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25491 BSP-1414F DRAINAGE TECHNICAL REPORT i . ~ DRAIN E TEC 1vgj HNICALJ ~~U~C O&jMENT REGE~~OKANE COUNTY ENGINEER'S OFFICE i _j J U H 04 1996 for the OR mw ~ PR4JECT # SPOKANE COUNTY ERIVERWALK 77TP" ~ TURN TO CQUNTY ENGINEER ADDITION PU D ~ . ~ ~ - .~~~~IVED _ fjUN 10 1996 . MAY 1996 -r-' LRE* ~ ; Prepared for: J - PACIFIC PROPERTIES 14410 Bel-Red Road Bellevue, WA 98007 9 ~ Prepared By: ~ Inland Pacifzc Engineering Company p 707 W. 7th Avenue - J Suite 200 ~ Spokane, WA 99204 (509)458-6840 ~ . - r--~ 1 ~ -1 ~ ~ DRAINAGE REPORT ~ for the . --t , Riverwalk 7th Additlon PUD Plat Spokane County, Washington ~ May 1996 Prepared for: , PACIFIC PROPERTIES ' 14410 Bel-Red Road Bellevue, WA 98007 ~ Prepared by: Inland.Pacific Engineering Compariy 707 W. 7th Avenue ~ Suite 200 Spokane, WA 99204 J (509)458-6840 - T e~i~m roveme ts hown i~ tih~s e o~ s an ~alculaions co ►orm ~o t~ e.,,;~~.`'' . . . ~:a - `t'. ' ~ b - - ~ ons o te ' okane o ~n. t.a~ndards or Rod a : ew~r C st~ruc~ton «a d t- ~po a - unty ' , el'u~.e ;or . tormwat~~ an~a.e. .en . 1~1 design de~'a 'ons . ha e bo -en approv . ~ ~Uy 4 e a e o ~ : , ~e a~ p ove tes g . n,s ' ~ - ~alcuiat~io o ~ons ~ ctio . IN, ~ This regort has been prepared by the staff of Inland Pacific Engineering Company under the direction of the undersigned professional engineer whose seal and signature appeaz hereon. . 25462 ~ - 4NAL T` EXPfRf S 9/24 ~ Todd R. Whipple, P.E. ~ ~ Riverwalk 7th Addition PUD Drainage Narrative , ~ ~ GENERAL '-The first phase of the Riverwalk 7th Addition PUD Plat is a 28.0 acre development of 95 single family residential lots located north and east of the intersection of Mission Avenue and Barker ~ ~ Road, within Spokane County, Washington. The site is currently vacant with field grass, alfalfa and fallow fields as the predom.inant land cover and vegetation. Single family residential development lies directly to the north. and west. A 1" to 400' scale vicinity and location map have ~ been included within the technical section of this document. ~ PURPOSE The purpose of this report is to determine the extent of storm drainage facilities which will be required to dispose of the increase in stormwater runoff created by the development of the ~ Riverwalk 7th Addition plat. The storm drainage facilities on this project will be designed to ~ dispose of runoff from either a ten year or fifty year design storm, depending upon basin size. This development is within the Aquifer Sensitive Area of Spokane County and is subject to '208' requirements. For this project, the 10-year curve from the Spokane, Medical Lake, Reardon, Cheney and Rockford intensity curves was used, as well as the SCS iso-pluvial rainfall curves. Per direction from Spokane County, the SCS curves have been further refined with the NOAA ~ - iso-pluvial curves. ANALYSIS METHODOLOGY Per the Spokane County Guidelines for Stormwater Management, the Rational Method, which is recommended for basins less than ten acres in size, will be used to deternune the peak discharges ~ and runoff volumes for all onsite basins. All off-site basins and all on-site basins larger than ten acres will use the SCS Method to determine peak d.ischarge and runoff volumes. PROJECT DESCRIPTION . ~ This phase of the Riverwalk 7th Addition plat comprises 951ots of the approved 3931ots in the ~ approved preliminary plat and SEPA documents. The Riverwalk 7th Addition subdivision is located in the NE 1/4 of the SW 1/4 of Section 8, T. 25 N., R. 45 E., W.M. within Spokane County, Washington. . ~ , . 1 ~ Inland Pacific Engineering Company D1 Riverwalk 7th Addition Plai Drainage Report ~ ~ ` TOPOGRAPHY The existing site sits along the south side of a low ridge sloping gently southward towards Mission Avenue from Indiana Avenue. Within the plat the natural topography was used as much as possible to route storm drainage. However, due to the flat slopes and the County's minimum ' requirements for slope, many of the roadway profiles have been forced down to facilitate drainage ~ by localizing low spots for pond placement. Due to the flat slopes encountered, no concentrated _ pre-existing flows were observed nor were there any signs that anything other than sheet flow and ground absorption have occurred on this site. ~ The general slopes within this plat vary from flat to nearly flat with the maximum existing slope at 0.005/ft. Generally, the area within this platted portion of the overall preliminary plat would be ; - characterized as flat. For development purposes as stated the natural sloping was used for design and is maintained as possible throughout the project. ; SOILS ~As can be seen from the accompanying soils map from the Spokane County Soils Survey as ~ performed by the SCS, the site consists of one type of soils within the Class B type. This soil type is described as follows. ~ GgA - Garrison gravelly loam, 0 to 5 percent slopes: Soils within this soil type are some what ~ excessively drained soils formed in gravelly glacial outwash material from a variety of igneous rock. Surface runoff is slow, and the hazard of erosion is slight. Spokane County Guidelines for ~ Stormwater Management indicate this to be a Soil Group Type B and pre-approved for drywell installation. Hydrologic Soil Classification - B DRAINAGE NAR.RATIVE Offsite ~Based upon the general geographic tendencies of this site, no appreciable amouats of offsite flows are expected for this phase. f~ Onsite As this plat is within the aquifer sensitive area of Spokane County a11 onsite drainage will be collected and treated using the "208" runoff method as described in the Spokane County . + . Inland Pacific Engineering Comparry D2 Rivenvalk 7th Addition Plat Drainage Report L`-1 _ Guidelines for Stormwater Management. To facilitate this analysis the Riverwalk 7th Addition plat was divided into 27 permanent sub-basins ( A through Y3). Although there are 27 basins, ~ these basins have been combined where practical to utilize the same pond. Table 1 lists the basins ~ and pond combinations for easy reference. ~ ~ s r-l-, ~ ~ ~l ~ ~ - ~ . _J Inland Pacific Engineering Company D3 Riverwalk 7th Addition Plat Drainage Report 1 _j ~ ( ~ Table No. 1- Pond and Basin Summary MMM a ~ i, i► BAS~NS' .R Basins onds o[ Area Mmpervtous SNree ' eighte ot•al rea (-S~ ,►C„ ~ a~e , - ~ A A 45014 13279 4879 0.33 1.03 ~ B B 33675 11177 4877 0.37 0•77 - C C 42705 12650 4250 0.34 0.98 ~ D D 36602 11305 5005 0.35 0.84 E E 19450 6290 2090 0.35 0.45 F F 73756 18043 6493 0.29 1.69 ~ G G 15122 4190 2090 0.33 0.35 H H 58498 19548 6948 0.37 1.34 I I 73875 22100 9500 0.34 1.70 ' 1 1 76810 23165 10115 0.34 1.76 K K 30642 10202 4952 0.36 0.70 L L 64882 18717 6117 0.33 1.49 M M 36182 11632 5332 0.36 0.83 N N 44339 12869 5819 0.34 1.02 a O O 61378 18819 6966 0.34 1.41 P P 31229 8679 2379 0.32 0.72 Q Q 26635 8364 3114 0.35 0.61 ~ RI RT 42059 10621 3271 0.30 0.97 S S 26271 10451 4651 0.41 0.60 RT RT 109690 32636 14636 0.34 2.52 ~ ` U U 179713 26113 10363 0.22 4.13 ~ V V 80568 24609 9909 0.34 1.85 ° w W 15805 5979 2829 0.41 0.36 ~ X X 5302 2659 1609 0.50 0.12 Y1 Y1 23985 14592 14592 0.58 0.55 ~ y2 Y2 31525 19236 19236 0.59 0.72 ~ Y3 Y3 9069 5341 5341 0.56 0.21 Inland Pacific Engineering Company D4 Riverwalk 7th Addition Plat Drainage Report "208" Caleulations ~Within each basin the streets are divided into sub-basins by curb drops, inlets, catch basins and high and low roadway profiles where swales and no curbs are used. These facilities capture upstream stormwater runoff from the imp~rvious street surface and direct the runoff into grassy '208' ponds. As shown on the '208' calculation worksheets included, the '208' storage volume ~ provided is adequate to perform '208' treatment for the runoff created by the first half inch of ~ rainfall. In some cases, the ponds are not quite large enough to provide '208' storage for all of the upstream runoff. In such cases the excess is carried over to the next downstream ponds which ~ provide adequate capacity for the carty-over flows. However, for the Riverwalk 7th Addition ~ plat no carryover flows are anticipated, therefore, there are no intermediate ponds included.. ~ Curb Drop, Inlets and Catch Basin Calculations It is necessary to check the adequacy of the curb drops, inlets or catch basins provided to divert the runoff from the gutter into the '208' ponds. Should these be required, the curb drop, inlet and ~ catch basin calculation sheets included show the required lengths of curb openings, or single curb drops with lengths greater than 4.0, as well as the adequacy of the inlet grates or catch basin ~ grates. For curb drops greater than 4.0', either multiple curb drops are added or the curb drops ~ are lengthened as required. ~ DRAINAGE CALCULATIONS SUMMARY Calculations have been included for Drainage Basin considerations such as QTR 55 and pond ~ routing calculations, Peak Flow, Time of Concentration, "208" sizing, drywell requirements, inlet ~ sizing, curb drops as well as culverts and pipe flow some of which are summarized below with the ~ remaining calculations included in the appendix. Within the calculation section and where it has been determined necessary for clarity, several ~ sketches, as well as details from the plans have been incorporated to demonstrate assumptions and ~ conclusions. ~--q ~ r7 . o~. r~ . Inland Pacific Engineering Company DS Riverwalk 7th Addition Plat Drainage Report BASIN DESCRIPTIONS ~ Basins A th ro ugh Y3 ~ Within this plat, and due to the general geographic features, several basic assumptions were followed and can be used to describe each basin. First, due to the relative flatness of the plat and project vicinity, minimum road grade is limited to 0.008'/ft; second, the swale section carried over from Riverwalk 1 st, will only provide at a maxirnum 25-percent of the calcualted capacity; third, a large tract pond if practical will be used in the open space area; fourth, all other ponds will be of ~ the lot pond configuration; fifth, that where practical, drywells will be minimized by combining basins and providing piping between ponds. ~ All of these steps have been used in various basins throughout the drainage design of this project. ~ Inland Pacific Engineering Comparry D6 Riverwalk 7th Addition Plat Drainage Repon -J e ~ ~ Table No. 2- Pond and 208 Basin Summary . M ~ in nd '0~ a~ a WIRMufred-RO IPMEHUMM-11-61 et~ ~K~r ~ 1 'eui d ~ A A 203 406 426 1B ~B B 203 406 426 1B -C C 177 354 375 1B j6-D D 209 418 426 1B ~ E E 87 174 180 1B ~ F F 271 542 798 lB G G 87 174 180 1B ~ H H 290 580 691 1B I I 396 792 1097 1B ~ J J 421 844 990 1B ~ K K 206 412 419 1B ~ ~ L L 255 510 676 1B M M 222 444 470 1B N N 242 486 500 1B . . O O 290 580 600 1B p P 99 198 210 1B ' Q Q 130 260 275 1B Rl RT - - - - r S S 194 388 400 1B RT RT 610 1240 1800 l B ` U U 432 864 1132 2B V V 413 826 , 1088 1 B " W W 118 • 236 256 lA ~ X X 67 134 143 1 A Y1 Y1 608 1216 3010 n/a ~ o y2 y2 802 1604 3906 n/a ~ Y3 , Y3 223 446 805 n/a Type A is a Spokane Standard Drywell - Single Depth, Capacity 0.3 cfs - Type B is a Spokane Standard Drywell - Double Depth, Capacity 1.0 cfs Inland Pacific Engineering Comparry D7 Riverwalk 7th Addition Plut Drainage Report ~ ~ Table No. 2- Pond and 208 Basin Summary ~ Ri~erwalk 7th Acidi~io.n - BA ~ ~'U - Ba in o I~d 208 olume ~48 rea 208 rea ~ rywells Req 'red (c~ eui~red (s~ P ovided (ss ' qu r d* , A A 203 406 426 IB B B 203 406 426 1B C C 177 354 375 iB D D 209 418 426 1B ~ E E 87 174 180 1B F F 271 542 798 1B G G 87 174 180 1B H H 290 580 691 1B 1 I 396 792 1097 lB ~ J J 421 844 990 1B K K 206 412 419 1B ~ L L 255 510 676 1B r--` M M 222 444 470 1B ~ N N 242 486 500 1B ~ O O 290 580 600 1B ~ P P 99 198 210 1B ~ Q Q 130 260 275 1B - R1 RT - - - - ~ S S 194 388 400 1B ~ RT RT 610 1240 1800 1 B ~ U U 432 864 1132 2B V V 413 826 1088 1B ~ W W 118 236 256 lA ~ X X 67 134 143 1 A ~ Y 1 Y 1 608 1216 3010 n/a Y2 Y2 802 1604 3906 n/a Y3 Y3 223 446 805 n/a Type A is a Spokane Standard Drywell - Single Depth, Capacity 0.3 cfs ~ - Type B is a Spokane Standard Drywell - Double Depth, Capacity 1.0 cfs Inland Pacific Engineering Company D7 Rivenvalk 7th Addition Plat Drainage Report ~ ~ _Table No. 3- Curb Drop/Catch Basin Summary ,,A~ T-11' IR _ , i o, :as,•n5 , - I'~ III j„ar , 1 . . ~~t -tQ, - RT RT Sump - ~ Q Q Continuous - ~ W W Continuous - U U Sump - V V Sump - Y 1 Y 1 Sump (All) - ~ Y2 Y2 Sump(All) - q ~ Y3 Y3 Sump(All) - Per Spokane County Guidelines curb drops in a sump condition have a capacity of 4.0 cfs Per WSDOT Hydraulics Manual, Grate Inlet, has a sump capacity of 13.0 cfs NOTE: Only curb drop and grate calculations were performed for those cases "On Grade", curb drops and catch basins in sump condition are ~ assumed to handle 4.0 cfs. ~ ~ ~ ~ ~ Inland Pacific Engineering Company D8 Riverwalk 7th Addition Plat Drainage Report ~ ~f ILL ~ IvV~`:~E7C_fl V~ - r I,VUI~t (Joins sheet 58) __."___--A` A NA L R. 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Area (acres): 0.30 Date: 5/18/96 Grass Area (acres): 0.73 Imp. Area "C": 0.90 . Grass Area "C": 0.10 ~ . I~ \(Imp. Area)(Imp. "C")= 0.2700 (Grass Area)(Grass "C")= 0.0730 1.0300 0.3430 Weighted "C"= 0.3430 0.33 ~ 1.0300 ~ ~ ✓ t . . . ~ - ~I ; 1 . - i ~ ~ ~ ~-Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition ~ Basin: B IPE Job Total Area (acres): 0.77 Designer: Imp. Area (acres): 0.26 Date: ~ Grass Area (acres): 0.51 Imp. Area "C": 0.90 Grass Area "C": 0.10 (Imp. Area)(Imp. "C")= 0.2340 . ~ (Grass Area)(Grass "C")= 0.0510 0.7700 - 0.2850 _ Weighted "C"= 0.2850 0.37 ~ 0.7700 ~ ~ _J - Weighted Runoff Coefficient Caiculation - Project: Riverwalk 7th. Addition `f Basin: C IPE Job 96070 ~ Total Area (acres): 0.98 Designer: B. Howard Imp. Area (acres): 0.29 Date: 5/18/96 V Grass Area (acres): 0.69 ~ Imp. Area "C": 0.90 Grass Area "C": 0.10 (Imp. Area)(Imp. "C")= 0.2610 ~ (Grass Area)(Grass "C")= 0.0690 ~ 0.9800 0.3300 Weighted "C"= 0.3300 0.34 ~ 0.9800 , ~ ~ -I ~ ~ r~ -Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition ~ Basin: D IPE Job 96070 Total Area (acres): 0.84 Designer: B. Howard Imp. Area (acres): 0.26 Date: 5/18/96 V Grass Area (acres): 0.58 Imp. Area "C": 0.90 Grass Area "C": 0.10 (Imp. Area)(Imp. "C")= 0.2340 I~ (Grass Area)(Grass "C")= 0.0580 0.8400 0.2920 Weighted "C"= 0.2920 0.35 0.8400 ~ ~ ~ . , ~ Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition ~ Basin: E IPE Job 96070 Total Area (acres): 0.45 Designer: B. Howard Imp. Area (acres): 0.14 Date: 5118/96 • Grass Area (acres): 0.31 ~ Imp. Area "C": 0.90 Grass Area "C": 0.10 (Imp. Area)(Imp. "C")= 0.1260 ~ (Grass Area)(Grass "C")= 0.0310 0.4500 0.1570 Weighted "C"= 0.1570 0.35 ~ 0.4500 ~ i ~ Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition Basin: F IPE Job 96070 -Total Area (acres): 1.69 Designer: B. Howard Imp. Area (acres): 0.41 Date: 5/18/96 L Grass Area (acres): 1.28 ~ Imp. Area "C": 0.90 Grass Area "C": 0.10 ~ _ (imp. Area)(Imp. "C")= 0.3690 (Grass Area)(Grass "C")= 0.1280 ~ 1.6900 0.4970 Weighted "C"= 0.4970 0.29 . 1.6900 > ~ - ~ ! ~ ~ ~ ~ - 1 I Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition Basin: G IPE Job 96070 - Total Area (acres): 0.35 Designer: B. Howard Imp. Area (acres): 0.10 Date: 5/18I96 Grass Area (acres): 0.25 --Imp. Area "C": 0.90 Grass Area "C": 0.10 (Imp. Area)(Imp. "C")= 0.0900 ~ (Grass Area)(Grass "C")= 0.0250 0.3500 0.1150 ~ Weighted "C"= 0.1150 0.33 0.3500 ~ ~ ~ ~ t i Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition ~Basin: H IPE Job 96070 Total Area (acres): 1.34 Designer: B. Howard Imp. Area (acres): 0.45 Date: 5/18/96 ~ Grass Area (acres): 0.89 Imp. Area "C": 0.90 L Grass Area "C": 0.10 (Imp. Area)(Imp. "C")= 0.4050 ~ (Grass Area)(Grass "C")= 0.0890 _ 1.3400 0.4940 Weighted "C"= 0.4940 0.37 ~ 1.3400 ~ ~ ~ I , ~ . ~I I ~ , I ~ - J Weighted Runoff Coefficient Calculation . Project: Rivervvalk 7th Addition Basin: I IPE Job 96070 Total Area (acres): 1.7 Designer: B. Howard , Imp. Area (acres): 0.51 Date: 5/18/96 4J Grass Area (acres): 1.19 Imp. Area "C": 0.90 Grass Area "C": 0.10 ~ ~ ~ (Imp. Area)(Imp. "C")= 0.4590 ~ (Grass Area)(Grass "C")= 0.1190 1.7000 0.5780 t ~ ~ Weighted "C"= 0.5780 0.34 1.7000 , s ~ . ~ , i 1 ---Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition -Basin: J IPE Job 96070 r-, Total Area (acres): 1.76 Designer: B. Howard ' Imp. Area (acres): 0.53 Date: 5/18/96 ~Grass Area (acres): 1.23 - - imp. Area "C": 0.90 i ~ Grass Area "C": 0.10 ` .t (Imp. Area)(Imp. "C")= 0.4770 ^ (Grass Area)(Grass "C")= 0.1230 1.7600 0.6000 Weighted "C"= 0.6000 0.34 ~ 1.7600 ~ ~ ~ ~ f 1 I ~l I, -1 . 8 \ ~ Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition Basin: K IPE Job 96070 - Total Area (acres): 0.7 Designer: B. Howard Imp. Area (acres): 0.23 Date: 5/28/96 Grass Area (acres): 0.47 ~ Imp. Area "C": 0.90 ~ Grass Area "C": 0.10 1 (Imp. Area)(Imp. "C")= 0.2070 ~ (Grass Area)(Grass "C")= 0.0470 ~ 0.7000 0.2540 Weighted "C"= 0.2540 0.36 0.7000 ~ .J r--- ~ . ~ . I , ~ ~ r ~ Weighted Runoff Coefficient Caiculation Project: Riverwalk 7th Addition ~ Basin: L IPE Job 96070 Total Area (acres): 1.49 Designer: B. Howard Imp. Area (acres): 0.43 Date: 5/28/96 - Grass Area (acres): 1.06 Imp. Area "C": 0.90 , Grass Area "C": 0.10 (Imp. Area)(Imp. „C")= 0.3870 (Grass Area)(Grass "C")= 0.1060 _ 1.4900 0.4930 Weighted "C"= 0.4930 0.33 1.4900 , - ~ ~ . ~ - ~ ~ I ~ . I ~ ~ Weighted Runoff Coefficient Calculation Project: RivenNalk 7th Addition Basin: M IPE Job 96070 Total Area (acres): 0.83 Designer: B. Howard Imp. Area (acres): 0.27 Date: 5/18/96 ~ Grass Area (acres): 0.56 ~ Imp. Area "C": 0.90 Grass Area "C": 0.10 ~ (Imp. Area)(Imp. "C")= 0.2430 ~ (Grass Area){Grass "C")= 0.0560 _ 0.8300 0.2990 s _ Weighted "C"= 0.2990 0.36 - 0.8300 ~ ~ . - Weighted _Runoff Coefficient Calculation , Project: Riverwalk 7th Addition ~ Basin: N IPE Job 96074 ~ Total Area (acres): 1.02 Designer: B. Howard ~ lmp. Area (acres): 0.30 Date: 5/18/96 Grass Area (acres): 0.72 ~ Imp. Area "C": 0.90 _ Grass Area "C": 0.10 ~ ~(Imp. Area)(Imp. "C")= 0.2700 ~ (Grass Area)(Grass C")_ - 0.0720 1.0200 0.3420 Weighted "C"= 0.3420 0.34 ~ 1.0200 . _J ~ ~ Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition v Basin: O IPE Job 96070 ~ Total Area (acres): 1.41 Designer: B. Howard Imp. Area (acres): 0.43 Date: 5/18/96 Grass Area (acres): 0.98 ~ Imp. Area "C": 0.90 Grass Area "C": 0.10 (Imp. Area)(Imp. "C")= 0.3870 (Grass Area)(Grass "C")= 0.0980 ~ 1.4100 0.4850 ~ Weighted "C"= 0.4850 0.34 ~ . 