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HomeMy WebLinkAboutStorm Drainage Engineering - PLN General - 4/28/1998 STO" DRAINAGE COMPUTATIONS FOR BELFAIR SAND & GRA VEL PIT April 28, 1998 PREPARED BY A•D•A ENGINEERING, L.L.C. 'FwB' ARMSTRONG, DeGROOT&ASSOCIATES ENGINEERS AND SURVEYORS P.O.BOX B47 EX • $. Q �...� ` (371 NW LINDVIG WAY) POULSBO,WASHINGTON 98370 PHONE(360)779-6633 BAINBRIDGE ISLAND(206)842-6123 FAX(360)779-7031 BOMW sand&cravei vema3 The enclosed computations for the Belfair Sand and Gravel Pit were calculated using the WaterWorks 4.11 program. The SBUH method was utilized. The Belfair Sand and Gravel Pit is located at 2493 Old Belfair Highway in Mason County. The site lies in the NE 1/4, NE 1/4, SEC. 17, T 23 N, R 1 W, W. M. The hydrologic input for the stormwater model follows: Rainfall 6 - month = 2.4 inches 2 - yr. = 3.7 inches 10 - yr. = 5.0 inches 25 - yr. = 6.0 inches 100 - yr. = 7.0 inches Site Total Area 41.18 ac. Less No Cut Areas 4.00 ac. Less Buffer 6.72 a Mine Area 30.46 ac. Pre Developed Basin Soil Type = Everett Gravelly Sandy Loam Hydrologic Group = A Pervious: Area = 30.46 Acres CN = 42 Impervious: Area = 0.00 Acres CN = 98 1 Bctfaif Sand&Gneel 962943 Time of Concentration = 21.85 minutes Length = 1690' Design Storm = 2, 10 & 100 yr/24 hour Post Developed Basin Soil Tvpe = Everett Gravelly Sandy Loam Hydrologic Group = A Pervious: Area = 27.18 Acres CN = 68 Impervious: Area = 3.28 Acres CN = 98 Time of Concentration = 48.48 minutes Length = 2.170' Design Storm = 2, 10, & 100 yr / 24 hour Active Vining Period Basins A, B& D Combined Soil Type = Everett Gravelly Sandy Loam Hydrologic Group = A Pervious: Area = 22.00 Acres CN = 72 Impervious: Area = 1.02 Acres CN = 98 Time of Concentration = 8.31 minutes Bci&w Sand&Grz%vi 9(r2%3 Length = 1,900' Design Storm = 25 yr. /24 hour Basin Soil Type = Everett Gravelly Sandy Loam Hydrologic Group = A Pervious: Area = 7.44 Acres CN = 72 Impervious: Area = 0 Acres CN = 98 Time of Concentration = 6.13 minutes Length = 880' Design Storm = 25 yr. /24 hr. Conclusion The analysis looked into three conditions on the site. They are the pre-mining condition (forested), the post-mining condition (8 lot subdivision on terraces with reforested slopes) and the active mining period. The reclaimed site will require a detention pond 90' wide by 280' long with 3' : 1' slopes with a storage volume of 8 ac-ft. The release from this pond will match the 2, 10 & 100 yr/24 hr. pre existing release rates. The pond should have two cells minimum. The physical location is in south east corner of the property with discharge to a bioswale or other acceptable water quality facility and discharge to a existing drain system which ultimately reaches the Union River. The analysis did not include any allowance for infiltration. The