0 M 'o '• T i v C41 N z �z Nrn -N+-+ rAW a orb " � A 0 a 1 1 1 1 Scenario: Storm 2 Inlet 2-2 CV li P-3 Inlet2-1 Inlet2-3 li 18" F.E.S. Title: Jehovah's Witness Project Engineer: Shane Boyle ...\242-01 jehovah witness\drainage\stonn 2.stm North Star Design, Inc. StormCAD v4.1.1 [4.20141 03/07/06 11:39:50 AM 0 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 [l 1 ' N O N O, ca d m 11 1 1 CR N CR J � 5 C7 a= C 1 O) C C 3x"' aoa 0 O E m cp cq A J O O O d Q O O O 0 rn rn yax o v v 7 LO r 7 m c Oi o o c LO 0 rn 0 A c aro o 0LO v 0 O CD rn0 rn rn aU v v v D E m v m ai of o �, D a a v o_ mrnrn vvv E o CR � a7 C of 0 Oi d a)-- v o v >= rn rn rn m e v v v D r 0 U N N 0 to M a'>v 0 <n cl a 5 c1 Cl ❑ L Cl) V O CLc C! O) N ,^ N _ O ❑ r O O O L O N O lL 0. U v) O o LO O o mod roco >ILL O) CO co a) 0)0 0 C7 M It O O O O M L U) N Of c co O N J C O y !n (n C C C w N a0 N c E'.0 o� Z N a) a W J � N CO CL a cL 0 ID O r 0 0 N 4 UrT Label: 18" F.E.S. MITI: 4,952.00 ft Sump: 4,949.15 It Profile Scenario: Base Label: Inlet 2-1 Rim: 4,952.50ft Sump: 4,949.47 It Label: Inlet 2-2 R m: 4,952.25 It Sump: 4,949.87 ft - — — — ------- 47�--J - -- - ------------ ...... ... . ....... . ... . . ........ ... 4,952.50 4,951.00 Bevation (ft) 4,950.00 4,949.00 0+00 0+20 40 0+60 0+80 WOO o n 20 1+40 1+60 1+80 2+00 Label: P-1 Up. Invert 4,949.47 ft Dn. Invert 4,949.15 ft Label: P- L: 81.00 ft Up. Invert 4,949.87 It Size: 18 inch Dn. Invert 4,949.47 It S: 0.003951 fVft L: 102.34 ft Size: 12 inch S: 0.003909 ft/ft Title: Jehovah's Witness Project Engineer: Shane Boyle untitled.stm North Star Design, Inc. StorrnCAD v4.1.1 [4-20141 03/07/06 11:38:49 AM C Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 1 Project: Pipe ID: 1 culvert ai=section Ign Discharge Q=; 74_cfs Diameter D = 18.00 inches Edge Type (choose from pull -down list) Inlet Type = Squarz Endf'rofecttari Invert Elevation le = 4940 50: ft et Invert Elevation O, _">: 4948.33{ft Length L = 34ft 5 ning's Roughness n-value n =,' ....,..0 01l6 d Loss Coefficient Kb =, (i,10' Loss Coefficient K. Q eater Water Surface Elevation El. Yi = Ak d ft Cross Sectional Area ...................... ....................... ...................... A. sq t .rt Slope So =i Q U049 fttft ial Flow Depth Y=i:.:.:.:::::1...5.0>;ft al Flow Depth YC _ ?%<'»' €';06< ft dwater Depth by Inlet Control Water Depth by Inlet Control dwater Depth by Outlet Control ...................... ,ater Depth for Design d='<<<:€t?$ ft on Loss Coefficient over Culvert Length Kf = Q of All Loss Coefficients Ks = iwater Depth by Outlet Control HW-outlet= 2 03 ; ft ian Headwater DeathZ03.:jft D Ratio = HW/D= ....................... Storm 3.xls, HW-Pipe 3/7/2006, 12:13 PM 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 12" F.ES. A ,p MH 4-1 N ct QIN WO Outlet MH 4-2 Scenario: Storm 4 Title: Storm 4 Project Engineer. Shane Boyle ...\242-01 jehovah witnesskdrainage\storrn 4.stm North Star Design, Inc. StormCAD v4.1.1 [4.2014] 03/07/06 11:45:25 AM 0 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 I 1 [I 1 u 1 m J V IT V m (� O) Of Of 3x'-' vvv 0 O E N ii m J O CO n V IT CL Iq E c 'Caoo com;co rn � rn 3U 0 O m co o c 3 ad ao ao 00 y � N v C cl C C, v v v D m N O O dC n n n O V V Cm � Of Of O) C O 0 °°0 E m 0 mC n n n dmom- v It v O O O N C v a_ v v 7 U / N N N O v Q � L (o N 7 � O � L n fo N G C N N U� N— O O O O y rn 0 o Cc n ao 0 C LLL m U co w co O O O Vl O TLL N N I, m m n N o. N to 0 ti� o00 0 0 0 rn o m L O� C O - CO N J C L L L N N N E O i8 Z Z N m a m J � N M adrL o o m N � a K a C m Lea Nv N QC aE w U o wN a a` E 1 0.LO ENO 4Co. n; LOM. O IT E E N C O113 N N O O O O 0) 0) v v v v vo Cm fA tl-- O uj � o (V Lo C? �O)v N� a E im V-19 (oLo It Iq vv �� CV- c(0 a a) m (0,04 .»moo �SSo 0 �CMJ,MO Ctl- CV- InO W 04 C) (1 NoNN >> —� N =) 0 Vj A C C OS d N N00 NN > >(O �o �O ��O_iA5(n 1 1 1 1 1 1 1 1 i M 1 CURB CUTS RECTANGULAR WEIR EQUATION CE REFERENCE MANUAL - 7TH-LINDEBURG 19-10-14 LOCATION: Jehovah's Witness PROJECT NO: 242-01 COMPUTATIONS BY: SB - SUBMITTED BY: North Star Design DATE: 3/7/2006 CURB CUT MINIMUM WIDTH % = (2/3)*C l.b*sgrt(2g)*HA(1.5) where % = flow (cfs) Co = discharge coefficient 0.62 g = gravitational acceleration = 32.2 ft/s b= width of curb opening H= height of curb opening Design Point 1 Q required = 7.6 efs In = 0.50 ft solve for: b = 6.48 ft check: Q = 7.60 cfs USE 6.0 FOOT CURB CUT FIND ACTUAL DEPTH: h = 0.53 ft 1 [] APPENDIX C DETENTION POND SIZING CALCULATIONS I I irl 1 1 I c I MINIMUM RETENTION VOLUME REQUIRED