1.4100 a^ 0 ~ I-- ~ Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition Basin: P IPE Job 96070 ~ Total Area (acres): 0.72 Designer: B. Howard imp. Area (acres): 0.20 Date: 5/18/96 Grass Area (acres): 0.52 imp. Area "C": 0.90 Grass Area "C": 0.10 ~ (Imp. Area)(Imp. "C")= _ 0.1800 (Grass Area)(Grass C'l 0.0520 ~-°-0.7200 0.2320 ~ Weighted "C"= 0.2320 . 0.32 ~ 0.7200 ~ ~ ~ ~ Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition Basin: Q IPE Job 96070 ^ Total Area (acres): 0.61 Designer: B. Howard W Imp. Area (acres): 0.19 Date: 5/18/96 Grass Area (acres): 0.42 Imp. Area "C": 0.90 Grass Area "C": 0.10 ~ (Imp. Area)(Imp. "C")= 0.1710 (Grass Area)(Grass "C")= 0.4420 0.6100 0.2130 Weighted "C"= 0.2130 = 0.35 0.6100 ~ , ~ . ~ ~ Weighted Runoff Coefficient Calculation ~ Project: Riverwalk 7th Addition ~ Basin: R IPE Job 96070 ~ Total Area (acres): 1.71 Designer: B. Howard Imp. Area (acres): 0.48 Date: 5/18/96 ~ Grass Area (acres): 1.23 Imp. Area "C": 0.90 - Grass Area "C": 0.10 (Imp. Area)(Imp. "C")= 0.4320 (Grass Area)(Grass "C")= 0.1230 ~ 1.7100 0.5550 ~ Weighted "C"= 0.5550 0.32 1.7100 ~ ~ ~ Weighted Runoff Coefficient Calculation ~ ~ Project: Riverwaik 7th Addition Basin: R1 1PE Job 96070 ~ Total Area (acres): 0.97 Designer: B. Howard , Imp. Area (acres): 0.24 Date: 5129/96 Grass Area (acres): 0.73 ~ Imp. Area "C": 0.90 _ Grass Area "C": 0.10 (Imp. Area)(Imp. "C")= 0.2160 ~ (Grass Area)(Grass "C")= 0.0730 0.9700 0.2890 ~ Weighted "C"= 0.2890 0.30 0.9700 --Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition Basin: RT IPE Job 96070 - Total Area (acres): 2.52 Designer: B. Howard ~ Imp. Area (acres): 0.75 Date: 5/29/96 • Grass A.rea (acres): 1.77 ~ Imp. Area "C": 0.90 ~ Grass Area "C": 0.10 ^ (Imp. Area)(Imp. "C"}= 0.6750 , (Grass Area)(Grass "C")= 0.1770 2.5200 0.8520 ~ Weighted "C"= 0.8520 0.34 ~ 2.5200 F ✓ ~ ~ ~ Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition Basin: S IPE Job 96070 ~ Total Area (acres): 0.6 Designer: B. Howard Imp. Area (acres): 0.23 Date: 5/18/96 ~ Grass Area (acres): 0.37 Imp. Area "C": 0.90 ~ Grass Area "C": 0.10 7 (Imp. Area)(Imp. "C")= 0.2070 (Grass Area)(Grass "C")= 0.0370 r- 0.6000 0.2440 Weighted "C"= 0.2440 0.41 0.6000 0 ~ ' ~ ✓ Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition Basin: T IPE Job 96070 o Total Area (acres): 0.81 Designer: B. Howard Imp. Area (acres): 0.28 Date: 5/18/96 , _ Grass Area (acres): 0.53 Imp. Area "C": 0.90 Grass Area "C": 0.10 - (Imp. Area)(Imp. "C")= 0.2520 (Grass Area)(Grass "C")= 0.0530 ~ 0.8100 0.3050 Weighted "C"= 0.3050 0.38 0.8100 ~ - ~ Weighted Runoff Coefficient Calculation Project: Riverwalk 7th Addition Basin: U IPE Job 96070 V~ Total Area (acres): 4.13 Designer: B. Howard ~ imp. Area (acres): 0.60 Date: 5/18196 Grass Area (acres): 3.53 ~ Imp. Area "C": 0.90 ~ Grass Area "C": 0.10 ~ (Imp. Area)(Imp. "C")= 0.5400 (Grass Area)(Grass "C")= 0.3530 4.1300 0.8930 Weighted "C"= 0.8930 0.22 ~ 4.1300 ~ ~ ~ Weighted Runoff Coefficient Calculation Project: Riverwaik 7th Addition Basin: V IPE Job 96070 Total Area (acres): 1.85 Designer: B. Howard Imp. Area (acres): 0.56 Date: 5/18/96 Grass Area (acres): 1.29 ~ Imp. Area "C": 0.90 ~ Grass Area "C": 0.10 ^ (Imp. Area)(Imp. "C")= 0.5040 ; (Grass Area)(Grass "C")= 0.1290 . 1.8500 0.6330 4~- Weighted "C"= 0.6330 ~ 0.34 1.8500 ~ s ~ E ~ ~ ~ - Weighted Runoff Coefficient Calculation Project: Riverwaik 7th Addition ~ Basin: W IPE Job 96070 - Total Area (acres): 0.36 Designer: B. Howard Imp. Area (acres): 0.14 Date: 5118/96 Grass Area (acres): 0.22 ~ Imp. Area "C": 0.90 ~ Grass Area "C": 0.14 o (Imp. Area)(Imp. "C")= 0.1260 (Grass Area)(Grass "C")= 0.0220 0.3600 0.1480 Weighted "C"= 0.1480 0.41 0.3600 ~--t ~ ~ ~ ~ ~ ~ `rn Weighted Runoff Coefficient Calculation ~ Project: Riverwalk 7th Addition ~ Basin: X IPE Job 96070 ~ Total Area (acres): 0.12 Designer: B. Howard Imp. Area (acres): 0.06 Date: 5/18/96 Grass Area (acres): 0.06 ~ Imp. Area "C": 0.90 ~Grass Area "C": 0.10 (imp. Area)(Imp. "C")= 0.0540 ; (Grass Area)(Grass "C")= 0.0060 B 0.1200 0.0600 Weighted "C"= 0.0600 0.50 0.1200 ~ - . E , . ~ ~ ~ . ~ f ~ ~V - , ~ ~ s ~ ti-- 0 ~ ~ ~ ~ ~l ~--CURB DROP ANALYSIS ~ ~ ~ Inland Paci,fic Engineering Company . Riverwalk 7th Addition Plat Drainage Report CURB INLET CALCULATIONS Curb Inlet Depression = 2 in. Standard Curb Inlet Length = 4 ft. Upstream 10-Yr. Gutter Roughnes Reciprocal Depth Lengtr Curb Inlet Impervious Peak Flow Slope Coeff. Cross slope of Flow Required Sub-Basin Station R/L Area c.f.s. S n Z Zln d" Qa/La" Q/(Qa/La) Remarks _ Q. 28+72 L 3114 0.57 0.0159 0.0160 50 3125 0.11 0.074 7.72 Need 2 curb drops W 28+72 R R 2829 0.43 0.0159 0.0160 50 3125 0.10 0.066 6.47 Need 2 curb drops , .J A ~ • R1~~B4~1MII'~' , ~ P{] Calculated per Figure 18 of Guidelines Calculated per Figure 16 of Guidelines A 4 foot curb drop with a 6" gutter has a capacity of 4.0 cfs in sump condition. i ~ ~ ~ PIPING DIAGRAMS BACKWATER CALCULATIONS PIPE FLOW CALCULATIONS ~ a ' e 9 ~ I1~ c ~ Inland Pacific Engineering Comparty . Riverwalk 7th Addition Plat Drainage Report ~ ~ Trapezoidal Channel Analysis & Design ~ Open Channel - Uniform flow ~ ~ Worksheet Name: Comment : a 0 Solve For Discharge Given Input Data: ~ ~ Bottom Width..... 2.00 ft o I Left Side Slope.. 3.00:1 (H:V) ~ Right Side Slope. 3.00:1 (H:V) ' Manning's n...... 0.030 ~ Channel Slope.... 0.0080 ft/ft . Depth............ ~ Computed Results: ~ Discharge........ ~ Velocity......... 1.47 fps Flow Area........ 0.69 sf ~ Flow Top Width... 3.50 ft ~ ' Wetted Perimeter. 3.58 ft Critical Depth... 0.18 ft ~ Critical Slope... 0.0254 ft/ft Froude Number.... 0.59 (flow is Subcritical) ~ ~ 0 , ~ ~ 9 ~ 6 ~ ~ Open Channel Flow Module, Version 3.41 (c) 1991 ~ Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 ~ ~ ~ ~ Trapezoidal Channel Analysis & Design ~ Open Channel - Uniform flow Worksheet Name: ~ Comment: Solve For Discharge Given Input Data: Bottom Width..... 2.00 ft ~ Left Side Slope.. 3.00:1 (H:V) ~ Right Side Slope. 3.00:1 (H:V) Manning's n...... 0.030 Channel Slope.... 0.0080 ft/ft Depth............ i Computed Results: Discharge........ ~ Velocity......... 2.15 ps Flow Area........ 1.75 sf ~ Flow Top Width... 5.00 ft Wetted Perimeter. 5.16 ft Critical Depth... 0.39 ft Critical Slope... 0.0207 ft/ft Froude Number.... 0.64 (flow is Subcritical) ~ i I ~ y i ~ ~ ~ I ~f 1 ~ Open Channel Flow Module, Version 3.41 (c) 1991 Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 v~ 1 ~ ~ Pipe Flow Calculation Basin RT = Flow 0.640 cfs Out IE 2027.72 Diameter 1.00 ft In IE 2028.44 Slope 0.0063 ft/ft ~ n 0.0240 L 115.00 ft d/dia A R Q V =Depth of f! ow, d 0.90 ft 0.90 0.7445 0.2980 1. 63 2.19 Flowing Full 1.00 ft 1.00 0.7854 0.2500 1:53 1.95 6 Critical Depth 0.330 ft 0.33 0.2260 0.1848 0.64 2.83 Normal Depth 0.450 ft 0.45 0.3428 0.2331 0.64 1.87 ~ HWc 0.517 ft 4 HWn 0.531 ft OUTLET CONTROL 9 = HWp ft M t 1 { ~ ~ ~ • ~ ~ -J ~ ~ Circular Channel Analysis & Design ~ Solved with Manning's Equation ~ Open Channel - Uniform flow ~ Worksheet Name: Comment: Solve For Actual Depth ~ ~ Given Input Data: ~ Diameter.......... 1.00 ft Slope 0.0063 ft/ft J Manning's n....... 0.024 Discharge......... 0.64 cfs a Computed Results: Depth 0.45 ft Velocity.......... 1.86 fps Flow Area.......... 0.34 sf Critical Depth.... 0.33 ft Critical Slope,... 0.0192 ft/ft Percent Full...... 45.08 % Full Capacity..... 1.53 cfs a QMAX @.94D........ 1.65 cfs Froude Number..... 0.56 (flow is Subcritical) ~ ~ ~ ~ Open Channel Flow Module, Version 3.41 (c) 1991 ~ Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 ° Pipe Flow Calculation Basin RT ~ Flow 1.400 cfs Qut IE 2027.37 Diameter 1.00 ft In IE 2027.62 ~ Slope 0.0063 ft!ft n 0.4240 ~ L 40.00 ft d/dia A R Q V - " Depth of flow,d 0.90 ft 0.90 0.7445 0.2980 1.63 2.19 ~ Flowing Full 1.00 ft 1.00 0.7854 0.2500 - 1:53 1.95 i ' ~J - ~ Critical Depth 0.500 ft 0.50 0.3927 0.2500 1.40 3.57 Normal Depth 0.750 ft 0.75 0.6318 0.3017 1.40 2.22 HWc 0.796 ft ~ HWn 0.864 ft 'OUTLET CONTROL . HWp ft ~ ~ ~ ~ ~ f~ . ~ a, ~ Circular Channel Analysis & Design Solved with Manning's Equation ~ Open Channel - Uniform flow Worksheet Name : Comment: ^ Solve For Actual Depth ' ~ Given Input Data: Diameter.......... 1.00 ft ° Slope 0.0063 ft/ft Manningfs n....... 0.024 Discharge......... 1.40 cfs 8 ~ Computed Results: Depth 0.75 ft ~ Velocity.......... 2.21 fps ~ Flow Area......... 0.63 sf i ' Critical Depth.... 0.50 ft ~ Critical Slope.... 0.0209 ft/ft ~ ' Percent Full...... 75.15 °s Full Capacity..... 1.53 cfs QMAX @.94D........ 1.65 cfs Froude Number..... 0.46 (flow is Subcritical) ~ ~ Open Channel Flow Module, Version 3.41 (c) 1991 - Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 Pipe Flow Calculation Basin RT ~ Flow 0.640 cfs Out I E 2027.72 Diameter 1.00 ft In IE 2028.44 Slope 0.0463 ftfft _ . n 0.0240 ~ L 115.00 ft d/dia A R G~ V - ~ . . ~Depth of flow,d 0.90 ft 0.90 0.7445 0.2980 1.63 2.19 Flowing Full 1.00 ft 1.00 0.7854 0.2500 1:53 1.95 E _ ~ Critical Depth 0.330 ft 0.33 0.2260 0.1848 0.64 2.83 ~ Normal Depth 0.450 ft 0.45 0.3428 0.2331 0.64 1.87 HWc 0.517 ft 3 HWn 0.531 ft OUTLET CON7ROL HWp ft F 0 1 l~ i ~ ~t Circular Channel Analysis & Design Solved with Manning's Equation . Open Channel - Uniform flow Worksheet Name: _ ~-°-Comment : ~ Solve For Actual Depth . Given Input Data: Diameter.......... 1.00 ft ~ Slope 0.0063 ft/ft Manning's n....... 0.024 Discharge......... 0.64 cfs Computed Results: . Depth 0.45 ft Velocity.......... 1.86 fps Flow Area......... 0.34 sf Critical Depth.... 0.33 ft Critical Slope.... 0.0192 ft/ft - Percent Full...... 45.08 % Full Capacity..... 1.53 cfs QMAX @.94D........ 1.65 cfs Froude Number..... 0.56 (flow is Subcritical) ~ 6 i L ~ ~Open Channel Flow Module, Version 3.41 (c) 1991 M Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 ~ Pipe Flow Calculation 6asin RT ~ Flow 1.400 cfs Out IE 2027.37 ` Diameter 1.00 ft In IE 2027.62 Slope 0.0063 ft/ft n 0.0240 ` L 40.40 ft d/dia A R Q V Depth of flow,d 0.90 ft 0.90 0.7445 0.2980 1.63 2.19 tFlowing Full 1.00 ft 1.00 0.7854 0.2500 - 1:53 1.95 ~ Critical Depth 0.540 ft 0.50 0.3927 0.2500 1.40 3.57 ~ Normai Depth 0.754 ft 0.75 0.6318 0.3017 1.40 2.22 ~ ~ HWc 0.796 ft HWri 0.864 ft OUTLET CONTROL ~ ' HWp ft ~ ~ ~ i s : . a w, ~ ~..x , ~ Circular Channel Analysis & Design ~ Solved with Manning's Equation Open Channel - Uniform flow Worksheet Name: - Comme nt• . Solve For Actual Depth Given Input Data: Diameter.......... 1.00 ft Slope 0.0063 ft/ft Manning's n....... 0.024 . Discharge......... 1.40 cfs ~ Computed Results: Depth 0.75 ft Velocity.......... 2.21 fps Flow Area......... 0.63 sf Critical Depth.... 0.50 ft Critical Slope.... 0.0209 ft/ft Percent Full...... 75.15 0 ~ Full Capacity..... 1.53 cfs QMAX @.94D........ 1.65 cfs ~ Froude Number..... 0.46 (flow is Subcritical) ~ ~ ~ a ~ ~ ,Q. . , . ; ~ ~ ~ o ~ ~ Open Channel Flow Module, Version 3.41 (c) 1991 Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 ~ ~ ~ . Backwater Calculation Sheet - Riverwalk 7th Addn. Pipe Segment C132 - Out CB 1 to CB 2 1 Q 1.40 0.64 2 Length 40.00 115.00 3 Pipe S¢e 1.00 1.00 4 n 0.012 0.013 5 Outtet EI. 2027.37 2027.72 6 Inlet EI. 2027.62 2028.44 . Slope 0.0063 0.0063 7 Barrei Area 0.79 0.79 8 Barrel Vel. 1.78 0.81 9 Vel. Head 0.05 0,01 10 TW EI. 2028.12 2028.62 11 Frict.loss 0.05 0.04 12 Entr. HGL EI. 2028.17 2028.66 13 Entr. Head loss 0.04 0.01 14 Exit Head Loss 0.05 0.01 15 Outiet Ctrl. EI. 2028.27 2028.68 Inlet Ctrl. HW 0.999 0.634 16 Inlet Ctrl. EI. 2028.62 2029.07 17 Appr. Vel. Head 0.00 0.00 18 Bend Head Loss 0.00 0.00 Junct. HL Coeff. 0.00 0.00 19 Junct. Head Loss 0.00 0.00 20 HW Elev. 2028.62 2029.07 Grate E1. 2029.80 2030.54 Freeboard 1.18 1.47 ~ r-- f ~ ~ TIME AND 208 CALCULATIONS ~ ~ ~ ~ ~ Inland Paci, fic Engineering Comparry . Rivenvalk 7th Addition Plai Drainage Report ~ ~ . , . . , , ~^c:ir: ~ w~~ ~.k BOWSTRING METHOD PROJECT: Riverwalk 7th AddiHon PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addftion ~?V?~}M1}~ DETENTION BASIN DESIGN BASIN: A . ~i~`~{~i~~•.v~{tiii`} BASIN; A 10-Year Design Storm DESIGNER: B. HovYard 1hlnL~~Li ± 51 5~..~.~;t DATE: 5/31/96 Tot. Area 1.03 Acres 1 KSNLµ ~~KK45\ Imp. Area 4879 SF ~.,•h C~ 0•33 Ci iSi~,i• % tii n~~4}~ {•:'S ?i ~i~;,:~:>.••~~~Time IncremeM (min) 5 :••tl,,:•..,,.,.•.,, y`41`11\1X~51.4~4 CASE 1 :~•:4;.<,;.,;:<v:<: Time of Conc. (min) 5.89 .L,,•.,wt•.,.,~„ ~ •..~,:•:,;<::<,.,::;..,~ Outflow (cfs) Design Year Flow 10 100 ft. Overland Flow ?"~`:~•;`•.~A,,.,,,,a tiL~5LL4tiNtrit~'.,NL 5\\5 V V Y.tiN•.4HhltillL~C \X~ Area (aares) 1.M tt1L1L Y. n11 LV.VJ.ini\N • NNY rvious Area ~~y ft 4879 Ct = 0,15 Impe- l ltti~~M1l~tV.~M1W: ~ti5\ • L = 100 ft. ;,.~•..,K~,.,...;•..~,; ~,C' ••,:~,~„•:,t.:<;:<::,~ Fador 0.33 :it•t ,<,.:..0x, n = 0.40 "206' Volume Provided S = 0.020 Al'Pa ~ C 0.343 tx+:• \~l~ ~Ntt1•.~LK~l„11 Tc = 4,44 min., by Equation 3-2 of Guidelines ~4:~?~~~~•':~~•':~~~:~<~??~: wn \vntiLi4xti}}}~v.~. Time Time Inc. Intens. Q Devel. Vol.in Vol,Out Storage , . ~>.x ~ : . z••:~•,>t;;:«;:<>:;;,a 187 ft. Swale flow (min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu ft) V :~'1iti1~4 4~11N,KV LL1N'1•:N Z1 = 3.0 For Z2 5.89 353 2.92 1.00 475 353 122 Z2 = 3 Type B=1.0 n= 0.030 Rdled = 3.5 5 300 3.18 1.09 438 300 138 s= o.o» 10 soo 224 077 sss soo -47 ;~?`~`;KJY'`•k~'~~'';`:: ;:}:::?~~:~x~,'>.'.:'>.•;~i,: 15 900 1.77 0.61 619 900 -281 'ii?~i+iii$~~t~ 20 1200 1.45 0.54 657 1200 -543 d = 0.394 ft. t'`'~"~`~"''•~'':~~'~'" 25 1500 121 0.42 672 1500 -828 ;a ~;K,.t fM1:Ci~.l.• t A R Q Tc Tc total I Qc 30 1800 1.04 0.36 685 1800 -1115 ;a } g;. ?.L, i2Nk M ~/~/y~/{~ w/ ~II~1 7 ~ i~VV O~o V~ O.V~ WV L~M W ~~1V1 0.47 ~-----0.19 ------1.00 ------1.46 ------5.89 ------2.92 ~-----1.00 40 2400 0.82 0.28 709 2400 -1691 45 2700 0.74 0.25 716 2700 -1984 Qpeak for Case 1= 1,00 cfs ;;;~<•K<~::>n;i~ 50 3000 0.68 0.23 728 3000 -2272 tiivn' t :•:.s<;;.;, 55 3300 0,64 0.72 751 3300 -2549 60 3600 0,61 0.21 778 3600 -2822 65 3900 0.60 0.21 827 3900 -3073 CASE 2 ~$+kk{•kix~5~{k' Livx•fi 70 4200 0.58 0.20 859 4200 ,3341 Case 2 assumes a Time of Concentration less than 5 minutes so that the ~~'}••µt4}` •~••~`r 75 4500 0,56 0.19 887 4500 -3613 peak flaw =.90(3.18)(Imp. Area) = 0.32 cfs 80 4800 0.53 0.18 894 4800 -3906 85 5100 0.52 0.18 931 5100 -4169 •.,,•.~,,t2;`c;.>;2>;;;a itt?.tt\..•:.,v :v...y \4;':`;`'t``:`:"2•~"k 90 5400 0.50 0.17 947 5400 -4453 v..:•:u.t~t ::2•,LiS•..i. So, the Peak flow for the Basin is the 9reater oi the two flows' 95 5700 0.49 0.17 978 5700 -4722 1.00 \N~~~tiKttix ♦ 100 6000 0.48 0.16 1008 6000 -4992 Cil~l ~i?Ltt}~kiiv }ti~}i••~~i~,~,}~,t4y~ ~1VN~ti,{M\L~5 ~\lL\ {1N:titit\~44 \~5~ L\ YhNY.~11\ V•\5'~N, W ~}•.}}•.Lti ;i208, ORAINAGE POND CALCULATIONS 5vn•n}v.v:.v.ti•.~}•.~~v Required'208'StorageVolume •:2,iti♦ 4\`2:.•.•:.t,t,xt Impervious Area x,5 in 112 iNft 243 cu ft hN~` z'~:~SV.\5 M % :~~c~.,, , 208' Storage Volume Provided cu ft ~,..~a.,. . . . REQUIREMENTS -10 YEAR DESIGN STORM , : ; s , ~ : : ~ Ma)dmum Stora9e Re9uired Bawstrin9 138 cu ft 111`.51LLY.N•.V.SNtltiN~ 151'.LllN♦X~l\~yNM1}µn Z1`.1}~h1~.`.NN~yullti\ \ '}:'•?~~`~'~'~:~~~'~~;'~~4 Number and Type of Drywells Required 0 Single ~c;~v~~`„ 1 Double ~ ~ ~ ~.v~a-~ . I ~ IY I l*^ ~ f ~ f . _,~4 R _fa ~ . ..~~}1 .».......~I x i:..wt_.w_ •,.i.....v~r•.l , MwrMiw~_m.bII~!+.rsueCr.n.mJMhis.'a~r,iw.t...sr.r. ..r.r......~:,~.~..n.F..~u.v~~4.'a+iie.wY+~,.,.,..I:~11L141~M1~~~ . . ...a..._ ......vae...x ...r......._,.,s .~e.,.,_r..r ..r.~. . r~ BOWSTRING METHOD PROJECT: Riverwalk lth Addition PEAK FLOW CALCULATION PROJECT; Riverwralk 7th Addition DETENTION BASIN DESIGN BASIN: B ; < ~ BASIN: B •~~;~~~i~ 1QYear Design Storm DESIGNER: B. Hw►rard Tot. Area 0,77 Aaes DATE: 5/31I96 :'•aa~,~: a~ ~NN4\ Lh1~~5y Imp, Area 4817 SF C = 0.37 ~•'.~i;:1• lx`}+xn4~x}ti µttit{v'L{>. ~ti4~5~ S~iiX Time Increment (min) 5 iitiikuCx•.{4..~{>. iiti • / 4tiLM1N5tilt~ttLtS~litNti r CASE 1 of Conc. min) 5.96 ky\5l tiK4y Ll`5~ ~LµS~~ ` Outflow (cfs) I 100 ft. Overland Flow Design Year Flow 10 :~.c•.,:~:;<•:,;:`::`~Area (acres) 0.77 •.~v.v:.ti•.y ~+i4 ~«•.<<:~v.~ •.~v~ ~i~i tiv~'~Ln ~ni.~~• ~v. (~it = 0,15 t~.+ lmpervious Area (sq ft) 4877 4 •ii~5>.'~~.iii~>,•.~i:ix ~ Ln}5•y~nvnS.Lxvx L= 100 ft Factor 0.37 v.x t.vnL»•.x~xv.t• n= 0.40 ~ 208' Volume Pravided u~xxx45xi~~•.x s = 0.020 ~area ~ c 0.285 Yt~; 2~•`.~.t:t~>L2~ Tc = 4.44 min., by Equation 3-2 of Guidelines r«.:'%-•h3 Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage ••~~<:~;;`,?<;,;~ min sec iNhr cfs cu ft cu ft cu ft 187 ft. Swale flaw ;<•:;i;;.?;:x:.,;~;;,;:.x { ) { ) ) ~ ) t } ( ) ~ ) \':tiLS14tN5ti451~5i11ti1•~~~~~~~~~ ~ \1:'.'v':4l' liiti\~~ \L:l•.4ti Z1= 3.0 ForZ2 5.96 358 2.90 0.83 396 358 39 t4'ti~:i:~i•.•~?tiiti~(1 Z2 = 3 Type B=1.0 z~~~~::': i n= 0.030 Rolled = 3.5 5 300 3.18 0.91 364 308 64 }V ~lLSK S= 0.017 10 600 2.24 0.64 461 600 •139 15 saa 1.77 0.50 515 soo -M ..;..r~~~.h,.~~. . ii:t~•.t'K??~:;;;,:t.,t~ d= 0.367 ft. 20 1200 1.45 0.41 546 1200 -654 . . . `~}.u.~ 25 1500 1.21 0.34 559 1500 -941 A R Q Tc Tc total I Qc 30 1800 1.04 0.30 570 1800 -1230 v.1ix rK~i~.~;L~k ~ - Z}~x 35 2100 0.91 0.26 576 2100 -1524 \ 0.40 0.17 0,83 1.53 5.96 2.90 0.83~a:';i:~ii~i::';i?i;;; s 45 40 2400 0.82 0.23 589 2400 2700 0.74 0.21 595 2700 -2805 • Qpeak for Case 1= 0.83 cfs Y~„:•~;K 50 30/~0/~VV 0/~ 0.6I~8~f 0.19 605 3~~0V0/~V 0~ -239~5/~ `•.\tiN1N ~ 41. ~ ~ W O•Y 0.I1V V/~~4 W ~VI V ~/y~/~~ /~~ry O.//~~V1 I 0.1I '4i4ti W WVV 7 VTI ~/~p~7 W /~~/~/~./~1 W WW CASE 2 ..M%-65 3900 0.60 0.17 688 3900 -3212 z"~ ' <:.~K,•k•..ti 70 4200 0.58 0.17 714 4200 -3486 Case 2 assumes a Time of Concentration less than 5 minutes so that the ~:;;~x;>ii~;:;;;; 75 4500 0.56 0.16 738 4500 ~762 ~~ry► p/► ~p/y~ O.JJ C' O.1J C 7~ `!VW peak flow =.90(3.18)(Imp. Area) = 0,32 cfs ~Y J A [1/y~ -4057 ti"ii~StivLx~yStiux•} ~V '1aA! 85 J~ W O.JG O.~J W -4326 2L•`."'~"~~itik~~~~~~' ;•t~~,ti„z"~.x:~~~ 90 5440 0.50 0.14 787 5400 -4613 , ~~,K•v:,~,~~.••r.• ~~~a':~;;tii~:t~:~ So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0.14 813 5700 -4887 0.83 cfs 100 6000 0.48 0.14 837 6000 -5163 `5'.•.5'.54ti~45'45\4 5451 n•.x;.x~L~~>.~i>.~i`.