soils found onsite are highly permeable. At the time of final pond design, infiltration should be 3 BeUr Smd&Cn ml 96.2943 considered as it can significantly reduce pond size. During the active life of the mine storm water is handled quite differently. Water is not discharged at the south east comer of the site at all. Three basins A, B & D (see map) have existing ponds. Basin D drains to a pond in the south east corner of the mine. The water is then pumped back up the hill to basin B where it enters two ponds. The water then can overflow to a french drain where it infiltrates and on occasion exists the site in a drainage located on the south line of the site. This drainage ultimately reaches the class III stream on the west side of the site. The ponds located in A, B & D have a combined volume of 11.49 ac-ft. The analysis indicates 6 ac-ft. is needed for the 25 yr./24 hr. event. The ponds that exist today are of adequate size to detain the regulatory storm with a zero discharge. Basin C does not have a pond for detention. Discharge is to a ravine in the northeast corner of the mine_ Downstream of this ravine are single family residences. When active mining of this area occurs a detention pond will be needed for this basin. This pond should be designed for the 25 yr./24 hr. event. A detention pond 100' wide by 110' long with 2' : I' slopes with 80,840 cubic feet of storage will be needed to have a zero discharge. An option to the new pond in Basin C is to route the water down to the pond in Basin D. The existing pond system in A, B & D has the excess capacity to handle this runoff. In conclusion the storm water system in place today, properly maintained and operated, appears to be adequate to detain /retain the regulatory storm event. Water quality requirements are met by infiltrating any discharge to a french drain which is a Best Management Practice. 4 4/30/98 7 : 56 : 27 am A.D.A. Engineering page 1 BELFAIR SAND AND GRAVEL 4/28/98 RECLAIMED SITE CONDITION DETENTION FACILITY BASIN SUMMARY BASIN ID: PRE100YR NAME: BELFAIR SAND & GRAVEL PRE MINE SBUH METHODOLOGY TOTAL AREA. . . . . . . : 30.46 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 7.00 inches AREA. . : 30. 46 Acres 0. 00 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 42 . 00 0. 00 TC. . . . . 48 . 28 min 0. 00 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 300. 00 ns: 0. 8000 p2yr: 3 . 70 s: 0. 1790 TcReach - Shallow L: 480. 00 ks: 3 . 00 s: 0 . 1790 TcReach - Channel L: 910. 00 kc: 5 . 00 s: 0. 1810 PEAK RATE: 2 . 24 cfs VOL: 2 . 53 Ac-ft TIME: 960 min BASIN ID: PRE10YR NAME: BELFAIR SAND & GRAVEL PRE MINE SBUH METHODOLOGY TOTAL AREA. . . . . . . : 30. 46 Acres BASEFLOWS: 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 5. 00 inches AREA. . : 30. 46 Acres 0. 