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HomeMy WebLinkAbout20042494.tiff NOVEMBER 2OO3 FINAL DRAINAGE STUDY HILL-N-PARK SUBDIVISION Prepared for. JER PARTNERSHIP Contact: Mike Thomas 1317 15th Avenue Greeley, Colorado 80631 (970) 686-7200 Prepared by. PICKETT ENGINEERING, INC. Contact: Greg Bowdish 808 8th Street Greeley, Colorado 80631 (970) 356-6362 r 2004-2494 s-� HILL-N-PARK SUBDIVISION FINAL DRAINAGE STUDY I. General Location and Description A. Location The site is located in Weld County, being a part of the south half of Section 26, Township 5 North, Range 66 West of the 6` P.M., County of Weld, State of Colorado. The site is bordered on the north, south, east, and west by residential land. B. Description of the Property Currently, the site's storm runoff is uncontrolled. There is one major storm runoff control device controlling the storm runoff generated by 49`h Street. Said ditch, which carries the 49`h Street runoff along the southern portion of the site, does not release stormwater onto the site, and will not be considered in this drainage report. Stormwater runoff generated by this site flows to the Ashcroft Draw. The site is currently unimproved and the vegetation is short grasses. _ Currently the subsurface soil consists of excessively drained loamy sand. According to the Flood Insurance Rate Map (FIRM) for Weld County, Colorado, Panel No. 619 of 1075, Community Panel No. 080266-00619 C, dated September 28, 1982, the proposed residential lots are located in Zone C. The residential lots are not located in the 100- - year floodplain. C. Proposed Site Plan The proposal is to develop approximately 13, single-family residential units totaling approximately 2.6 acres. II. Drainage Basins and Sub-basins A. Existing Drainage Basin Descriptions To analyze the existing conditions, one drainage basin was identified. Basin El's historical use is defined as agricultural and it was delineated based on a topographical survey provided by Michael T. Thomas. Basin El historically drains into the Ashcroft — Draw. B. Proposed Drainage Basin Descriptions The proposed drainage basin, D1, was determined from the grading plan, the layout of the streets, and other factors that determine basin size and shape. The basin is shown on the Developed Drainage Map (see Appendix). III. Drainage Design Criteria A. Regulations/Development Criteria The Urban Storm Drainage Criteria Manual specifies development of a storm drainage system that will be adequate in size to carry the 10-year-frequency storm, at a minimum. The criteria for the site are to develop a storm drainage system that will route the developed 2-year and 100-year stormwater flows and convey them to a detention pond located on the site. The detention pond is designed to mitigate the developed flows and release them at a controlled, 5-year historic rate to the Ashcroft Draw Basin. The Urban Storm Drainage Criteria Manual (published by the Urban Drainage and Flood Control District, Denver, Colorado), as well as good engineering practices, have been used to calculate the stormwater runoff and to design the stormwater facilities for this site. B. Hydrological Criteria