FAA METHOD (100-YEAR INTERIM CONDITION) LOCATION: Kingdom Hall of Jehovahs Witness PROJECT NO: 242-01 COMPUTATIONS BY: SB DATE: 5/16/2006 Equations: A trib. To pond = 2.91 acre QD = CiA Cioo = 0.73 Vi = T*CiA = T*QD Developed C*A = 2.1 acre Vo =K*QPo*T QPo = 0.00 cfs (Retention) S=Vi -Va K= 1 (from fig 2.1) Rainfall intensity from City of Fort Collins IDF Curve Storm Duration, T (min) Rainfall Intensity, i (in/hr) QD (cfs) Vol. In Vi (ft3) Vol. Out Vo (ft) Storage S (ft) Storage S (ac-ft) 5 9.95 21.0 6298 0 6298 0.14 10 7.72 16.3 9772 0 9772 0.22 20 5.60 11.8 14178 0 1 14178 0.33 30 4.52 9.5 17165 0 17165 0.39 40 3.74 7.9 18937 0 18937 0.43 50 3.23 6.8 20443 0 20443 0.47 60 2.86 6.0 21722 0 21722 0.50 70 2.62 5.5 23216 0 23216 0.53 80 2.38 5.0 24102 0 24102 0.55 90 2.22 4.7 25292 0 25292 0.58 100 2.05 4.3 25950 0 25950 0.60 110 1.93 4.1 26874 0 26874 0.62 120 1.80 3.8 27342 0 27342 0.628 Required Storage Volume: 27342 ft3 0.628 acre-ft x2 = 1.255 acre-ft I I r r t LOCATION: PROJECT NO: COMPUTATIONS BY DATE: POND 1 POND 2 100year WSEL Spillway Elevation 100 year WSEL Spillway Elevatior STAGE -STORAGE TABLE (INTERIM CONDITION) Kingdom Hall of Jehovahs Witness 242-01 SB 5/16/2006 100 yr Retention Volume Required = 1.255 acre-ft Stage (ft) Surface Area (ft) Incremental Storage (ac-ft) Total Storage (ac-ft) 4947.7 0 4948.0 415 0.001 0.001 4948.5 4,340 0.023 0.024 4949.0 9,020 0.075 0.099 4949.5 10,960 0.114 0.214 4950.0 13,260 0.139 0.353 4950.37 14,316 0.119 0.471 4950.5 14,670 0.042 0.513 Stage (ft) Surface Area (ft) Incremental Storage (ac-ft) Total Storage (ac-ft) 4947.0 6,305. 4947.5 7,320 0.078 0.078 4948.0 8,350. 0.090 0.168 4948.5 9,430 0.102 0.270 4949.0 10,525 0.114 0.384 4949.5 11,660 0.127 0.512 4950.0 13,180 0.142 0.654 4950.37 17,082 0.130 0.784 4950.5 18,390 0.051 0.835 Total Storage = 1.255 Ci MINIMUM DETENTION VOLUME REQUIRED FAA METHOD (100-YEAR ULTIMATE CONDITION) LOCATION: Kingdom Hall of Jehovahs Witness PROJECT NO: 242-01 COMPUTATIONS BY: SB DATE: 5/16/2006 Equations: A trib. To pond = 2.16 acre Qo = CA Clop = 0.89 Vi = T*CiA = T*Qo Developed C*A = 1.9 acre Vo =K*QPo*T QPo = 1.08 cfs (0.5 cfs/acre) S=Vi -Vo K= 1 (from fig 2.1) Rainfall intensity from City of Fort Collins IDF Curve Storm Duration, T (min) Rainfall Intensity, i (in/hr) Qp (cfs) Vol. In V; (ft3) Vol. Out Vo (ft) Storage . S (ft) Storage S (ac-ft) 5 9.95 19.1 5738 324 5414 0.12 10 7.72 14.8 8905 648 8257 0.19 20 5.60 10.8 12919 1296 11623 0.27 30 4.52 8.7 15641 1944 13697 0.31 40 3.74 7.2 17255 2592 14663 0.34 50 3.23 6.2 18628 3240 15388 0.35 60 2.86 5.5 19793 3888 15905 0.37 70 2.62 5.0 21154 4536 16618 0.38 80 2.38 4.6 21961 5184 16777 0.39 90 2.22 4.3 23046 5832 17214 0.40 100 2.05 3.9 23646 6480 17166 0.39 110 1.93 3.7 24488 7128, 17360 0.40 120 1.80 3.5 24914 7776 17138 0.39 130 1.60 3.1 23992 8424 15568 0.36 140 1.40 2.7 22607 9072 13535 0.31 150 1.20 2.3 20762 9720 11042 0.25 160 1.15 2.2 21223 10368 10855 0.25 170 1.10 2.1 21569 11016 10553 0.24 180 1.05 2.0 21800 11664 10136 0.23 Required Storage Volume: 17360 ft3 0.399 acre-ft -1 11 m L N O) a7 C W N_ N Z G � Z c a p y a } F- r � f0 0 c J co cy w � N U C r t � ti 7 Ct d GG C 00 _ a7 a) + �..� L N II 7 Q x co g t ' o rn �o Orn O E � U O L N Ica C 00 O �\ ram. N rn z h V a) E co a) ; E 2 c �o _ O i R > y Co �� a cn z o m ci ns z¢w zCA m 00U) OFF e t C3 Q W L W E LM �0...OUrrA o m �� �I Li 3 m w 3 m o r' 2 A LL NC O c E_ o w 3 0 N O ♦ > n U d O O y� U v Q m o 3 O N a1 Im 1=% O O 7 y M w N N dr IL O O W E E CD e m F ILo N Z O a c � M O O O O z u u u u E L ur 3 3 c o 0 o m a cjL_E�� _ E ° = a' po a7 c oQ v a7 U O a o r .N L N aacr ) :k a y G N 0 N a7 ¢ Q o O E �- LO C! eL 3U-2 11 LOCATION: PROJECT NO: COMPUTATIONS BY DATE: WQCP 100 year WSEL Spillway Elevation 1 II STAGE -STORAGE TABLE (ULTIMATE CONDMON) Kingdom Hall of Jehovahs Witness 242-01 SB 5/16/2006 100 yr Detention Volume Required = 0.399 acre-ft Water Quality Volume Required = . 