00 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 42 . 00 0. 00 TC. . . . . 48 . 28 min 0. 00 min ABSTRACTION COEFF: 0. 20 TcReach - Sheet L: 300. 00 ns: 0. 8000 p2yr: 3 . 70 s: 0. 1790 TcReach - Shallow L: 480. 00 ks: 3 . 00 s: 0. 1790 TcReach - Channel L: 910. 00 kc: 5. 00 s: 0 . 1810 PEAK RATE: 0. 88 cfs VOL: 0. 79 Ac-ft TIME: 1320 min BASIN ID: PRE2YR NAME: BELFAIR SAND & GRAVEL PRE MINE SBUH METHODOLOGY TOTAL AREA. . . . . . . : 30. 46 Acres BASEFLOWS: 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 3 . 70 inches AREA. . : 30. 46 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 42 . 00 0 . 00 TC. . . . . 48 . 28 min 0 . 00 min ABSTRACTION COEFF: 0. 20 TcReach - Sheet L: 300. 00 ns: 0. 8000 p2yr: 3 . 70 s: 0. 1790 TcReach - Shallow L: 480. 00 ks: 3 . 00 s: 0. 1790 TcReach - Channel L: 910. 00 kc: 5 . 00 s: 0. 1810 PEAK RATE: 0. 27 cfs VOL: 0. 15 Ac-ft TIME: 1320 min ........... �� :, ; ............... . -:::.......... CLASS-JII STREAM ..... i Q .. ..............:.................. .� SE BACK ........"......... .... "1 :: ..............::::'..::..::::::::......:::::::::::......::::::: :......... ,< ..........::.. :r•:'• ;'9�; y v' 3 ::: :::::........ PON n: j, .. a r , - t- ':�:: ..._�.,,:"...., _ ... .. , .. �`J •:," >.l - .:yam••• •:#•. `►'.' .. /` :j SETBACK CL ... S`• POND ,." •''•.,.:" . :. �.:'`�<... ..... .•'� �O� •.1'. •�. ` .� 00U 'L W '�' -T{+•:., CD CL _ A. AR�I LEMEMD 'cy` pj PROPERTY LINE A84 Sa � TREE LINE SET�- FLOW DIRECTION DACK LINE AWN! O DRAINAGE BASIN 8894 EXIBIT OF '.�ftISTER'�' — — ASSUMED WORM 12MWAME [PLAN mpua 3 APRIL 20001 250 0 250 5 0 0 750 8ZCD0N V 71 V=K AlW,W.3 L MASON GOLWN'WA P.O. BON 8<7 A•®•'� .EaGmEmoma1 LLC PNONE:POULS(1 O)7 WA 7870 9 38831 B.I.PHONE:(X18)842_5123 " ' FAX: (360) 779-7031 DRAWN: BPS CHECKED: H AA SCALE:1'-230' JO t2.Sca e 1 250 DESIGN: RBG DATE:S 8 SHEET 1 Of 1 FILE NO.: 4/30/98 7: 56: 27 am A.D.A. Engineering page 2 BELFAIR SAND AND GRAVEL 4/28/98 RECLAIMED SITE CONDITION DETENTION FACILITY BASIN SUMMARY BASIN ID: PRE6MO NAME: BELFAIR SAND & GRAVEL PRE MINE SBUH METHODOLOGY TOTAL AREA. . . . . . . : 30. 46 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 2. 40 inches AREA. . : 30 . 46 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 42 . 00 0 . 00 TC. . . . . 48 . 28 min 0. 00 min ABSTRACTION COEFF: 0. 20 TcReach - Sheet L: 300. 00 ns : 0 .8000 p2yr: 3 . 70 s: 0 . 1790 TcReach - Shallow L: 480. 00 ks: 3 . 00 s: 0. 1790 TcReach - Channel L: 910. 00 kc: 5 . 00 s: 0. 1810 PEAK RATE: 0. 00 cfs VOL: 0 . 00 Ac-ft TIME: 0 min BASIN ID: PST100YR NAME: BELFAIR SAND & GRAVEL POSTMINE SBUH METHODOLOGY TOTAL AREA. . . . . . . : 30. 46 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 7 . 00 inches AREA. . : 27 . 18 Acres 3 . 28 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 21. 85 min 8 . 