The design storms used were the 2-year (minor) and 100-year (major) for developed discharge. The City of Evans rainfall intensity/duration/frequency curves were used to obtain data for each specified storm. The Rational Method was used to calculate historic and developed stormwater runoff. C. Hydraulic Criteria The stormwater conveyance system will be designed to capture and convey the minor and major storm events. The allowable street capacity for the major event will be based on a maximum depth of 18" from the flowline of the street. The allowable street capacity for the minor event is based on a maximum depth that will not allow the stormwater to overtop the curb of the street. The major event will be routed, determined by allowable street capacities. The structures used to convey and capture the major and minor storms were designed using techniques developed or adopted by the Urban Drainage and Flood Control District and the Terramodel® computer-aided design program, hydraulic module. D. WaiversNariance From Criteria No waiver or variance is requested. 2 E. Stormwater Quality Considerations Stormwater quality will be mitigated on-site during construction with the use of silt fencing, vehicle tracking devices, and inlet and outlet protection devices. Long-term stormwater quality will be obtained by providing a 40-hour water quality capture volume (WQCV) in the detention pond and running the controlled stormwater release over grassed areas. IV. Wetland Preservation and Mitigation There are no wetlands present on the site. V. Drainage Facility Design A. General Concept Proposed drainage patterns for the site will be similar to the historic flow path. Flows from Basin D1 will be routed through the site by the proposed street's Detention Pond A. Detention Pond A's storm flows will be released at an attenuated 5-year historic rate to the existing gutter flow line of Yosemite Drive. B. Specific Details 1. Detention Pond A _ Detention Pond A will be constructed in Outlot A, located in the northeast corner of the site. The 5-year historic storm flows will be released, while the 100-year developed flow is detained. The 5-year historic runoff was calculated to be 1.13 cfs; the 100-year developed runoff into the pond was calculated as 17.97 cfs. The detention pond outlet structure will be constructed to have a water quality orifice plate and a 5"-diameter orifice on a 12"-diameter outlet pipe. The pond will provide water quality capture volume before the controlled release of 1.13 cfs through the orifice and into the gutter of Yosemite Drive during the 100-year storm. The pond will have adequate volume to detain the developed 100-year storm. If the outlet structure should ever become plugged, a 10'-wide spillway has been designed to allow the pond to overtop by providing a controlled release of 3.4 cfs during the 100-year storm. Sideslopes of 4:1 have been utilized throughout the detention pond. The following table summarizes the calculated stormwater runoff quantities and pond design parameters. Drainage basin area routed through the pond 3.40 acres Developed 100-year discharge 17.97 cfs 3 Developed 100-year release rate 1.0 cfs