~ ' DRAINAGE POND CALCULATIONS Required'208'StorageVolume Impervious Area x.5 in 112 Wft 203 cu ft ~ti1M14h{lH\1\l11\4~ l11 ti ny~u+~i~nv. 248' Storage Volume Provided cu ft .~x};x~x•wty .,~..'L: i`?::;<?i•':~;~?~:~>v~;µ;;;' ORYUVELL REQUIREMENTS -10 YEAR DESIGN STORM Maximum Storage Required by Bowstring 64 cu ft Number and Type of Dryvwelis Required 0 Single 1 Double ~Ui56<x+»?P?!b)Dd5? . . . . . . s~. . _ . . _ ..,..,w..~,. x..... _,*vaNrwu.ry...,...~•~.ue.._ ..+asrteY9talSXe~T1.t.,..'+F! , ...i1 c.~r:.*~i~.aNii~~r.a:. • ' _ b. M r „ke:• . _ ' ,r ~ , ~'46'4i'w,r fsyrc ~BOWSTRING METHOD PROJECT: Rivervvalk 7~ Addi~on ~ t % ~ DETENTION BASIN DESIGN BASIN: C PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addibon ~ ~~xr K~ BASIN: C ~'•}}"~`'~~~.`taYear Desi9n Storm DESIGNER: B. HowaM DATE: 5131156 Tat. Area 0.98 Acres ~ t„ ~ ti 4\l4 ti N\H Imp. Area 4250 SF 411h~.1141 L ' Ci = 0.34 `::"•.'t'2~: ~;R,Y;>.t 4~1•~11115 Time IncremeM (min) 5 CASE 1 Time of Cortc. (min) 7.01 Y}#?}~+44 }5~~.~xmu =140 ft. averland Flow Outflow Year,Flow 10 g( i~i?~iiii:ti;+•'.tiiiyk~jHtiS A~' `8Cf es) 0•98 .45144`.1NM5N•.N Ct = 0.15 Impenrious Area (sq ft) 4250 1ti~:5tiLl N~N\N~14111L 5lN tiN~15ti11\YN41N5t 5µ ~LN445txuxh 1 1 L= 1p~ 1~/~~ V R. 4Nyti51y'.11iNN1~N~X5\\ C Factor 0.34 4V 45 4~4\L ~ ~ = 0.~ :;K « y` t ~ „K%x %'208' Valurr~e Provlded w;~. S= 0.020 ~}~~µY;~K•:,•K ~,x~~i qrea' C 0.330 y~V.41~1\:\ till\Kl1x~M1 LNYL.L\LL'.tL~LNL~~LNS\ Tc = 5.43 min.i EQuation 3-2 of Guidelines ~~^~•.~~~>~x"~~~~~>,~ti Time Time Inc. IMens. Q Deve1. Vd.ln Vol.Out Storage LS;hv (min) (sec) (infir) (cfs) (cu ft) (cu ft) (cu ft) 160 ft. Swale flaw ~>~~K~~l,.t~~:',~.: - - - >:;t;~;:~;ti; Z1 7.01 421 2.68 0.88 498 421 78 = 3,0 Fot Z2 Z2 = 3 Type B =1.0 n= 0.030 Rdled = 3.5 5 304 3.18 1.05 422 300 122 S= 0.010 k;k.~~~;rix;~~•.~~µ~~ 10 600 , 2.24 0.74 549 600 -51 N41 , 15 soo I.n 0.58 sos soo -291 d= 0.417 ft. 20 1200 1.45 0.48 643 1200 -557 ~ii?;:;x~~;;<<i~•K~>~;k 25 1500 121 0.40 656 1500 4944 •451 L A R Q Tc Tc total I Qc 30 1800 1.04 0.34 667 1800 •1133 ~\vy1115i{:~ti±1~.5~\5K ~ "~l • 35 2100 0,91 0.30 674 2100 -1426 •{ii}i~•.i~~ri1N~`ii~~~ 5~+ , ~i.~ ~1iti~ ♦ o.sz 0.20 0.88 1.58 7.01 2.68 0.88 ao 2400 0,82 0.27 sae 2400 -1712 YJ 2700 0.14 0.24 694 27V1J '2106 Lv.u4Y•.4•?:'i:•..•.,',.,,~• Qpeak for Case 1= 0.88 cfs 50 3000 0.68 0.22 705 3000 -2295 ti~x•.~ 4 55 3300 0.64 021 727 3300 -2573 ~ tiii~ii~ti}•ni'~~'i} so ssoo 0.61 0.20 753 36oo -2847 65 3900 0.60 0.20 801 3900 -3099 CASE 2 70 4200 0.58 0.19 831 4200 -3369 ~~~~M1 ♦V.SHl~y 1+{±ih1\11nL~1N~1.\5~~ Case 2 assUmes a Time of Concentratian less than 5 minutes so that the <i;;~ }•~~x;~:" 75 4500 0.56 0.18 858 4500 -3642 peak flow =.90(3.18)(Imp. Area) = 0.28 cfs 80 4800 0.53 0,17 865 4800 -3935 ••~w~: ; 85 5100 0.52 0.17 900 5100 -4200 ~ % U.~ 90 5400 0.50 0.17 915 5400 4485 L•.\4N\LtiLS 95 5700 0.49 0,16 945 5700 -4755 So, the Peak flaw for the Basin is the reater oi the two flows, O.W a~ Cl(s uxt.x}}xtii~tix~ ~ 1/►/~ W VW ~p 0.16 91 ~ ~/y~/~ V ~.`IO M J ~JW ~/yy{ 1f 1T/y~~ lL! tlti1'\Hll\tiyV.~ l 11}}y iil\ll\ 1\4511X1X~ ~ 11\ti15Y 1KXiNHm 'x 0~208' DRAINAGE POND CALCULATIONS ti~5i•.5••.L~~v.ti~i~ i~ti ~ `1VtA'•5't.'A'•L~ a~, Required'208 Storage Vdume .•;>:,;~>.'<;;;>.;;,,:<„~ = Impervious Area x.5 in I 12 iNft 177 cu ft NY.\15\LNlS\HN11LNh L'4'.yt5«5lltillil\i'\ti\t • 1N1Y 'A'}.\\LV L\441i4N~U\1Y ♦~Y.1 208' Storage Volume Provided cu ft Sti1tl}lLLlLi% iN~l1 % % 31%,y~ri,'~1 DRYWELL REQUIREMENTS • 10 YEAR DESIGN STORM Maximum Stara9e R"`1ufred by Btiwstring 122 cu ft •,•~.,~•1.,•.,,,~;,,~ H{1\\11\1111~\'yh~~NL~ ••1+ ;)L~.}1lLN}\L5~ N.41\lN\L{{ ~51t~141N1•, L44 \1 Number and Type of Drywells Required 0 Single ~ i Double ~ ~ , ~ ~ ~ ~ ~ . ~ ~ _ . I ~ ~ ~ ~ ~ E~ ~ ~ . _ . ..vr ty.c~HOaY~N4rILW~H~.•. r.....s~,..~~s:., M..aa~.c..~ ...rw . .,~...,.:jwvrv.rnr+wlf._~LM ~1G~f. ,i~01[iiLtit~[,?tutll! . ~t~'nAr+A,ieftiY.K.vd.Nn',~R.I~IQfR9~.htG°l~t~li~t^'.Yettl!%~ ✓ `f'wNC~++7N1AY~?'•1,4••^'WMI~:\1'~I' '"~W~ BOWSTRING METHOD PROJECT: Riverwalk 7th Addition PEAK FLOW CALCULATION PROJECT: Rlverwalk Tth AddKion DETENTION BASIN DESIGN BASIN: D BASIN: D 1QYear Desi^n Storm DESIGNER: B. Howard ~7 i~::'"•'~a`'•,`"~,:~` Tot. Area 0.84 Acres DATE: 5l31196 ImP• Area 5005 SF C = 0.35 RM x 'zxz'% . Time IncremeM (min) 5 CASE 1 Time of Conc. (min) 7.41 yii:<~}<tii~~ \ ! - ,,..>.•.:,.,..t,,.:•. OUtfIOW CfS 1 z~,•.,~.•.2•.,.•.,.•.,.~•.~. ~`ti}.v.4w.v.rvn~•n~t ~•n~v.v.~v.~w.w.v 140 ft. Overland Flow Design Year Flow 10 tit~;~4}•.~yti~~~ii4~i{±i+~ Area (acres) 0.84 ••,:;,:,,K;,;S,•. Y.lL1L~,ti1L}14 _ , ' K}~C+L•:titi`x•tit.~4 [7P.fV 'Si' ~ % Im wus Area ft\ 5005 ~ Ct = 0.15 ~.\{LLLlLYf 4LNti\l~l r L= 140 ft. >..x<<>....«.•«: 'C Factor 0.35 ~ n = 0.40 208' Volume Provided .ti•,~ S = 0.620 ;,•:~~,;~...,•~:.,:.,ti•.,,r) ; ;i~;;,;.~;i<:::,.:.::,♦y Area " C 0.292 5~ti4Htil1\11~~{ti~tti~ti♦' 5\~L}'.nNV.1'. HY ytix~ i 5ti~,4 Tc = 5.43 min., by Equation 3-2 of Guidelines Time Time Inc. IMens. Q Devel. Vol.ln Vol.Out Storage 215 ft. Swale flow (min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu ft) ~:h;~•:<: Z1= 3.0 ForZ2 7.41 445 2.61 0.76 455 445 10 N1'.iii11{:::1\1511Z2 = 3 Type B=1.0 ii;, 5 300 3.18 0.93 373 300 73 n = 0.030 Rolled = 3.5 ' S= 0.013 10 600 2.24 0.65 491 600 -109 ,~~~;~'`•?~i~ti•`.:.~ 15 900 1.17 0.52 543 900 -357 . ~~~~'••:..~~:,<~<~:~~<`>.<~ d= 0.375 ft. 20 1200 1.45 0.42 572 1200 -628 ,,,~.::':',.:.;~:',•~:e~, 25 1500 121 0.35 583 1500 -917 iti'.':\\ ~'~~~~'lA~'•h4 kiiii>±` ~:~~•.~L i~ A R Q Tc Tc total I Qc 30 1800 1.04 0.30 593 1800 -1207 ~~35 2100 0.91 0.27 598 2100 •1502 w <<x.~;..,..~x 0.42 0,18 0.76 1.99 7.41 2.61 0,76 %40 2400 0.82 0.24 611 2400 -1789 `X 45 2700 0.74 0.71 616 2700 -2084 . • . . . ~SV.Q Qpeak for Case 1= 0.76 cfs 50 3000 0.68 0.20 626 3000 -2374 'i'•;~i<;>''•;;,;:>;.:~ i:iNi,",cii?,",ti;`;•:.~ rJJ 3300 0.64 0.19 645 3300 -2655 :,~,""222t;~k t} ,60 3600 0.61 0.18 668 3600 -2932 'Z,` % CASE 2 65 3900 0.60 0.18 710 3900 ~190 ~70 4200 0.58 0.17 137 4200 3463 ~ficx3M Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0.16 761 4500 -3739 v.+~•.+~nv.tx•.vnw.tiE 'tixxvr5•.~tv.tuM1xv. peak flow =.90(3.18)(Imp. Area) = 0.33 cis VI! 4800 0.53 0.15 766 4800 -4034 VJ p~ C J1OQ O.[Jn L O.+I[ J 797 5100 ~K{•~~iii~i~5ii~tiii W-4303 Lh~L•.L 11Y.uv\H ~`"'`~`'';~:;;'•~r 90 5400 0.50 0.15 810 5400 -4590 95 5700 0.49 0.14 837 5700 -4863 So, the Peak flow for the Basin is the 9reater of the Mro flows, ~ 100 6000 0,48 0.14 852 6000 -5138 0.76 cfs }}•r.}ti~~~};n}~~vnv:.tiv 208' DRAINAGE PONO CALCULATIONS 4xu Requfred'208' StorageVolume L~}1L~. ~L1\1`5~111`5 •,::~:;,::r~~~;~~;;Y;,;;4 = Impervious Area x.5 in ! 12 iNft 209 cu ft titiCiti~<i«•.~xxx~tix4 u•:.; n•.}r.vr~x~i~w~ ~xxxt~ \.ti{~4`•~}`.\11NX}1LL <y::~; :.}`}}•n•.`xy~~~ `''``::`::~'':''"x 208' Storage Volume Pro+rided cu ft ',:uii:.:~2ii,:~ 5\1N 45~NV.5•.~ 5\4hlti{' 1~154~1~L1V StiLitiiltiL~ DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM Ma)dmum Storage Required by Bowstring 73 cu ft 4~L L\~L{\t~ti:YfJtA` L~1y.111'~~LtiV 1\~ti\~ ~t•J ~~Lti5+4.L\1•xtil~ \tiN1 \41(•4Nt'.N~51N\N\HN' «Number and Type of Drywells Required 0 Single 1 Double o . ~ . C---] 1, ~ C7 . . _...._.~,w.e.a.a.r..._.~... _ r,.:a lu ~...Jn:.~.i_..a~d... .~i.~ • ....r..n.... . _ ,I.. . .~'__,_i_- - wr . ...ta•. a.~rs►~~ro~~.'.' ~ar~ra4/if¢lN.b~41i~4SiW1O." ~~At~Y~ff'~~PM~~~~ BOWSTRING METHOD PROJECT: Riverwalk 7th Addidon PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addition DETENTION BASIN DESIGN BASIN: E µyHh 1 } h~5 BASIN: E ~~1QYear Design Storm DESIGNER: B. Haward Tot. Area 0.45 Acres a;`µ~,` DATE: 5131/96 i %i}i`~~~M ~y{ c J [ 51•. yN.~• Imp. Area L y11J11 f L:.,tiiLSV. %4iJn~iGtx C = 0.35 2.."i;.~r:~:• z~a Y.NC N~µ ~uY.l v45tiylti;l~~~W Time IncremeM (min) 5 ~tiii~5~~~y~tNYl.411HY lx5•.ttv:lf.'.1V.1 CASE 1 ~>~~~^v Time of Conc. (min) 7.87 5\\\~N4\'\\lti\•.L'.{4\L1 }L+>Z~4+vnL~ti+~}}x+w j~ L~~ (Cl.'~) I 150 ft. Overland Flow Design Year Flaw 10 Area tacres? 0.45 Ct = 0.15 Imperviais Area (sq ft) 2090 ~~~.~,..r~•~~,:4•.,•., ,,Y L = 150 ft, ,C. 0.35 Factor \~44\\~L~~1~~1~5N n = 0.40 ~;•hri~;,<;:h,>.,>:>:.~:;%%k.~'208' Volume Provided S= 0.010 k~'.•..r;" ;<:v;~ AfP.a' C 0.157 % % ~''~a ~ ~:~w: Tc = 6.97 min,, by Equation 3-2 of Guideline.s .hy.~ Time Time Inc. IMens. Q Devel. Vol.ln Vol.Out Storage 75 ft. Swale 8ow (min) (sec) (infir) (cfs) tcu ftI (cxi ft) (cu ft) _ fLNS`lSNt`'.4Y.N11`l 415tiV.4'.5V.111•i.1A ~~~~~rri ~~~~~r~r~ ~SY~\LV L tiY ~ ~•W.l \Y.\LlM1~ Z1= 3.0 For Z2 7.87 472 2,53 0.40 252 472 •220 Z2 = 3 Type B =1.0 <.>.~;•:t„•u:M~„~a n= 0.030 Rolled = 3.5 k 5 300 3,18 0.50 201 300 -99 10 600 224 0.35 287 600 -333 S = 0.010 15 900 1.77 0.28 295 900 -605 R''r,~:i;.'v d= 0.310 ft. 20 1200 1.45 0.23 310 1200 -890 25 1500 1.21 0.19 315 1500 -1185 30 1800 1.04 0.16 320 1800 -1480 A R Q Tc Tc total I Qc % % ~u4~>. 11~ ti•.L~~v %35 2100 0.91 0,14 323 2100 -1777 0.29 0.15 0.40 0.90 7.87 2.53 0.40 40 2400 0.82 0.13 330 2400 -2070 45 2700 0.74 0.12 332 2700 -7368 Qpeak for Case 1= 0.40 cfs 50 3000 0.68 0,11 337 3000 -2663 55 3300 0,64 0,10 348 3300 -2952 xsM`,~60 3600 0,61 0.10 360 3600 -3240 CASE 2 65 3900 0.60 0.09 383 3900 -3517 70 4200 0.58 0.09 397 4200 ,3803 i2;22i2;2i{ Case 2 assUrtes a Time oi Concentration less than 5 minutes so that the ;~~;~x~•75 4500 0.56 0.09 410 4500 -4090 ; ~ t a. ~ z ~ .,w,w,,,.,~..,,.v.,•.,.,; peak flaw =.90(3.18)(Imp. Area) = 0.14 cts 80 4800 0.53 0.48 413 4800 -4387 ,,,~,w,~•.L•.,,~.~..,,,,• :t.c?.y>µ;'t~i:t;?`;a •w~85 5100 0.52 0.08 429 5100 -4671 : 90 5400 0.50 0.08 437 5400 -4963 `;'~:.`:,i`:`>..<•~ ..L,ti,,, •,~K~::..;;~.>.;;L,x;Y 95 5700 0.49 0.08 451 5700 -5249 So, the Peak flaw tor the Basin is the greater of the two flows, 0.40 CfS 100 6000 0.48 0,08 464 6000 -5536 xin~.>.• i~+>.::ux•nxtv iv {W~.551L'li5tY.4)•.~1 ~\4~KNNKHL~45NL ~!~y}l~ 5Y. 1~LY15~H x~~~~ti~L~~~v:v.{ii~i~• \5\'.t Y'.•:.1•JY1\45•. R208' DRAINAGE POND CALCULATIONS Nt151'~\t' •.4'AH1 Required'208' Staage Vdurte ~1NtiN~)4N1~~ • = Impervious Area x.5 in ! 12 inlft 87 cu ft 4~5\4ti t\..~ . `ts`~~';~ NX5~4~4 A44L~V.5~V ~'1~K 5}L5 208' Storage Volume Provided cu R .t t,~`''>.;.;,.a,•, ~ {iu .}1~v;•.y~ ORYWELL REQUIREMENTS -10 YEAR DESIGN STORM • 2;'2}v l~5 \M1~iLN~1111}.LN•.~ L ii5 x• .x•.ti~}}~tiu~~ i+ Maxlmum Starage Required by Bowstring -99 cu ft ~4 x+v...1x», Zy~ iitl\tiNh 441yt\1Lw Number aRd Type of Drywells Required 0 Single 1 Double c7)-, 117 ~~.w3 . _ a~• = - _ . , ~..~.,.~L.-._ _.u...,..W......,,.~..•,.a.,~rtfli~iYi~i' r~ ~..ee . vw..~. rNr.enritititiei~q ' . ~`"'"Sa~i~iAMhll~irm~w ..~Ma9e°~r.s. :.4.+taec~ ta6v~e+f~al~fM'UIIIl~f4~l ~~'BOWSTRING METHOD PROJECT: Riverwalk 7~ Addftion PEAK FLOW CALCULATION PROJECT: Rivervvalk 7th Addition DETENTION BASIN DESIGN BASIN. F BASIN: F 10-Year Oesign Storm DESIGNER: B. Howard Tot. Area 1.69 Acres DATE, 5f31J96 Imp. Area 6493 SF C = 0.29 Time Increment (min) 5 ~n~ii~ p~ xxL v. ~7 CASE 1 Time of Conc, (min) (~.VJ • NN•415~\{•.\\ • \14H1'.51NmMl•N :;t:x;'??:C,•h;~. OUNlOW(C(S) 'I w~x xx~nti + 150 ft. Overland Flow Qesign Year Flow 10 1VL45\~~'4t\~\•• •5L K;;;;~:,:~<'; Area (acres) 1.69 i?``:<•`•~;~;x~" Impervious Area (sq ft) 6493 Ct = 0.15 yyii 1µ,' L= 1JV Il. V t~i'~;iii}i~tiy,~} . Factor 0.29 1 208 Volume Provided ' n= 0.40 1 S= 0,010 Area' C 0.497 w: 2`:22't`•`.'{2`?~5~i Tc = 6.97 min., by Equation 3-2 of Guidelines u~~~.~•.,•."~~~~>~ ~ Time Time Inc. Intens. Q Devei. Vol.ln Vol.Out Storage i;x:; 285 ft. Swale fiow (min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu ft) ~K~ i~;:i?:~~i••;?`•:;??;"~;a========= ,•..:;.,.•..r >.v,~ Z1= 3.0 For Z2 9.85 591 2.25 1.12 886 591 295 .~....,•.:,.;,,;,,~1: Z2 = 3 Type B =1.0 n= 0.030 Rolled = 3.5 5 300 3,18 1.58 635 300 335 S = O.0/~/~W ~;#~a,~;:?;~;~:~. 10 WV LN~ ry/~/~~/~~ //~//~4 1.11 892 ryww.w //yy~//~ 1 ~1't\{•.ti5'tiNti~\l' WV iVL 1l1l ti 4tiV 5" 54• • \Yn' 4 M1 yh'}i }.\~:V.S'ti~4\ti\l ,..~~.~~•:.r~.,.,,.,,,.~ 15 900 1.77 0.88 968 900 68 d= 0.476 ft. ;•.":"..~"..`~.""L,~x 20 1200 1.45 0.72 1010 1200 -190 ,'~''4\~}1i'l~\~ti 4i~111 ~i~ 25 1500 1.21 0.60 1023 1500 4n },:,v.~,;;,' A R Q Tc Tc total I Qc j~ ~4 30 1800 1.04 0.52 1034 1800 -766 L\\H1\ti\~1L4~• 35 2100 0.91 0.45 1041 2100 -1059 5\••~h 5\•5.N\NL~ 0.68 0.23 1.12 2.88 9.85 2.25 1.1240 2400 0.82 0.41 1060 2400 -1340 `"..~..""•~,~"k'~~} 45 2700 0.74 0.37 1067 2700 -1633 ~4<Si>.ii•{L~~ "C'~n~ Qpeak for Case 1= 1.12 cfs Y\+1+111~11L`N`K}}ti ~ 50 3000 0,68 0.34 1682 3000 -1918 ~i. ~iitLVnx 4~' 14 55 3300 0.64 0.32 1114 3300 -2186 ;x~;v:.;i~;;Ki•~;iK~60 3600 0.61 0.30 1152 3600 -2448 LNN\NY.ti~N CASE 2 65 JJ1l1/ q~yy~ O.W c^ O. y~ 3.7y~ .~Q ~LyLJ ry1JV -2677 ~";;u''•; i ~•``•;~~:x~;~ii>`"• 70 4200 0.58 0.29 1269 4200 -2931 >;x~>..•:. ~::••.?~t4~:~~ Case 2 assumes a Time of ConceMration less than 5 minutes so that the ; 75 4500 0.56 0.28 1308 4500 -3192 peak flow =.90(3.18)(Imp. Area) = 0,43 cfs 80 4800 0.53 0.26 1317 4800 -3483 85 5100 0,52 0.26 1370 5100 -3730 90 5406 0,50 0.25 1392 5400 -4008 4~L1~•.454LLttLNt51'.5\YAy 4ihh4~lti~ti~NLH~' S,µ1~ So, the Peak flow for the Basin is tlhe greater of the two fl~ows, ~ 5700 0.49 0.24 1437 5700 -4263 1.12 cfs 0`h.~,:100 6000 0.48 0.24 1479 6000 -4521 }~Y~ \y ~;\Y~~ 1~ LX44vNly~ti4N 1\5~11114\llllti. N1 'N}V.f. ti N\ll~~ l'.StiN`L' Ll~~ t}~NLNL1y\ ~'\`{~'~•ti\~t4 208' DRAINAGE POND CALCULATIONS Required'208' Storage Vdume L~Y.K5~1 5titi 1.tihti1: l 11 ~ = ImPervious Area x.5 in 112 inlft 271 cu ft ~KtiX\ h}~ V\ 1t\ ;i~~ L~L4}i42i~y N1V.LN 5~ v.y 208' Storage Vdume Prov~wed w ft xxu~ ~~.t~xx ti x•nxxxtiLx x ~ti2iii•.vn~5~t~~~~~~~~ NY.14'l.YAH\N\1\\NN •.\.1ti•.11Y11H\ \\1l'1ti Y YLY.tilX1\\L'A~ ,~?;~DRYWELL REQUIREMENTS -10YEAR DESIGN STORM Maximum Storage Required by BoH►string 335 cu R l 4h4~Lt14111•.1Y.W[•1 Number and Type of Drywelis Required 0 Single 1 Double ~ ~ . 1 1 F---.~ ' . ~ . , . ~ ~7~ L . _ . . __.~~..s~.z..:irr..,.::: yi:~y6;Y;i~i'^,r~•,, . - . .ri.x , _..r..,r.t.u...~.., .vriitiiwx. - n,r•. -rt ' ' ' rIM1~irStlilliiriiA ~r-.r. , . '{~YI~",PM!fntl"'~7~i'1~q'~!'~W»A~A~~ 5,.,,. y........w BOWSTRINGMETHOD PROJECT: Rivervvalk7thAddftian PEAK FLOW CALCULATION PROJECT; Rivervvalk 7th Additfon DETENTION BASIN DESIGN BASIN: G ♦KL1~lZ}~\L\N4 BASIN: G iµLN1N;11\~. 10-YearDesign Storm DESIGNER: B. Howard r::DATE: 51311'966 Tot. Area 0.35 Acres "1L5`Y\V.1K5\X\NM ~ 4~.~Ltiti55~y11 L 1Nti1 tyi~.~ii5~5~tiii~iiv:i-0i+q Imp. Area Iy LV9N S[ f C ~ 0.33 44115N54ti~v45~+{' 1L1~14< <y5~~`N'i'.Ny~ ` L X4i15X~\ Timelnuement (min) 5 141L5 \ 5\ 5 5 k CASE 1 Time of Conc. (min) 7.65 % `~1~~5• l54 5 DU~OW (CfS) I \i«~;s.t2~2,x# ~ \5111~~~5L1K1$L~ ~;i.;,,,,,;~«;~•^•~~ Design Year Flow 10 140 ft. Over1and Fbw ,~~n•~., ~z'~~i~i +niK ,~y` Area (acres) 0.35 Ct = 0.15 ~ x• Impervious Area (sq ft) 2090 L= 140 ft. 'C Factor 0.33 n= 0.40 x~,,;.~i~~. '208' Vdume Provided S = 0,010 ~Area ` C 0.115 }t' 1\N\N}411{~G ~14 4'A\1t11\.51LhNhN1{hH~ Yti\LStiN\:5~1~ ~1\hti N1l1~NKLlNK1W. 5 Tc = 6.68 min., by Equation 3-2 oi Guidelines Time 7ime Inc. Intens. Q Devel. Vol.ln Vd.Out Storage cu ft cu ft min) (sec) (iNhr) (cfs) (cu ft) ) 15 ft. Swale flow ( ~ :x:; ~"}`~;c• •:;z;c„~:x .x~ ~ritiiuvl4t~}: }.uxx \vkx}L Zi - 3.0 FOf Z2 `?,`it;;;.~\tit;22~;:..2• 7.65 459 2.57 0.30 182 459 '?n ~ :•L ~'i~L:i4ti ~v.ti~i~ Z2 = 3 Type B =1.0 ;y:.:~~,,;~•:;~,;~ •.~,.r •`:2:i:t2;2•':: ;:t?::~'M`•.<. n= 0.030 f\Qlled = 3.5 htit~~4{w:{}~~?~•'.i{~{, "~rxr<z~AK~i~•':x";" 5 300 3.18 0.37 147 300 -153 S- 0.010 10 600 2.24 0.26 195 600 405 t~iti~titi\i\1 kNlNtilti 15 900 1,77 0.20 215 900 -685 K~l }1NL14\tik\L~ d= 0.280 ft. ZO 1200 1.45 0.17 226 1200 -974 ~♦'~~1~M~~~"+~;;~~t,~L~.~i~ 25 1500 1,21 0.14 230 1500 -1270 ~.L5ti14':':SlS{tiM1lS•.y{~,~ A R Q Tc Tctatal I Qc tiax•.xti~vn•.v~•x,11 30 1800 1.04 0.12 234 1800 -1566 ~~Kti] i i i~«µti, 1N}41{~~Li\ ~vl1t Z4~1} {\yt, 35 2100 0.91 0.10 2100 ~1864 % ~.t.,;:;...,.,. 0.24 0.13 0.30 0.97 7.65 2.57 0.30 40 2400 0.82 0.09 241 2400 -2159 as 2700 0.74 0.09 243 2700 -2457 15N5\~h\~5Y.5'1.5\~1~ Qpeak for Case 1= 0.30 cfs 50 3000 0.66 0.08 247 3000 -2753 ~ ~xx~xw:::.vnx•.4, `~`~';;?:`?~;i':>•'::": 55 3300 0.64 0.07 254 3300 -3046 ~i~`L~~ti i•.v.~~tA•.5~4 :i ;;t;:. ;j.;60 3600 0.61 0,07 263 3600 -3337 CASE 2 66 3900 0.60 0.07 280 3900 -3620 70 4200 0.58 0.07 291 4200 -3909 Case 2 assumes a Time oi Cortcentration less than 5 minutes so that the t~~~~~~~~•~~<~ 75 4500 0.56 0.06 300 4500 4200 peak flow =.90(3.18)(Imp. Area) = 0.14 cfs 80 4800 0.53 0.06 302 4800 -4498 85 5100 0,52 0.06 314 5100 -4786 90 5400 0,50 0.06 319 5400 -5081 ;,~;~.•:~;~;v; ,K ~ ~ 5700 0.49 0.06 330 5700 -5370 So, the Peak ftow fot the Basin is tlhe 9reater of the two flows 0.30 Cis 100 6000 0.48 0.06 340 6000 -5660 .,vti.. : :`,•:'t;::;;Qi:~.•..;42•:4+ ~L~}H5N1H1'.t ~tNlNV V.~14LNNY NN511•~ V 4lNl4N5M14Nt ,lLtSNNLLttN4NNl1t( tNht45Ntt~\'.N:'.XNl~ tK1tN11M11~•.}'.NN\l\L~ DRAINAGE POND CALCULATIONS Required'208' Storage Volume \:.V V.4:.5i•A.'~.5\t' Lt~•. 5:l\ll tii5.'SY.Y.L Impervious Area x.5 in 112 iNft 87 cu ft LL4V.Si'.4'{{::~\'4\ 1ti' ~:ti~}~:t:i+~tiv ~i>ii~ii. ..~v.~••.y.•}v.ti~}syt ixt~x~x+~}x{{~~ . 2pg~ Storage Vdume Provided cu ft ;~~`~?2t'.` ; '~:~~:~`r DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM , ,,,,a. Ma)dmum Storage Required by Bowstring -153 cu ft '•;;i;;;:;;.~~'{',•"'•};;;,`tk ~t~w•.w`+nHtiu~1~~'4k Number and Type oi Drywells Required 0 Single :Z* U 1 Double U71, F~~ AMNE';x BOWSTRING METHOD PROJECT: Rivenrvalk 7th Addition PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addition DETENTION BASIN DESIGN BASIN: H BASIN: H ~`~~~~~~~«;;~"'•~<=10-Year Design Storm DESIGNER: B. Howard Tot. Area 1.34 Acres DATE: 5131196 ::>~t~~x:>::::~;w;•i;~ Imp. Area 6948 SF hti ly L µL~N~llt~\ C = 0.37 1'• l{ l 4y\LiY \ •.,~'~;:~~r~Tme IncremeM (min) 5 „Xk~' Time oi Cona (min) 9•19 CASE 1 «'t,,...•. outflow (cfs) 1 •..,11,,,,,•n~~,. Design Year Flow 10 140 R. Ove~land Flow ~ti ~.~L5N5\15NLKt~ i tii~ 4lK5VA\'.}~'•}1x1~j ~;.~..;a~*:~•zArea (acres) 1.34 Cl = 0.15 ''++~'.'i iL • i tt ~L xxvnx Impervious Area (sq ft) 6948 ~2'...•.LL2~. ..,.,...~.,y L= 140 ft. C Factar 0.37 n ~ V.'Af^ V ded ?208' Volume Provi S - 0.010 'i,t?,iKt, t~ ♦ Area C 0.494 ,,.,....~,.~a i<..<;:t::t ;•,.x1N~11N5L4X i4 4iL151\N Tc = 6.68 min,, by Equation 3-2 of Guidelines Time Time Inc. Intens. Q DeveL Vol.ln Vd.Out Stotage min) (sec) (iNhr) cfs cu ft cu R cu ft 250 ft. Swale flow ( ( ) ( ) ( } ( 1 +J~511 Z1= 3.0 Fa 72 9.19 551 2.34 1.16 855 551 304 Z2 = 3 Type B=1.0 .,<::x ~~~';i:•'::i~ n= 0.030 Rolled = 3.5 5 300 3.18 1.57 632 300 332 S= 0.008 10 600 2.24 1.11 871 600 271 v. tix5v:.v..vx~xt», 15 soo 1.77 0.87 951 soo 51 ••,:.,,:ix;. 