91 min ABSTRACTION COEFF: 0. 20 TcReach - Sheet L: 340 . 00 ns: 0. 4000 p2yr: 3 . 70 s: 0 . 5000 TcReach - Shallow L: 780 . 00 ks: 27 . 00 s: 0. 0100 TcReach - Channel L: 330. 00 kc: 21. 00 s: 0. 1290 TcReach - Channel L: 720. 00 kc: 21. 00 s: 0. 1220 impTcReach - Sheet L: 300. 00 ns: 0. 0110 p2yr: 3 . 70 s: 0 . 0100 impTcReach - Shallow L: 480. 00 ks: 27 . 00 s: 0. 0100 impTcReach - Channel L: 330. 00 kc: 21. 00 s: 0 . 1290 impTcReach - Channel L: 720. 00 kc: 21. 00 s: 0. 1220 PEAK RATE: 19 . 91 cfs VOL: 9 . 57 Ac-ft TIME: 480 min BASIN ID: PST10YR NAME: BELFAIR SAND & GRAVEL POSTMINE SBUH METHODOLOGY TOTAL AREA. . . . . . . : 30 . 46 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 5. 00 inches AREA. . : 27 . 18 Acres 3 . 28 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 21. 85 min 8 . 91 min ABSTRACTION COEFF: 0 . 20 TcReach - Sheet L: 340. 00 ns: 0 . 4000 p2yr: 3 . 70 s: 0 . 5000 TcReach - Shallow L: 780. 00 ks: 27 . 00 s: 0. 0100 TcReach - Channel L: 330. 00 kc: 21. 00 s: 0 . 1290 TcReach - Channel L: 720. 00 kc: 21. 00 s: 0. 1220 impTcReach - Sheet L: 300. 00 ns: 0. 0110 p2yr: 3 . 70 s: 0. 0100 impTcReach - Shallow L: 480. 00 ks: 27 . 00 s: 0. 0100 impTcReach - Channel L: 330. 00 kc: 21. 00 s: 0. 1290 impTcReach - Channel L: 720 . 00 kc: 21. 00 s: 0 . 1220 PEAK RATE: 10. 51 cfs VOL: 5 . 56 Ac-ft TIME: 480 min 4/30/98 7 : 56: 27 am A.D.A. Engineering page 3 BELFAIR SAND AND GRAVEL 4/28/98 RECLAIMED SITE CONDITION DETENTION FACILITY --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN ID: PST2YR NAME: BELFAIR SAND & GRAVEL POSTMINE SBUH METHODOLOGY TOTAL AREA. . . . . . . : 30. 46 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 3 . 70 inches AREA. . : 27 . 18 Acres 3 . 28 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 21. 85 min 8 . 91 min ABSTRACTION COEFF: 0. 20 TcReach - Sheet L: 340 . 00 ns: 0. 4000 p2yr: 3 . 70 s: 0 . 5000 TcReach - Shallow L: 780. 00 ks: 27 . 00 s: 0. 0100 TcReach - Channel L: 330 . 00 kc: 21. 00 s: 0. 1290 TcReach - Channel L: 720 . 00 kc: 21. 00 s: 0. 1220 impTcReach - Sheet L: 300. 00 ns: 0. 0110 p2yr: 3 . 70 s: 0 . 0100 impTcReach - Shallow L: 480. 00 ks: 27 . 00 s: 0. 0100 impTcReach - Channel L: 330. 00 kc: 21. 00 s: 0. 1290 impTcReach - Channel L: 720. 00 kc: 21. 00 s: 0. 1220 PEAK RATE: 5. 32 cfs VOL: 3 . 26 Ac-ft TIME: 480 min BASIN ID: PST6MO NAME: BELFAIR SAND & GRAVEL POSTMINE SBUH METHODOLOGY TOTAL AREA. . . . . . . : 30. 46 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 2 . 40 inches AREA. . : 27 . 18 Acres 3 . 28 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 21. 85 min 8 . 91 min ABSTRACTION COEFF: 0. 20 TcReach - Sheet L: 340. 00 ns: 0. 4000 p2yr: 3 . 70 s: 0 . 5000 TcReach - Shallow L: 780. 00 ks: 27 . 00 s: 0. 0100 TcReach - Channel L: 330. 00 kc: 21. 00 s: 0. 1290 TcReach - Channel L: 720. 