Pond volume required to 17,298 ft3 (0.4 ac.ft.) detain the 100-year runoff WQCV volume required 3950 ft3 WQCV outlet invert elevation 34.0 ft Top of WQCV control structure 35.0 ft Invert elevation of 5" orifice 34 ft Pond spillway elevation 35.80 ft Top of pond bank elevation 36.80 ft WQCV provided 6900 ft3 Pond volume provided to detain 18,800 ft3 (0.43 ac.ft.) 100-year runoff Freeboard 100-year plugged outlet condition 1.1 ft Refer to the Appendix for detention pond sizing and outlet structure calculations. C. Conclusions When developed, the site's total runoff will be increased, but the rate of runoff will be decreased for all storms larger than the 5-year storm. The proposed streets and storm sewer system will capture the increased runoff from the site and route the storm flows to the detention pond. This detention pond will mitigate the developed flows and release them at a controlled rate to the Ashcroft Draw Basin. Water quality control will be provided before flows leave the site. The design of the proposed drainage facilities will not adversely affect adjacent sites, and exceeds the Urban Storm Drainage Criteria. VI. References A. The Urban Storm Drainage Criteria Manual, Volume I, published by the Urban Drainage and Flood Control District, Denver, Colorado. B. City of Evans Storm Drainage Criteria Manual, Volume I, March 1997. C. Soil Survey of Weld County, Colorado, Southern Part, published by the United States Department of Agriculture Soil Conservation Service in cooperation with the Colorado Agricultural Experiment Station, issued September 1980. 4 VII. Appendix A. Vicinity Map Page 7 B. Existing Drainage Basin Map (11 x 17) Page 8 C. Developed Drainage Basin Map (11x17)17) Page 9 D. Basin Description Page 10 E. Storm Drainage Calculations Page 11 F. Time of Concentration Calculations Page 12 G. Table RO-2, Conveyance Coefficient, C„ Page 13 H. Flood Insurance Rate Map Page 14 I. Percent Imperviousness Calculations Page 15 J. Table RO-5, Runoff Coefficients, C Page 16 K. Figure 3.2-1, Intensity/Duration/Frequency Curves, Evans, Colorado Page 17 L. Gutter Stormwater Conveyance Capacity for Minor Event Page 18 M. Gutter Stormwater Conveyance Capacity for Major Event Page 19 N. Sidewalk Chase Modeled as a Box Culvert Page 20 O. Existing Drainage Map (24x36) Sleeve 1 P. Developed Drainage Map (24x36) Sleeve 2 ot APPENDIX VICINITY MAP NOT TO SCALE f f II � d s '•w f 1 f ,. .a - t _ I] ,_;_�f`. � '� E t 47-1/BE fork 1i1� . ax r1 t f F-11 1- JLi �� . i 'r 1 1 Prairie k IL 1 ti14. , tI. 1 �, rI L-- h1 ±�u_JIL, iiiIIuFL , I I, . Li L it ) „_____.‘ 2,a-Pr-,,,,,-17,,Bra-s\s, ::2,-,, \., .. Ali -- k te H i , i ,:t."1--r-1.3.."1.4\frarsl. ka-.11.i iq, P 4 �-cam.r J� m /N 7.- 1 f(' 54� r y� r� -I- ,11�t-•'`�.