0.057 acre-ft Total 100 yr Volume Required = 0.455 acre-ft Stage (ft) Surface Area (ft') Incremental Storage (ac-ft) Total Storage (ac-ft) 4947.7 0 4948.0 415 0.001 0.001 4948.5 4340 0.023 0.024 4948.76 6774 0.033 0.057 4949.0 9020 0.043 0.101 4949.5 10960 0.114 0.215 4950.0 13260 0.139 0.354 4950.32 14167 0.101 0.455 4950.5 14670 0.160 0.514 0 Detention Pond Outlet Sizing (100 YR ULTIMATE CONDITION LOCATION: Kingdom Hall of Jehovahs Witness PROJECT NO: 242-01 COMPUTATIONS BY: SB SUBMITTED BY: North Star Design, Inc DATE: 5/16/2006 Submerged Orifice Outlet: release rate is described by the orifice equation, Qo = C.A. sqrt( 2g(h-E,)) where % = orifice outflow (cfs) Co = orifice discharge coefficient g = gravitational acceleration = 32.2 ft/s Ao = effective area of the orifice (ft) Eo = greater of geometric center elevation of the orifice or d/s HGL (ft) h = water surface elevation (ft) Qma = 1.08 cfs outlet pipe dia = D = 12.0 in Invert elev. = 4947.70 ft Eo = 4947.82 It It = 4950.32 ft - 100 yr WSEL Co = 0.62 solve for effective area of orifice using the orifice equation Ao = 0.137 ft' 19.8 in2 orifice dia. = d = 5.02 in Check orifice discharge coefficient using Figure 5-21 (Hydraulic Engineering) d/D= 0.42 kinematic viscosity, v = 1.22E-05 ftZ/s Reynolds no. = Red = 4Q/(pdv) = 2.70E+05 Co = (K in figure) = 0.62 check Use d = 5.00 in A o = 0.136 ft' = 19.63 in 2 Qo = 1.07 cfs DetPond-FINAL.xls I I Emergency Overflow Spillway Sizing LOCATION: Kingdom Hall of Jehovahs Witness PROJECT NO: 242-01 COMPUTATIONS BY: SB DATE: 4/3/2005 Equation for flow over weir _ to of berm \L Q = CLH" + 5��0� ®e®V�4�OP1 where C =weir coefficient = 3.1 � L H = overflow height 17 100 yP WSEL L = length of the weir The pond has a spill elevation 0.2 ft above the maximum water surface elevation in the pond 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. Q100 = 18.10 cfs Spill elev = 4950.50 ft Top of berm elev.= 4951.00 Weir length required: L = 16.5 ft Use L = 140 ft H= 0.12 ft v = 0.25 ft/s 100 yr WSEL = 4950.32 ft I 1 I 1:ag-31►1 0 ►tee 11 i EROSION CONTROL CALCULATIONS i I 'r I It C I I I I � � � � � @ 11 \ � \ � $ . k / � \ . / m < j \ $ \ \ � �3 » - _ \ \ \ & § •• d / { / �� \ 2 R c _ � k ` < / !E t - 2 m=® & ] ( o U) | \ ) J 5w § §) § §! @N@ � § 2EA §§ ]2 - mr ] k§ \� �§ \ 0: ƒ)] \\\ �)) . . d�\ \4. 42 \/( / 0 / 02 �/) /� \\0 k g § ® 2 t E0 )gaQ] °°° )g)�� e§/ 4j«j« 27J LFE North Star Design 700 Automation Drive, Unit I Windsor, CO 80550 EFFECTIVENESS CALCULATIONS PROJECT: Kingdom Hall of Jehovah's Witness STANDARD FORM B. COMPLETED BY: SB DATE: 07-Mar-06 EROSION CONTROL C-FACTOR P-FACTOR METHOD VALUE VALUE COMMENT BARE SOIL 1.00 1.00 SMOOTH CONDITION ROUGHENED GROUND 1.00 0.90 SEDIMENT BASIN 1.00 0.50 ROADS/WALKS 0.01 1.00 GRAVEL FILTERS 1.00 0.80 PLACED AT INLETS SILT FENCE 1.00 0.50 STRAW MULCH 0.06 1.00 ESTABLISHED GRASS 0.08 1.00 STRAW BARRIERS 1.00 0.80 EFF = (I -C*P)* 100 MAJOR SUB BASIN AREA EROSION CONTROL METHODS BASIN BASIN (Ac) 1 1.56 BARE SOIL 0.76 Ac. ROADS/WALKS 0.80 Ac. STRAW MULCH 0.00 Ac. ROUGHENED GROUND 0.00 Ac. ESTABLISHED GRASS 0.00 Ac. NET C-FACTOR 0.49 NET P-FACTOR 0.16 EFF = (1-C*P)* 100 = 92.1% 2 0.61 BARE SOIL 0.08 Ac. ROADS/WALKS 0.53 Ac. STRAW MULCH 0.00 Ac. ROUGHENED GROUND 0.00 Ac. ESTABLISHED GRASS 0.00 Ac. NET C-FACTOR 0.14 NET P-FACTOR 0.32 EFF = (1-C*P)* 100 = 95.5% 3 0.74 BARE SOIL 0.74 Ac. ROADS/WALKS 0.00 Ac. STRAW MULCH 0.00 Ac. ROUGHENED GROUND 0.00 Ac. ESTABLISHED GRASS 0.00 Ac. NET C-FACTOR 1.00 NET P-FACTOR 0.50 EFF = (1-C*P)* 100 = 50.0% TOTAL AREA = 2.91 ac TOTAL EFF = 82.1 % REQUIRED PS = 77.4% Erosion.xls 1 of 1 I I 11 I i I r CONSTRUCTION SEQUENCE Project: Kingdom Hall of Jehovah's Witness Date: March 7, 2006 Indirate with bar line when ennstnudinna will nrrurr and when BMP's will he installed/remnved in relation to the construction phase CONSTRUCTION PHASE (Week/Month) 1 2 3 4 5 6 7 8 9 10 11 12 Grading (Include Offsite) Overlot DetentionA(VQ Ponds Swales, Drainageways, Streams WIN Ditches Pipeline Installation (Include Offsite) Water Sanitary Sewer Stormwater Concrete Installation (Include Offsite) Area Inlets Curb Inlets Pond Outlet Structures Curb and Gutter Box Culverts, Bridges Street Installation (Include Offsite) Gradiing/Base Pavememt Miscellaneous (Include Offsite) Drop Structures Other (List) BEST MANAGEMENT PRACTICES Structural Silt Fence Barriers Contour Furrows (Ripping/Disking) Sediment Trap/Filter am go gas am Vehicle Tracking Pads Flow Barriers (Bales, Wattles, Etc) Inlet Filter Sand Bags Bare Soil Preparation Terracing Stream Flow Diversion Rip Rap Other (List) Vegetative Temporary Seed Planting Mulching/Sealant Permanent Seed Planting Sod Installation Netting s/Bla nkets/Mats Other (List) 1 I Cost Est [_1 I I I I I EROSION CONTROL COST ESTIMATE Project: Kingdom Hall of Jehovah's Witness Prepared by: SB ITEM 1QUANTITY JUNIT COST/UNIT ITOT=ST Silt Fence 1500 LF $3 $4,500 Straw Bale Barrier 7 EA $150 $1,050 Gravel Inlet Filter 3 EA $150 $450 Construction Entrance 1 EA $550 $550 Subtotal Contingency (50%) Total $6,550 $3,275 $9,825 CITY RESEEDING COST Reseed/Mulch 3.4 ACRE 1 $775 $2,635 Subtotal Contingency (50%) Total $2,635 $1,318 $3,953 EROSION CONTROL ESCROW AMOUNT $9,825 I Page 1 3/7/2006 1 1 1 1 1 1 1 1 i 1 Riprap Calculations LOCATION: Jehovah's Witness PROJECT NO: 242-01 COMPUTATIONS BY: SB SUBMITTED BY: North Star Design DATE: 3/7/2006 From Urban Strom Drainage Criterial Manual volume 2, June 2001 (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 d = tailwater depth, ft Pd = riprap sizing design parameter V = design flow velocity at pipe outlet, ft/s Storm 2 18" RCP Q = 7.55 cfs D = 18 in = 1.5 ft d = 1.06 ft V = 5.1 fits Pd = (V z + g*d),5 = 7.8 (From Figure HS-20, use Type L riprap) Basin Depth: From Table HS-9, D50 = 9 in From Equation HS-17. Riprap depth = 1.75 * D50 = 16 in Basin Length: From Equation HS-18, L = 4 * D = 6.0 ft From Equation HS-19, L = D.5 * V/2 = 3.1 ft Basin Width: From Equation HS-20, W = 4 * D = 6.0 ft Riprap.xls USE: 6' W x 6' L x 16" Type L Riprap Page 1 3/7/2006 Riprap Calculations LOCATION: JehovaWs Witness PROJECT NO: 242-01 COMPUTATIONS BY: SB SUBMITTED BY: North Star Design DATE: 3/7/2006 From Urban Strom Drainage Criterial Manual volume 2, June 2001 (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 d = tailwater depth, ft Pd = riprap sizing design parameter V = design flow velocity at pipe outlet, ft/s Storm 3 18" ADS Q = 7.55 cfs D = 18 in = 1.5 ft d = 1.06 ft V = 5.1 ft/s Pd = (V 2 + 9*d) 5 = 7.8 (From Figure HS-20, use Type L riprap) Basin Depth: From Table HS-9, D50 = 9 in From Equation HS-17. Riprap depth = 1.75 * D50 = 16 in Basin Lenoth: From Equation HS-18, L = 4 * D = 6.0 ft From Equation HS-19, L = D.5 * V/2 = 3.1 ft Basin Width: From Equation HS-20, W = 4 * D = 6.0 ft USE: 6' W x 6' L x 16" Type L Riprap Riprap.xls Page 4 3/7/2006 Riprap Calculations LOCATION: Jehovah's Witness PROJECT NO: 242-01 COMPUTATIONS BY: SB SUBMITTED BY: North Star Design DATE: 3/7/2006 From Urban Strom Drainage Criteria/ Manual volume 2, June 2001 (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 d = tailwater depth, ft Pd = riprap sizing design parameter V = design flow velocity at pipe outlet, ft/s Storm 4 12" PVC Q = 1.08 cfs D = 12 in = 1 ft . d = 0.56 ft V = 3.0 ftts Pd = (V 2 + g*d).5 = 5.2 (From Figure HS-20, use Type L riprap) Basin Depth: From Table HS-9, D50 = 9 in From Equation HS-17. Riprap depth = 1.75 * D50 = 16 in Basin Length: From. Equation HS-18, L = 4 * D = 4.0 ft From Equation HS-19, L = D 5 ` V/2 = 1.5 ft Basin Width: From Equation HS-20, W = 4 * D = 4.0 ft USE: 4' W x 4' L x 16" Type L Riprap Riprap.xls Page 2 3/7/2006 Riprap Calculations LOCATION: Jehovah's Witness PROJECT NO: 242-01 COMPUTATIONS BY: SB SUBMITTED BY: North Star Design DATE: 3/7/2006 From Urban Strom Drainage Criterial Manual volume 2, June 2001 (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 d = tailwater depth, ft Pd= riprap sizing design parameter V = design flow velocity at pipe outlet, ft/s Curb Cut Q = 7.6 cfs w= 6 ft H= 0.5 ft V = 2.5 ft/s Pd = (V 2 + g*d)s = 4.7 (From Figure HS-20, use Type L riprap) Basin Depth: From Table HS-9, D50 = 9 in From Equation HS-17. Riprap depth = 1.75 * D50 = 16 in Basin Length: From Equation HS-18, L = 4 * H = 2.0 ft From Equation HS-19, L = D,5 * V/2 = 0.9 ft Basin Width: From Equation HS-20, W = w + 4 * H = 8.0 ft USE: 8' W x 4' L x 16" Type L Riprap Riprap.xis Page 3 F-"Biel 11 ► e A FIGURES AND TABLES ,, 1 I i No Text ��(carw+rrav-n�.. 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 .8.03 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 1 4.69 29.00 1.32 2.25 4.60 30.00 1.30 2.21 d 4.52 Table 3-3 ' R=CtSi, bWM= XMIM C BFSCffiiT3 PM cams 'tE ANUMZS cbarac«e of surface Rif coefficient p' Streets, Parking Lots, Drives: 1 Asphalt.. 0.95 Concrete................................. 0.95 Gravel....................................... ' 0.50 Roofs .......................................... 0.95 Lawns, Sandy Soil: Flat<2$..................... 0.10 Average 2 to 78., ................15 0.0.15 Steep>7% .................................... Lawns. Heavy Soil: ' Flat<2$............................... 0.20 Average 2 to 7%........................ 0.25 ' ... Steep>78...................... 