00 kc: 21. 00 s: 0 . 1220 impTcReach - Sheet L: 300 . 00 ns: 0 . 0110 p2yr: 3 . 70 s: 0 . 0100 impTcReach - Shallow L: 480 . 00 ks: 27 . 00 s: 0 . 0100 impTcReach - Channel L: 330. 00 kc: 21. 00 s: 0 . 1290 impTcReach - Channel L: 720. 00 kc: 21. 00 s: 0 . 1220 PEAK RATE: 1. 66 cfs VOL: 1. 38 Ac-ft TIME: 480 min u zx udx d ii yn w 000JQNU1 Pw Eli ►-A II 0 II z � II II H H ko II II H :3: 00 zz0 NOONI--xU1N00 II 0 t2i cn � NNtnJtn � w II w �-3 '0t II n ►-3 In w mwwkD0 II tii '=J II Ht+i rn v, wotnocnJ00U1 II II r II II ►-3 O J uKz II I'd �-3 II C7 W JJF-' Oo000� O1NN II 51 LTiOH 000000000 II P -1h3i II Hr II II o 1-1 z H NIA , N) H u x u UlOh4a, rnU1N W II 0 x C 0HkDm �orn4�:6OJ II MSC O C7 II cn rnoocoX� P.. rn P. 0P- IIi00r x1 II NJNJcnMkoo. rn `,d '!i 0 II J ko In Ij N 0 W In P. 0 O 9 6) IIIli C7 Cl t7 M 0 n n 0 0 0 0 II rt M �n1-hM �hMM �t t-' II x II C7C7 II II II En II a > II O If Wwww W w W Li II > > �s II Ctrs II 0 �i rt II t+i �J IIn (D 4 (D a F- a P- rnrnrnrnrnrnrnrnrn II m tr II Jrl- �j II II (D II N (D II 0 II � F'• II 004 II II II II II II II II II II II II II 'zi II sy II W II (D II II II 4/30/98 7 : 56: 28 am A.D.A. Engineering page 6 BELFAIR SAND AND GRAVEL 4/28/98 RECLAIMED SITE CONDITION DETENTION FACILITY STAGE DISCHARGE TABLE MULTIPLE ORIFICE ID No. DIS1 Description: BELFAIR SAND AND GRAVEL Outlet Elev: 100. 00 Elev: 98 . 00 ft Orifice Diameter: 1. 5322 in. Elev: 104 . 90 ft Orifice 2 Diameter: 4 . 5645 in. Elev: 107 . 10 ft Orifice 3 Diameter: 4 . 9219 in. STAGE <--DISCHARGE---> STAGE -DISCHARGE---> STAGE -DISCHARGE---> STAGE <--DISCHARGE---> (ft) ---cfs-- ------- (ft) ---cfs-- ------- (ft) ---cfs-- ------- (ft) ---cfs-- ------- 100.00 0.0000 102.60 0.1027 105.20 0.4550 107.80 1.6907 100.10 0.0201 102.70 0.1047 105.30 0.5042 107.90 1.7463 100.20 0.0285 102.80 0.1066 105.40 0.5478 108.00 1.7993 100.30 0.0349 102.90 0.1085 105.50 0.5874 108.10 1.8501 100.40 0.0403 103.00 0.1103 105.60 0.6238 108.20 1.8990 100.50 0.0450 103.10 0.1122 105.70 0.6578 108.30 1.9462 100.60 0.0493 103.20 0.1140 105.80 0.6898 108.40 1.9919 100.70 0.0533 103.30 0.1157 105.90 0.7201 108.50 2.0363 100.80 0.0570 103.40 0.1175 106.00 0.7490 108.60 2.0795 100.90 0.0604 103.50 0.1192 106.10 0.7767 108.70 2.1216 101.00 0.0637 103.60 0.1209 106.20 0.8033 108.80 2.1627 101.10 0.0668 103.70 0.1225 106.30 0.8289 108.90 2.2028 101.20 0.0698 103.80 0.1242 106.40 0.8536 109.00 2.2421 101.30 0.0726 103.90 0.1258 106.50 0.8776 109.10 2.2806 101.40 0.0754 104.00 0.1274 106.60 0.9008 109.20 2.3183 101.50 0.0780 104.10 0.1290 106.70 0.9234 109.30 2.3553 101.60 0.0806 104.20 0.1306 106.80 0.9455 109.40 2.3917 101.70 0.0831 104.30 0.1321 106.90 0.9669 109.50 2.4274 101.80 0.0855 104.40 0.1336 107.00 0.9879 109.60 2.4625 101.90 0.0878 104.50 0.1351 107.10 1.0084 109.70 2.4971 102.00 0.0901 104.60 0.1366 