° .' -+'-l "_�'zY -Fy�.r P`+y •'il f - es-7-11i- ... • I, . I I -- 6, . - _ GRAPHIC SCALE t"-30' �- - N EXISTING DRAINAGE MAP 0 30 60 90 Q G;m PROJECT CONTROL A w" z BASIS OF BEARING: I N ; LL Beginning at the East Quarter of said Section 9 IL yy and Assuming the Eaat line of said SE 1/4 as V—O pe Bearng South 00 09 19Colorado Eas , beiPlane a Grid -1 O - Bearing of the Colorado State Plane Coorlainate _ U 9yntea, callorthof Zane, 2North Amer icon Oaths 1983/92. I W— U tzo sl a distance of 262].22 feet with all other bearings contained herein relative thereto:SYMBOL m my'y COORDINATES REFERENCE: I Caorldinetea paned on the Colorado State Plane RR CoaH0lnete System being the East Quarter Corner of Section 9 at mil DRAINAGE ARROW N 1299416.86 E 3172515.62 A A • BASIN DESIGNATION Di \ I B • AREA IN ACRES VERTICAL DATUM: BENCHMARK - CP PIN' No. A REBAR, AS DESCRIBED r '� a c C - COMPOSITE 2-YEAR RUNOFF COEFFICIENT IN KING SURVEYORS TOPOGRAPHIC SURVEY !PROJECT A a 0 - COMPOSITE 100-YEAR RUNOFF COEFFICIENT 20021461. ELEVATION DETERMINED BY GPS OBSERVATIONS. 63 2CFII b NCP 1298292.24 33 4' - E • 3171595.12 ti 9E . °9a9 ELEVATION • 4977.11 (NGVO 29) 0 I ES S.44 QI DESIGN POINT 2a) gk a Oc Y El oN ae _a I Wham 06 8 "'t CD -'p \ Y co I Jigs aasG= • YOSEMITE DRIVE a° = s • �\ \ \ ill 4 \ N FOR APPROVAL l \ \ \ • i _ __ ____ . _. V •� ! 1. ! NOT RELEASED 1 \ , \. \ \ \ ,' /. — . _J ``,a N FeneoNsnwGDON 11 •� I ! 1 ! •• R. , '' \ Nev TED O S 1 �. \ 1 N 1 \ �� \ 1 1 \\ \1'\ �. \\ !! •♦.��, \`'\ 111 his \ \\ \\ 1\ !LI •\•` r. �� •0 $ �� ��■■■r■■■ \ /\\ 'Ni' a • \ r ` \ \\ \I ` \\ \\ \\ / h f-I \\ \\ \ • \ \ \\ l\ \ M 1 \ > 0 �' • I, o` • Oi \\ \\ \ \ \ \\ -✓ • \\ \\ A Q • N. \ \ \\ \• N. - \ \ CN N. 3 \\ _ \ ` \\ \ • \ a `\ _ O '\ \• \ \ '\ \ \ \ NN '' I DI 4 J V v A / • V A i• J b N al i \ N. iiii \ 8 � j n \ 4-' \ \ \ ` III IN "I • `\ f '� l \ / `\ \\ ----\\ • \ • \\ \\ �\ \ r \\ a /' \ • N � a • A_ _ ~ --- Ni_ — -- iiriiii■». pit_ Ua O,. ¢ o ut w 2 Cl w I.. Ol en ci u ..... C-5.2 OB Ka In`° i • A 02-050 • STORM DRAINAGE PLAN GRAPHIC SCALE 30' PROPOSED DRAINAGE MAP 0 30 60 90 �H 11. z w1a W° 0Bp I STORM NOTES PROJECT CONTROL >a I. ALL PIPES ENTERING IS SEWER STRUCTURES SHALL BE GROUTED BASIS OF BEARING: ��p 0 � 41 LEGEND TO ASSURE CONNECTION IS WATER TIGHT. Beginning at the Eest Quarter of said Section 9 V Z anti bearing Souytt t00 East I1ne of said SE IN as U Z Z 0 EXISTING PROPOSED SYMBOL 2. STORM PIPE WE MORE THAN 5 1%1 PERCENT SHALL BE .44 Beer1 g ofmtlnleDLalore0o Stets being One CDONUInate N L-W? U v REMOVED AND REPLACED AT THE CONTRACTORS EXPENSE. System. North Zone, North Amerlean Datum 1983/92. inta 3. CAUTION - NOTICE TO CONTRACTOR a distance of 2627.22 feet with all other bearings II n n It =. — SECTION LINE BOUNDARY THE CONTRACTOR IS SPECIFICALLY CAUTIONED THE LOCATION coma toed herein relative thereto: —�++-- ii) RIISDRAINAGE ARROW AND /OR ELEVATION OF EXISTING UTILITIES AS SHOWN ON THESE PLANS RIGHT OF MAY RIGHT OF WAY IS BASED ONRECORDS OF THE vARIOUS UTILITY COMPANIES AND WHERE COORDINATES REFERENCE: POSSIBLE. MEASUREMENTS TAKEN IN THE FIELD. THE INFORMATION IS PROPERTY LINE PROPERTY LINE A A ' BASIN DESIGNATION NOT TO BE RELIED ON AS BEING EXACT OR COMPLETE. Coorldinates based on the Colorado State Plane B • AREA IN ACRES Coorldinats System being the East DUarter Corner ----4.---- EDGE OF ASPHALT —.