20 1200 1.45 0.72 994 1200 -206 d = 0.483 ft. 25 1J1N ~/y~ 1.21 0.W 1 WJ /yy~ 1JV1! [/y~ "491 : A R Q Tc Tc total I Qc 30 1800 1.04 0.51 1021 /1800 -779 ~}\`ySXN~lti`~~~1`M1451~ ~ (~IVV 0.91 a.~ 1028 `1VV -10I2 ~ ti{~'14N~~tiv~:i\1:i•.M1i ti SV.X\N•!.n•.`\~HM1 t 0.70 ------0.23 ------1.16 ------2.51 ~~r---9.19 ------2.34 ------1.16 40 2400 0.82 0.41 1048 2400 -1352 . . 45 2700 0.74 0.37 1056 2700 -1644 •`:i;;;:~;;:;:;t::% % Qpeak for Case 1= 1.16 cfs titiNlLS\15~~x?~;~„~ 50 30pp 0,68 0.34 1071 3000 -1929 :•.t~.,t, , ;?x:.:z~~?K•?=.:~~>: 55 3300 0.64 0.32 1103 3300 -2197 ~}Q/y~ c ~~/y► n,~Cn 4~5x~ik~ti {»t W JINV O.V1 O.JU 1141 J171/V 'GYJJ 65 3900 0.60 0.30 1212 3900 -2688 CASE 2 70 4200 0.58 0.29 1257 4200 '2943 .aLti•.t•>x:...,v:,..;,,y Case 2 assumes a Time of Concentratian less than 5 minutes so that the 75 4500 0.56 0,28 1297 4500 -3203 ♦KSlLLK . peak flow =.90(3.18)(Imp. Area) = 0.46 cis 80 4800 0.53 0.26 1306 4800 -3494 ..;<<,.~„~•.,.~~::;;;;;., 85 5100 0.52 0.28 1358 5100 -3742 t;.::: ti•.~,.>:.~,.:: 90 5400 0.50 0.25 1380 5400 -4020 So, the Peak Row for the Basin is the 9reater of the two flows' 95 5700 0.49 0.24 1425 5700 -4275 1.16 cfs 100 6000 0.48 0.24 1467 6000 -4533 • • x1v.~~~tiu+ iti~v:iiti~iiii:~>i~.x•:.5, xL~y.+xx1xv.; ~.tiv.\ '.SLN~~NLl1N\lVl.Nht' DRAINAGE POND CALCULATIONS ReQuired'208' Stora9e Volume 'tiiSiCiii•.v.~:..v.:Z L•.tiN ImpeNious Area x.5 in / 12 inift 290 cu ft SLN~~tiil tlM1 N•.•.•.v.lt\ ~L•lHµSlNKaN`.\S:Y:.\, ~ l4'~5\~511'K~1 5~151\ l1N}N {L 5K5lNl~'~K ti1:\1y} L 54i41\~1:M11\ .^..~;`4 208' Storage Volume Provided cu ft ~.1ti1+\ti4\1 5ti`\ L\~~ti5`: Yl} NlM~4y1 4 + i~}•.`}~y}i~ DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM +vi?SA • tit+ti~++t L1il:tit':~•11~•. Ma)dmum Storage Required by Bowstring 332 cu ft NLlYh A 4 `N4::{1~5iLYiy151S5~y ♦'.1llN~ 1 1~ M„>?;,;Number and Type of Drywells Required 0 Single ~~xti4:~~•.'.xLrii i~ ~ lSSk\~~4i~1 Double >k5?.Wi}ktiS} ~ _ ~ ~s ~~,,w4} ^YCVi6i~.£s._ .i.=_ ~ • . ~ .~_~y !Y'a''., ,r.. r .•~+isf4 t _ =v.a M•c~K.CA[MnrcI . _t . •t,atiernfiM5::::k~i~r:.~u.iaJ.:.~:ri{~rtb.~m.s. .rw . iul ~~'~ia'=_ - LiY~r~ir.,i R'~1M~t1YfWflO~l1~11~\*ti~i "~~n~~~~~surra~nn~.wi ~.1N~Y~"!Mi~1r~?!~:'+R~'~ NV.X NN1\n\ BOWSTRING METHOD PROJECT: Riverwalk 7th Addition PEAK FLOW CALCULATION PROJECT: Rivervralk 7th Addition DETENTION BASIN DESIGN BASIN: I 5~ BASIN: I 1o-Year Design Storm DESIGNER: B. Howard xxxa Totii~•`. v . DATE: 5/31/96 . Area 1.70 Acres Imp. Area 9500 SF k''titt. ,x,.~,..•n~.}v.r• C - 0.34 ' ~~~5x5'L.t~li5~•.45`15tiL Tme IncremeM (min) 5 Time of Conc. (min) 6,85 CASE 1 r.~ r• OUtfIOW (CfS) I ;~Design Year Flow 10 75 ft. Overland Flow Area (acres) 1.7 ♦ A w.v.~vniti Ct = 0.15 %%t impervious Area (sq ft) 9500 L= 75 ft. WC Factor 0.34 5 }x.1~~iv.ir.Yn ~ K"~ ~ n= 0.40 208 Volume Provided h~4LtNX XS.. s= 0.020 %%;X*:%; kMK}~w Ar~ ~ c o.sra ~ Tc = 3.73 min,, by Equation 3-2 oi Guiddines •`•4i~~~ } L ~.ti~~ *k v aI;III'k:; Time Time I~. IMens. Q Devei. Vol.ln Vol.Out Storage i :t 350 ft. Swale flow r~•,.~2,11•:..5,ti ~ / (min1 /1 lsec) l /iNhr) / 1cfs) / 1cu ft \cu ft~ ~cu ft~ l 41\L\ltin4 .4~1 \Ly15\ti5XiN1•f}:V} t 1~4'.\4:!•5l~`N.\4141•.4 ~x v.w.v.5xxvnti~5~4 c.V Q~J 411 ^ L.7+ 1 1.CJC V WL p~y 411 YJ ,~C Z+ I ~ ~.O For Z2 V1 ti5~t•.v.5x4xxi:}v.i•,v N54':5V 511K 15l\51\~\. Z2 = 3 Type B =1.0 w4•: x~v.~:w: ~v•:. n = 0.030 Rolled 3.5 5 300 3.18 1.84 739 300 439 :u}•:;~`~~``~":: r•t„t 4 2 •ri.:t,.151; v:, S= 0.009 10 600 2.24 1.29 958 600 358 .;;i;~15 900 1,77 1.02 1064 900 164 d= 0.527 ft. 20 1200 1.45 0.84 1123 1200 -77 #~i'•:;;:;;;;;;?'."`,M;"`~ 25 1500 121 0.70 1147 1540 -353 A R Q Tc Tc total I Qc 30 1800 1.04 0.60 1166 1840 -634 - ~;i;~K;~~};5~~~~ 5 435 2100 0.91 0.53 1178 2100 -922 1l );4{1~5Y1Y~5.~ 0.83 ------0.25 ------1.56 ------3.12 ------6.85 ------2.71 ------1.56 `~~•,~'~;k;ir~ 40 2400 0.82 0.47 1204 2400 -1196 ~45 2700 0.74 0.43 1215 2700 -1485 Qpeak for Case 1= 1.56 cfs 50 3000 0.68 0.39 1234 3000 -1766 «~}•pn}•.~•::.; }v.v.}v.Q 55 3300 0.64 0.37 1272 3300 -2028 .,;,:~:.;..;~;•.;••,~>~~v:,~,lh1LYAY.N1\l % 60 3600 0.61 0.35 1319 3600 -7181 CASE 2 t#~~+;+~i»~i•1{ti 4tii ti~ 65 3900 0.60 0.35 1401 3900 •2499 70 4200 0,58 0.34 1455 4200 •2745 Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0.32 1542 4500 -2998 peak How =.90(3.18)(Imp. Area) = 0.62 cfs 80 4800 0,53 0.31 1513 4800 -3281 ti~i'~~iL;iti;iti~~~~•'.\ 85 5100 0.52 0.30 1575 5100 -3525 ti ~ x 5~} '3: 90 5400 0.50 0.29 1601 5400 -3799 ~~}i~~•. ti~~i:E~i4•,' So, the Peak flow for the Basln (s the greater of the two flows, XS~ N•tiNN~ 95 5700 0.49 0.28 1654 5700 4046 1.56 cfs 100 6000 0.48 0.28 1703 6000 -4291 L •LKti45`F5.~5~\ % % ititititi~5~~ L MVM1 5l~\ •.\SLHh • S+ i~~~{?~\2` t ;n1ti v.;•.5u~~ -•.~`.~~'.tii~~ii~ ~i •;`':•":'z 208' DRAINAGE POND CALCULATIONS •.2t4•,,w.`X`2:`•`.1t ::2•`.t % Required'208' Storage Vdume t% i%i "~"51:4~y~}}A~~ Impervious Area x.5 in /12 INft 396 cu ft • „•.5.`;.,4;,,,,,~.., ,:.;.•:::..::.:.'.tt,q ,..,x,•.,,, ~.i:~ii,;<•::.....K,..~,.. 208' Storage Volume Provided cu ft . . •.l .l w ~i txv.v~w.x~~•,v Lx•.+v.+wnx•.u•.i: DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM ~%Naximum Stcxage Required by Bowstring 451 cu ft ~ ~x u51v.k \\1~44\ i\~ LVti\5K~ ~~;4~,:~;;,;~~~~~~~•~ Number and Type of Orywells Required 0 Single r. . ~ s~~>i±';Saicao-a~a+ri 1 ouble tr ' ~zt9C.1Y'11N."a..YS. ~ ~tti..~v,fr• _ ..nC27/tmi~" • .~:'.a+r - 544N1y ~•~kK K~ BOWSTRING METH00 PROJECT: Riverwalk 7th AddiBon {L ZW~.1N`LNti~tti\Yt PEAK FLOW CALCULATION PROJECT: Rivemalk lth Addition DETENTION BASIN DESIGN BASIN: J ;}K"`'.~•~,.~~~K~~~w BASIN: J ~`"K~x~,i;?<;r'";~ 10-Year Deslgn Storm DESIGNER: B. HowaM ,1%': x., . DATE: 5131f96 `,.~.tit:~:;.~~;,•~,t•.. Tat. Area 1.76 Acres Imp. f1rea 10115 SF 11 : C = O.~IT ,4 X'h5'\k1115 y u4 Tme Inuement (min) 5 ;t;~ Tme of Conc. (min) 6.38 CASE 1 ;.•.,,:~;,;;t,~~,.,,~~ i;; ;~~i~ ~•;;tt;;c;x~ Oumow (Cfs) 1 ~,:<;~;ii.~:i•.~,,,...,,~..,• Desi n Year Flow 10 75 ft. Overland Flaw ,~,v:`.•..,•.",;;,.,.~ 9 x~x~} v • x aaes1 1.76 1KN`N\41N5V.a,;~ Area ~L•,,,at~: 4~~1H411`.'A~SV .5t Ct = 0.15 Impervious Area (sq ft) 10115 YL\15tLV.5}N;l' ~511♦ \Nll ~l Ni~ti~14~♦\SL~.1i y'C Facta 0.34 L= 75 R \`~N'.~n41N\411`4~\11~Y NLL{ Al4\\ n= 0.40 rN q~ UCume Provided 0.600 S = 0.020 .2•.~,;.l.t,~.....~ Tc = 3.73 min., by Equation 3-2 oi Guidelines M'-mK?;r X. Time Tme Inc. IMens. Q Devel. Vol.In Vo1.0ut Storage ~ w.s•?.. 302 ft. Swale flow %(min) (sec) (inlhr) (cts) (cu ft) (cu ft) (cu R) k S..w.•,,,•,;,,;... .•:h.~•..,•;~: •:1 ;#t,~~t _a e__o===== ~e__n_=== =°ac=~oo Y. yY`~::v::•..;:::.y,ti • = 6.38 383 2.60 1.68 861 383 479 Z1= 3.0 For Z2 t.;::;;;:'<'''i<,": K•~z~ Z2 = 3 Type B =1.0 <:;;:•,;,;.•K„~a n= 0.030 Rolled = 3.5 5 300 3,18 1,91 767 300 467 <?,:x~;;a?;?•,;;;~:a S 0.009 10 6ry1J1! ~ 2.24 1.34 ~p .7~1 600 ~p Jo ~ 1 15 900 1.77 1.06 1094 900 194 d= 0.542 n. ZO 1200 1.45 0.87 1157 1200 -43 25 1500 121 0.73 1183 1500 -31 T t:...:: ?>.:>.t;L• a~;;,~ A R Q Tc Tc total I Qc 30 1800 1.04 0.62 1204 1600 -596 ~`<~a„`'"",?•~?~:~;t, ,x,..,, 35 2100 0.91 0.55 1218 2100 -882 0.88 ======0.26 ==----1,68 ------2.64 ------6.38 ------2.80 ------1.68 40 2400 0.82 0.49 1245 2404 -1155 S.xKUVav.tv~ti~iii4 ti x~~x}:x•.v.uv. as 2700 0.74 o.a~ 1257 2700 -taas Q ce ~ ~ ~pV 0.41 1~ J ~1l1l1! /yy~ -17G ~ f0~ V~.' ~ ~ ~.W ~ •\~~Ki J/► U J1l1 ~/yy~ N ~.{7yJ ~ 55 3300 0.64 0.38 1317 3300 -1983 v2: i•iQi~~:"tiy ;{~5iit 60 36UO 0,61 0.37 1365 3600 -2I35 3 CASE 2 ,65 3900 0.60 0.36 1451 3900 -2449 1 \N1 N )~'~"`~5`'•, 70 4200 0.58 0.35 1507 4200 -2693 hN11~1N4 ~ t\{L~51* Case 2 assumes a Time of ConcentratEon ~ss ~an 5 minutes so that the 75 4500 0.56 0.34 1556 4500 -2944 `K ,"~,:i;;• `~.i.? peak flow =.90(3.18)(Imp. Area) = 0.66 cfs 80 4800 0.53 0.32 1568 4800 -3232 ♦♦~~'~\~ii~~'x~• '%'y y1~4L••Lti 4ttti~ti\ 85 5100 0.52 0.31 1632 5100 -3468 90 5400 0.50 0.30 1659 5400 -3741 xL ti ~~iufi ~ti v7 ~y~ So, the P~k flaw for the Basin is the 9reater oi the iwo flows, ~i;i;€~` 95 5700 0.49 0.29 1714 5700 -3986 ,;.%M 1.68 Cfs 100 6000 0.48 0.29 1765 6000 -4235 ,•.,.,•:.L DRAINAGE POND CALCULATIONS „ti 1;.~,tka~:t?'`•~'C Required'2a8' StorageVdume l5 5 L ~•.llti 5K5 Impervious Area x.5 in I 12 inlft 421 cu ft \:iYlti\ •W. KX1W l:5 15V.5\L51 NNy\N51'.t4HVAl 1n41'.5V.4 ~ ~'.5~tii4tial\M15 V. N.S V.1~ . N~NNY.5Y.11 \ 5L~1\ti\1•t\~lSV.Y•( .~•..,,.,x }54.22H\,:i2~.~.~:..•.~,• 208' Storage Volume Provided cu ft ~.~`.•;;22:;::"::.y.,...,; 11~\NV.`l}k 415~41111k DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM •.5;t;• Ma)amum Stora e R uired b 9 ~Q Y Bowstrin9 479 cu ft ih;~ : ~ ; Number and TYPe oi DM~I~ ReQuired 0 Sfn9le ~a„~'•..;.~~.;~~>'; 1 Qouble o . ~ . . o _ ~ ,y. t i a'1 - wA~t~h!Y~rw~ ^e'ya ,,~y n . , , ~ . ~ w - v . r:•. i~ie.~.ru -1. rV A ,,a. ~~~yy, _ _ _ !'~ia~u = . , Y~~ _r.r!a~'~irr•rirlj[,. i~it~~~.zf~ ~ 1~YiL1r~ 'l.~~MrW.+/~~al~dr`lYpbfltlV~MiY1M'kHR.¢M!!~N!~!~".'~P~iw1M~.{'E7~ ~(•'•;u'~ BOWSTRING METHOD PROJECT: Riverwalk 7th Addition _KLK51L5N X NSV.\ N5 N4 t1 i PEAK FLOW CALCULATION PROJECT: RiveMralk 7th Adtli~on Z. W. DETENTION BASIN DESIGN BASIN; K M}\11K44\11l BASIN: K OESIGNER: B. HawaM ~^2, ,~x~• 10-Year Design StoRn Tot. Area 0.70 Aaes DATE: 5131196 ti~•• ;;r „ ImP. Area 4952 SF .K. . c = 0.36 y •`•"'.•`.'tttYL~2ti v`'~ .:,;~:~,...,w..~,,,}~•h:%'Time Incrertent (min) 5 x CASE 1 ±}kiµit1~µ5hL~z~;~?Time of Conc. (min) 8.56 1% ~ Outflow (cis) 1 130 ft. Overland Flaw Design Year Ftow 10 Area (aaes) OJ Ct O.~ 5 Impervious Area (sq ft) ~2 ~h ~14, ~A~;~;:~ ";~k C1 Factor 0.36 L= 130 ft. 1 n= 0.40 208' Volume Provided s = 0.010 area • c 0.254 ~ . ; ~..,3 ti}: z~i k,`~~ti Tc = 6.39 min., by Equation 3-2 of Guidelines N\4'AN1 }\•x~4 f:~t;~• ~`""r'.~"~• Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage 185 ft. Swa1e eow ~~~~\(min) sec~ ~in~r) = (cfs) (cu ft) -===-tcu ft) cu ft) ~KUti~x% ~ N••~Lt~l4y' ~ ~ Z1= 3.0 Fot Z2 ~%`8.56 514 2.43 0.62 423 514 -89 Z2 = 3 Type B =1.0 ; :•;;:<<>.;~~:>.:;:~;~.: 5 300 3.18 0,81 325 300 25 n = 0.030 Rolled = 3.5 ; S= 0.008 :;a~;10 600 2.24 0.57 441 600 -159 N1i~V ~Y.NNN ~ 15 900 1.77 0.45 483 900 -417 d= 0.381 ft. 20 1200 1,45 0.37 506 1200 -694 ~'`}•~~~l~~`~`~4}~25 1500 1.21 0.31 515 1500 -985 ~45(`~~\yA51tiV:1~riiLl1' A R Q Tc Tc toNal I Qc 30 1800 1.04 0.26 522 1800 -1278 x„ 35 2100 0.91 0.23 526 2100 -1574 ------0.44 ------0.18 ------0,62 ------2.17 ------8.56 ------2.43 ------0.62}~ ~ 40 2400 0.82 0.21 536 2400 -1864 45 2700 0.14 0.19 540 2700 -2160 •`l"~`4 ~:~~{~•,;;`;~":?,i<; Qpeak for Case 1 0.62 cfs 50 3000 0.68 0.17 548 3000 -2452 = ~„v.~..~•: ~ 55 3300 0.64 0.16 565 3300 -2735 t;"..,",",~ 60 3600 0.61 0.15 585 3600 ~015 tx.`r',X~i,;;;i' CASE 2 % 65 3900 0.60 0.15 621 3900 -3279 ~ t" 70 4200 0.58 0.15 644 4200 -3556 ~ti5~ti~~~i~~~ ♦k•.~~ ~ K1 \'N~\~N1Xti~N\ Case 2 assurnQS a Time of Concertration less than 5 minutes so that the ,f~"Y•••11 `,K~',)L` ~ 75 4500 0.56 0.14 665 4500 -3835 Y4Lti' \t~NNtitiN{yy~l1~ p e ak flow =.90(3.18)(Imp. Area) = 0.33 cfs ;rx;h; ;,~;,x~;;~~ 80 4800 0.53 0.13 610 4800 -4130 85 5100 0,52 0.13 697 5100 -4403 5400 0.50 0.13 708 5400 -4692 r~W % 90 I% 95 570~ 0.49 0.12 731 5700 -4969 So, the Peak flow for the Basln fs the greater of ~e two ftows, „x~N•..,;;,;,xA;~,;1~~;155~ A -S/~ O~VL C~ k;15;ti1N1\111H1K\n\1 ~W WW O.~ O.I/~ • TW WW 4I ` 4ti11\'f.1NNK`A 41N+Nlll\•N.\111•.}1" 15\151y tl`~•.N1\\11S1ti yi\+1~' 5l\\titi 1l\1111ti1 ~+++\l1~\~~ Y1NLti'.~~{l\l' 4 1~155~ ` 1}tiLN \ti\1 LM11i5{L1Lilt`1 ~N1~N~~ ~ \\L5 zL1\1• M1"1}41K1` 208' DRAINAGE POND CALCULATIONS L~ `.~~M~'SI Required 1208 StorageVolume Impenrious Area x.5 in ! 12 iNft 206 cu ft i i•::x u'i~•'..•n~~}~y tii .a • x u 1t •.txxiii~i~i ~tiLXd ~x}x 208' Storage Volume Ptovided cu ft Yy.X~~1`N5lL1H LL~~, \e1 1 •14.\41LN\ \ DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM Ma)amum Storage Required by 8owstiing ZS cu ft l5X„~Lt 5 L 1L % Number and TYPe of DM~Ils R uired 0 Sin9le i a ~1 : MKS.,; ,L~kt <<„•.:..:..a~..~ 1 Double k+A:ass..vaw3usauo- ~ i r"71 t„J~.7)~ -j _ _ . ..ri:.~.. . . . ' _ t <<a.dw'Y'M+~4AS.~avsrr~hrr~r.,x.dlK-.. _...w._,...~.w. ~w~v r.. .a un. vw~r,~;r~.•twr.lF , .MYa1y .+r 4 +A:4#lW.. . _ . ~ ~ v. . . , n . . . ~+nt~ a ' " R,,.. . w y.~ ~Y.:55,-15ytiy y~y BOWSTRING METHOD PROJECT: Riverwalk 7th Addiiti~on ~ ~5V PEAK FLOW CALCULATION PROJECT: Riven~ralk lth Addition DETENTION BASIN DESIGN BASIN: L BASIN: L `~ryK-~"~~-:}` ~ ~1aY~r Desi9n Storm DESIGNER: B. Howard t;.~t;" Tat. Area 1.49 Acres DATE: 5131196 iv mtii~i:ii• Imp. Area 6117 SF C O./4~W x~~:~; A( K ~ ~ :1HVt`.5~ ~Ni x ♦~n. r`Ly+N1ltL41 ~ y : k~<$iv ~ ~ Time Increme~ (min) 5 y., w~"^ ~ CASE 1 ~A.. Time oi Conc. (min) 8.67 Outflow (Vfs) 1 145 ft. Overland Flow Deslgn Year Flow 10 Area (acres) 1.49 µ Y. } M1LK41~.y ' Impervious Area (sq ft) 6117 Ct= 0.15 } L= 145 ft. ,C Facta 0.33 ~ L K}•µW.N\1\l M1' 1 n= 0.40 :,~`~;:y~, 208' Volume Provided S= 0.010 Area' C 0.492 ;zTc = 6.83 min•, by Equatlon 3-2 of Guidelines ~a•.~; •,;.~;..•,r Time Time Inc. IMens. Q Devel. Vol.ln Vol.Out Staage ~ min) (sec) (infir) (cis) 1cu ft~ cu ft (cu ft) 185 ft. Swale flow 1 ~ a ,:.~•.,;::'•v;~; ~~yY~2;y w:<,.."`;;~} ===o-°° ~_a=o==== i{{ri~iv`<i:5 Z1= 3.0 For Z2 , 8.67 520 2.42 1.19 828 520 308 Z2 = 3 Type B =1.0 n= 0A30 Rdled = 3.5 5 300 3.18 1.56 629 300 329 S= 0.008 10 600 2.24 1.10 856 600 256 w:15 900 1.77 0.87 931 900 37 d= 0.487 ft. ~'•"`:";<;<~ 20 1200 1.45 0.71 982 1200 -218 ~;;~;.~.,~'•:;i~ :;;i;;~ /y~ 25 1J/~/~ VV ~ 1.21 0.59 ~ ~7JV p 15/1A0 -5VL ~>.tiit~~?i:<ii?ii• .5v.v..~vrn.xti v..•:::.~..:•.,•.~x1 ti % A R Q Tc Tc total I Qc ~ 30 1800 1.04 0.51 1011 1800 -789 ~ ?a~~"'%i;i:~wx35 2100 0.91 0.45 1019 2100 -1081 ' ; ; 0.71 0.23 1.19 1.84 8.67 2.42 1.19 40 2400 0.82 0.40 1039 2400 -1361 45 2100 0.74 0.36 1047 2700 -1653 .`,:`;;"„<`t`~•:' 50 3000 0.68 0.33 1062 3000 -1936 Qpeak for Case 1= 1.19 cfs 55 3300 0.64 0.31 1094 3300 -2206 60 3600 0.61 0.30 1133 3600 -2467 xS 44\~1151,~\tiLl CASE 2 ~`;::,,;~a:•r•,;,•~ 63 3900 0.60 0.30 1203 3900 -2697 1~ 5 `4ti` .NN14 t LS5'. SYL~yxxxN 70 azoo 0.58 0.29 11248 azoo -2952 LK14N~'A\~\~~tl•.u~1 Case 2 assumes a Time ot Concentration less than 5 minutes so that the 75 4500 0.56 0.28 1288 4500 -3212 L ~5 ~L ~~~~x~, `tt1,1AX peak flow =.90(3.16)(Imp. Area) = 0.40 cfs K~~~~µ'♦x~; ;~:;?>;?~i:A. 80 4800 0.53 0,26 1297 4800 -3503 5N5•L:n'\.Nti{~HS~iN 85 5100 0,52 0.26 1349 5100 •3151 4♦5\~ 5~'ti~iyy«1:11\ 514~5~K•.}\5•h~14uN4Ni /y~/~~ ~/~p~~/~~/~~ O.~y/~~ Or//~iV 13I ~ 4lN•SV1.~N`S:l4lKii1\\\♦ VV V7VV W 71 ' V"~V4/~./~1 ~~{~/~~//~/y~ V ~VW So, the Peak flaw for the Basin is the greater of the two flows, ;;a;~L4~~~4~L;~L«:~:,;,,• 95 5700 0,49 0.24 1416 5700 -4284 100 6000 0.48 0.24 1458 6000 -4542 1.19 CIV ; +L ti.}~ttixx5xxxti '~`"~~;?r 208' DRAINAGE POND CALCULATIONS Ll; Lxin ~xRequired'208' Storage Vdume Impervious Area x.5 in /12 iNft 255 cu ft •~tv.,;;:;;~t,.<. titi~v `,xu..~ytL % K N1.1`Lh~\`.~1 .5yy544 1 i~, t"., 208 Storage Volume Provided cu R ~~ii<•'.~~•:iai~tii;,~.ti~~ti tii~ titiiiitiiiit~ •kx DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM KK1~V.•.YhNNlYA \~\~.K :t4:::•.1l1tNl ln Y::h1\l4Y.t'AN•.titi1 L•. N'.:YY:.tl'.11H1X1S\41V Ma)umum Storage Required by Bowstring 329 cu ft vn+xxxv. 5x~xt~.vn \4l~lN~l}~'h\1~54~4ti iiv:i~ N~55{4 Al l~ Kttit lyt;~ ...w}>,Number and Type of Drywelts Required 0 Sirxx~le r,;;:~>.::•~~:,; 1 Double .1}ikk:4k~. l . I- . . . m„ ya5, m . . ( Y7 . . . . ...~._.i_.,a.w . i. :vw«rv-...,:rtry...~nr~.•.dx„1•~. _ -.'alAf~lR4^rRR+w.r.~ , ..y~..r..~.l` rw+~.l,.rd e ~ ,'r^ ~ r •:r;f:~u •'1l~airl.r,~ . . . M~..rv*►' • w BOWSTRING METHOD PROJECT: Rivervuafk 7th Addrdon PEAK FLOW CALCULATION PROJECT: Riven,+ralk 7th Addftion a x µ DETENTION BASIN DESIGN BASIN: M BASIN: M M`; w%, % 10-Year Design Storm OESIGNER: B. Howard Tot. Area 0.83 Acres DATE: 5131/96 Imp.Area 5332 SF . C = 0.36 'MMx' ~,%'H~~ ; v x;~v ?Time IncremeM (min) 5 CASE 1 Time af Conc. (min) 8.72 nw x5.~ ~~~«ti~.~' ~xx•.ti ~y (/~}c VM1x\Y•\\M1l\~4V.'h:Ll!2VI~7) I 0utflo7~ ` \tLL441' „,.~„..,...K x Nntiti41y141Y. 130 ft. averland Flow Design Year Flow 10 51L5M1V.XKY~~4 Area (acres) 0,83 ,~,.z` "♦~"~,.,.,`.,,.,':r = 0.15 Impervfous Area (sq ft) 5332 (~KVNY.StiNt`5~4\~iL. L= 130 ft. ;4\;'C Facta 0.36 ~{ti~LLY 5 SN N x m nhvry 5 5 24l n= 0.40 2 '208' Volume Provided % S= 0.010 H`5 5~5 5 Area' C 0.299 5 + Tc = 6.39 min., bY EQuation 3-2 of Guidelines Time Tirre Inc. IMerts. Q Devel. Vd.ln Vd.Out Storage 206 ft. Swale flow (min) (sec) (infir) (cfs) (cu ft) (cu ft) (cu ft) t~,.~v.v - - - } za ;,3., = Z1= 3.0 ForZ2 8.72 523 2.41 0,72 505 523 -18 ~ N`t`{atititil Z2 = 3 Type B =1.0 n= 0.030 Rolled = 3.5 X;%:r;x;?~ 5 300 3.18 0.95 382 300 82 S~41, S = 0.008 xi#ii:`~;~~:~`•``.i?~';;;;~ 10 600 224 0,67 521 600 -79 :~,~<;~,;.,<.,:~,~,~•;~ 15 900 1.77 0.53 570 900 -330 d= 0.404 ft. 20 1200 1.45 0.43 597 1200 -6Q3 •ti'i4ii3v~h %`"r;: ~•x#~;~;~ 25 1500 121 0.36 601 1500 -M A R Q Tc Tc tatal I Qc :;:'><;~i /y 1~5~ 1800 -11~8/~5/~ ~ 30 1800 1,04 0.31 615 L1W 0.91 0.27 VLV 21W -IIVV 0.49 0.19 0.72 2.33 8,72 2.41 0,72 40 2400 0.82 0.25 632 2400 -1768 % 5Nry,~ 45 2700 0.74 0.22 637 2700 -2063 Qpeak fa Case 1= 0.72 cis ~50 3000 0.68 0.20 646 3000 -2354 ;"~<;.~Y..;•::;;~~r~~~ 55 3300 0.64 0.19 666 3300 -2634 60 3600 0.61 0.18 689 3600 -2911 NN \KlN1•.~NL1~N CASE 2 65 3900 0.60 0.18 732 3900 -3168 Nhh~t\•.1NN'.N'.W.4n N5,\itV.1N~1•.1\1M1Y.5L~ 70 4200 0.58 0.17 759 4200 -3441 v.tiv.+•µi•A•.~ti~~xx~ Case 2 assumes a Time of ConceMration less than 5 minutes so that the 75 4500 0.56 0.17 783 4500 -3717 Na~Y.N~4Hti '.+\\1NY peak now =.90(3.18)(imP. Area) = 0.35 crs so aeoo 0,53 0.16 7e9 4800 -aot t 85 5100 0,52 0.16 821 5100 -4279 •`.Kriiiiiiiii ~ii~x 1\Y.HNlLNnL11NNk 90 5400 0.50 0.15 834 5411 -4566 N1Nl'.tLNN\LK51NlL , the Peak flow for the Basin is the greater of the twn flows, 95 5700 0.49 0.15 861 5700 4839 0.72 cfs ,•.,...•.,.,.,,..,•.,.,,x~ +\VA~•AY.14tlNNttNLi 100 6000 0.48 0,14 887 6000 -5113 N{1~{~l\'.~Y ~ :1~.5"\LLl• 5\~i~y1 V.~ 1H\LNN'.N\\ Yl4\\SLNY.ti ~L\ 1\~ll\ilNtS\lVf.~• N\N1N\4\\1l\* ~ti5Y.5tN~NV.N:V.4•.ti4 LK1N~\tiNXNLN\tiNY Y.11N1H\NLY.tin\ 1'.SL.•.L\a~ 1t5N51ti51 5\N\Nti\ttil DRAINAGE POND CALCULATIONS -;;':;R.1% k. Required'208' StorageVolume ,.~„w.