107.20 1.2363 109.80 2.5312 102.10 0.0923 104.70 0.1381 107.30 1.3420 109.90 2.5647 102.20 0.0945 104.80 0.1396 107.40 1.4273 110.00 2.5978 102.30 0.0966 104.90 0.1410 107.50 1.5019 102.40 0.0987 105.00 0.3212 107.60 1.5695 102.50 0.1007 105.10 0.3967 107.70 1.6321 4/30/98 7 : 56: 28 am A.D.A. Engineering page 5 BELFAIR SAND AND GRAVEL 4/28/98 RECLAIMED SITE CONDITION DETENTION FACILITY --------------------------------------------------------------------- --------------------------------------------------------------------- STAGE STORAGE TABLE TRAPEZOIDAL BASIN ID No. STOR1 Description: BELFAIR SAND & GRAVEL Length: 280. 00 ft. Width: 90 . 00 ft. Side Slope 1: 3 Side Slope 3 : 3 Side Slope 2 : 3 Side Slope 4 : 3 Infiltration Rate: 0. 00 min/inch STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- 100.00 0.0000 0.0000 103.10 89145 2.0465 106.20 201768 4.6320 109.30 340016 7.8057 100.10 2531 0.0581 103.20 92400 2.1212 106.30 205816 4.7249 109.40 344927 7.9184 100.20 5084 0.1167 103.30 95679 2.1965 106.40 209891 4.8184 109.50 349866 8.0318 100.30 7660 0.1759 103.40 98983 2.2723 106.50 213993 4.9126 109.60 354834 8.1459 100.40 10258 0.2355 103.50 102312 2.3488 106.60 218122 5.0074 109.70 359832 8.2606 100.50 12879 0.2957 103.60 105665 2.4257 106.70 222277 5.1028 109.80 364859 8.3760 100.60 15522 0.3563 103.70 109044 2.5033 106.80 226460 5.1988 109.90 369915 8.4921 100.70 18188 0.4175 103.80 112447 2.5814 106.90 230669 5.2954 110.00 375000 8.6088 100.80 20877 0.4793 103.90 115875 2.6601 107.00 234906 5.3927 110.10 380115 8.7262 100.90 23588 0.5415 104.00 119328 2.7394 107.10 239170 5.4906 110.20 385259 8.8443 101.00 26322 0.6043 104.10 122806 2.8192 107.20 243461 5.5891 110.30 390433 8.9631 101.10 29079 0.6676 104.20 126309 2.8997 107.30 247780 5.6882 110.40 395636 9.0826 101.20 31859 0.7314 104.30 129838 2.9807 107.40 252126 5.7880 110.50 400869 9.2027 101.30 34662 0.7957 104.40 133392 3.0623 107.50 256500 5.8884 110.60 406132 9.3235 101.40 37489 0.8606 104.50 136971 3.1444 107.60 260901 5.9895 110.70 411424 9.4450 101.50 40338 0.9260 104.60 140576 3.2272 107.70 265330 6.0911 110.80 416747 9.5672 101.60 43211 0.9920 104.70 144206 3.3105 107.80 269787 6.1935 110.90 422099 9.6901 101.70 46107 1.0585 104.80 147862 3.3944 107.90 274272 6.2964 111.00 427482 9.8136 101.80 49026 1.1255 104.90 151543 3.4789 108.00 278784 6.4000 111.10 432895 9.9379 101.90 51969 1.1931 105.00 155250 3.5640 108.10 283324 6.5042 111.20 438338 10.063 102.00 54936 1.2612 105.10 158983 3.6497 108.20 287893 6.6091 111.30 443811 10.188 102.10 57926 1.3298 105.20 162742 3.7360 108.30 292489 6.7146 111.40 449314 10.315 102.20 60940 1.3990 105.30 166526 3.8229 108.40 297114 6.8208 111.50 454848 10.442 102.30 63978 1.4687 105.40 170337 3.9104 108.50 301767 6.9276 111.60 460412 10.570 102.40 67039 1.5390 