0.35 3.2.7 Time of Concentration In order to use the Rainfall Intensity Duration Curve, the time of concentration must be )mown. The time of concentration, Tc, represents the time for water to flow from the most remote part of the drainage basin under consideration to the design point under consideration. The time of ' concentration can be represented by the following equation. Tc = to. + t; Where: T, = Time of Concentration, minutes t,. = overland flow. time, minutes tt = travel time in the gutter, swale, or storm sewer, minutes The overland flow time, t,., ,can be detexmined either by the following equation "Overland or the Time of Flow Curves" from the Urban Storm Drainage Criteria Manual, included in this report (See Figure 3-2). ' Lo*7(1-1-CCf)D112 Tav— SU3 Where: T" = Overland Flow Time of Concentration, minutes S = Slope, 8 C = Rational Method Runoff Coefficient D = Length of overland Flow, feet' (500, rm»,imy+ ) C= = Frequency Adjustment Factor The travel time, t,, in the gutter, swale, or storm sewer can be estimated with the help of Figure 3-3. 3.1.8 Adjustment for Infzsq=ent 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. May 1984 Design Criteria Revised January 1997 3-5 DRAINAGE CRITERIA MANUAL (V. 1) TABLE RO-3 Recommended Percentage Imperviousness Values Land Use or Surface Characteristics Percentage Imperviousness Business: Commercial areas 95 Neighborhood areas 85 Residential: - Single -family Multi -unit detached 60 Multi -unit attached 75 Half -acre lot or larger " Apartments 80 Industrial: Light areas 80 Heavy areas 90 Parks, cemeteries 5 Playgrounds 10 Schools 50 Railroad yard areas 15 Undeveloped Areas: Historic flow analysis 2 Greenbelts, agricultural 2 Off -site flow analysis when land use not defined 45 Streets: Paved 100 - Gravel(packed) 40 Drive and walks 90 < Roofs 90. Lawns, sandy soil 0 Lawns, clayey soil 0 " See Figures RO-3 through RO-5 for percentage imperviousness. .RUNOFF? Based in part on the data collected by the District since 1969, an empirical relationship between C and the percentage imperviousness for various storm return periods was developed. Thus, values for C can be determined using the following equations (Urbonas, Guo and Tucker 1990). CA = KA + (1.31i' 1.44i' + 1.135i — 0.12) for Ca >:0, otherwise CA = 0 (RO-6) CCD = KCD :+ (0.858i' — 0.786i' + 0.774i + 0.04) CB = (Cl + CCD )l2 in which: i = % imperviousness/100 expressed as a decimal (see Table RO-3) (RO-7) 06/2001 Urban Drainage and Flood Control District RO-9 STRUCTURAL BEST MANAGEMENT PRACTICES 0.50 0.45 0.40 70.35 t 0.30 0.25 > 0.20 U 3 0.15 0.10 0.05 0 00 1. DRAINAGE CRITERIA MANUAL (V. 3) I Extended Detention Basin 40-hour Drain Time Constructed Wetland Basin 24-hour Drain Time i 6-hr drain time a = 0.7 12-hr drain time a = 0.8 7Rit 24-hr drain time a = 0.9 I 40-hr drain time a = 1.0 I � Retention Pond, Porous Pavement Detention and Porous Landscape Detention 12-hour Drain Time I 0 0.1 0.2 0.3 0.4. 0.5 0.6 0.7 0.8 0.9 1 Total Imperviousness Ratio (i=1,,.01100) FIGURE EDB-2 Water Quality Capture Volume (WQCV), 8IYh Percentile Runoff Event 3- S-42 9-1-99 Urban Drainage and Flood Control District 1 1 f i 1 1 1 1 1 1 1 1 1 1 1 1 1 1� 1 DRAINAGE CRITERIA MANUAL (V.3) 10.0 MLO 4.0 2.( 1.0 a) 0.6( aD Co 0.4( E m C 0.21 U T N 7 0 0.11 • • 1610 STRUCTURAL BEST MANAGEMENT PRACTICES EXAMPLE: DWO = 4.5 ft WOCV = 2.1 acre-feet SOLUTION: Required Area per Row = 1.75 in 2 EQUATION: WQCV a= K 40 in which, K40=0.0130WQ +0.22DWQ -0.10 (b (r C a O� Qr 3 O� o` 2 I 0.01 0.02 0.04 0.06 UJ U U.Gv U.9U v.ov J ,U c.v -•- Required Area per Row,a (in.2 ) FIGURE EDB-3 Water Quality Outlet Sizing: Dry Extended Detention Basin With a 40-Hour Drain Time of the Capture Volume 9-1-99 Urban Drainage and Flood Control District S-43 Orifice Plate Perforation Sizing Circular Perforation Sizing Chart may be applied to orifice plate or vertical pipe outlet. Hale Oia (in) Hole Oia (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 j 0.313 2 0.08 0.15 0.23 I 3/8 0.375 2 j 0.11 0.22 I 0.33 7/ 16 0.438 2 0.1 S 0.30 I 0.45 1 /2 0,500 2 0.20 0.39 1 0.59 9/16 0`563 3 .. I 0.25 0.50 1 0.75 5/8 0.625 3 0.31 0.61 0.92 11 /16 1 0.688 3 0.37 0.74 1.11 3/4 0.750 3 0.,'4 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 I 0.99 I 1.99 2.98 1 1 /4 1.250 4 1.23 ( 2.45 i 3.88 1 3 8 1.375 4 11,48 2.97 4.45 1- 1 /2 1.500 4 1.77 3.53 5.30 1 5/8 1 1.625 4 1 2.07 4.15 6.22 1 3 4 1. 550 4 2.41 4.3.1 7.22 1 7 8 1 1.875 4 2.76 5.52 ( 8.28 2 2000. 4 3.14 6.28 I 9.42 n = Number of columns of perforations Minimum steel plate thickness 1/4 5/16 " 3/8 " Rectangular Perforction Sizing Only one column of rectangular perforations cllowed. Rectangular Height = inches Req_:red Area per Row (sq in Rectangular Width (inches) _ c Urban Drainage and Flood Control District Drainage Criteria Manual (V.3) Rectangular Hole Width Min. Steei Thickness 5,. 