•;,µ;~;.,,~;w Impervious Area x.5 in 112 iNft 222 cu ft yl`4 1~ LLLS\~5111\5l ` i~.tx xx•.5v. Lv. t~ 1~ •.;~ti 208' Storage Volume Provided cu ft y'~"~i~ ~iiiii 4'i\~~lNN1l\Ali~N\\\5 ~ N1\514t44NLY.\Hll\11 DRYWELL REQUIREMENTS-10YEAR DESIGN STORM N145L4lvkvLStilltiN\N~ Maximum Storage Required bY Bowstrin9 82 cu ft XNWM5N5C~}ti\5~l\u N,i+~L`~ ~ri\544\1\~5\%\Nli\li~ ~ Nti15XhK5'hV•.~M1•.Nti«1 • ~""""~„"`"""t`' Number and TYPe of DMweNS Required 0 Sin9le 1 Double ~ . ~ 1~ ,gp~ M°i f I BOWSTRING METHOD PROJECT: Riverwalk 7th Additian NL X .\1 wjL PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addition N 1\44tW. 'DETENTION BASIN DESIGN BASIN: N v'0.u+xkxhy'~x5 BASIN: N 10-Year Desi n Storm DESIGNER: B. Howard Tot. Area 1,02 qc~s '^'^+•++~}v:5~i~f,• 9 %X ;~DATE: 5131196 •`.ti h..iiti`2>.~ 2'+.{,`v:tv. Imp. Area 5819 SF C - ,.•:"?2?."Lt,'".t.xt.y~~v~ /~~p~ 'NKySµ~l\4tNtV \ ~45X• ~.,r1 'tY.;•h~~nt\tz?ti\;:^~~ h1N11\4K`i~`'~` •~~5t ti~x v ti k ix Time Increrrent (min) 5 CASE 1 Time of Conc. (min) 8.18 ♦5 OUtflOW (CfS) I : L4tY• 2. •2,~:H 95 ft. Overland Flow Desi9n Year Flow 10 ;.~e:<i„r:c;;.;~,;•r,"~ ,.,:,,x~•^',;M. Area acres 1.02 ~~Kx4i{~~•nLV~titiiiti Ct = 0,15 %t, % Imperoious Area (sq ft) 5819 ,Nt~ 1N1 t k 1 L= 95 ft. •C1 Factor 0.34 n = 0.40 '208' Volume Provided x~t~;x S= 0,010 x~;~~x~x~~` 'Area' C 0.342 Tc = 5.30 min•, bY Equation 3-2 of Guidelines ~"~"'r?~~~~}~;• s..::i,.,,,•.~:. ::k:•`.;:;t„y„w~,, Time Time Inc. IMens. Q Devel. Vol.ln V01.0ut Stotage ~'+~Ht~ti~xuti 266 ft. Suvale oow (min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu ft) ;~2;~;~•~;~ ;;~:a~~ - - - Z1= 3.0 Far Z2 ------8.18 ~1 ------2,48 =-----0.85 ~ % ~ 5 •K'hHSV.\ 5 5y~♦5\N NvJ.S\YJl.t. 72 = 3 Type B =1.0 StiNNti Yti$N` S~~tiNY n= 0.030 Rolled = 3.5 5;154H4~~~\~1~J1\}5Lti\ 5 340 3.18 1.09 437 300 137 tl4tlhl\4V.•:'~ \tit ~ ~ s= 0.008 10 soo 2.24 a.n 587 sao -13 . }4i~' '}L \ ~•i25ii ~iix~v.titi4ii~ , f~ ~ 7lA/ 1.77 0.61 {7`}V ~7VN p 1Y{A:t1x'.i;1• V d ~ 0.429 Il. ++tiii~iu }~20 12{)0 1.45 0.50 678 1200 -571 25 1500 1,21 0.41 690 1500 ~10 % A R Q Tc Tc total I Qc `30 1800 1,04 0.36 700 1800 -1100 - - ~,;t,,:;.~ , - 35 2100 0.91 0.31 706 2100 -1394 •:1Y~h\lySY 40 2400 0.82 0.28 720 2400 0.55 0.20 0.85 2.88 8.18 2.48 0.85 •1680 :2 z ~45 2700 0,74 0.25 726 2700 '1974 Q k for Case 1= 0.85 cfs pea ~~i4 :~•":,`µ`µk 50 3000 0.66 0.23 736 3000 -2264 55 3300 0.64 0.22 759 3300 -2541 60 3600 0.61 0.21 786 3600 -2814 L'.t1N1Kt11\X CASE 2 65 3900 0.60 0.21 835 3900 -3065 LNN~Y114•.NNL 70 4200 0.58 0.20 866 4200 -3334 1'1:~ti ~1Yh11lx11N L'1L4•.V1~.\N~M1M1L ~4 N H1\~hM1 \ Case assumes a ime o oncentration lesss than 5 minutes so that the ;~,»•~~~c; ~ 75 4500 0.56 0.19 894 4500 -3606 peak flow =.90(3.18)(Imp, Area) = 0.38 cfs 80 4800 0.53 0.18 900 4800 -3900 85 5100 0.52 0,18 937 5100 -4163 90 5400 0.50 0.17 952 5400 -4448 1ti15'.ML\•.1\'.5\11N So, the Peak flaw fa tlhe Basin ls the greater af the two ffoyws, 95 5700 0.49 0.17 983 5700 -4717 w~;.~•:;,;;: x, 0.85 cfs ,<iii;;;" ~<'>:;:~;K • 100 6000 0.48 0.16 1012 6000 -4988 4•..v.,.,.>,,.k.;t,,; N\L`~Li\{1~l•,\X♦lll1 t +•AN1Nµ~111V.1Nt1\ t \titi411~14NN5Y:.N1tY~ kttt22`t?ii''t2it}22ii~iK 54NiV5Nx.}L~}~'.1;4208' ORAINAGE POND CAICULATIONS , k' 2 tx. xCti~}51iti~?~ti•:ti~~m~ti Required'208' Storage Volume ~•~.}}'i:~.}}•.tiv.~txtiL = Imperoious Area x.5 in 112 INft 242 cu R itiCii>.4iii~ti~{u'i•~•wL'. xxx~x~ ~x~Lxxv:.v.tilx•.~iL 208' Storage Volume Provided cu ft ;;",%%%%%%%%%%DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM v:.tt~:`:•x;t,K ~ Maximum Storage Required by Bowstring 137 cu ft ~ti+uxtin~imx~ "2u\2"'tt`.:, . y~xkiti}~~~ L Number and Type of Drywelis Required 0 Single „ ~ Y>. tit+14 « Ly '$J~>~~U~44i\ 1 Double dS:?Y L~j k L f l f J ~ . , . .'.r'~.v.~. x~k. . -.or «...Mni~.srw . r r.=•ti,,.M.~w3l~Ar~[~cx..~.~.va~rl.w.'n~M.e~►]ei..~ a ~ .y ~..~r_........ ...u.... . _,.oar.f.n.., b46r....e.... . . . . . - . ...f BOWSTRING METH00 PROJECT: Riverwalk 7th Addition K.•. K PEAK FLOW CALCULATION PROJECT: Rivervralk 7th Addftion ~,~~~~;i{~,;♦~;~i,~:`' DETENTION BASIN DESIGN BASIN: 0 \µ15ti{~)ul~ 1NLh}1t~N BASIN: 0 1QYear Design Storm DESIGNER: B. Hawab Tot. Area 1.41 Acres rl} XN4)'}il;<Y;;,:~ DATE: 5/31/96 Imp. Area 6966 SF . :k`2::.k`::::•'.t;;' C ~ 0.34 }x } xtu» v • r.•n~ Z x tiix~i' ~i~. Time InaemeM (min) 5 ~LN\ {•~LL)ll CASE 1 ~n~~~~~ «~y ~4 Timeof Conc. (min) 9,00 N5h\ t115111ti~ 1 LS OU~OW fCfS! I ~ \ 115 ft. Overland Flow Design Year Flaw 10 41\~11niµ1~ltL~}~~14~ ♦ Area (actes) 1,41 y~`n4 .t~:tt Ct = 0,15 j;~g;'~',~,+}~:~ Impenrious Area (sq ft) 6966 t~%iv 5 ni}i~ YC' y 1 1 L= 115 R. C Factor 0.34 Yl\~1N5{~» 5 1 4 n = 0.40 '208' Volume Provided ..~~;•...?a . •v. 4x;,xLtxx~x $ = 0.010 ~?'%:$Af@d ~ C 0.485 i~~~4»nu~x 2?'.t`?2`:~5•.i~~t~~`~ \4\V:`tiLNKSLL1'A+1yN~ %~SlL\it\\\1~ ti\LL11~5L~% }`1:4:.•~::..~1\t\4\tN t Tc = 5.94 min., bY Equatlon 3-2 of Guidelirtes I;~ . t.:.::•.;..;,• . ~ 1L1ti~MN~•M1l „L?,;,;v:;i„ Tirtie Time Inc. IMens. Q Devel. Vol.ln Vol.Out Storage 305 ft. Swale flow (min) (sec) (inmr) (cfs) (cu ft) (cu ft) (cu ft) i; x r>.~~~; x• N1.~1H15~~C1kri`\)K;~~~~~~~~~ aM1~111~ 5•..~~K4tiV5iV Z 9.00 J' ^.37 1.1C J VJL p+~ J`1V ~ ~ ~.O For Z2 41}i: ti4 t~i•:xr>;• IV L VL = V 1ype V~1.a 1 L x~5~~\'4ti{\~{\411 ~ ~ N{}\.`l1ti'.54{•.\ n= 0.030 Rolled = 3.5 5 300 3.18 1,54 620 300 320 ~ .~:•~,.;~:,~.L,,, S= 0.008 10 600 224 1,09 851 600 251 % % `N1\4'MV.:.\ti\•~L~S.'~5' 15 soo 1.77 0.86 930 soo 30 d 0.481 ft. 20 1200 1.45 0.70 973 1200 -227 = x t; ~..•,?`i~ N 5~ti'1•tti % fNl 25 1500 121 0.59 988 1500 -512 A R Q Tc Tc total I Qc 30 1800 1.04 0.50 1001 1800 -799 r~~;;;<;;;;;i;;~~ 35 2100 0.91 0.44 1008 2100 -1092 , 0.69 0.23 1,15 3.06 9.00 2.37 1.15 Mtiµl.l.i1Na:x 40 2400 0.82 0.40 1028 2400 -1372 ,'v:~ E~%':' >45 2700 0.74 0.36 1005 2700 '1665 Qpeak for Case 1= 1.15 cfs ;.,~50 3000 0.68 0.33 1050 3000 -1950 55 3300 0.64 0.31 1081 3300 -2219 60 3600 0.61 0.30 1119 3600 -2481 i,:#; :,,;,;.,•t<;;,;~~~ CASE 2 i~`~;;~;;~,~;~? : 65 3900 0.60 0.29 1188 3900 -2712 70 4200 0.58 0.28 1233 4200 -2967 Case 2 assumes a Time of Ca►cenhation le.ss than 5 minutes so that the 75 4500 0.56 0.27 1272 4500 -3228 peak flow =.90(3.18)(Imp. Area) = 0.46 cfs 80 4800 0.53 0.26 1281 4800 -3519 •..;a>.,~:,,:;~t;~ 85 5100 0.52 0,25 1333 5100 -3767 ::;,.~•,.t:,,..~t~t ~ Yi ~~p~~/~~/~~ '-~{/~~~p~~/~ 4N\1\1111\Y.%~L5 l p~~/~~/~~ O.y~/~~ W 0.//~ `4 1354 VlVV 7V~V i~ti~iti.~5::~:~ ~ VT/V `\NltV.41{ti4~\ y \ So, the Peak flow for the Basin is the greatet of the two ftows, ~ 95 5700 0.49 024 1398 5700 -4302 ~xi~ti~nux~ kti 5 1.15 cfs 100 6000 0.48 0.23 1440 6000 -4560 llY.4`t •A11'.111~ Kµ51V.•.1\tiLlY. 1Ltiti1'.\{1\l\ t`}1y.4\45:1~ \15Hl~N~L`.4i~XLN,J.•:.11H~1N1'h~ tty}4~~4V.~:41\l5N . . };?:}}~x~n'Q~ mp208' DRAINAGE POND CALCULATIONS ' Required'208' Storage Valume Impervious Area x.5 in 112 iNR 290 cu ft 4\titiV x+ L5Li1 tYlM1NNl~~ \ L5Xti5tx.xllvn~l:•4.1'.N'.~ Lµ•,ti} 5~~iivi'ti::•xv.~~y 4 \ . 1l •~4ti1'h`"' ` • t~i's :208' Storage Volume Provided cu ft ti~. .~v~ i+ii• x»M1\ ~~i~v. ♦ µL ~ ~4 , ~~t« DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM ,:,R%*%: Ma)dmum Storage Required by Bovstring 320 cu ft iitii~~~• '~4'nti~~+:; .`u•`.2'~;. ~ ~7fii~4,k;k Number and Type of Drywells Required 0 Single 1 Double e . , CD L I BOWSTRING METHOD PROJECT: Riverwalk 7th Addition PEAK FLOW CALCULATION PROJECT: gASIN; Piverwalk 7~ Addition : µ1~; ~$r , paEYE~NTDIO~N9 B SSI ESIGN DESIGNER: B. Howard 5t~~1L~1~X~~Y NNN~Y t1\N.YAa \iti~~lti:5\NN•.N14 Tot, Area 0.72 Acres x>~~~<~>•;~~~<w~~~~~:~ DATE: 5131/96 ♦\i~~v.~,x•.S~L•.i~L~~~C ti:'`3~itiii`i•::"•:i`ti Imp. Area 2379 SF {~Yh•.4NVL4H1\44\Lyt~tii4~v.ti:ii~i~iiiiu~~i'4+t~,{Ci - 0.32 . ,x,,. Time Incremer~ (min) 5 CASE 1 # ixxm Time of Conc. (min) 8.76 •..t t, ~•.MN Oumow (Cfs) 1 135 ft. Overland Flaw . ..a•..t„`~";" X Design Year Fbw 10 N\41V.5V.n}1\NY.t Area (acres) 0,72 Ct = 0,15 Impervious Area (sq ft) 2379 ? x;~~ . . ;e;,•. L= +'C IJJ I p l. {C Factor V.JG n = 0.40 ` •`.~'208' Volume Provhied tt •t•~ ~•x~•t,~#;;; •h~ i\\~.Y.4Y.\N\5 S~ 0.010 A(P.a ~ Ci 0.232 ~ l2$~S .2• ti'\'~ii•~ •k.. Nii•',•`.~}> > + i•v~ •iti Tc = 6.54 min., bY Equation 3-2 of Guidelines ' Time Time Inc. IMens. Q Devel. Vol.ln Vd.Out Stora/y~~~ Ll~.~L'.Nt4V_ 1'. ll'.5 y 190 ft. Swale flaw ;;;;;;<;~~?•.;+`;u~~ (min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu ft) \H\\5:~4}`•i5\411A ~ 1X..h11• N ~ ~ ~~~~r~~ ~ •'.iyti{tii+:x}•.x 1{11:nN } L N Z1= 3.0 ForZ2 ••`,~'~::~~x~;;~~h~•4~~ 8.76 525 2.40 0.56 393 523 -133 72 = 3 Type B =1.0 % n= 0.030 Roped = 3.5 5 300 3.16 0.74 297 300 -3 1~/~/~~ S - 0.009 ~ ti <<2•'.t'," L`t1N}• 10 WV L ~/~/~p/~~ .L4 0.52 T/V WV p~~/~~~ ry/~/~~/~~ -1W 15 900 1.77 0.41 443 900 -457 d= 0.361 R. 20 1200 1.45 0.34 464 1200 -736 y~~{1\11x5ti` 115KLN ~~x„' 25 1500 121 0.28 471 1500 -1029 Z; ?~x YM V}.M1~\7pH; ~ LlS A R Q Tc Tc total I Qc ' 30 1800 1.04 0.24 477 1800 -1323 ~'\ti'~,i1}~ t~ - ~~,....~;;x:;<;::;~ 35 2100 0.91 0.21 481 2100 -1619 0.39 0.17 0.56 2.71 8.76 2.40 0.5640 2400 0.82 0.19 491 2400 -1909 ::'}~~v~ : :y5x I~7W 0.74 O.1I M!W /y0 'Lryy~~ / YJY LLW `,`?•2~{2;2•'t~~ L ~ Q ak for Case 1= 0.56 cis ~~•~••~Y~ Pe 50 3004 0.68 0.16 501 3000 -2499 55 3300 0.64 0.15 517 3300 -2783 60 3600 0.61 0.14 535 3600 -3065 ;~t~ ~ i CASE 2 65 3900 0.60 0.14 568 3900 -3332 •".•"•:,i,;;";;',^~x 70 4200 0.58 0.13 589 4200 -3611 '1.11NllL~L Case 2 assumes a Time of Concentration less than 5 minutes so thffi the 75 4500 0.56 0.13 608 4500 -3892 `~11Y.\tN4NNlllS~y\ ai 80 4800 0.53 0.12 612 4800 -4188 peak fla~u =.90(3.18)(Imp. Area) = 0.16 cfs ` 85 5100 0.52 0.12 637 5100 -4463 90 5400 0.50 0.12 647 5400 4753 ~.'~\LV•.\5i15Y:ti11~ So, the Peak flaw for the Basin is the greater oi the iwo flaws, ~95 5700 0.49 0.11 668 5700 -5032 ~.tixx 0.56 CfS 100 6000 0.48 0.11 688 6111 -$312 1 LINLKNLI~\~ ~}y♦4N541L1114\ ~141Y4\X' 5 ll{ll~\ 4L1YyN~:}N~ ~ ~,~Z08' DRAINAGE POND CALCULATIONS ' ' •\\L\1514Y 1 'L 114 Required'208' Staage Vofume 'S".LJ }1i`111L1h1.LM1l1 •.x•:.i<~ = Impervious Area x.5 in I 12 inlft 99 cu ft ~iiii>.iii~:•'.i iti~.~~. ~ xti 5y ~•.x~.~t~~ . \4`y t`1v..24 :A;;~ 208' Storage Volume Provided cu ft ~ixiLL~) )~~v.titix•.~~ 1Lti:4 \L5L1~~ 514L5Y.~\ i.uv:n~~15 ♦ ~~k •`;;'':";`k,";~`~~ORYWELL REQUIREMENTS -10YEAR OESIGN STORM NLN :'•5\tih ` 4iL•.1\{1~4\\; ~i4~ Maximum Storage Required by Bowstring -3 cu ft }~`•:t„t.x~.,,~t~ Number and Type of Drywells Required 0 Single v • •t~v.x~~~4~♦t ~5~`~y LL5H5Y.,+N1L115 4L•~1~• ' Double kawu3xasw.3~s.ry. 0 CD . . . ~ . . . . . .......cn.M~~:..a. . . ._..cY i.. ♦ ~ . r.. . ~ _ . 41KN4 BOWSTRING METH00 PROJECT: Riverwalk 7th Addition PEAK FLOW CALCULATION PROJECT: Rlverwalk 7th Addition ~ DETENTION BASIN DESIGN BASIN: Q zrz BASIN: Q ~~~:a~.~:.10-Year Qesign Storm DESIGNER: B. Howard Tat. Area Q.61 Acres '~~~.k~ "DATE: 5131196 Imp. Area 3114 SF u~` ,M1 L~~ C = 0.35 ;~ra;'~z~ ~4µ~h ~ •'~Tlme Inaemem (min) 5 t;.,.....~•.v.,.•., `411N\NK\NN t`.1YA•A114 1 CASE 1 Time of Conc. (min) 7.98 ~...,L,.•.,,,.r„•:. ,•.:.,.•.,•.,,,......~r Outflow (cfs) 1 iiti~ ~iii•.i~HSiu~tixt`• L'N\N5~nN11•.}~l ~ 130 ft. Overland Flow Design Year Flow 10 ~LN,~NKNtiy ♦ ~LZ~ µtiK~ 0•61 rQ~^ (a~~) N•MY.NLN~W' ^ ~ A 5 ~4LL ~NtiIYA~t~t\Y SSX~ L15~•lL•.1\44N~4 ; .t,.....~t~,•.,,..,,: Ct = 0.15 ~ ~~•.~x~,x Impervious Area (sq ft) 3114 . yti,~.µ.~.~.~\♦.•n~...,w L= 130 ft. ~ ti 4 5~115L•QY\l~ IC Factor 0.35 n = 0.40 ♦y208' Volume Provided hL}`11~N 444 N4145LS ~\lM1 4•.t•.ti::;,l\ 44 S0.010 ~~v Area' C 0.213 Tc = 6.39 min,, by Equation 3-2 of Guidelines tt} S tVl45Ll~ly Time Time Inc. Intens. Q Devel. Vo1.ln Vol.Out Stotage wv.5v.xty cu ft1 160 ft. Gutter flaw min) ~ sec1 iNhr cfs1 cu ft1 (cu ft) ) ~ t., . .tµ•.%w.:~v~ ~4'A\4n~5~ti4~vNL1tiLV:~ Z1= 50.0 Far Z2 7.98 479 2.51 0.54 343 479 -135 Z2 = 3.5 TypQ B=1.0 SH~ t)tiuu4}«'tii~`}» n= 0.016 Rdled = 3.5 5 300 3.18 0.68 272 300 -28 : ii;;<;..,.~~~.;::~~~;• , S= 0.016 '•`~~•.':k'•c"i;~~<~~~ 10 600 2.24 0.48 364 600 -236 , , ~ K~,~?a• x•;~~~K~ 15 900 1.77 0.38 401 900 -499 d - 0.109 ft. ~,'•z?i;i;:i i~ :>~i::i „20 1200 1.45 0.31 421 1200 -779 ;,;'•,:,,y„a.~::• 25 1500 1.21 0.26 429 1580 -1071 A R Q Tc Tctota1 I Qc 30 1800 1.04 0.22 435 1800 •1365 ~~iNz.~ii;~ 35 2100 0.91 0.19 439 2100 -1661 1 L 5L'. 1511.~L1\5~ 0.32 0.05 0.54 1.58 7.98 2.51 40 2400 0,82 0.17 448 2400 -1952 " •x'\22it2iY?`Yi:" aJ 0.74 0.16 451 27~ `;:.;;:;::•`.::.;ct~ `~tt~ Qpeak fa Case 1458 cfs i`;::::~.:.}.•,•. ~ 50 3000 0,68 0.14 458 3000 -2542 ti ~~+4xxt~~+~`i np~ ~JS .~MJ 0.64 0.14 47L ~ 'LVLB ;"r, 60 3600 0.61 0.13 489 3600 -3111 CASE 2 65 3900 0.60 0.13 519 3900 -3381 /y~/~~ ~~o //y~~~/~~ 7 ~/y~/~~//~~ 4#L,LL2• 1 O ~LW O~W O.1li VN/ ~LVV -WV~ ~}`~µ1\~'.VNL•~ t~N\ Case 2 assurres a Time of Concentration less than 5 minutes so that the µ i'kL}NN~41~~L'.11NN1 75 4500 0.56 0.12 556 4500 -3944 in}Mxitii} Pe 4800 -4240 ak 8aw =,90{3.18 ImP• Area) - 0.20 cfs 80 4800 0.53 0,11 560 85 5100 0.52 0.11 583 5100 -4517 90 5400 0.50 0.11 592 5400 -4808 So, the Peak flaw for the Basin is the greater of the tw+o flows, „`«,••~,,,,,~x~,,;~ ~ 5700 0.49 0.10 612 570~ ~088 0.54 cfs 100 6000 0.48 0.10 630 6000 -5370 v v.vntux ~ 208' DRAINAGE POND CALCULATIONS t:~`:;;;';i:•`•;,': Required'208' Storage Volume :a.,.,•..a~~i; ImpPrviaus Area x.5 in ! 12 iNft 130 cu ft titi1~N ~~~~1\M144~ iC{ K }ti:~~~xM % 4 NL\L 4 4 5\41\%4~% % ~~ry~208' Storage Vdume Provided cu ft tiai"n uuiM1wi?'iii}.~ i~' ~ `•m+x1 ~t~tiux•. L . ~v ,t i~~>,%,?:i':~~ DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM N1'.4t\45\111tiN1N~\\5l }5 4~1\N1Lh\\N1N•.111\ Ma)dmum Storage Required by Bowstring -28 cu ft L1tiC5~'i~LL1~1Y.N•.~`} ti •.v NNlt1\\~ ~ { ~1ti♦~~51~ilti\\lY ~41x 11yL11~51}\1lV.~ X5 N ~L1'.~1 l \ti tiL C\5~ 5'.~'.4NlN1t+\Z}G' Number artd Type of Orywells Required 0 Single % ?'.\4. 45\N\\ \ % t 5i~51~411ti1 5\y}~' ;ti;y;;..~;;~~ 1 Double L-'~j L-2 C::~ C77 F. C71 f. . - . . _ . ~ . . . . , . . . . . . _ . . - - _ . , , . BOWSTRING METHOD PROJECT: Riverwalk 7th Addition PEAK FLOW CALCULATION PROJECT: Riverwalk 1th Adddion DETENTION BASIN DESIGN BASIN: R BASIN: R ; , 10-Year Design Stam DESIGNER; B. Howard Tot. Area 1.71 Acres DATE: 5131196 Imp. Area 7344 SF • 1 `M15\Yn 11 C = 0.32 ; . K ;.,,,t ,<:~;;;~x•, • ,;}\\lY.ti'.51Vh~5ti4\~ ; Time InuemeM (min) 5 ~h4 1NN1+'.1ny 1•!.1 L :'.~•M44~.4i151M14M1N1 ~Nlt\N~tiN\H•.l\1L+' CASE 1 T i m e of Conc. (min) 7.98 \4ti\~N1YAN\~1'AS•,.ti1 ' ♦Lt;\t1tiNLNtt1ti1♦141ti / 4Ktl~5LNVNtt\•dSNn O~V~~ ~CfS\ ~ 1 }µ}yNN1tiN4NK `~5Y.5\' ~ Desi n Year Flaw 10 100 ft. Overland Flow • 9 ~L:~•~:~ Area (acres) 1.71 •.`l,,•:.,.,,,•..,•.u Y.~t:.5'AYY `.\SNYtit455'.~Y.\\M1~ 'AA r 1N1'ALN~NN C• ~ O•1,~j " Impervious Area (sq ft) JYY \ NL.tA.1HN1, 'C' Factai 0,32 = 1M VV ft. ~SV.lLNL~41144ti~14151',.~11'XN•.~* 4441~45ti~5L~titiY.\~5 O.~ 4 h µ~`i }``5~~ ~M ~w Volume Provided I I ~ti~;./~ ~ S= 0.010 ~ XN~V.S$~i';%Area' V 0.r LL} titilK5Y1'.♦4' ~'A 451V1.5~NK)NLNL' LS~~VA'.tith N44}5~ ~~W.{~ltiN4• Tc = 5.46 min•, by Equation 3-2 of Guidelines ,$~,gK,~,,.,.,,.,•.~,.~ ~Arµ„1 Time Time Inc, Ir~ens. Q Devel. Vol.ln Vd.Out Storage % 250 ft. Gutter flow ~ %:r':a (min) (sec) (inlhr) (cfs) (cu ft) (cu ft) (cu ft) iiii«~i~ ~ iiii.v~% yti ti 1, Z1= 50.0 For 72 7.98 479 2.51 1.40 895 479 416 ZZ = 3.5 Type B =1.0 ~:??~.;?`~:;;;::~:;;~;~r,:;•?i;:~, n= 0.016 Rdled = 3.5 ~ 5 300 3.18 1.76 709 300 409 k`iiii{.;;•.~iti.: • S = 0.008 ~4»xit'u5~x 10 600 2.24 1.24 948 600 348 % r 15 900 1.77 0,98 1044 900 144 d= 0.178 ft. 20 1200 1.45 0.80 1097 1200 -103 11L\N'h4NtY.L~AN 25 1500 1.21 0.67 1117 1500 -383 r:,;•~ ,<~;<;;' A R Q Tc Tc total I Qc 30 1800 1.04 0.58 1133 1800 -667 • 1ti~1~44ti{51 \{l~~ N?}1]iNN ~ 35 2100 0.91 0.51 1143 2100 -957 ' 0.85 0.09 1.40 2.51 7.98 2.51 1.40 40 2400 0.82 0.46 1166 2400 -1234 t ~~?}iK;~•~'r; 45 2700 0.74 0.41 1176 2700 -1524 Qpeak for Case 1= 1.40 cis 50 3000 0.68 0.38 1194 3000 -1806 KN'.NN1N 55 3300 0.64 0.36 1230 3304 '2070 60 3600 0.61 0.34 1274 3600 '2326 CASE 2 65 3900 0.60 0.33 1353 3900 -2541 70 4200 0.58 0.32 1404 4200 -2796 t~~ti~n~~~:i•`.~~i~Case 2 assumes a Time of ConcenUatiion less ttran 5 minutes so that the 75 4500 0.56 0.31 1449 4500 -3451 peak flow =.90(3.18)(Imp. Area) = 0.48 cis 80 4800 0.53 0.29 1460 4800 -3340 iL~~L11Yh.)~41~5x1~• 8/~5~ V 5/100 0.52 0.29 1519 5100 ~SS1 7 •k W 'IVV 0.50 0.28 1544 VT/V -WW So, ihe Peak fiow for the Basin is the greater ot the two flows, K95 5700 0,49 0.27 1594 5700 -4106 1.40 Vfs yl4}1~1H1ti451~1\tiS1x~~M1 100 6000 0.48 0•27 • ~2 6000 -4358 N \4yy1Lti\5'.\44~145 t~l:~L~\ Y~441y~{\4y15151 ti•.~\ ;.t,R~,~k ~:208' DRAINAGE POND CALCULATIONS <;ii: equired1 1 torage olume SLVt'~~uxt5u4v.tiul }+.}+•Vm.•.yr.}ti~t+tiu3 15'.ti L'.kii{ Impervious Area x.5 in / 12 inlft 306 cu ft tiiLV~ti; : ' ♦ ~xxx}µ y}},L'\XLN \ ~ 4 1411 \1 1L `lNY,M1ti1l4K\Nl ~5\~ 208' Storage Volume Provided ai ft DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM t\•.1\NlL~~ttl~'.1}NtilM N'h1145\LtN4t~'.11~4 hAa)cimum Stora9e Re9uired bY Bowstrin9 416 cu ft N~~ YAnLY5ti1lN\NN1 Y.}1~11N14~i~}~N4\i5\' x ..K'JN.5tiN1HtiNN; ~ \xwtiuu~tuvv.~5~ Number and Type of Drywells Required 0 Single 1 Double ~~}}?V}.1+;.}~~k\1? . . _ . . „ _ ~1Hw.._....:✓.~1lii..Lla,. , . . _ .....i.~ .....:e.°J.st:a_.....~ . . . . BOWSTRING METHOD PROJECT: Riverwalk Tth Addition PEAK FLOW CALCULATION PROJECT: Riverwalk 71h Addition DETENTION BASIN DESIGN BASIN: R1 ; 10-Year Design Storm DESIGNER: B. Howard "'~':"~A'• }1 BASIN: R1 ~1M4}y~~1t ~ Tot. Area 0.97 Acres ~y•^~~;~'~~~~~ DATE: 5129196 i{} i~{' ii• ti~ Imp. Area 3271 SF ~ ~ ~Y~ N\NKNLIVA C = 0.30 ~it itNt::1.5t141N•.l ~~ti~NNY.S.VN.yYAN Time InaemeM (min) 5 iLSY'•:i2'+.`>;:22„`t2;.n CASE 1 4~+5titi}~niv.tiv.ixti•ni~ Ttme of Conc. (min) 10.32 L` 4•ASYoY ~y~~}~~~~y~\IIV1~ (V1~7 /~r■c) 1 ~~lLtiL~Y.5N • y 5L x~k 135 ft. Overland Flow ~~<~~x~ a Design Year Flow 10 NZNti`5 `15' M1 }Nn}L 5ti yl 5•~h~~ ~ ;,.~~,~:>,..,,~•.,?~Area (acres) 0.97 ~yV 1N .~\~~5~\Vh~l•h~ % '.NNl\\ NSLNN~~h. LL \X•. ~4•'• ~yx`4"`••`~; Impervious Area (sq ft) 3271 Cl ~ 0.15 _ L~ 1I~ft. Y1t•'+~~,, C' Factar O./~ W % zw~~ • *%~'208' Volume Provided n= 0.40 > LL L x xti 'tixtLw ~ t} y %nr~~nti kv. ' i S = 0.010 ~ „r;,,; ~,Area C 0.291 ~n~; `a i f:7 ~ {~RSti ~t}~ , Tc = 6.54 min., by Equation 3-2 of Guldelines ~n Time Time Inc. Intens. Q Devel. Vd.ln Vol.Out Storage (min) (sec) (inmr) (cis) (cu ft) (cu ft) (cu ft) 236 ft. Swale flow ~ a~•:;,•.