105.50 174174 3.9985 108.60 306448 7.0351 111.70 466007 10.698 102.50 70125 1.6098 105.60 178037 4.0872 108.70 311158 7.1432 111.80 471633 10.827 102.60 73235 1.6812 105.70 181926 4.1765 108.80 315896 7.2520 111.90 477289 10.957 102.70 76368 1.7532 105.80 185842 4.2663 108.90 320663 7.3614 112.00 482976 11.088 102.80 79526 1.8257 105.90 189784 4.3568 109.00 325458 7.4715 112.00 482976 11.088 102.90 82708 1.8987 106.00 193752 4.4479 109.10 330282 7.5822 103.00 85914 1.9723 106.10 197747 4.5396 109.20 335135 7.6936 4/30/98 7 : 56: 29 am A.D.A. Engineering page 7 BELFAIR SAND AND GRAVEL 4/28/98 RECLAIMED SITE CONDITION DETENTION FACILITY --------------------------------------------------------------------- --------------------------------------------------------------------- LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- -PEAK- STORAGE <--------DESCRIPTION---------> (cfs) (cfs) --id- --id- <-STAGE> id VOL (cf) ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- 2YR .......................... 0.14 5.73 STOR1 DIS1 104.83 7 3 ac-ft 10YR ......................... 1.00 11.56 STOR1 DIS1 107.05 8 5 ac-ft 100YR ........................ 2.54 22.14 STOR1 DIS1 109.81 9 8 ac-ft 4/30/98 7 : 33 : 50 am A.D.A. Engineering page 1 BELFAIR SAND AND GRAVEL ACTIVE MINING PERIOD 25 YR STORM ZERO DISCHARGE --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN ID: ABDMINE NAME: BELFAIR SAND & GRAVEL 25YR SBUH METHODOLOGY TOTAL AREA. . . . . . . : 23. 02 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 6. 00 inches AREA. . : 22 . 00 Acres 1. 02 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 72 . 00 98 . 00 TC. . . . . 8 . 31 min 5 . 00 min ABSTRACTION COEFF: 0. 20 TcReach - Sheet L: 300. 00 ns: 0. 0500 p2yr: 3 . 70 s : 0 . 1460 TcReach - Shallow L: 600. 00 ks: 13 . 00 s: 0. 1460 TcReach - Channel L: 1000. 00 kc: 20. 00 s: 0. 1460 PEAK RATE: 14 . 90 cfs VOL: 5 . 98 Ac-ft TIME: 480 min BASIN ID: CMINE NAME: BELFAIR SAND & GRAVEL 25YR SBUH METHODOLOGY TOTAL AREA. . . . . . . : 7. 44 Acres BASEFLOWS: 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 6. 00 inches AREA. . : 7 . 44 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 72 . 00 0 . 00 TC. . . . . 6 . 13 min 0. 00 min ABSTRACTION COEFF: 0. 20 TcReach - Sheet L: 300. 00 ns: 0. 0500 p2yr: 3 . 70 s: 0 . 1420 TcReach - Shallow L: 580. 00 ks: 13 . 00 s: 0. 1420 PEAK RATE: 4 . 74 cfs VOL: 1. 86 Ac-ft TIME: 480 min 4/30/98 7 : 33 : 50 am A.D.A. Engineering page 4 BELFAIR SAND AND GRAVEL ACTIVE MINING PERIOD 25 YR STORM ZERO DISCHARGE --------------------------------------------------------------------- --------------------------------------------------------------------- STAGE DISCHARGE TABLE MULTIPLE ORIFICE ID No. DIS3 Description: BS&G C POND DISCH. Outlet Elev: 100. 00 Elev: 98 . 00 ft Orifice Diameter: 0 . 