1 41 6„ /4 .. 7" 5/32 8„ 5/16 .. 9" 11 /32 " 101. 3/8 ,. >10" 1 /2 ,. Figure 5 WOCV Outlet Orifice Perforation Sizing I �-- Oo c.0 -cd- N rn Do CO � N 00 m rn 0) 0 O 00 DO 00 00 O O O O O O O O O x — .zo4olej quaui-4snfpV MOUJI10 Mal 14 o ° 44 0 41 �1 U .~i 4a ji C � N � -r1 IC o � CL) id A'' 3 0 .� 44 44 41 v O 1 1. 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 280 5 Closed Conduit Flow Red K 1.2 - N % Red = I vlo 1 •; �.,c. ttdv Figure 5-21 ' Flow coefficient K and Red/K versus the Reynolds number for orifices, nozzles, and venturi meters (20, 23) I 1 11 1 O G Oa 0 U N z N a a 0 U a 0 G4 ao W 44 M o a0+000 o vvino� In WWWWm o a+o,olo+000000 o vvva'u�rnmmmo .r mWmWWmmmmm o Wo+o+a+o,atio�0+a+o,o�o,000 o vervvvvv�vvvvinlnln M co COCOWWmmWmWWmWWW . . . . . . . . . . . . . . . . . . . o va vavevva vvvvervva vvv N W W m W W m m W m W W m W W W W W m W W 0 onvow vow f-rl rnrrrPrl�hr W W W W W W o v�rvavvavva�srervavvvvvavveraa�er � coWmeocoaommmCDWmWWCococoWcoWWWWWWW O mNmv0m nWe0�ge wwr.rnrnrtnrrr W W W . .......................... 0► Mvd'vvvvvilvvvvvvvvvvv IV vsrvvv cocoGOCOWmmoDmWaoCDWWaococoCID WWWWWWWW O 1 91e m-w-TMIn010%D%Q%Q%D%D%V%0%0%0%0 r rrrrr . . . . . . . . . . . . . . . . . . . . . . . . . . . W M v v v v v v v v v v v v v v v v v v v v v v v 4 v m m W m m m m m m W W W W W W co W W co CID co W Co W CO co O v0\rINMMvvvwrMtnW inlnMwwto W %D%DID%0%V %0r . ........................... r e+fMvvvvavveavvavvvvvvvv�vaar mCOWmWmWmmWWWWWWWWWWCOWWW WWW O 010W OrI eiN Ne'1MMe'f vvvvvvvvin In In to t0 \0 . ... .. . .... . . ....... %o M mm4Tgv v.:vVvIVvvqwv�vqwvvvvvvv mWmcoWWmeoCDCDODtocoWmWWWWWWWW WWW r. 0 In N to n CO 01 0 0 rl rt ri N N N N N m M M M M v v v v v Mtn NNfe7M . . *4v .d'vvv vvvvvvvv44444 OD WCOCDODCDCDWmCDCOWCDWCOWcoW coW COWCOCDWCO P w (l� atoCoco mWWWam0%cc000 av NNMmMmMMm i"f A r4 A M M M MA M A 4 v d' vv &0 WeoWWWmcocoODcocoODeomWmcoWWmWWWWWW o �DInmo.-INmOwvtnentov%D%C%D%onnrrWWwC%0% . . . . . . . . . . . . . . . . . . . . . . v 4 N N 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 W W- m m m CO W W W W W W W W W W W W W W W W W in ."194mtn 000pgNNMMMvvvvvinlnm%0%D%0rr M ri N N N N M M M M M M M M M M M M M M M,M M M M M M WWmWCOWmWmmCOWmW WWW WmWW WW CD co co O MN10 co 0►0V4N N M M M v v v v v v W W W ICY %D %0%0%0 M 0iV .-1 rl ri rl N N N N N C4 N N N N N N CV N cV N N N N N CO com COW WmcomWWWCOWcocoW W co co W W W co co W Ln In In m N M qv In %0 t� n r co CD CD 01 01 0% Of 01-01 0 0 0 0 0 0 r.r.r...14 4 1.C4 N N N N N rWW WCOWmCDWCDCOWWCOWWmWmcowW W W co W O VIn 0 MIn IDm W 010 Oo ri.-I ri ri N N N N M M M M MM N co 01 O O O O O O O ri ri rl rl ri 'i ri rl rl rl rl r! rl .i •i rl .i rrmGOCOCCCDCID mCoWWWCO00WOOWmWWCID WWWW In CO NCDrlvinl-rm0%0%OOrirlrirl riNNNMMMMM ei %D W W 010;0;0 0;0 4;14 CO8OOOOOOOOoOOOO rrnrrPrnrinreoCD W W W CD co co W W Co W W W co O t0 M 0 v r 0% 0 rl N M M v v In In In In %0 10 %D 1D r r w %0 %D ri v�0nrnt�mCOCOCD ComWWWCOWWWWWWWWW rnnrnrrrrnrnnnnrrrnnrrnrrr In o,ov%onmmnr-n%0%cwtnvvMMNNcn%C-WV4m%D O O N N N N N N N N N N N N N N N N N N N rl rl rl r♦ O O r r n r n P n r n P r r n n r n r n n r in r r r r lr x E-o 0000o00000OOOOOO000OOOOOOO 0E o0000000000OO0000000000000 �64 r1NnImtn%Drm0l01-4N'e' vin%Dr co 0%otnoin0lnO a `� rl 9-4 9-4 rl rl rl rl .i rI N N M fn qw V 0 Table 88 C-Factors and P-Factors for Evaluating EFF Values. ' Treatment C-Factor P-Factor BARE SOIL ' Packed and smooth......................................:........................ 1.00 1.00 Freshly disked ..... Rough irregular surface . 1.00 0.90 SEDIMENT BASINfTRAP................. 1.00 0.50"� ..................................... STRAW BALE BARRIER, GRAVEL FILTER, SAND BAG ................ ... 1.00 0.80 SILT FENCE BARRIER ..................... .. 1.00 0.50 ASPHALT/CONCRETE PAVEMENT .................................................... 0.01 1.00 ' ESTABLISHED DRY LAND (NATIVE) GRASS ................. _........ See Fig. 8-A 1.00 S00GRASS ............................................... ..... 0.01 1.00 ............................. ' TEMPORARY VEGETATION/COVER CROPS .................................... 0.450 1.00 HYDRAULIC MULCH @ 2 TONS/ACRE ................................ ............ 0.1001 1.00 ' SOIL SEALANT ............................ ......0.01-0.60M 1.00 EROSION CONTROL MATS/BLANKETS ' GRAVEL MULCH Mulch shall consist of gravel having a diameter of appro)amately 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 a antino oracs seed apply mulch at a rate of 2 tons/acre (minimum) and adequately anchor, tack or crimp material into the soil. 1 Slo- e M 1 to 05......................... 0.06 1.00 .................. 1 to 15............................................... 0.07 1.00 0.06 1.00 21 to .:.............................................. 0.11 1.00 ' 25 to 33.............................................................................0.17 1.00 ... >33 . . 0.17 1.00 0.20 1.00 NOTE. Use of offer C-Factor or P-Factor vakres reporoed in ft table must be by doaatmtadom ' (1) Must be constructed as the first step in overlot grading. (2) Asmms 3) Hy mulches sus identified in Table h, between 11-4, thus 15 aor nd raMay 5 unless mLftm irrigated. a e�d� ' (4) Value used must be substantiated by documentation. 1 MARCH 1991 8-6 L� Table 843 C-Factors and P-Factm for Evaluating EFF Values (continued from previous page).. r Treatment C-Factor P-Factor CONTOUR FURROWED SURFACE Must be maintained throughout the construction period, otherwise P-Factor = 1.00. length refers to the down slope length. Maximum Basin Maximum Slope Length ' 1%) (feet) 1 to 2 400..........................................................................1.00 3 to 5 300 0.60 ..........................................................................1.00 6 to 8-200 0.50 ' ..........................................................................1.00 9 to 12 120 0.50 .............:............................................................1.00 13 to 16 80 0.60 ..........................................................................1.00 17 to 20 60 0.70 ..........................................................................1.00 > 20 50 0.80 ' .......................................................................... 1.00 0.90 TERRACING Must contain 10-year runoff volumes, without overflowing, as determined by applicable hydrologic ' methods, otherwise P-Factor = 1.00. Basin Slope M 1 to 2 t ............................................. ............................. ... to8 1.00 0.12 ..................................................................................... 1.00 0.10 13 to 16 1.00 0.12 ' _ .................................................................................... .............................................................1.00 17 to 20:.................................................:. 0.14 .............. ............1.00 > 20 0.16 ........................................................................ ...... 1.00 0.18 ' NOTE: Use of other C+Wtor or P-Factor vales reported in this table must bemftmdawdby documentwkn. MARCH1991 3-7 DESIGN CRRERIA 1 1 1 `1 1 1 1 1 1; 1 1 1 1 1 1 1 IC i DRAINAGE CRITERIA MANUAL (V. 2) 30 25 Im �Wlj 5 _ = *Grouted SIB Boulders--.- -----;---- -- I i , , I I HYDRAULIC STRUCTURES 1 2 3 4 5 6 7 8 Storm Sewer Diameter, D, or Height, H, in ft. FIGURE HS-20 Low Tailwater Riprap Basins for Storm Sewer Pipe Outlets—Riprap Selection Chart for Low Tailwater Basin at Pipe Outlet (Stevens and Urbonas 1996) 06/2001 Urban Drainage & Flood Control District HS-79 v o PROPOS♦D R.O.M.-� STORM 2 .Nos 61ETBON CIIEflE gtl FllNO / - LOT 4 OJa O.z i PRWOI DRAINAGE �'D EASEMENT ROWED ME L MPRN ITNp)"yyyyy INTO RETENPM/ MITS __________________________ - 0 ° Mgt II [TN AS MATCHED) ` 1 LOT 1 - 1 56 0.85 All Al I I eR 1 0 Other 301 QDESIGN POINT BASIN CRITERIA 0.26 0.9 10 m RUNOEF COEEFgENT AREA IN ACRES r FLOW DINECRON BAVN BOUNDARY ® .g1 SIX SLY EFHCE ® CONSWUCTM ENTRANCE RATTLES O INLET PROTECMW ® me UNT POND IN FLOW PIPES PROPOSED STMM PIPE m OARED EM MCTM EXITING V CMTWR EXISTING IF CCNTWR NR oS 5 CONTMR PRMOREO 1 CONTOUR PRAP `msS DITCH POND 2 TO BE UR➢ As A sE01MFNT TRAP OVPoHG CONSTRUCTION, POND SHNL BE CLFANEO 6 Rdt[NT AND MMW T TO nN GRAIDE NAM TO STE MMCATDN. Willi __-_______L �� RETENTION Et /. IFi -AE- _ _ XF- e_ _ - _ _ -ALL -- I / OUTTALL CURII 1 ,of As HATMEG) BURRO TF\`E R jm RIPMp (Rrv) ,) e9• IOIO 1 O pRCPD$D DRAM =_ eAssaur OUTI£AT i FNNO CMWGENL J ^4 An t : _ KEC ROM - - - L CED N D Ch CALL UTILITY NOTIFIiATION as j m m do OF COLORADo 1-800-922-1987 TO °swf cAn 2-BUSINESS GAYS IN ADVANCE C J5 a Q cY BEFORE YOU DIG. GRADc CR EXCAVATE 'RL�'� Dx THE ANKIND w uNDERwamD y C E U QI o MEMBER U➢LIFE5. e� Im so AllN s = 30 15 0 SD 60 �� n 3 0_la SCALE'. 