---c EDGE OF ASPHALT THE CONTRACTOR MUST CALL THE APPROPRIATE UTILITY COMPANY AT of Section g ati I Can: a c C . COMPOSITE 2-YEAR RUNOFF COEFFICIENT N 1299116.86 S 1 p LEAST 72 HOURS BEFORE ANY EXCAVATION TO REQUEST EXACT FIELD GUTTER FLOMLINE GUTTER FLOWLINE 0 COMPOSITE 2OO-YEAR RUNOFF COEFFICIENT OWTION OF UTILITIES. IT SHALL BE THE RESPONSIBILITY FL THE E 31J2515.62 w SIDEWALK SIDEWALK CONTRACTOR TO RELOCATE ALL EXISTING UTILITIES WHICH CONFLICT WITH PROPOSED IMPROVEMENTS SHOWN ON THE PLANS. i r- VERTICAL DATUM `ay8 — --�-- STORM SEWER 7F1C HANDICAP ACCESS Q A. COORDINATES !i THE STORM INLETS ANO MANHOLES DOES NOT INDICATE THE BENCHMARK CP PIN' No. A REBAR. AS DESCRIBED u m p a 4 a DESIGN POINT FLOXLINE CIF TIME STORM PIPE. SEE DETAILS TO DETERMINE PIPE ALIGNMENT IN KING SURVEYORS TOPOGRAPHIC SURVEY (PROJECT m Ol 3' NCCC- ArvO--- INDEX CONTOUR ...I CONCRETE CROSS PAN AND INLET PLACEMENT RELATIVE TO COORDINATE REFERENCE. FLONLINE 2Cp2PI61. ELEVATION DETERMINED BY GPS OBSERVATIONS. § rl §w •I'!� ELEVATION 011 INLETS IS THE ELEVATION. OF THE GUTTER. SEE DETAILS TO • 5 INTERMEDIATE CONTOUR STORM SEWER DETERMINE INLET FLONLIIE ELEVATION. E • 3298595.12 .. I Dyw P. $-me, GRADE BREAK LINE ELEVATION 4977.41 QgYD 291 ' OJ a3 b5 EN-q —AJ5O -- INDEX CONTOUR O1 4 m'" X ¢¢ I e$INTERMEDIATE CONTOUPgO �l� eDsa9■ EROSION CONTROL FENCEO °Sm2-�:SBASIN DELINEATION 'Dg$ V. �F 4 •. FOR APPROVAL \ \ I NOT RELEASED _ I \ \ \ .. TOR CONSTRUCTION I I \ \\ \+F. \ \ FEE I PRINTED ON S \ \ ` HL ELEV. •31.00 NOV ID.2005 v •..\ s, w YOSEMITE DRIVE ::emu \ tiQ \ � YE DETAIL MEET c-10111 III -1.. —i..---.� _ `.:--=- '�-l___`_r---`—�`-- - _ \\ \''. 1 ',MIL �1 -�� - 1 --____ J It `\ `m \ q 1 q 1 1 •• ti 'I i I .. .. I •• \ 1 FL ELEV. Q itt3V••♦ I \ i ••1. 1 \ \ OUTLOT A Er eB e% \ LI 41 ii l \ •�V V I bmn z sIDEWUX • ,v I in 1 I' V A 1 �\ R Y xxTA L _. F l; i vj� V vv v " . t 23v L.-* 1 LI \ \ \ IE t i a H A • . \ gola alh . y \ a. .V A \ o \\ CI)DNS ! \i(. '°'aaRaur •\\ li r s s' $ S 3 kg a g Bid I 11 \ •' / \ ` TIIIIININI1‘ 'I' Z ;� \ vv vv vv v �� v 4-1 lig a i. T n d w8 lit.-91::1 a -,_. . . .....11: ¢ z s --____ ----_-_-_-' - -- _ — _ _ _ z a ! Q 1 49TH STREET A S • c-5.1 El CRAMS .aa No TIE 9 m..mM�M°L 02-050 I I I I I I I I I I I I I I I I I I I NY.P.tSeediest. ) Wei County.Cobra& Pi MOM DRSd1PTDR Seals I Rune'CeeSlabnt Ov.IndFlow CeneenIaldw Fb •• 1 2 3 4 mipw Total Numb. Ann DeeedpIon C2 CS C100 LI S1 U $2 Cv V2 1.3 33 Cv V3 U S4 Cr V4 Sbpe LenMMi (eau) MI (%) A (%) Mb M) (%) Mb 00 f%) (lIi , El 3.395 Ensnog Conda ons 0 Oa 0 10 0 38 100 4 6 760 2.0 7.0 1.0 0.0 2.3 MO 01 3.395 Developed Basin B1 0 51 0 54 0.66 20 1 0 565 2.0 :0.o 2.6 0 2.0 7.0 1.0 0.0 2.0 703 • . I"' Shen RvnntCelevIsMone 02 000.eb Pickett Mng0lentq 11a. 1 O I I I I I I I I I I I I I I I I I I I ) ) Hill n Park Subdivision 11/1_.103 Weld County, Colorado PEI #02-050 STORM DRAINAGE CALCULATION Basin Characteristics Intensities Sub-basin Type AREA C2 C5 C100 Tc* 12 15 1100 Q Q Q BASIN 2-yr 5-yr 100-yr (acres) (min) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) El Existing Conditions 3.395 0.04 0.10 0.38 15.7 2.33 3.34 6.24 0.32 1.13 8.06 D1 Developed Basin B1 3.395 0.51 0.54 0.66 8.6 2.98 4.27 8.02 5.17 7.82 17.97 Use five minutes when calculations indicated a lesser value. Storm Runoff Calculations 02-050.xls Pickett Engineering Inc. I I I I I I I I I I I I I I I I I I I ) ) Hill n Park Subdivision 