~,.,~~;, - xi Zl - 50.0 FOfZ2 10.32 619 2,20 0,64 531 619 -89 Z2 = 3 Type B =1.0 n= 0.030 RaJled = 3.5 5 300 3,18 0.93 372 300 72 r,,.~;.y;.,;;,;;;~K•`•~ S= 0.014 Swale=3.0 10 600 2.24 0.65 524 600 -76 15 soo 1.77 0.52 572 soo -32e 'n x »yK~ii~ii{'~ y{/~ C~ y~/~ d~ 0.153 Il. %i~~`rii{iy ~ 1LW 1.AC 'N 0.42 NJ 1LW ~71/J y tryW ~ p~~ 25 15/W0 121 0.q.7J WL ~ ~/y~ 1J ~~G7 k~~:.tk`:2:~~;:~~• A R Q Tc Tc total I Qc 30 1800 1.04 0.30 608 1800 -1192 k. . } ,i ~ r 35 2100 0.91 0.26 612 2100 -1488 0.62 0.08 0.64 3.78 10.32 2.20 0.64} 40 2400 0.82 0.24 623 2400 -1 777 ~t ~;ttzt::~ • a"%,"~a 45 2700 0.74 0.22 627 2700 -2073 Qpeak for Case 1= 0.64 cfs 50 3000 0.68 0.20 635 3000 -2365 L\Z-.' cA 0.19 WYY Ilo WT p~ ~/y~/~~/~~ -//~~/~p~~/~ ~~-i~/ ~5vN~y~~1111\ti ~ ~ O~~} \h\N1NN5\1 i,';'~`~,~,• ,:;~k 64 3600 0,61 0.18 676 3600 -2924 :ii»;iix~ti' MLC CASE 2 65 3900 0,60 0.17 718 3900 -3182 70 4200 0.58 0.17 744 4200 -3456 ~y~.ti451nY15NK45v~ } 111':5Nti:1;1'At~}\~ Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0.16 768 4500 -3732 peak fbw =.90(3.18)(Imp. Area) = 0.21 cfs 80 4800 0.53 0.15 773 4800 -4027 NN\L ~ N N`t•l~ 85 5100 0.52 0.15 804 5100 -4296 N`.NtiKLy" + A\H1Yh~4~ 90 5400 0.50 0,15 816 5400 -4584 So, the Peak flow for the Basin is tlhe 9reater of the two flovrs, 95 5700 0.49 0.14 843 5700 -4857 ,:;~:,a♦st t :a 0.64 Cfs 100 6000 0.48 0.14 867 6000 -5133 ti~15\ti4\15V:. A4\•.1ti~. 11L11yti~Hyh. K NNti\ % \~l}11~ +1.y{ )µJ{1~~1_l4X♦n\lY W :.LMZ~LtiLN5'.11~51~ti~15h5tiL'LyHV•N~ ZOS' DRAINAGE POND CALCULATIONS ..•.ti,,,4~.,•..,, p ~~,1'n•.tiL,.`,w5•.y+`.',1 R eqVired'208' Storage Volurre , ~ r~ ~ ;;;~;;~~~~`~y~♦N~~L~~~M~~ = Impervious Area x.5 in 112 iNft 136 cu ft i\ri 1\\S1XtiNLt ~~Vy.'~ x5 xtix x NN5K5XLNL~LK~~ i«~ii`}~ji1xmx # 208' Storage Volume Provided cu ft 4`5 <<}`}x.1x»>~.~ 4 45144µ\N15N\'A \~~~~45\~•\4Lt454\\ti~~ +1 \tx\1KLx1LiN'.Lt ~x'.x~ K~.•"~.~` DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM Maximum Staage Required by Bawst~ing 72 cu ft l t 5XNV 4%~ti~NS\11 4N44•.M1 \y1•A~LyS\ {\'.l' K,,;r K Number and TYPe oi D~Ils R~uired 0 Sln9le 1 Double ~ L . . ~ „y. .~w_.... ,._.~i.l~~l ..i~.. ' .r_.. n. .i ,S..a arit~7~Y~ y1t.K.uyArt'inl/W~...S.t ~ Wt1~lYGfifF~L• ~C~MR.• ~ ~~I~11~1{ ~_-~iL~[ ~~~~5. J~ . Y ....w_ ~i[r7.~Y.A~.YRFd1:A~'I~~ ~'xK~'~~^t>;:~'•~~~:r BOWSTRING METH00 PROJECT: Riverwalk 7th Addftion PEAK FLOW CALCULATION PROJECT: Riverwalk lth Addition `zDETENTION BASIN DESIGN BASIN: RT ;t•.,, Desi9n Storm DESIGNER; B. Howard BASIN: RT 10-Year ,•:.,,~:•:.4„kz~;~ Tot, Area 2.52 Acres DATE: 5/29196 ui ~ ni 4 ti u~ Imp. Area 14636 SF ` ii C _ 0,34 x'•x.tt;w:K •~,i"~ a • a~~ ~v Time IncremeM (min) 5 Ki3tii ixxx~: CASE 1 ~Time of Conc. (min) 1.57 QlltftCW (CfS) 1 l K5» NS~},~4" t K` ,ti L~ri NN1•• 135 ft. Overland Fiow Design Year Flow 10 2.52 rp~9 (a ~Vl W/~~ps) X A N1N{1\ ~V.l~tx • "4 Ct = 0.15 :Impervious Area (sq ft) 14636 L= 135 ft. 'C' Facka 0.34 ♦ •A 5' .N'.\ \ + \~N4N L ~ 1 208 Valume Provided n= 0.40 1 S= 0.010 ~••":•;i<ii~~<~~~„ Are'a' C 0.857 Tc = :;m M 6,54 min., by Equation 3-2 of Guidelines Time Time Inc. Intens. Q Devel. Vol.ln Vol,Out Storage r.:,,•,:;v•K , 236 ft, Gutter (low 2<•~.~>:~~~~:~,~~.~~ (min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu ft) Zi - 3.0 FOt Z2 7.57 454 2.59 2.71 1349 454 ~ ~1• :5,1~.~h1«1k NNLV'~~tiKS~YN Z2 - 3 Type B -1.0 n= 0.016 Rolled = 3.5 5 300 3.18 2.72 1095 300 795 ;~r~t~~~„•.,•.~•.:; S= 0.014 10 600 2.24 1.92 1448 600 848 ~t~t:4..; ,.:;•,,;,,,y'~ ;::..~`•.t„•:::;t;,~.~~a 15 900 1.77 1.52 1599 900 699 d= 0.440 ft. 20 1200 1.45 1.24 1683 1200 483 25 1500 1.21 1,04 1715 1500 215 A R Q Tc Tc total I Qc ~~r~~:~~<>•;;;~;~ 30 1800 1.04 0.89 1742 1800 -58 .<<;~..;:• 35 2100 0.91 0,78 1758 2100 -342 ~n~T~ titi v. •.ti~v~ 0.58 ======021 = ====2.22 ------1.03 ------7.57 ------2.59 ------2.22~;{~~:::::;., 40 2400 0.82 0.70 1795 2400 -605 •;<,;<.x,aj~ 45 2700 0.74 0.63 1810 2704 -890 P~ 50 3000 0.68 0.58 1838 3000 -1162 Q k for Case 1= 2,22 cfs ;~~:;,:,"•,•.,;::'a 55 3300 0.64 0.55 1694 3300 -1406 t•:\;;• .;;>;:t;~,,,' h~~....L,.~..t;...,.,2~ 60 3600 0,61 0.52 1962 3600 -1638 CASE 2 65 3900 0,60 0,51 2084 3900 -1816 i,~r?;~,`<:•v<:<;;~;;~3 70 4200 0.58 0.50 2164 4200 -2036 Case 2 assumes a Time of Concentration !ess Hran 5 minutes so that the 75 4500 0.56 0.48 2233 4500 -2267 t~:sr<::?:~::; :t~•~ peak ftaw =.94(3.18)(Imp. Area) = 0.96 cfs : 80 4800 0.53 0.45 2250 4800 -2550 ,,,::,,•.:~`,i::`"~} ~ 85 5100 0.52 0.45 2341 5100 -2759 1•flllt.l~th.~ h,Yyti1 90 5400 0.50 0.43 2380 5400 -3020 5ti':.1N1••h hN So, the Peak flaw for the Basin is the greater of the two flows, 95 5700 0.49 0.42 2458 5700 -3242 2.22 cis , 100 6000 0.48 0.41 2531 6000 -3469 x~•,,.2.;::;.;;.i•.,xy. •.~'4N:.~N~ti\:LKS~; NNilVhtii~11~ 11\1144 \Y.NLV.N\'.11'.4N1 208' ORAINAGE POND CALCULATIONS .c•:.<•.; k•...~ tS.~Y Required'208' Storage Volume :..~v:. tvnv M1k k;~~ = Impervious Area x.5 in 112 iNft 610 cxu ft i~:~g;~ x~u•x+u `v:k~~~.~~~~~~~• 208' Storage Volume Rravided cu ft i}}C?Av{'1' Liui>.~i•'.~iK ~h~4iNKM15N5~5\NY 4~` M` lY. 1NLNtl•. ti, A~5V.5~~5V.5Y.lW DRYWELL REQUIREMENTS-10YEAR DESIGN STORM •v.M1`ti\{2 AL'ALN4114~• Ma)dmum Storage Required by Bowstring 895 cu ft ;%x xNumber and Type oi Drywells Required 0 Single ;',•x:~,,,,`;~?,;'.>.2::,; ,r:.,~,•.,.:.:,~,,.,, , 1 Doubk 71 ED ,i , c _ R..'....~..f..a»-_.•.~.. ,._.,.a..,. ...._..,..`xr . A.~r,.~.t~52M(a~,~'n[-.., . .:a,':>.::er,!'+10.6~~swluw7aMN.~i..:~...~nr,.. l:a`~~A~!'..:OfY±'ti'@11~~:~13~!b"~.•a''''Jtl,"N~,,...,.. ,,.ay. v .l.,.~ k':.L•~.:,K,+~ BOWSTRING METHOD PROJECT: Riverwalk 7th Addition PEAK FLOW CALCULATION PROJECT: Riverwaik7th Addition BASIN: S DETENTION BASIN DESIGN BASIN: S } 1QYear Design Stonn DESIGNER: B. Howard M%k2;?~r Tot. Area 0.60 Acres DATE: 5/31/96 Imp. Area 4651 SF ~~`5 M 5 , C = 0.41 ; ~~~L~H`H• ~SyN 1i ~VK~Sy 4~:LY:51 •.4l ~~••:~~~~~~~~~~x~~ t,Time Incremert (min) 5 : NNL'.1LtL•hSYAY.5V.5~ CASE 1 Time of Conc. (min) 6.91 ~ y.4.4 . `ii~i«•x..~~x{~i' ' ~~5v.i~ti~4~~iy~~titivntiv~~ • oY Imy~1 /~\IIV~~ ~ 4 \lAl'S5t5'{~h~1ti~V15ti1' (VIV) I 60 ft. Overtand Flow % Design Year Flaw 10 4V SNVtiN4 •.K A Area (aaes) 0.6 5\1`L15\'~i!~~54~ti\~{HL* L 5•MtiN\15\\5N4i1•.~ Ct = 0.15 ~w„?v;,;;r?; Impervious Area (sq ft) 4651 a,:~~,a~.•.;... L= 60 ft. Factor 0.41 . y}iii~ ;ti '208' Volume Provided n = 0.40 ;i~`:~~k?k S= 0.010 k 11 }~~;~Area ` C 0.244 % ` ~ Tc = 4.02 min., by Equation 3-2 of Guidelines Y~ Time Time Inc. IMens. Q Devel. Vol.ln Vol.Out Storage % ~ti~tti~i~ti 4 l / (i ) \ ! \ / ~ / ~ min sec Nhr cfs cu ft cu ft cu ft 250 ft. Swale flow ~fi~:a, % >•:%Y a~z~ 4~. ~~~iit 1y Z1= 3.0 Fot Z2 6.91 415 2.70 0.66 365 415 -49 Z2 = 3 Type B =1.0 ?.>•.:c ; n= 0.030 Rolled = 3.5 S 300 3.18 0.78 312 300 12 ~,..:::~.....:.,,•.,..,,•.,,S = 0.008 rr;;:i~:i~<;i,?.♦;i~~ 10 600 2.24 0.55 405 600 -195 1NW.4LM111ti11\~5 15 soo 1.77 0.43 aso soo -aso d= 0.390 ft. ZO 1200 1.45 0.35 474 1200 -726 25 1500 1.21 0.30 484 1500 -1016 A R Q Tc Tc toral I Qc 30 1800 1.04 0.25 493 1800 -1307 35 2100 0.91 0.72 498 2100 -1602 0.46 0,18 0.66 2.89 6.91 2.70 0.66ri; ;;,i~"~ 40 2400 0.82 0.20 508 2400 -1892 ,~.~„•.v... K,~ 45 2700 0.74 0.18 513 2100 -2187 Qpeak for Case 1= . 0.66 cfs 50 3000 0.68 0.17 521 3000 -2479 55 3300 0.64 0.16 537 3300 -2763 tl}•MXNNIKX4 , 60 3600 0.61 0.15 557 3600 -3043 1i14.1~511•11N14 `11'AiN'.N4\ti4~4 5 CASE 2 65 3900 0,60 0.15 592 3900 -~308 ;ta ♦♦♦3586 "''~~yV"~``♦1` 70 4200 0.58 0.14 614 42()0 - " N~~~N}5\NLN. Case 2 assumes a Time oi Concenhation less tMan 5 minutes so that the x,~~;i:;~;;~3~a 75 4500 0.56 0.14 634 4500 -3866 ~v:80 4800 0.53 0.13 639 4800 -4161 peak flaw =.90(3.18)(Imp. Area) = 0.31 cFs 85 5100 0.52 0.13 665 5100 -4435 90 VIVV ~~p~~/~~/~~ 0~50.12 676 VTVV ~~p~~/~~/~~ ~I i 7 3~~~\tiM1~t11tiN1~K`~.,ti151\•KS~L ~W 4 \Nlti` 1 11N `~~}y\ So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0.12 698 5700 -5002 0.66 cis 100 6000 0.48 0.12 719 6000 -5281 tv.~~~vu+xxt % tvi:i:i~~L~u~ »y x ~2"2ii2iiiiiiii}~~~~• .'?*?§208' DRAINAGE POND CALCULATIONS 4411V111\L ~LLN Lti L'.1, Required'108' Storage Volume vtih •.N 1LLh'h~+N5N,;N\~ _ Impervious Area x.5 in 112 iNft 194 cu ft Y~L•1\\ ~~111\\114Y~4 ~4~~11~'•' y\'AN111 «~}•:\41\t~~Y1\Y114~N51 \t5•.LN\ti~L\StiUy \y ~•.~;14441tiL~itiC5yii1~' 2qg Storage Volume Provided cu ft ' X ~ ~x.~x1r.v.~lti~5 • ORYINELL REQUIREMENTS -10 Y •,,;t•:~„~,~;~, .,r Maximum Staage Required by Bowstring 12 cu ft ~L~1~•µA4VSy~NW~.µC45} • ~.l\.Nlxm\L\`L•l~k %-%Number and Type of Dryweiis Required 0 Single 1 5`\ti ~`5 ~ ~~1 Double ~ ti>k`..ki~p~,~.~.. 5 L-Li 07s'411Nl--" L". 04. ..~..Wo J. `fanW✓~ ~ ~ I ..~~-,J ~ ~...e...~ ~ L., . ' . . . . . .~'.A;~~..~~~...._ . . . . . r _ ~.h- _ >•~w~; v}~~~~Lx~~~ BOWSTRING METHOD PROJECT: Riverwalk 7th Addition LK: 1 \~N~l.51t PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addition DETENTION BASIN DESIGN BASIN: T BASIN: T 10-Year Deslgn Storm OESIGNER: B. Hovvard Tat. Area 0.81 Acres DATE: 5131196 ~\{t\K~\5i~tii5~`.ti{ 1 • Imp. Area 7292 SF :;;;t;,,~:tt~~x:k; Kt: :Y ;,;:>.2.,~:.,•.,,,.,,,~, Ci = .38 "•`~'Cy;:i;;,;;: t :•."x2.:,iii~i'v`., Time Increment (min) 5 u,.t,~t•.w•..L..~..~,v~y CASE 1 Time of Conc. (min) 8.30 gg~4t~m%,.?t',•• %~s OUtflOW (CfS) 1 K5K \ • 'h5L~5lN'.h4W ~ p ti ti~x•.iv.4x yV Design Year Flow 10 "}'^~'^~~♦V`~~."^~:~; J Il. Overfand Flow ti,'vniiitiKL~LNLkyitiv ~ Area (aaes) 0.81 Ct = 0.15 Imperviars Area (sq ft) 7292 ► p 5 SKXY.4 541 i. L~ ~7 ryV Il. iti ~.titi i~ti~`•. :~i.v 'V, Factor 0.38 }yw. v~Lx~ u•.t~v: v.x5~~~.4vn~x• 2.. n = 0.40 • ~ ~`~~v"~"~~:~•.';'208' Vdume Provided :t~,:;~~;.~c'.., ~.ii~}•.5u5~ S = 0.010 ,.~•.,~,.,~,"•.~^,i.,.~.•Afea' C 0,305 ' ♦ x5t~.5u4x ~ iitiiv. mx45x.• x5~v.ti:•. iivti~vn ti5xiC44vhiy t' •tx~x ;iii'vk.~ii'~it Tc = 5.13 min., by Equation 3-2 of Guidelines ;Zr- c~"":'• % Time Time Inc. Intens. Q Qeve1. Vol.ln Vol.Out Storage 270 `5}•~•5 .LV. \N~N.`.N~Y, ~p/~ ^lILn / /~[m- /~1' 1\prt. GY ImyN~ I (■~NII k;,~:~:,•::~~...2..\t., l ~ ~ ! ( ) 45Y.1 ti11:~1~~~1~:\ly min ~7GL IIYIII VIV VY VY VY ♦`'.1V1 '.NM1lL1•:AVl~~~~~~~~~ Z1= 50.0 For 72 8.30 498 2.47 0.75 502 498 4 x4xx.v Z2 = 3.5 Type B =1.0 n= 0,016 Rdled = 3.5 5 300 3.18 0.97 390 300 90 S= 0.008 10 600 2.24 0.68 526 600 -74 N•y.hY~ L 15 900 1.77 0.54 577 900 -323 ;~:':54:4N1titi4~•:4~ti l~ ~;?22:.•'.:t;t..;:,.•`.;' d= 0.141 ft. 20 1200 1.45 0.44 606 1200 -594 z;,";iii?h;?<i~~ :~:~«;:~x::;:.>.:• 25 1500 1.21 0.37 616 1500 -884 A R Q Tc Tc total I Qc 30 1800 1.04 0.32 625 1800 -1175 ::::':t;•.}ti,tyik;'.{~$:ks2. 35 2100 0.91 0.28 630 2100 '1470 0.53 0.07 0.75 3.17 8,30 2.47 0.75 SRZ,VL14ti tiLSti~~~N~ 40 2400 0,82 0,25 643 2400 -1757 45 2700 0,74 0,23 648 ?TOO -2052 tx•.u•.titi~~ Qpeak for Case 1= 0.75 cis ~~~•~'~~~~~~«~H~~~ 50 3000 0.68 0.21 657 3000 -2343 ~LV.vliltitiNlLNt1L 55 3300 0.64 0.20 677 3300 -2623 ~~;i:i~;:as•.v:•,?•.,.~t ..:.,•.:,.`..\4t,~2:::. 60 36W 0.61 0.19 701 3600 -2899 i<iii~C ~tik>iK:ii:'~~~• J71A! Q.W 0.18 7`IJ J.T A/ 171~ CASE 2 •1~aii ~/~i~i w<i~ ;:x 70 4200 0.58 0.18 773 4200 -3427 N„l +t~l~{\itilL~lY.lLl Case 2 assumes a Time of Concentration less than 5 minutes so tMat the ~ 75 4500 0.56 0.17 798 4500 -3702 peak flow =,90(3.18)(Imp. Area) = 0.48 cfs ;`,'"t` i~i• ~ 80 4800 0.53 0.16 803 4800 -3997 xx•. i 85 5100 0.52 0.16 836 5100 4264 ~v.:i:90 5400 0.50 0,15 849 5400 -4551 , ~.,....J i ~~xµ: 95 5700 0.49 0.15 877 5700 -4823 So, the Peak flow for the Basin is the 9reater of the two flows, 0.75 Cfs "`~ai?~~?•:n: 100 6000 0.48 0.15 903 6000 -5097 ti\41L441~5V~'ti'~.S~NtiN\' :t~~'•:;?: ~ ~ 208 DRAINAGE POND CALCULATIONS ReQuired'208' StoraSeVdume ~y~.y~~~4~~M15~141~1`t} = impervious Area x.5 in 12 iNft 304 cu ft M1 LM11W.tiV~LNY`'~.~N l~tll4+~`~l\`1`ty`L~ L~•..•,... y. • •~~iii~~i~.i~ti~~ti~x{~ i~i<'>:;,~>.?,,,,v.,,,•.,,, ti»ti~x~uwu ~ ,":.V'""„`•. 208' Storage Volume Provided cu ft ti}>.iit~4•:~~iii~\++xi~1 t5~u•u~~+~~~ i~~ti{'i4 ` ~ri`;?~a% `,.~~DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM ~~w~%~~~~~~~~<~~<~~s Maximum Storage Required by Bowstring 90 cu ft 5~~51~N 1N~•A ' L`l\'~1\'.4Y.t\~111N1,1} ,SLtti LLN~\~1111 \~t Number and Type of Drywells Required 0 Single 1 Dauble . . . N..4_ . . ~ . ~ ~ . _.:.~~..~:,~..~y y _ w_..~..y._~.. . . . , . B4WSTRING METHOD PROJECT: Rivervualk lth Addiaon PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addition OETENTION BASIN DESIGN BASIN: U BASIN: U 10-Year Design Storm DESIGNER: B. Haward 1NN.Ni Tot. Area 4.13 Aaes ~K'•~„;~ 5~ DATE: 5131196 ImP• Area 10363 SF i}ix}~}+~~i~~~w c = a.n \'MYA N~Al~ti~ Ly11411~1~~ Time Increment (min) 5 ~54N: 1~ :\NtXN•A541' CASE 1 ~"5{},L'Time of Conc. rmin\ 8.78 i \ / Outflow (cfs) 2 { h~•.ixxu x 125 ft. Overland Flow t; ; k Deslgn Year Flow 10 ii}i'x#~ i~~4~ ~ (a) 4. '+MtiKi\~ii~}«~i `w.Cii ~ ~ . Ct = 0.15 Imperviaus Area (sq ft) 10363 ti ...L1ttit? ~N115.?~,~: N~11• y~ L= 125 R ii~~%ii~~ ~~i V, Facta O.LL n = 0.40 %Z208' Voiume Provided S = 0.010 E;Area' C 0,893 M; 4 ..v.t Tc = 624 min., by Equation 3-2 of Guidelines ;,~;~♦?`t~y5~t~` ~x~\ ti14\.5"5Y•1\•.LY.1\44\Y ~kTlme Time Inc. IMens. Q Deve1. Vd.ln Vol.Out Staage K1'f".45 \\'.ti `f.45at5 280 ft. Gutter fiow % ; (min) (sec) C) (cfs) ( ) ( } ( } ;;inlhr cu ft cu ft cu ft '~~i, 1C2~vr>.`:t..t,'~•..Ky° ~ ~ ~ ,,,,•..~,.~y 21= 50.0 For Z2 8.78 527 2.40 2.14 1513 1053 460 7-2 = 3,5 Type B=1.0 ?i «~:~i:M1~{:}}::i~~'.{~i• n= 0.016 Rolled = 3.5 5 300 3.18 2.84 1142 600 542 ?:~;i:`:<>~:•:tv;.~'}~ ` S= 0.008 10 600 2.24 2.00 1558 1200 358 % 15 soo 1.n 1.5e 1706 1800 -sa d= 0.209 ft, M 20 1200 1.45 1.29 1786 2400 -614 g%'`~:r 25 1500 1.21 1.08 1814 3000 -1186 A R Q Tc Tctotal I Qc 30 1500 1.04 0.90 1838 3600 •1762 L5; 4V.1N}h1Nh~1N~K$ 35 2100 0.91 0.81 1852 4200 -2348 1.16 0.10 2,14 2.53 8.78 2.40 2.14~ii~;40 2400 0.82 0.73 1889 4800 -2911 45 2700 0.74 0.66 1903 5400 -3497 = r~:%:~::,>.::>.;,~•;;~ Qpeak fa Case t 2.14 cfs 50 3000 0.68 0.61 1930 6000 -4070 55 3300 0,64 0.57 1988 6600 -4612 y0 r iiivnK}l}+xtivm~ ~ O.b') O.~ LVW 7LyW V~~~ H1Y. ,:,,.♦.,1,. casE 2 ss 39oo 0.60 0.54 2186 7800 -5614 ti1\N{N•Al N Ly l~ 70 4200 0.58 0.52 2268 8400 $132 t; H}Ht~ Case 2 assumes a Time of ConceMration less than 5 minutes so that the 75 4500 0.56 0.50 2340 9000 -6660 peak flow =.90(3.18)(Imp. Area) = 0.68 cfs 80 4800 0.53 0.47 2357 9600 -7243 85 5100 0.52 0.46 2451 10200 -7749 t '~i' iu ui}~ 4. 90 5400 0.50 0.45 Z~~ 10800 -8309 So, the Peak flow for the Basin is the greater of tfie two flaws, '"•A`"' 96 5700 0.49 0.44 2573 11400 -8827 ~111Y11S5 k\i5i.~~ 2.14 cfs . M ~yy~ ~p ,~q cAn ~L ~W 6WV ~.`f0 Q.'IV 2P1J ~JJ~71 •t~ ti~~ti 5v.x ~G{~i{~i1itiM1V.S\ti4\~41X4 L'~ll{~~ 111,4Y N~51~\ \1 \(♦yN44 ~<~,~~~;~5.~~.yn~ 208' DRAINAGE POND CALCULATIONS ~}1\14':Sti:L \t}n+4~l511~ , Required'208' Storage Volume ~ Y. N~NH~Ix Impervious Area x.5 in 112 iNft 432 cu ft N14ttirii15i1♦ Y~~ ~m( {iy,tA}M1ti`N}±`\ 115N yi 4, A $ 208' Storage Vdume Provided cu ft DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM 45L4 l4~4}l,L 1% %1% MaAmum Storage Required by Bowstring 542 cu ft Z~~ i4\Kiay~ ~4 tii~v.iu ut ~ :,~~`•:...~t.,.,y x ti•n .tX4x~~ "z~~ Number and Type of Drywells Required 0 Single ~2ti•`.2~tS: ~ ~.i•`.}~ii2iiy }•.~xt~4«•4 2 Double ~U4:tti?::~~Sk>5++}ti } , d s. . . ~L~~ L'j . . , v.. H~..a . _ . . . . .1rif..-J~~r.~ . i4~ . . _ .r..I- , a ;h~ ..w~ w~.:er.l~w, ~ . .,.+.x.. _...oa , , ~...moe,iV~yr►....~ . . • M1N1Hti V.SV 1\~4 \ti BOWSTRINGMETH00 PROJECT: Riverwalk 7th on PEAK FLOW CALCULATION PROJECT: Rfvervvalk 7th Addition DETENTION BASIN DESIGN BASIN: V .'x~.~:a'•~i;;:t:t~ BASIN: V 14-Year Design Stortn DESIGNER; B. Howard Tot. Area 1.85 Acres DATE: 5/31196 Imp. Area 990/9 SF C ~ O.~/4 N}S t ~L 5N5\~l k K,~`' ` ~.~k % ~.~~Time Increment (min) 5 CASE 1 ~~.h~',4 ~Time of Conc. (min) 8.86 oYlI1Vw (Ci1J) ~ ''22t.v.~\;y...} 4~t.;,,ti4''•.5?tt..'•:t' 130 ft. Overland Flow ~`5V 1 L} 1Ny;; pESign Year Flow 10 Y.~~LH~\1C tirM~~ Area (acres) 1.85 'ti ?2222k't`~''};;.,~t Ct = 0.15 ~ Impervious Area (sq ft) 9909 \\5' ~l~liµ1Nx L= 130 ft. Factor 0.34 ;:t,zttt~ttts; ~ , ~'•;;>w:~~;,<a` $ n= 0.40 208' Volume Provided S = 0.010 Area C 0.633 14 SHt~l~1'.~V.nl4}, 1l ~'S•hlY.1\N'.1~NiM1~ Tc = 6.39 min., by EquaUon 3-2 of Guidelines Time Time Inc. IMens. Q Devel, Vol.in Vol.Out Storage L , : 250 ft. Gutter 8ow (min) (sec) (inmr) (cfs) (cu ft) {cu ft) (cu ft) x,,,.~~, „,,.•::.,..,,v.,,~ 8.86 532 2.39 1.51 1078 532 546 Z1= 50.0 ForZ2 Z2 = 3.5 Type B =1.0 1151Yti1ti~` x n= 0.016 Rdled = 3.5 5 300 3.18 2.01 809 300 509 S= 0.008 '~i~i•"~~'{ 10 600 2.24 1.42 1107 600 507 '~5\ti~Lll~ti~\LtLlL.tti V 15 soo 1.77 1.12 1211 soo 311 d = 0.183 rt. 20 1200 1.45 0.92 1267 1200 67 ii;}ii{S~}+1}Y • 25 1500 1.21 o.n 12e7 >soo •213 ~'~i ti+x4xu A R Q Tc Tc total I Qc 1~ 30 1800 1.04 0.66 1304 1800 -496 " 2100 0.91 0.58 1314 2100 -786 ~ ,,;~„•.,:.,.~,.«L~~;k , 0.90 0.09 1.51 2.47 8.86 2.39 1.51 40 2400 0.82 0.52 1340 2400 -1060 s: .,:.,t•.,~,.;, ~ }}~tx~x 45 2700 0.74 0.47 1349 2700 -1351 111N1ti L1' LN~ti1l~{ti\SltiYi•.1 Qpeak for Case 1= 1.51 cfs 50 3000 0.68 0.43 1369 3000 -1631 55 3300 0.64 0.41 1410 3300 -1890 •t \~~\'.~55~L~\ ::60 3600 0.61 0.39 1460 3600 -2140 CASE 2 65 3900 0.60 0.38 1550 3900 -2350 ...;,L.;.a~ ;.a?>.?;; 70 4200 0,58 0,37 1608 4200 -2592 4544M1\~•~:vy~,YY.Y1\+ Case 2 assumes a Time of Concentration less than 5 minutes so tthat the •::~>;iii,:~ii<„'it<:' 75 4500 0.56 0.35 1659 4500 -2841 peak flaw =.90(3.18)(Imp. Area) = 0.65 cfs 80 4800 0,53 0,34 1671 4800 -3129 . 4YM1N~'.• uv.ti•J.ti1Y. aJ 5100 0.52 0.33 1738 5100 -3362 90 5400 0.50 0.32 1766 5400 -3634 So, the Peak Oaw fa the Basin is the greater of the lwo flows, ;~~'~'`<`~:'`"":•~'<~ 95 5700 0.49 0.31 1824 5700 -3876 •\~',\4'M141 S:S~ii}}:.:.:v.h •A' ~tY`...•:::.;.•.,•.,\,t'.~S 1.51 cis ~•<:~<~~~:~~:::~~ 100 6000 0.48 0.30 1879 6000 -4122 vtSM11`1lL 1Yi\lti`N~`1 ~1L~1LL111Nti1titiNltiti\ \L5 V.LNll\tiN1N1111Y ti}}4 \}141ti4L5\l•\~N\ ~208' DRAINAGE POND CALCULATIONS t~.ti}:...tt Required'208' Staage Volume • : : : . : ~ . . : ~ : 1V:1\11••Nh\ ~..'~.:.'.:::."..~:•.`•.,Y; = Impervious Area x.5 in / 12 iNft 413 cu ft \ 41V K 2a8" Storage Volume Provided cu ft }t.5 ~x•~w~~1t ~XS~ti ~~:4µ\ti5k it•. ~~iti5~4~ ~t ''<i~~~•: xtivmti~ {~..::~••:r~~ DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM t` ±'iii:M1~iX~ ~i~ui • Ma)dmum Storage Required by Bawstring 546 cu ft N\ ~ \5,\511~»+1111110,111 Number and Type oi Dtywaells Requlred 0 Single 1 Double ~ PROJECT: ~:x;; 'BOWSTRING METHOD , Riverwalk 7th Add~ion ti~y rLy PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addftfon DETENTION BASIN DESIGN BASIN: W k~'1F:um BASIN: W x'~ 1QYear Design Stonn DESIGNER: B. Haward Tot. Area 0.36 Acres DATE: 5131 f96 . ~-x3~;w 4 Imp. Area 2829 SF M~ HY~AlIl~ C _ O.YA1 NV\N `M1 ~tixtii~yx+~ LS;;vn t}1t `NtiNH~N5N5 ri` ~Time Irtcrement (min) 5 Nl'4ti\LtilltS:~.