1" 3C' ' Ott AT 0 STANDARD EROSION & T CONTROL CONSTRUINOTEifeaShn" DIP must be offfiea at least burly -low (24) noun pro, to onscllu artThe on sin pea 2 They, moll be no earth-ISL Ong Ability outnae the limit, logal anthe accepted p Ali ]. AT required pernli 3 It and courruction ALL final be nsta eG Bpg to anyPond Strutting y 9 Ta 9 ). e, o ryqu na ral Na ( III SOCH be ea t C . t .Imn'm Seoul as c rep o l.a n me ON mpa eMa constructionpane and vas= ALI MW At all full ,II Construct or the D"ww mall be responsible tar pnnnling and R dwyanug m-srb al 9 Yeepn g the property Whiceltr By as to 'I'd aor elm a a DIwW thin davy be mason a la, hisailing one nual At wall= Carl tncli(ue Shall Fore,. 5. P • v ot,tbn a protect" a rho position Bmawl OF n nm:'aRa.e far Immediate =aural= come= .nand for B,aSIP pre luty on I 6. n N npo,W ourin9 lady aeluriog addle (,b�awq, odes. a\Ilioy Inelolrallons, �Ing, d g, end mat ae Add ougevi C (Ion by r ping difivii o,L Z •Cget other parmanml or cwMl BMPs a Atalal Wn ti Ot C n(W) r N I. W protect lyre<. of .ar Was ,wnpn by told g nN r t l Thief (]G) den earne rpi red t n thirty ry by > t e installed InIroy v (.g. a/morn Iwmwang na . netalw w elnwnBe to m m e by the cu /c t\ 0 In In n OM don \ hum ion a tampwory bwamn) wosiw conflict me sera, N I I at OF a) Be 6,owled of a min al,wa fee (^) .aKs and often w egn<Ikant p 1i alwn d, llrM Or We ntry non ry rr Yew m trials thecontinued t-a perfamwce Of mho 1,tM M luncpw L ir b) Rwi M planes al such Rme IS all the wrrwnaing e'maNM areas are ,uxclwtly ir etRbrtm We dM .led by tee @notion pwNa N,ant= o) 41 R ION ap Ne@ Mn vlX ly ewm oe aterml by Me woo M" _ w Qp ITT a� 1 Mon Y ✓o whorl, the W Moll b nspmsWs lean p L -or uc and III owl of on aeawM =d dean horn 6oAye bXOMndun Sidthe Other pao I fiilll'w 91 oFw ltw Mal wmedwWy dwn OCR spy c s@ cum mats s Fed°vtwul an 1111i octalea ae.hillther public lots of vex and man eie o b Wind e.an or, Cleaned a the e Sid of each eon g try, 10. AS ,e ,Wlmmu. Ponlalwry Mow w pared r e ar eunapu, Yalu a ro of Sid dWOe m= non all holes so ae.at to tad" their release into any .mare of the Unit" Sloe! 11. No sM a Re Mal e,cx ton 10) Last in height All cYppn m aad be prawted Gwn w Sit wnFli by Auna PAKNI 'alma and pwblae. of All My c etod 8 mOinkg anon thdry (30) days @hot be son one mulched. 12. Ti etwm W Mums c by Of delwlVu puree Sul be ,male spa storm eA«, 4ntl So the a upon c MetW of the III and bOwe III ION malmenance 0~ to Me BNy/cwlny byNwnwww. Awwwpw III 13 Oq Mdxarn and Colorado DlecFpg@ Permit Syl (Clips) rwulrwlmt, alma n umaew to eYmmge w allow the d aqe a1 any palmane an cmtwnwolm .otw byre a=etrul Won. Pa dOnt, moues, but are not Ilmrtea to dlsearead building mmwlme, Z Lutlt wdawL Nanmae, al andgooplad ct , Iran. Sid sanrt�y, waste The aW t Q ry Mat aree al l thtake wn tww w wo,y to o. the proper J CmtO mpt Land dh of pollutants An the to In aswe=aana. Sign Sir one al spmlwde Iwd, "SO and M1 requwUhns INTERIM RETENTION POND SUMMARY INTERIM RETENTION REWIRED 11255AC.FT. POND 1 VOLUME PROVDED 1 0.471 AC. FT. POND 2 VOLUME PROVIDED 0.784 AO FT. TOTAL VOLUME PROVIDED 1.348 AC. FT. 1W YR HWL 4950.37 RELEASE RAZE 0.0 LIPS. LOT 1 DETENTION POND SUMMARY (ULTIMATE CONDITION) ULTIMATE DETENDON REOUIREO 0.399 AC, FT. ULTIMATE WO VOLUME REWWRED 0.05> AC. FT. TOTAL VOLUME REQUIRED 1 0.455 AC. FT. TOTAL VOLUME PROVIDED 1 0.514 AC. FT. 1W YR HAEL 1 4950.32 MAX RELEASE RATE I 1.08 Cie. 14�A MYgnetM asp YMI LAW Poll an ua Tfarconcrete di chute washout Ae V/ J YyI b cwomry Adoe to pw in vCmwtotwed Old located at least PINY IWO O iM O"y LOT Sir wOkw,oy dI g construction Upon c,ri le(m of dwonvaa, O W MtMtM i t@� Wt mmwlal . be rwnwe and prc y dip of Are, to b�iHa o onto@ IS TMe lNdua lie eWment dose not rion So lots we an spa of Due unw Ali F O INSW-rq @slim=t/wan 0 Lm Mat Shot be Installed and maintod ed m s o, J U WMCr Uy stni m dwwmnW by thewonpn contra ingwta. (Vfithrn LOMpnd OF Q I Cry). in Bann all 9mfer a C O (C AP lot (6. Pn, C • .ro t,, n O Sit Of Tac .'@• gee LL) The Shall wf Widely memwn are determined ''1@Ise@@aY. dM:cted by w CRY/Ca Q � as ntra. (� 3f DRAINAGE SUMMARY TABLE DESIGN POINT AREA ESSIG. AREA ACRES C 10 C IN Tc 10 MIN Tc 100 MIN 0 10 CFS 0 100 CFS 1 I 156 0.65 0.82>.0 J.) 11.2 2 2 O.b1 0.86 1.00 5.0 5.0 2.5 6.0 3 1 3 0.74 1 0.20 0.25 11.1 11.1 0.5 1.3 4 1 a 1 01 1 0.20 1 0,25 1 11.2 11.7 (1 0.7 zX w Y�z Q City of Fort Collins, Colorado ID UTILITY PLAN APPROVAL APPROVED'. City Englnew Cale CHECKED BY SHEET Mole, So Mdstewot,r LILLY Cate CHECKED BY stwm.ote, Utility Dan 6 CHECKED BY: FoIMs n Recrol Date CHECKED BY. 6 OF 20 TnMc EngA✓ Dole CHECKED BY: Al Nob No. 242-01