12003 Weld County,Colorado PEI#02-050 TIME OF CONCENTRATION CALCULATIONS INIT. INIT. INIT TM 1 TRVL 2 TRVL 3 TRVL 4 Tc= Total Tc= TOTAL BASIN L1 S1 C5 TI L 2 V T2 L 3 V T3 L 4 V T4 Sum Ti L 10i(L/180) To (ft) (%) (min) (ft) (8s) (min) (ft) (Ns) (min) (ft) (f/s) (min) (min) (feet) (mk) (min) El 100 3.0 0.10 12.5 480 2.5 3.2 0 0.0 0.0 0 0.0 0.0 15.7 580 N/A 18.7 Di 20 1.0 0.54 4.6 685 2.8 4.0 0 1.0 0.0 0 0.0 0.0 8.6 705 13.9 8.6 i rJ Storm Runoff Calculations 02-050ids Pickett Engineering Inc. RUNOFF DRAINAGE CRITERIA MANUAL(V. 1) L = length of overland flow(500 ft maximum for non-urban land uses, 300 ft maximum for urban land uses) S= average basin slope (ft/ft) Equation RO-3 is adequate for distances up to 500 feet. Note that, in some urban watersheds, the overland flow time may be very small because flows quickly channelize. 2.4.2 Overland Travel Time. For catchments with overland and channelized flow, the time of concentration needs to be considered in combination with the overland travel time, t„ which is calculated using the hydraulic properties of the swale, ditch, or channel. For preliminary work,the overland travel time, t„ can be estimated with the help of Figure RO-1 or the following equation (Guo 1999): V =C„Swe'5 (RO-4) in which: V=velocity(ft/sec) C = conveyance coefficient (from Table RO-2) S„.=watercourse slope(ft/ft) TABLE RO-2 Conveyance Coefficient, C. Type of Land Surface Conveyance Coefficient, C. Heavy meadow 2.5 Tillage/field 5 Short pasture and lawns 7 Nearly bare ground 10 Grassed waterway 15 Paved areas and shallow paved swales 20 The time of concentration, re, is then the sum of the initial flow time, t, and the travel time, t„ as per Equation RO-2. 2.4.3 First Design Point Time of Concentration in Urban Catchments. Using this procedure,the time of concentration at the first design point (i.e., initial flow time, t;) in an urbanized catchment should not exceed the time of concentration calculated using Equation RO-5. t` +10 (RO-5) 180 RO-6 06/2001 Urban Drainage and Flood Control District 13 I I I I I I I I I I I I I I I I I I I Imo;,. 26 APPROXIMATE SCALE ._______--_ 500 0 f-t t--i t--i 4701 NATIONAL FLOOD'MIRANDA PRONNAY I 1' � 1 FIRM FLOOD INSURANCE RATE MAP a� WELD ------7--�� COUNTY,UN� , ZONE A4 COLORADO 2,1 TTI1TINCOBPORATHD AWIA Q6----- -------------7 PANEL 619 OF 1075 — OEE MAP INe[F ROq PANELS NOT PRIXTEeI--7\5 I 1--e, COMMUNITT•PANEL NUMBER I 080266 0619 C - - 49TH STREET MAP REVISED; SEPTEMBER 28. 1982 '< 1 Sal hyrY[Ilck ItMN[ntent ageac ;fedend longer=MMlpifp!tion This is an official copy of a portion of the above referenced food map. It was extracted using F-MIT On-Une. This map does not rdect changes or amendments which may haat been made subsequent to the dote on the title block. For the latest product information about National Flood Insurance 1 Program food maps check the FEMA Flood Map Stag et www..mec.fema.gov F Client 12. �/kf' j�.�� 1:. JobPE /l project yV//ti, / `^rk Calculations for t= '✓S4 r ALCVS Made by`J.51)Date /! / i !/ZChecked by Date Sheet of PICKETT ENGINEERING, INC. xi st 54.4 eta ....../ 1✓✓v/'t /Ir fo% f / /Nre-rilleill >,,.f Are° Cc.c.rc. � .3q --1") Ascot , t t Cc c ree-' ) O, Yo' Ciithd-f' 0,44 . . =0- VI, &i5 , . 