~KSK54 \1 hV.•.l1}NSN ;„x•~~~~z~ii, CASE 1 ii ~ Time af Conc. (min) 1.27 iiirii;y» `oYIIMY (bls) 0.3 140 ft. Overland Flow Design Year Flow 10 ` ti LN. t LLL444L N'.{t4NKtilt~ ~k Area (acres) 0.36 ~ ~SKKl\N~NKti1VS G= 0,15 Impen~ous Area (sq ft) 2829 L NK5♦~:5K~ L= 140 ft. ;C1 Factor 0,41 S~xL Z.t;.~:t 5 l tl *%h5'. 1 1 n= . X;v. 208 Vdume Provided % S ~ 0.010 Area' C 0.148 ~.141tiY111\M11~; ~ L \ ♦ \\1~1Xtiti ~tilNlti ~tiltti ~4 Tc = 6.68 min., by Equation 3-2 of Guidelirtes Time Time Inc. IMens. Q DeveL ; Vol.ln Vo1.0ut Stora9e t,..;" t ~ ~w\~tiKxx 130 ft. Gutter flow min, (sec infir cfs cu ft cu ft cu ft N1 YM1µti N%yj4; 4 ~ ~ ~ , = = x lhy~;yy5 l L'f.5~ Z1= 50.0 Fot Z2 ;~~;~<x~• 1.27 436 2.64 0.39 228 131 97 ~Lytiti1~t~ti}`5}«lxky«ti$ Z2 = 3.5 Type B =1.0 ~,..,."~,,,~.x,• n= 0.016 Rolled = 3,5 5 300 3.18 0.47 189 90 99 S= 0.159 10 600 224 0.33 248 180 68 ♦NN•.Nt•ti µ 15 900 1.77 0,26 275 270 5 tiy11{ y \ ~~,y; d= 0,063 ft. 1~-y;,,,<<:~ `k 20 1200 1.45 0,21 289 360 -71 25 1500 1.21 0.18 295 450 -155 v. v...~".;;<:>„?.• A R Q Tc Tctotal I Qc 30 1800 1•04 0,15 300 540 -240 - ~'~;;~Y~ 35 2100 0.91 0.13 303 634 -327 0.11 ------0.03 ------0.39 ------0.59 ------7.27 ------2.64 ------0.39 40 2400 0.82 0.12 309 720 -411 ~'L:`;~•~;;` t 45 2700 0.74 0.11 312 810 -498 ; •ti,a~,~t~,?,~?~,ii?; Qpeak f~ Case 1= 0.39 cfs n ~50 3000 0,68 0.10 317 900 -M 55 3300 0.64 0.09 327 990 -M iy:•.Y.SL'.\41N411n ;.t;;i;:;i;;~•'~ . 60 3600 0.61 0.09 338 1080 '742 CASE 2 e5 3900 0.60 0.09 sss 1170 -a» .,`;.a. 1 % {x~1 Ay0/~ I~/~ 'V0 p~ ~a YLW 0.58 0.09 q J~ 1GW 7 Case 2 assumes a Time of ConceMration less than 5 minutes so that the 75 4500 0.56 0.08 385 1350 -965 ~itiii~5}\~}~X\1h11V~ peak 8ow =.90(3.18)(Imp. Area) = 0.19 cis 80 4800 0.53 0.08 389 1440 •1052 LN ~.~{1•.N\ \Nti~~ ti5•M5 At' 7•`:;y;;. BJ 5100 0.52 0.~ ~ 1~ '11~ 90 5400 0.50 0.07 411 1620 -1209 }i,i~'vt.wwCtiy} v+i 4 xiiLL~5xLLk \y\M~1 h45\K So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0.01 424 1710 -1286 iM%iti~'<4titi4?ii>.~ 0.39 cfs ix~'?;~;x 100 6000 0.48 0.07 437 1800 -1363 • ~5~px~ ~l ''.#:;.22•..~ tiy.~• 208" DRAINAGE POND CALCULATIONS 1K41VYlf.\tiN W;;;~;~'•~;?>~~'>:~: Required'208' Staage Volume :'~'~~N,`~n'~"~" = Impervious Area x.5 in 112 iNft 118 cu ft 4ti\4NL11'.`1l~y,h 4~ 4N 5•A5V.N4 \ ~l ,,l~LXMl 5~1M1 V`1NNx 208' Storage Volume Provided cu ft ;;x'~~~ ~i''•k<~i.~~tiuxl DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM Ma~dmum Stora9e Re9uired bY Bowstnn9 99 cu ft a ~ \~~{t2iiC~i«•',:t ~•;r~;;;~;;;~;;~:~; Number and Type of Drywells Required 1 Single 0 Double ~ L"" L--j ~ xxtiuati~x4w~~titi~44~ }14~L~•.4`~~~151Lt X`v`•~ BOWSTRING METHOD PROJECT: Rivenrralk 7th Addition Z54~ti 4ti4Lh~}L`N~N;l PEAK FLOW CALCULATION PROJECT: Riverwalk lth Addition DETENTION BASIN DESIGN BASIN: X ,x :::.;`>.i;;r~?f•X;x$~ BASIN: X laYearDesi nStonn DESIGNER: B. Howard Tot. Area 0.12 Acres 9 z~;;4•':..i.<i,;.,:>.x: DATE: 5131/96 Imp• Area 1609 SF ,•:.,,..z.,""" C ~ O.JV 2{~:}22~}`n•`.i"t'~Z Y`"'~ Time IncremeM (min) 5 P.~•nxx ti CASE 1 Tme oi Conc, (min) 5.42 ii:.• :.,at;; Outflow (cfs) 0.3 60 ft. Overhand Flow Desi9n Year Flow 10 , , Area (acres) 0.12 Kl~\LL1Yy• ` ~~\\•i4'A~4 1~ 5 Ct = 0.15 Impervious Area (sq ft) 1609 ~.15....•.....'.i. ....•.t... ~ ' L = ~\\5K1\`1iN{t1Ll~x~ C Factor 0.50 .•..,•.k.,at`?< .SLLlLNt~4\•:ht'f.l•f. n = 0.40 '208' Volume Provided µ SHLL\l~ 4 X Xti ~tiV ~1~:ti\\l S= 0.010 Area' C 0.060 • `C ""`ti;:;;,;Nt2::: % tiL 4 h14N1'~~~N,N\ 1Ll iL\tilN\\l `y~~t:;:t~::,~`:.; Tc = 4.02 min,, by Equabon ~2 of Guldelines ;Kr,, Time Time Inc. IMens. Q Devel. Vol,ln Vol.Out Storage 90 ft. Swale tlow (min) (sec) (inmr) (cfs) (cu ft) (cu ft) (cu rt) ,.x ;~~,;~;;~;ii:;;::;:<i~--------- - - Z1 = 3A For Z2 z` ";.-ti~x 5.42 325 3.07 0.18 80 98 =17 Z2 = 3 Type B=1.0 n= 0.030 Rolled = 3.5 5 300 3.19 0.19 77 90 -13 ,~,v. S= 0.009 Swale=3.0 10 600 2.24 0.13 95 180 -85 /y~/~ ~ J MJ 1.!7! 0.11 107 ~O '1W ~Y~~21y2.k:2ki>yi+~~`1 d= 0.235 ft. ,••r;;~,rr,;:•;.~;;,~x 20 1200 1.45 0.09 114 360 -246 25 1500 1.21 0.07 117 450 -333 ,L;.t~;.•. ~~~~1 A R Q Tc Tc total I Qc 30 1800 1•04 0.06 119 540 -421 '„2~•,, w5ii5w5~\'i•.~i~.54ti~,• JJ W q~ Z1/y► 0.91 V.W 1L r~1 630 'J ~UJ S~LnL~~~x♦ \t;4}54` .tily~~4~tiill• 0.17 0.11 0.18 1.40 5.42 3.07 0.18~xL}µ 40 2400 0.82 0.05 124 720 -596 45 2700 0.74 0.04 125 810 -685 ,ti~~.~•:5iy»5, Qpeak for Case t= 0.18 cfs 50 3~00/0~ 0,6/~8~ 0.0/~T 4~ 12A7 9/y0~W 0/~ -773 ll~l:f i1~1y54~ri O.rf O.V 1V1 V 1/W ~ WVV 60 3600 0.61 0,04 136 1080 -944 CASE 2 I1~'l lI k 1554ti14515t~k11\}'uti~ ~ V W/y~/~./~1 V O.V~/~yV/~~ 0.V 144 1170 I7O -1~/~~//~/~~ 1 VLV ~~11}~k1Nti4\1\`~ 1`~~k ~%zTO 4200 0,58 0.03 150 1260 -1110 Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0.03 155 1350 -1195 peak 8ow =.90(3.18)(Imp. Area) = 0.11 cfs icr,~>„~„k60 4800 0.53 0.03 156 1440 -1284 ~:~;85 5100 0.52 0,03 163 1530 -1367 90 5400 0.50 0,03 165 1620 -1455 ~;::`•..::`.?`•.;:<;.c:..~ So, the Peak flow for the Basin is the 9reater of the lwo flows, 95 5700 0.49 0.03 171 1710 -1539 0.18 cis 100 6000 0,48 0.03 176 1800 -1624 1, ~ L.: . \N~~lt~5{~~ll\:~111\41` \5~ ~%5l \~V L\\5\~5X~45\W 1\ 5~\1\.~5445\~`~ll~llti41 : ~~~\{1iM1 ~ DRAINAGE POND CALCULATI ONS ~l 1~\ l'41\ti\\4 5 ;.i;~ ,~:•.,a~,. Required'2a9' Storage Vdume 111N1K5\ Impervious Area x.5 in f 12 lNn 67 cu ft r}5}1x~ ` y~~u~u~titik ~ x~~ ;?x5;~; 208' Staage Volume Provided cu ft ~1~ DRYWELLREQUIREMENTS-1QYEARDESIGNSTORM ~Ma)dmum Storage Required by Bowstring -13 cu ft `.NLl LNtM1llS\L5N4+\,ti` ~ k~~ l\11x1N~1ti~~~145x tl LN44L1X~nt\ l~ «~iy~xx t 'u' Number and Type of Drywelis Required 1 Sirigle 0 Double .r . . - r~j L.,-.j L .,..r,<..a.w..._,..,-...n•.,.,~..,...~_.... - .r., - .....X- .1.."~,.A1'ii.-a........,.., BOWSTRINGMETHOD PROJECT: Rivervvalk7thAddition ~µ{N~~LNilS'''St PEAK FLOW CALCULATION PROJECT: Rivenaralk 7th Addidon DETENTION BASIN DESIGN BASIN: Y1 a~„ ~~,..;~ti~~• ~,~•.,•.,.:•..,,.~x.~.a . , BASIN. Y1 <~~:~'<~~`~,•~> 10-Year Design Storm OESIGNER: B. Howard l 1NlNN5t1~5X~ y 5\ ~yA tG•u~.~ • xtiw v.xn~ TVI . /1~. 0.55 Acres 4 ~k~~~`~} n`}~ DATE: 6/3l96 Imp. Area 14592 SF C = 0.58 ~ ~ . ~ Time Inaenwnt (min) 5 V ti'~i{ \xNN x~ Time of Conc. I11in) 5./~/~ CASE 1 V:: tl4'\y\\1♦ Y.5\~ll~tM1\NN`\ L~L L~N~Y•VL'.11+N ` ~A s ti\L,'.'\M1tiY11.1 V O w..,z•Kt~;,,..;r,•;? W 1\. OvGriarvd FIHtI Design Year Flaw 10 ~p~ ~p~ Ll \4K~~llL~tit ~IGa(~IW) 0.55 ct = a~s Impervious Area (sq ft) 14592 ...:k~:;•A; L•.:a"...•.,~,.~ L= 30 ft. 'C Factor 0.58 ~ y~5' ~4~\1titi \til~ n= 0,02 Z?~~,~};~~v:, x~:~?"~'208' Volume Provided S = 0.020 Area ~ Ci 0.319 Tc = 0.31 min., by Equation 3-2 of Guideiines '~~.`'1~~}~r~♦` ~4'~`'~~~ Time Time Inc. Irtens. Q Devel. Vo1.ln Vol.Out Storage '.\`SYLKN~45L1\titi ti~ ~ .,.~~..tti,~ti;~•:.:.,.. ~ 87 R. Gutter @aw (min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu R) `:~:"♦t~:~;::;::t,: y:~ _ 55 •1L•.V.SY.{.ltY:~lt~` \5':~lLl~l'.\\N:itih.il'.~M'1(--------- Z1 = 50.0 For Z2 .,,::.µ`~..,~•.;.1.....~..,~ :..:.:.•.~,,,xxv;:5.00 300 3.18 1.01 408 0 408 Z2 = 1 Type B =1.0 n= 0.016 Rolled = 3.5 5 300 3.18 1.01 408 0 408 S= 0.008 ~~;~~'~^`~?w 10 600 2.24 0.71 502 0 502 15 900 1.77 0.56 566 0 566 ~,x„~.ti; L~.~>..:: ;•;;x , d= 0.161 ft. 20 1204 1.45 0.46 602 0 602 .~.,,,v.,..•.,;.,,~ 25 1500 1.21 0.39 618 0 618 • vn~ t ~~'~5{L A R Q Tc Tc total I Qc 30 1800 1.04 0.33 631 0 631 ~4 ~iv.xx~ yy>>xxL~ti xx ,#..2.,.~•.,....~:...•.. 35 2100 0.91 0.29 639 0 639 C77~CL~~~ C~~~~C7C~ ~~II~O~~~~ ~~~~C~~~~ C~~~ C~~~~~C~~ °~~BO~C7 }~ti~~~•.~;v..,Mi}Lj`i~~ ~ .tix.. 0.66 0.08 1.01 0.94 5.00 3 .0:26 ;18 1.01 40 2400 0.82 654 0 65:4 n::~;??~;;~~;~•;:,•<.:,, -40 sr ~ ?~'~,y~''~; . , • ' ~ 3;, ~ . ~ 2,7 ~ ~ 65~~• pl , . ~ 661 . . ~ry~y~► ~p ry~ Ir.~} ~w~j . Qpeak for Case 1~ ~.O~ Cils JV J1l1N O.LL' 61 J 0 V I J v. ~k~"~~ti•.~~k;~ki\ ~y/~~~ 55 /(y~~~~~~ O.VT ~/~p~ O.//~rY ~/yy~~ WV ~ O V /~W y}♦y~{y1~Y.4~N4}ltiL}Ll~' WVV 1F~~\'.15Y.\it~Li':5\ t~•. 5 A'",.:..•.".,..N,~„60 3600 0.61 0.19 720 0 720 CASE 2 ~.:.,,,,:••i~: , 65 3900 0,60 0.19 766 0 766 ' 4iY.lt~LNtil41h\\\ ltilh\Lt{lititi~•:ti{111L 70 4200 0.58 0,19 796 0 796 Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0.18 822 0 822 K+xxv.xti peak flow =.90(3.18)(Imp. Area) = 0.96 cfs 80 4800 0.53 0.17 829 0 829 ~::;;:;;;?;::y~~'•'~~;~ ~~•::,;,,::;<••;~~:a;;` 85 5100 0.52 0.17 863 0 863 zZ;;;%%';;;;;;; ~;t;~~r'c~~ 90 5400 0.50 0.16 878 0 878 tYtii~~•i\1N\~N:4N So, the Peak flow for the Basin is the greater of the two flaws, a:.; ~~••~•~95 5700 0.49 0.16 907 0 907 1.01 cfs 100 6000 0,48 0.15 934 0 904 ~uti t ~•'.~`5µ`~'•~k+~~~ ~~Y2L ~"5~L5• y\N 1\\\~ \H\~i~~14~K1Nh "5N5`N\LN5 ~Y51Lyy1 ~~tiSU1tiL1~i,ti,•, ~•L~`~ DRAINAGE POND CALCULATIONS y;.+~'~y•i0.~`i' i^Ciit •y•, . Required'208' Storage Volume 511111HN}5 1~1N4 .i2}:,• ,mn ~~v "•"~'~;~~'~~4~ = Impervious Area x.5 in 112 iNft 608 cu ft ~KLNLNLN~1•.\1N 1\SlhY. i iiiiivnw.~~~ \h•.1'.~1tL 208' Storage Volume Provided cu ft LG`l1\\LµL14l 1ti15\`4 1 Nxl4xt\l~ti\NiKS`ti~• DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM Maximum Storage Required by Bowstring 863 cu ft } Number and Type of Orywells Required 0 Single }z ; %ERR Daible ~ _ . . ~ I 1 ~ LJ L"~~ L" tt , BOWSTRING METHOD PROJECT: Riverwalk lth Addition .:,.~„k ~wi i~ PEAK FLOW CALCULATION PROJECT: Rivemlk 7th Addftlan DETENTION BASIN DESIGN BASIN: Y2 :;:.;..,:;r,;;.L4y.u1m~~51x• ~ BASIN: Y2 L4tikN~M1Y{4~\51 10-Year Design Storm DESIGNE Howard NVA\} M{ll L\L'~l'.1X~}:,< DATE: ~/31196 Tat. Area 0.72 Acres r;~;,..,• Imp. Area 19236 SF ~~~5N5y'•54• H'.N11X~Z1~ 55L~5~~5t1~~5\Ltl ~~~~\1tN.4YLiYY tiS~NV~\~tiKtii`•1ti11' C = 0.59 ,~~;,:;•..~•.«.~,.~,r,~ xx.+,:µ;y;~~,.,i~::,~•, t~M\`N11tiLK5 ~ ~y5k •;~,~v. ;~Time Incremert (min) 5 ti ti ti~ vntxn5 ' ~x 1 ~ti * CASE 1 u'~ 1114ri NL i 1 Tlme of Conc. (min) 5.00 yl N1 }tti~itik µ}iii~i%NM~Outflow (Vft) O ~H51~4 ti1i4},.;>z~ 30 ft, Overland Flow Des a.i9n Year Flow 10 H,•.,,.;:: ,•.,,a Area (acres) 0.72 ,:;2H2;;?tY;tctt~. y~~ Vl ~ Q.1[ J Impervious Area (sq R) 1(~~7LJV NN4\4 514. 5x{•:::::. 1 1 l= 30 ft. % C Factor 0.59 t%%: 1 4l .4~L5Y.'h`k n = 0.02 ~'208' Volume Provided m } ltSY S~ 0.020 Ar~ ~ V 0.425 ~ ~;;'t~: ~,`~`~~~t`2~•`~~ 515N y55ti.15~\~ Tc = 0.31 min., by Equetion 3-2 of Guidelines ;;;~~„?k ~ x~~:' Time Time Inc. Intens. Q Devel, Vol.ln Vol.Out Storage ~411L1 'f.5~N5N\, 114 ft. Gutter flow (min) (sec) (infir) (cfs) (cu ft) (cu ft) (cu ft) t;:•.,, ,L` 4i•.~ii~~m::•.« 5 L'n ~x xv.~x•. 4 ~+t~ Z1= 50.0 For Z2 5.00 300 3.18 1.35 543 0 543 Z2 = 1 Type B =1.0 n= 0.016 Rolled = 3.5 5 300 3.18 1.35 543 0 543 S= 0,008 10 600 224 0.95 668 0 668 `y,;~Hw,:,;2An~ 15 soo 1.77 0.75 753 o 753 5'h YMN d= 0.179 ft, 20 1200 1.45 0.62 802 0 802 i u {{~xLxLxl«ti 5 ti;uLxx•.iw.v.4 25 1500 1.21 0.51 823 0 823 v., v A R Q Tc Tc total I Qc 3///~~~0 /1800 1.04 0.44 840 0 840 % ~ ~ ~ 1•.114NV~5ti'.n ~ L1 VV 0.91 OrW ~1 O ~1 +~ti1 ti~v'•.}}}~;. 0.82 0.09 1.35 1.15 5.00 3.18 1.35 40 2400 0.82 0.35 872 0 872 45 2700 0.74 0.31 881 0 881 Qpeak ior Case 1= 1.35 cfs 50 3000 0,68 0.29 896 0 896 55 3300 0.64 0.27 925 0 925 ,:;;;,,,:r::,;~; 60 3600 0.61 0.26 959 0 959 ..t~;,;♦.,:.,,~x 511VKltil\'.51NL~~ CASE 2 .•r.~: 65 3900 0.60 0.25 1020 0 1020 i%:i+.~}1y'ri%}ti7~ii ~t~2 70 4200 0.58 0,25 1060 0 1060 ViLl`\ti4\V.4{y5~~14\ Case 2 assumes a Time of ConceMration less than 5 minutes so that the 75 4500 0.56 0.24 1095 0 1095 peak flow =.90(3.18)(imp, Area) = 1.26 cFs 80 4800 0.53 0.23 1104 0 1104 N\1l~NN•.tiV.S ~ ~•~<.:~`;:`~~:~:a~;~ 85 5100 0.52 0.71 1149 0 1149 90 5400 0.50 0.21 1169 0 1169 So, the Peak flow br the Basin is the greater of the two flows, Y~`~"~`~'•. 95 5700 0.49 0.21 1208 0 1208 1.35 CfS 100 6000 0.48 0.20 1244 0 1244 \1:4 {~N41\'1\54 4~ V~ N':.~\1N1X.1NX1~ ii'ti~ttiii}~iiiti~~~~ti• ..#:2i•'.xtt,~xsi}}, L, 208' ORAINAGE POND CALCULATIONS ~,.fihx~t~r•~,~:: ~1~, } 1V.5. ttt ~4 v, ~ ux ~ ~>::V^>~~}••.~. ~ Required'208 Storage Volume , ,.~:t:.;.i. „N ti:•~Xl5•!5\ t % 4 = Impervious Area x.5 in ! 12 iNft 802 cu ft ♦tVl.StiV.\Yf•4Y.\l}lti~ ♦•.1N Xy1 lY •11'• 'M1~ w \~y iXKS n~ t1Y \NNNN Av. 5~ t ~ ~yN}N~ti \51~~ 5 W.L54L511t 208' Storage Volume Provided cu ft Vi55ti5i:X~\~NL{iyly\L• R5,~115\ !\~1ltiX~ 5l\\~l~Ntt}ll~l DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM ~;r♦~:??;?:~ti;~ Maximum Storage Required by Bouvstring 1149 cu ft •.tir!`25' ;~~\tiikL~xH x x1k} ~i{~~ l~i~i~ xL~}~yt<< • ~`~~~5,~::~.}.~~x♦~ Number and Type of Drywells Requlred 0 Single +~11\5'\1{~'J~itLL~LlI` ~~~.~~xiii~:•.~~:•.x.,} Y ERR Doubfe ~k161\:•~}ti})yVtiyw . . :.•kii.rtllL.~'~Of~/w.~hl,4-.rln~-~.:YJ.~+YJ1~1l~5 ~ r~4... _ . ......._u.ah..W~all1d11.`"_s~\~t•ilYLO~E'~c\.r.n.e....:A:l.r in'.Y.tW.. ~w n . Hl1 ~~~y £'ti~~l.24_ap~~ , t , . _ " . . _ rM.i~•'wK..i.• _IX. r~1YIl.'Y{Y ">i1':Ll.u~ . _ tW_.~nS'A~l~Nt~N\ 41' BOWSTRING METHOD PROJECT: Rlverwalk 7th Addition PEAK FLOW CALCULATION PROJECT: Rivervvalk 7th Addibon ;DETENTION BASIN OESIGN BASIN; Y3 BASIN: Y3 ` 10-Year Design Storm DESIGNER: B. HawaM Tot. Area 021 Acres t,,~}~~~~`~ x: `1xx~nL~ }n DATE: G13196 Imp. Area 5341 SF ~♦1'•~`StiLNti'tA15tiNNNN~ IIYAV'.1~5{'1\1•A151~ 5x~~mi• W N5 ~ ~.ti ~vntxtr.rktix+~. K♦\L\5.\Ny •~i.tl5N5`~ C - 0•56 `•5~~51Y.5115\4 \LLt1l Y~LtiLN1lt'{Y.54~5415Lt %Time Incremert (min) 5 e;X CASE 1 %%aTime of Conc. (min) 5.00 ~i14l5'.Y5 KS~ yy}~l\`51ti5 1~1}`155~ Outfloow (cfs) O ` } l1XN NlN1 41L51:}\M14 .1111 x ~\~t}~tN4:14V.1M14iN41 30 ft. Overiand Flow Design Year Flow 10 r`~~~'•' Ar~ (acres) 0.21 4N1\♦•{5 " \'.N♦y t1Ll~L N 5 5\ Ct = 0.15 Impervious Area (sq ft) 5341 V.lN ~L 51N1}\l L= 30 ft. 'C' Factot 0.56 n = 0.02 '208' Volume Pravided ~Lti4~1\`SlN~:SHlH +p S 0.010 f Q.+Iv ~ ~i~•`.~{i~2~~~ti.iiLi~i~~f 'S~~ V 1 k.2222,2ii.`i't•`.t.ii'., .tiv.LxxuLV.4~x4 x.•.x1x. Tc = 0.38 min., by Equation 3-2 oi Guidelines Time Time Inc. IMens. Q Devel. Vol.ln Vol.Out Storage 58 .1••4• ;u,;:~~::;>.>.;.•x~;;} . utter ow (min) (sec ) (iNhr) (cfs) (cu ft) (cu ft) (cu ft) 45ti~~1.•.1•.l }~.M1,S~N~~~~ ~ ~ ~ ~~~~~~~r~ \11`~+~ 1 M~~\t ZI " 50.0 f a Z2 5.00 300 3.18 0.37 150 0 150 % ~ % Z2 = 1 Type B=1,0 . A1~1N} N L 4y:,,•:'N~~ 4N~ n= 0,016 Rdled = 3.5 5 304 3.18 0.37 150 0 150 k :..;;.,..t,?,..•, 0,008 t• ~~~`#~^.t2:'t`'t't`~~ 10 600 224 0.26 185 0 185 ~ '~~•':,:;..,~;,?,ti,~ 5 soo 1.77 0.21 zos o 209 : M?::: d= o.~ ~a rt. :~:<x~,<;::..:.„w~♦~.~ 20 1200 1.45 0.17 ~ o m AY'.H\1Y.\N`\ 11~1~ i~nt'2:2~~ ~J 1~ 1.21 0.14 ~ Q ~8 ;~t,,~- ,2`C}~k`:v A R Q Tc Tc total I Qc ~;"-;:;t>.~,~:• 30 1l800 1.04 0.12 233 0 233 ~v?::. ;x 35 2100 0.81 0.11 236 0 236 0.31 0.0.5 0,37 0.81 , 5.00 3.18 0..3,7„?L;-%Z'<:40 2400 0,82 0,10 241 0 241 '7 ~ ~A~ r-J~,+•~'j~~ Nr. ~~+j '4~.~rA~;~~'~+S`'w~1a11'••~"~IfP, .~titiiyr,t,~A{rrri, K.a.^"e'~% o.f4 .1/~lJ 2 ~A '1ti1\'!.1'.4 t1~Vf: Qpeak for Case 1= 0.37 cfs . „ ~;;2i;~50 3000 0.68 0.08 24~ 8 0 248 +'iti+ •`.i' }'aCii}~yi>.iii' 55 3300 0•64 O~~ ~ 0 256 60 3600 0.61 0,07 266 0 266 ?~•:.ii..:,,:,? ;•':;.~:A CASE 2 lt`\\5ii4\L4NN'.41L4~ 65 3900 O•6/~~ W 0.0I7 LV ~ O y rVL L}t\}1N11 } iyuiji4•:5~~.1:5~~ 70 4LV1J 0.58 0.07 293 O 293 v>.tiii~~i•?:~(}~~::>;}}~} .~•n}•n}:~};+x~~~ liitti{•titi~iti~~{ti5111L 4 N•AN•.+1)WNNt\ Case 2 assumes a Time of Concentration less than 5 minutes so that the ,:r;~~,:,,;::,~,•. 75 4500 0.56 0.07 303 0 303 v.`;.}}t»~~+ux~i+5x peak flow =.90(3.18)(Imp. Area) = 0.35 cfs ~ 80 4800 0.53 0.06 306 0 306 ~'~•::.~~.:.~,~~,•.~~^y~µ k 85 5100 0.52 0.06 318 0 318 1Vl\~1~~45Y.tN•:5Lk5`\ ,1\54iii:ill:5~{L115i` 90 5T/V p,~/~■/~, O.' /1~/~ 324 O 324 .NlL1NN\5L45N1~~ W/~1 O.W \\L~V. 5` ~5•.` 51' \•11L4~ N•. tiN\\11\4~tiYh5 1 So, the Peak flow for tlhe Basin is the greater of the two flows, 95 5700 0.49 0.06 334 0 334 ~N~44\1\M14NN 11 5N\\Nn4\\5~ N N1N11 0.37 CfS 106DOO 0.48 O./~:v ~ O ~ u xv.t x~~5ti~~ 222`.. L.Yt.~.~,v.,,ti,.•. ; r,~,..,,.~.~;.~ 208' DRAINAGE POND CALCULATIONS 1iNti~N\N1•M1NS~~~Yft . Required'208' Storage Vdume {`~{:.f:11~~1:514N}~L} Impervious Area x.5 in 112 iNft 223 cu ft ~•;;,,xx;~ V` N' \\1~11Nt}1y~1 Y ~5ti1L1N1hlltti t ltitilL~tlt}11~ 208' Storage Volume Provided cu ft ~111y~14~LY.4ti`~1i~i\1 M14~+,`~~.~,~~ DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM \llL`5'..4K11\N~.' Y\1\L: ;:;,;:i;i, MaAmum Storage Required by Bowstring 318 cu ft ~ k~M1'~~~~L3v.1x5>ti~lµ, ~11•nti+vN{i+Ktiiiii~'{~. Number and Type of Drywells Required 0 Single ~ ~7VChU4~ h ERR Double ~~J „J, L-,.J 9LD L--,J L , J ~ D a f ; ~ FIGURES F 2 ~ ~ Uf~ A d 4a~ Inland Pacific Engineering Comparry . Riverwalk 7th Addition Plat Drainage Report ~ ~ . ~ ~ , . a E ~ 15 LF. OF 2 CIASS B ASPHALT CONCRETE ON-- ~ ~ ON 4' CRUSHED SURFACING TOP COURSE ~ ~ SEE OETAIL BELOW ~ . ~~___~_...._.-L'--------_.-~-------------------•----=--- p~ ~ r r ~ ~ . ~ ` ~ f . . ; ~r~ ~..ui " ' • , ~ ~ ~ ~ ~ ~CONCRETE INLET TYPE 1 J ~ ~ SPOKANE C0. STD. B-5 :T TYPE 1 PER STD. B-5 } STA.25+87.96 LT. ~ ~ T . A ON - LM RIVE R LAN GRATE ELEV.-2029.75 CONCREfE INLET TYPE 1 PER SPOKANE CO !V U 1Y STANDARD » ~ SPOKANE C0. STD. B-5 " ~ ~ 40 LF. OF 12 DW. CPE TYPE B" DRnNELL W~TH . T 4+73 21.5' T. . S=0.0063 S A, 2 , L TYPE 4 METAL FRAME & GRATE ~ _ ~ IE W)=2027.62 ;,L..QlA. CPF GRATE ELEV.-2030.54 STA. 25+50 25 RT. IE E =2027.37 GRATE ELEV.=2027.87 ~ ~ / ' . ' / 115 LF. OF 12" DIA. CMP ~ ~ 00 / - - . / S-0.0063 ~ _ -L- IDTH NCRETE . CURB INLET TYPE 1 ~2028,44 ~ _ IE S r ~ • . . _ ~ i ~ fOM ~ IE N-2020.72 PROVIDE 4 WIDTH CONCI , I • / APRON FROM CURB INLE _ . ~___J / ~ - ~ ~ TO POND BOTTOM . . . ~ ~ ' . , . . ~ ~ ~ ~ ~ , : . l . . ~ . ~ , . ~ • , . . . ~ ' ; . ~ " ~ . ~ . . . . ~ . , . , . • • . • ~ , ~ . . ~ . ~ ~ ..~..d ' . . ' . , ~ . ' ~6 ' . ~ . . . . • lO~D . . . . ~ . . . . . . . . . ~ . ~ ~ ~ _ ~ . » > . ~ , . , ~ . ~ ~ . ~ ti~ , , . ~ , ~ ~ ~ . ' • ~ • » ~ . ~ ~ ~ POND . ~ Tf M = ~ ~ =24 . BO .Q ELEV 2027.37 - ~ . , . , ~ . . POND ~Bt~TTOM AREA = 1800 SF . ; ~ ~ ~ ' ~ ~ ~ PERIM • _ ~ . ETGR . . 17.2 LF ~ ~ ~ ' TOP OF BERM 2030.45 . ~ . , 1, _ . . . _ _ VOL. RE~UIREO 895 CF . , ~ ~ ~ ' . ~ ~ YOL. PROYIDED = 900 F ~ ~ . , , C. , l ' i ~ , ~ . 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L~4•..~•' e~ ..n~, , ,~~U~i' ,I•±~.