0. 4,11/0 15 - DRAINAGE CRITERIA MANUAL(V. 1) RUNOFF 3 ^, - TABLE RO-5 Runoff Coefficients, C - Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups - 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0.04 0.15 0.25 0.37 0.44 0.50 5% 0.08 0.18 0.28 0.39 0.46 0.52 10% 0.11 0.21 0.30 0.41 0.47 0.53 - 15% 0.14 0.24 0.32 0.43 0.49 0.54 20% 0.17 0.26 0.34 0.44 0.50 0.55 25% 0.20 0.28 0.36 0.46 0.51 0.56 - 30% 0.22 0.30 0.38 0.47 0.52 0.57 35% 0.25 0.33 0.40 0.48 0.53 0.57 40% 0.28 0.35 0.42 , 0.50 0.54 0.58 - 45% 0.31 0.37 0.44 0.51 0.55 0.59 50% 0.34 0.40 0.46 0.53 0.57 0.60 55% 0.37 0.43 0.48 0.55 0.58 0.62 60% 0.41 0.46 0.51 0.57 0.60 0.63 - 65% 0.45 0.49 0.54 0.59 0.62 0.65 70% 0.49 0.53 0.57 0.62 0.65 0.68 75% 0.54 0.58 0.62 0.66 0.68 0.71 - 80% 0.60 0.63 0.66 0.70 0.72 0.74 85% 0.66 0.68 0.71 0.75 0.77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 - 95% 0.80 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 Type B NRCS Hydrologic Soils Group 0% 0.02 0.08 0.15 0.25 0.30 0.35 - 5% 0.04 0.10 0.19 0.28 0.33 0.38 10% 0.06 0.14 0.22 0.31 0.36 0.40 15% 0.08 0.17 0.25 0.33 0.38 0.42 - 20% 0.12 0.20 0.27 0.35 0.40 0.44 25% 0.15 022 0.30 0.37 0.41 0.46 30% 0.18 0.25 0.32 0.39 0.43 0.47 - 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0.36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 - 50% 0.29 0.35 0.40 0.46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0.37 0.41 0A6 0.51 0.54 0.56 65% 0.41 0.45 0.49 0.54 0.57 0.59 - 70% 0.45 0.49 0.53 0.58 0.60 0.62 75% 0.51 0.54 0.58 0.62 0.64 0.66 80% 0.57 0.59 0.63 , . 0.66 0.68 0.70 - 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0.71 0.73 0.75 0.78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% 0.89 0.90 0.92 0.94 0.95 0.96 06/2001 Urban Drainage and Flood Control District 16 ri'pre 3.4-s INTENSITY- DURATION- FREQUENCY CURVES - EVANS, COLORADO 9 Lidstone&AMecson.Inc 1994(eur_ NNQM N on ;as.:973) — i i 1 • . . . 3 I . 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I : l - • III I 444111 0 • 10 20 30 40 50 60 TIME IN MINUTES 3-5 17 Gutter Storm Water Conveyance Capacity for Minor Event Project: Hill n Park Inlet ID: D1 -'1-W T - Street Top of Curb or _ I Tx - Crown Allowable Depth— Y •w" Bx/ _____.- H d _ Si 1 -- 1 a yf Gutter Geometry — Allowable Depth to Gutter Flow Line for Minor Event H= 5.0 inches Gutter Width W= 1.50 ft Gutter Depression a= 1.1 inches Street Transverse Slope S,= 0.0089 ft/ft - Street Longitudinal Slope So= 0.0060 ft/ft Manning's Roughness n= 0.016 Maximum Water Spread for Minor Event T= 21.0 ft Gutter Conveyance Capacity Based On Maximum Water Spread Gutter Cross Slope(Eq.ST-8) S„= 0.0722 ft/ft Mater Depth without Gutter Depression(Eq.ST-2) y= 2.2 inches — Water Depth with a Gutter Depression d= 3.4 inches .- . Gutter Flow to Design Flow Ratio by FHWA HEC-22 method(Eq.ST-7) Ea= 0.25 Spread for Discharge outside the Gutter Section W(T-W) T,= 19.5 ft Discharge outside the Gutter Section W,canied in Section Tx Q,= 2.8 cfs — Discharge within the Gutter Section W(Q-Qx) ow= 0.9 cfs Flow Rate Based On Maximum Water Spread QT a 3.8 cfs Gutter Full Conveyance Capacity Based on Maximum Allowable Gutter Depth — ,Water Spread T= 36.1 ft Gutter Flow to Design Flow Ratio by FHWA HEC-22 method(Eq.ST-7) Ee= 0.13 Spread for Discharge outside the Gutter Section W(T-W) Tx= 34.6 ft Discharge outside the Gutter Section W,canied in Section Tx Q,= 13.2 cfs — Discharge within the Gutter Section W(Q-0,,) Q.