~1~r , • ~,;;u~~~~( ~iqfj, q ,i•- d :Z ~ ` ~ . ~ ;~f~ . - ~ ~ z~_i~.. ~ ' ~ ~ ` f7 C ~ j ~ ~ 1 ~ '!I r L ~ ~Y` " ~ ~ '~y~ r ~ ~ V' V , _ - . _ ~i t• ~ 1 ~ `4~~~~ N~r~ _ ~ C.~~I Ai'7~{I~~ ~ i:r M ~ ~ r~ t~ _ - jTti'f ~~l'--~ ( '~;4 ,I ~~}7i' 1' at~ .s n tL .,..y- ~'y ' w~~ , r - _ _ _ _ _ ~'r . ~ ~ ~~j~:~" _ ~ . - - _-,--~-`~~~~4.~..-~,; Q` ~ jp ~ " - - 4% ~ M Ia ~ {~OIf15 ;~iPt'I 761 _ - - - - - . ~,C,111~ 1 c~~.~ ~VU i ~ ~l~(I~) Fr~i. -1 I 1 1 Table No. 2- Pond and 208 Basin Summary ; A A 203 406 426 1B B B 203 406 426 1B _I ; C C 177 354 375 1B D D 209 418 426 1B _t a E E 87 174 180 1B F F 271 542 798 1B G G 87 174 180 1 B ~ H H 290 580 691 1B I I 396 792 1097 1B J J 421 844 990 1B ~ K K 206 412 419 1B L L 255 510 676 1B M M 222 444 470 1B N N 242 486 500 1B T, O O 290 580 600 1B - P P 99 198 210 1B/ ~ Q Q 130 260 275 1B Rl RT - - - ~ - ~ " r- S S 194 388 400 1B ~ RT RT 610 1240 1800,~ 1 B ~ ~ U U 432 864 1132 2B , V V 413 826 1088 1 B - W W 118 236 ~ 256 A ~ X X 67 134 ~ 143 1 A Y 1 Y 1 608 1216 / 3010 n/a ~ Y2 Y2 802 1404 3906 n/a Y3 Y3 223 446 805 n/a Type A is a Spokane Standard Drywell - Single Depth, Capacity 0.3 cfs . - Type B is a Spokane Standazd Drywell - Double Depth, Capacity 1.0 cfs Inland Pacifcc Engineering Company D7 Riverwalk 7th Addition Plat Drainage Report i s , ~ F - 1 4 - - Pipe Flow Calculation CB 1 to CB 2 Basin RT Flow 0.640 cfs Out ! E 2027.72 ~ Diameter 1.00 ft In IE 2028.44 ~ Slope 0.0063 ft/ft " n 0.0130 L 115.00 ft d/dia A R Q V Depth of flow,d 0.90 ft 0.90 0.7445 0.2980 3.01 4.05 Flowing Full 1.00 ft 1.00 0.7854 0.2500 2.83 3.80 Critical Depth 0.330 ft 0.33 0.2260 0.1848 0.64 2.83 ~I Normal Depth 0.320 ft 0.32 0.2167 0.1801 0.64 2.95 ~ _ HWc 0.517 ft INLET CONTROL HWn 0.523 ft HWp ft ~ ,j ~ ~ . . - , I ~ . ! Pipe Flow Calculation CB 2 to Outlet Basin RT Flow 1.400 cfs Out IE 2027.37 Diameter 1.00 ft tn tE 2027.62 Slope 0.0063 f#/ft n 0.0120 L 40.00 ft d/dia A R Q V . Depth of flow,d 0.90 ft 0.90 0.7445 0.2980 3.26 4.38 Flowing Full 1.00 ft 1.00 0.7854 0.2500 3.06 3.90 Critical Depth 0.500 ft 0.50 0.3927 0.2500 1.40 3.57 _ Normal Depth 0.470 ft 0.47 0.3627 0.2400 1.40 3.8-6~ 6 , f 4 J , HWc 0.796 ft INLET CONTROL - -1 HWn 0.817 ft - ~ HWp ft ~ y~ ~ ~ . , ~ 1 7 . ~ INLAND PACIFIC ENGINEERING, INC. June 3, 1996 , IPE Job #96070 ~ FCEIVED JUN 0 4 ~'tg9fi Spokane County Engineers Office 1026 Broadway ENGINEER SPOMUN~C~UNTY J Spokane, WA 99206-0170 Attn: Ed Parry, P.E. RE: Riverwalk (PE-1414-81) Dear Ed, Enclosed please find the submittal package for Riverwalk 7th Addition. At the request of our client, please accept and review the above referenced information as required under the recently adopted Snokane Countv Standards for Road and Sewer Construction. Enclosed you will find the following: a submittal checklist; two sets of the street and storm plans; two copies of the drainage reports; fire district approval letter; pavement depth matrix. Please let me know of any additional requirements for final acceptance. If you have any questions, please call at 458-6840.. S incerely, Inland acific Engireering, Inc. Todd R. Whipple, P.E. ` TRW/skm enclosures cc: Mike Miller, Pacific Properties file 707 West 7th • Suite 200 2020 Lakewood Drive • Suite 205 Spokane, WA 99204 Coeur d'Alene, ID 83814 509-458-6840 9 FAX: 509-458-6844 208-765-7784 • FAX: 208-769-7277 ~ ~ May 21, 1996 INLAND PACIFIC ENGINEERING, INC. W.O. No. #96070 Spokane County Engineers West 1026 Broadway Spokane, Washington 99260 ATTN: Mr. Ed Parry, P.E. " FiECE VED RE: Results of Soil Classification Testing Riverwalk 7th Addition JUN 0 y 1996 Liberty Lake, Washington SpOKANE COUNT`f ENGINEER Mr. Parry: Please find enclosed the results of soils classification testing by our subcontractor, Gifford Consultants, Inc. on a soil sample obtained from the above referenced residential development. The soil sample was obtained from McMillan Lane, Sta.44 + 05 at centerline, 2 feet below existing adjacent grades by members of our staff. We certify herein that the sample tested was obtained from the location stated above, and that based on the data enclosed, the USCS soil classification of GC is correct for the sample tested. Please do not hesitate to call if you have any questions regarding this letter or other aspects of the project. Respectfully, S. FET~ INLAND PACIFIC E GIN WAS Jer E. ~e~er son, P.E. o R~,a1 ~54 j~s n- ~ Project Engineer ,rs~pNA ILI J EP/ell IEXPIRES 11127/eP? ~ Enc. a.1960701so i Itest. wpf 707 West 7th • Suite 200 2020 Lakewood Drive • Suite 205 Spokane, WA 99204 Coeur d'Alene, (D 83814 509-458-6840 • FAX: 509-458-6844 208-765-7784 9 FAX: 208-769-7277 INLAND PACIFIC ENGINEERING Project: RIVERWALK 7TH ADDITION CALCULATED BY: MBZ Job No.: 96070 Disc.No.: File Name: MISS1 & MISS2 TYPICAL SECTION DATA 28-May-96 Roadway half width ENTER-> 29.5 05:06 PM Road Name ENTER-> MISSION AVENUE Left or Right ENTER-> LEFT Curb Type TYPE B COUNTY Station Interoal ENTER--> 25 MINIMUM MAXIMUM Curb EL Curb EL Edge Pave. CENTER % SLOPE EDGE DIST. % SLOPE EDGE DIST FROM (-4.5% (-2% to Gutter LINE CENTER- PAVEMENT CIL TO CIL TO PAVEMEN EDGE PVMT. from E/P + FROM E1P + SELECT- Design Top Curb STATION ELEVATION LINE ELEVATION E1P EDGE PAVE % SLOPE TO CURB CURB HGT) CURB HGT) ED ELEV % GRADE % Grdde 16.63 9.00 0.00 20.50 -0.47 0.01 34.40 16.74 34.76 34.74 9.00 -0.22 315.25 20.50 34.27 34.75 34.74 -2.03 -3.09 0,09 16.99 34.79 0.12 34.69 9.00 -1.11 -020 20.50 34.22 34.70 34.55 -2.76 0.76 020 17.24 34.82 0.12 34.64 9.00 -2.00 -0.20 20.50 34.17 34.65 34.35 -3.55 0,80 0.20 17.53 34.86 0.14 34,66 9.00 -2.22 0,07 20.50 34.19 34.67 34.58 -2.45 -0,79 0.23 17.82 34.89 0.10 34.63 9.00 -2.89 -0,10 20.50 34.16 34.64 34.35 -3.50 0.80 0.23 18.11 34.92 0.10 34.77 9.00 -1.67 0.48 20.50 34.30 34.78 34.58 -3.03 -0.79 0.23 18.39 34.96 0.14 34.78 9.00 -2.00 0.04 20.50 34,31 34.79 34.78 -2.03 -0.71 0.22 18.68 35.03 024 34.85 9.00 -2.00 0.24 20.50 34,38 34.86 34,57 -3.50 0.73 0.23 18.97 35.11 0.28 34.93 9.00 -2.00 0.28 20.50 34.46 34.94 34.80 -2.71 -0.80 0.23 19.25 35,23 0.42 35.10 9.00 -1.44 0.60 20,50 34.63 35.11 35.03 -2.39 -0.81 0.23 19,55 35.28 0.17 35.24 9.00 -0.44 0.47 20.50 34.77 3525 3524 -2,03 -0.70 0.24 19,85 35.33 0.17 35.31 9,00 -0.22 0.23 20.50 34.84 35.32 35.03 -3.50 0.70 0.24 20.14 35.41 028 35.47 9.00 0.67 0.56 20.50 35.00 35.48 35.26 -3.13 -0.80 0.23 20.43 35.48 0.24 35.56 9.00 0.89 0.31 20.50 35.09 35.57 35.49 -2.39 -0.79 0.23 20,74 35.60 0.39 35.68 9.00 0.89 0.39 20.50 35.21 35.69 35.24 -4.34 0.81 0.25 21.05 35.72 0.39 35.80 9.00 0.89 0.39 20.50 35.33 35.81 35.49 -3.66 -0.81 0.25 21.12 35.74 0.28 35.79 9.00 0.56 -0.14 20.50 35.32 35.80 35.32 -4.50 2,36 0.06 21.35 35.79 0.22 35.86 9.00 0.78 0.30 20.50 35.39 35.87 35.50 -3.92 -0.78 0.18 21.65 35.88 0.30 35.83 9.00 -0.56 -0,10 20.50 35.36 35.84 35.74 -2.50 -0.60 0.24 21.83 35.92 022 35.86 9.00 -0.67 0.17 20.50 35.39 35.87 35.86 -2.03 -0.67 0.14 21.96 35.95 023 35.86 9.00 -0.78 0.16 20.50 35.41 35.89 35,74 -2.76 0.94 0.10 22.26 36.02 0.23 35,96 9.00 -0.67 0,26 20.50 35.49 35.97 35,96 -2.03 -0.72cn 0.24 22.55 36.15 0.45 36.09 9.00 -0.67 0.45 20.50 35.62 36.10 35,75 -3.82 0.73p 0.23 ~ 22.83 36.30 0.53 36.21 9.00 -1.00 0.43 20.50 35,74 36.22 35.98 -3.24 -0.823~ t.A23 M 23.12 36.43 0.44 36.33 9.00 -1.11 0.41 20.50 35,86 36.34 36.22 -2,61 -0.89 24 23.42 36.57 0,47 36.46 9.00 -1.22 0.44 20.50 35.99 36.47 36.46 -2,03 -0.8'K~ .24~ 23.68 36,71 0.53 36.67 9.00 -0.44 0.79 20.50 3620 36.68 36.67 -2.03 -0.7~ CP21 M 23.98 36,79 0.27 36.78 9.00 -0.11 0.37 20.50 36.31 36.79 36.44 -3.82 0.76~ -M.23 i 2 ~ orn ~ z m m 3D 24.27 36.85 021 36.84 9.00 -0.11 0.21 20.50 36,37 36.85 36.67 -2.92 -0.79 023 24.55 36.93 028 36,89 9.00 -0.44 0.17 20,50 36,42 36.90 36.89 -2.03 -0.77 0.23 24.85 37.03 0.34 36,94 9.00 -1.00 017 20,50 36,47 36.95 36.66 -3.50 0.78 024 25.14 37.12 0.31 37.12 9.00 0.00 0.62 20,50 36.65 37.13 36.89 -3.24 -0.79 0.23 25.43 37.20 0.27 37.15 9,00 -0.56 0.10 20.50 36.68 37.16 37.12 -2.18 -0.79 0.23 25.72 37.29 0.31 37,21 9.00 -0.89 0.21 20,50 36.74 3722 36.89 -3.71 0.79 023 26.03 37.36 0.30 37,25 9,00 -1.44 0.13 20,50 36.78 3726 37.13 -2.66 -0.80 024 26.32 37.41 0.10 37.36 9.00 -0.56 0.38 20.50 36.89 37,37 37.36 -2.03 -0.79 023 26.61 37.45 0.14 37.31 9.00 -1.56 -0.17 20,50 36.84 37.32 37.13 -2.97 0.78 023 26.90 37.48 0.10 37.31 9.00 -1.89 0.00 20.50 36.84 37.32 36.90 4.18 0.80 023 27.19 37.45 -0.10 37.32 9.00 -1.44 0.03 20.50 36.85 37.33 37.13 -3.03 -0.79 0.23 27.46 37.43 -0.07 37.21 9.00 -2.44 -0.40 20.50 36.74 37.22 36.91 -3.61 0.80 0.22 27.60 37.42 -0.07 37.14 9.00 -3.11 -0.52 20.50 36.67 37.15 36.80 -3.82 0.81 0.11 27.75 37.40 -0.11 37.06 9.00 -3.78 -0.53 20.50 36.59 37.07 36.92 -2.76 -0.81 0.12 27.96 37.35 -0.24 37.06 9.00 -3.22 0.00 20.50 36.59 37.07 37.06 -2.03 -0.67 0.17 28.03 37.33 -0.27 37.06 9.00 -3.00 0.00 20.50 36.59 37.07 37.02 -2.24 0.55 0.06 28.31 37.29 -0.14 37.14 9.00 -1.67 0.29 20.50 36.67 37.15 36.80 -3.82 0.79 0.22 28.33 37.29 -0.14 37.14 9.00 -1.67 0.27 20.50 36.67 37.15 36.79 -3.87 0.18 0.01 28.62 37.21 -0.27 37.09 9.00 -1.33 -0.17 20.50 36.62 37.10 37.02 -2.39 -0.79 023 28.90 37.08 -0.46 36.98 9.00 -1.11 -0.39 20.50 36.51 36.99 36.79 -3.03 0.81 023 29.19 37.10 0,07 36.96 9.00 -1.56 -0.07 20.50 36.49 36.97 36.56 -4,13 0.79 023 29.45 37.21 0,43 37,14 9.00 -0.78 0.70 20.50 36.67 37.15 36.76 4,03 -0.78 020 29.61 37.17 -0.24 37.13 9.00 -0.44 -0,06 20.50 36.66 37.14 36.89 -3.29 -0.79 0,13 CENTER % SLOPE EDGE DIST. % SLOPE EDGE DIST FROM EDGE OF PVMT LINE CENTER- PAVEMENT CIL TO CIL TO PAVEMEN SAWCUT TO ELEVATION STATION ELEVATION LINE ELEVATION EIP EDGE PAVE % SLOPE EDGE PVMT, @ 2% FROM SAWCUT 29.78 37,13 -0.24 37,11 9.00 -0,22 -0.12 17.34 36,76 30.11 37.15 0.06 36.99 9,00 -1.78 -0.37 14.06 36.71 30.39 37.17 0.07 37.10 9.00 -0.78 0.39 11.26 36.87 30.67 37.29 0.42 37.25 9.00 -0.44 0.53 8.43 37.08 30.97 37.40 0.37 37.39 9.00 -0.11 0.47 5.47 37.28 31.26 37.47 0.24 37.54 9.00 0.78 0.52 2.56 37.49 31.54 37.56 0.32 37.56 9.00 0.00 0.07 0.00 37.56 0) o ~ t.. M m C n 0 Z 0 C= m ~ 4 ~ z m m ~ CY)o ~ m m . ~ the occupants of surrounding property. No illegal, illicit, noxious or offensive activity shalt be carried on within the Community, nor shall anything be done tending to cause embarrassment, discomfort, annoyance, or nuisance to any Person using any property cc within the Community. Without limiting the generality of the foregoing, no speaker, Q z horn, whistle, siren, bell, amplifier or other sound device, except such devices as may be W~ z used exclusively for security purposes, shall be located, installed or maintained upon the > exterior of any Lot unless required by law or unless specifically approved by the ~ ~ R1.1 ~ ° o Architectural Review Committee. ~ ~ z LU 6.11 Unsieht(v or Unkemot Conditions. The pursuit of hobbies or other (c o a_ activities, including specifically, without limiting the generality of the foregoing, the assembly of and disassembly of motor vehicles and other mechanical devices, which might tend to cause disorderly, unsightly, or unkempt conditions, shall not be undertaken outside of homes or garages. Garage doors shall be kept closed at all times unless they are in use. In addition, the storage of equipment, machinery, constructions supplies or any similar material on a Lot outside of the home and garage constructed thereon is strictly prohibited except as required during the remodeling or refurbishing of improvements on such Lot and then for not more than sixty (60) days. 6.12 Antennas. No television or radio antenna, tower, satellite dish, or exterior antenna of any kind shall be placed, allowed, or maintained upon any Lot or any portion of the Community without the prior written consent of the Architectural Review Committee. Each Owner and Occupant acknowledges that this provision benefits all Owners and Occupants and each Owner and Occupant agrees to comply with this provision despite the fact that the erection of an outdoor antenna or similar device would be the most cost-effective way to transmit or receive the signals sought to be transmitted or received. 6.13 Tree Removal. No trees that are more than six (6) inches in diameter at a point three (3) feet above the ground shall be removed without the prior written consent of the Architectural Review Committee. Notwithstanding all of the above, no consent or approval is required for the removal by an Owner of any trees, regardless of their diameter, that are located within ten (10) feet of the Owner's residence. . t 4 D~ra' na g-j.Catch basins and drainage areas are for the purpose of natural flow of water only. No obstructions or debris shall be placed in these areas. No Owner or Occupant may obstruct or re-channel the drainage flows after location and installation of drainage swales, storm sewers or storm drains. Declarant hereby reserves for the benefit of Declarant and the Association and their respective successors and assigns a perpetual easement across all Common Areas and Lots for the purpose of maintaining or altering drainage and water flow. 6.15 Sight Distance at Intersections. Ail praperty located at street intersections shall be landscaped so as to permit safe sight across the street corners. No fence, wall, hedge or shrub planting shall be placed or permitted to remain where it would create a Rivertivalk.C C Rs* page 16 of 32 9 14078 14964-2 AV203!.DOC 7/1l/95 r , v v v v . . ~ . . v r v . ~ . v ♦ t _ _ . . - - ~i Sp4KANE VALLEY FiRE OEPARTMENT Spokane County Fire Profect/on District No. I 10319 EAST SPRAGUE AVE, • SPOKANE. WA 99206-3676 •(509) 928-1700 • FAX (509) 927-2227 ~ R. Pat Humphtles cnar RECEIVED JUN 0 4 1996 SPOKANE COUNTY ENGINEER May 30, 1996 Department of Huilding 6 Planning Louis Webater 1026 w. Broadway Spokane, WA 99260 i RE: Final Plat PE-14 <-81 Riverwalk 6th an h Additi Dear Mr. Webster, ok to release. Water and access plans have been xeviewed. Sincerely, OLQ- 34&~ PauChase Fire Marshal PC/md cc: 8ruce Howazd Inland Pacific Enqineering ~ . . . . . . ~ ► • • Z WORKAUTHORIZATION AMENDMENT TO ATTACHMENT "A" DETAILED DESCRIPTION OF WORK Riverwalk 7th Addition (95 Residential Lots, and Mission Avenue) Construction Inspection IPE W.O. # 96070-1 - Inland Pacific Engineering will perform Construction Inspection services as outlined below and charge for said services on the basis of time and expense. A. ROAD CONSTRUCTION INSPECTION OF: 1. Earthwork and Subgrade Preparation. 2. Placement and compaction of all base material. 3. Placement and compaction of pavement. 4. Curb and sidewalk installation. 5. Drywells, inlets, and general facilities. 6. Temporary drainage facilities. 7. Erosion control. 8. Coordination with Spokane County. 9. Preparation and submittal of "Record Drawings". B. SANITARY SEWER CONSTRUCTION INSPECTION OF: 1. Excavation and trench preparation. 2. Line and grade. 3. Bedding and placement. 4. Side sewer service and markers. 5. Backfilling and compaction testing. 6. Air and mandrel testing. . Inspection page 2 7. Coordination with Spokane County 8. As-Built survey and preparation of "Record Drawings". C. Direct Expense 1. Mileage at $0.30 per mile. 2. DESCRIPTION OF WORK Inspection by IPE personnel or other agency personnel shall not relieve the contractor of his responsibility to construct the facilities covered by this agreement to the line and grade shown on the approved plans or as staked by the engineer. . 1. The scope of these construction engineering services includes: A) Periodic observation and reporting of specific construction activities on this projeet which include; Sanitary Sewer, Bases, Subgrade, Pavement, Concrete Curb and Gutter, Sidewalks, and Storm Drainage; B) Maintenance of all construction records related to construction activities outlined in paragraph "Au, and "B" above, which may include; daily inspection reports, manufacturers' certifications, material test reports, and correspondence; C) Assurance that the construction of the sanitary sewer and roads is according to the approved plans accepted by the Spokane County Engineer, Spokane County General Provisions, the Standard Specifications, and applicable portions of the WSDOT Construction Manual; D) Development of Post Construction Record Drawings for the Sanitary Sewer, and Street and Storm Drainage Facilities; it is understood the facilities inspected by firms other than IPE will be certified by those firms in a form acceptable to Spokane County; . E) Coordination of the testing of construction materials for compliance to the plans accepted by the Spokane County Engineer, Spokane County General Provisions, the Standard Specifications, and applicable portions of the WSDOT Construction Manual. Actual materials testing to be performed by others and billed separately from Inland Pacific Engineering billing. . - Inspection page 3 2. Prior to acceptance of the roads and drainage facilities by Spokane County, the Engineer sha!l submit all construction records and the Record Drawing to the Spokane County Engineer. The services described herein will be performed as needed and billed on the basis of time and expense as outlined in Attachment "D". You should budget $33,500.00 for the scope of services outlined above on a one time basis. Pacific Properties agrees to provide to IPE or arrange for appropriate certifications from other firms and to include provisions in their construction contracts to back charge their contractor for the cost of IPE services which may be required for re-inspection or re-testing of facilities which failed to meet the required . standards. Bil(ings for said re-inspections will be carefully identified on IPE's billing to Pacific Properties. Pacific Properties will be responsible to back charge their contractor. It is also understood that no work shall commence within any portion of the proposed Spokane County Right of Way without first obtaining a written permit and approved plans from the County Engineer. It is also understood that any project facilities constructed without adequate inspection and documentation by IPE will be removed and reconstructed in accordance with approved project plans and Spokane County Specifications, or IPE will not be responsible for project certification or submission of record drawings to the County Engineer. ~ Accepted: lnland Pacific Engineering Accepted: Pacific Properties , by: zlu~ bY; date: ~ ~ q~_ date: ~ 4~-