= 2.0 cfs Flow Rate Based on Maximum Allowable Gutter Depth QF= 15.2 cfs Gutter Design Conveyance Capacity Based on Minimum of QT or R`Qr — Reduction Factor for Minor Event R= 1.00 Gutter Design Conveyance Capacity for Minor Event Clam.= 3.8 cfs D28 Street Cap&Inlel.xls,Q-Minor 11/12/2003, 1:22 PM 18 Gutter Storm Water Conveyance Capacity for Major Event 7 Project: Hill n Park Inlet ID: D1 — r- T i Street Top of Curb or H-W_ I _ Tx Crown Allowable Depth \Qw /Qx� �.� H Y Sx dll 1_a 5f — IGutter Geometry Ilowable Depth to Gutter Flow Line for Major Event H= 5.0 inches Gutter Width W= 1.50 ft Gutter Depression a= 1.1 inches _ Street Transverse Slope Sx= 0.0089 ft/ft Street Longitudinal Slope So= 0.0060 ft/ft Manning's Roughness n= 0.016 Maximum Water Spread for Major Event T= 30.0 ft Gutter Conveyance Capacity Based On Maximum Water Spread Gutter Cross Slope(Eq.ST-8) Sw= 0.0722 ft/ft Water Depth without Gutter Depression(Eq.ST-2) y= 3.2 inches ater Depth with a Gutter Depression d= 4.3 inches +` Gutter Flow to Design Flow Ratio by FHWA HEC-22 method(Eq.ST-7) Ea= 0.16 Spread for Discharge outside the Gutter Section W(T-W) Tx= 28.5 ft Discharge outside the Gutter Section W,carried in Section Tx Qx= 7.8 cfs — Discharge within the Gutter Section W(Q-Q,) Ow= 1.5 cfs Flow Rate Based On Maximum Water Spread QT= 9.3 cfs Gutter Full Conveyance Capacity Based on Maximum Allowable Gutter Depth — IWater Spread T= 36.1 ft Gutter Flow to Design Flow Ratio by FHWA HEC-22 method(Eq.ST-7) E0= 0.13 Spread for Discharge outside the Gutter Section W(T-W) Tx= 34.6 ft Discharge outside the Gutter Section W,carried in Section T, Q.= 13.2 cfs — Discharge within the Gutter Section W(Q-Q,) Q.= 2.0 cfs Flow Rate Based on Maximum Allowable Gutter Depth Qr= 15.2 cfs Gutter Design Conveyance Capacity Based on Minimum of QT or R'Q. — Reduction Factor for Major Event R= 1.00 Gutter Design Conveyance Capacity for Major Event Claim.= 9.3 cfs D2B Street Cap&Inlet.xls,Q-Major 11/12/2003, 1:23 PM 19 — CivilTools BOX CULVERT DESIGN SPREADSHEET Calculate the headwater depth required for a box section culvert to pass the design flow Headwater Depth Calculation for a Concrete Box Culvert INPUT DATA Box Section Height:0.5 ft Box Section Width:4 ft Pipe Length (L):10 ft Pipe Slope:2.00% Design Q (Qd):7.82 cfs Entrance Type: on red to select Entrance Type:18 to 34 deg.wingwalls with top edge bevel Manning's'n':0.013 . - Tailwater Depth (TVV):0 ft OUTPUT SUMMARY Culvert is flowing:Part Full Headwater Depth (Hw) is:0.79 ft Culvert will operate under Inlet control Normal Flow Depth (Dn) is:0.30 ft Flow velocity in culvert is:6.57 ft./s Flow velocity at outlet is:6.57 ft./s Date: 11/12/2003 Time: 10:21 20 Final Drainage Study includes two oversized maps including : Existing Drainage Plan and Proposed Drainage Plan Please see Original File Hello