0117 in. STAGE <--DISCHARGE---> STAGE -DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> (ft) ---CfS-- ------- (ft) ---CfS-- ------- (ft) ---CfS-- ------- (ft) ---CfS-- ------- -------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------- 100.00 0.0000 101.60 0.0000 103.20 0.0000 104.80 0.0000 100.10 0.0000 101.70 0.0000 103.30 0.0000 104.90 0.0000 100.20 0.0000 101.80 0.0000 103.40 0.0000 105.00 0.0000 100.30 0.0000 101.90 0.0000 103.50 0.0000 105.10 0.0000 100.40 0.0000 102.00 0.0000 103.60 0.0000 105.20 0.0000 100.50 0.0000 102.10 0.0000 103.70 0.0000 105.30 0.0000 100.60 0.0000 102.20 0.0000 103.80 0.0000 105.40 0.0000 100.70 0.0000 102.30 0.0000 103.90 0.0000 105.50 0.0000 100.80 0.0000 102.40 0.0000 104.00 0.0000 105.60 0.0000 100.90 0.0000 102.50 0.0000 104.10 0.0000 105.70 0.0000 101.00 0.0000 102.60 0.0000 104.20 0.0000 105.80 0.0000 101.10 0.0000 102.70 0.0000 104.30 0.0000 105.90 0.0000 101.20 0.0000 102.80 0.0000 104.40 0.0000 106.00 0.0000 101.30 0.0000 102.90 0.0000 104.50 0.0000 101.40 0.0000 103.00 0.0000 104.60 0.0000 101.50 0.0000 103.10 0.0000 104.70 0.0000 4/30/98 7 : 33 : 50 am A.D.A. Engineering page 3 BELFAIR SAND AND GRAVEL ACTIVE MINING PERIOD 25 YR STORM ZERO DISCHARGE STAGE DISCHARGE TABLE MULTIPLE ORIFICE ID No. DIS2 Description: BS&G A,B,D POND DISCH. Outlet Elev: 100. 00 Elev: 98 . 00 ft Orifice Diameter: 0. 0117 in. STAGE <--DISCHARGE---> STAGE -DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> (ft) ---cfs-- ------- (ft) ---cfs-- ------- (ft) ---cfs-- ------- (ft) ---cfs-- ------- -------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------- 100.00 0.0000 102.60 0.0000 105.20 0.0000 107.80 0.0000 100.10 0.0000 102.70 0.0000 105.30 0.0000 107.90 0.0000 100.20 0.0000 102.80 0.0000 105.40 0.0000 108.00 0.0000 100.30 0.0000 102.90 0.0000 105.50 0.0000 108.10 0.0000 100.40 0.0000 103.00 0.0000 105.60 0.0000 108.20 0.0000 100.50 0.0000 103.10 0.0000 105.70 0.0000 108.30 0.0000 100.60 0.0000 103.20 0.0000 105.80 0.0000 108.40 0.0000 1M.70 0.0000 103.30 0.0000 105.90 0.0000 108.50 0.0000 100.80 0.0000 103.40 0.0000 106.00 0.0000 108.60 0.0000 100.90 0.0000 103.50 0.0000 106.10 0.0000 108.70 0.0000 101.00 0.0000 103.60 0.0000 106.20 0.0000 108.80 0.0000 101.10 0.0000 103.70 0.0000 106.30 0.0000 108.90 0.0000 101.20 0.0000 103.80 0.0000 106.40 0.0000 109.00 0.0000 101.30 0.0000 103.90 0.0000 106.50 0.0000 109.10 0.0000 101.40 0.0000 104.00 0.0000 106.60 0.0000 109.20 0.0000 101.50 0.0000 104.10 0.0000 106.70 0.0000 109.30 0.0000 101.60 0.0000 104.20 0.0000 106.80 0.0000 109.40 0.0000 101.70 0.0000 104.30 0.0000 106.90 0.0000 109.50 0.0000 101.80 0.0000 104.40 0.0000 107.00 0.0000 109.60 0.0000 101.90 0.0000 104.50 0.0000 107.10 0.0000 109.70 0.0000 102.00 0.0000 104.60 0.0000 107.20 0.0000 109.80 0.0000 102.10 0.0000 104.70 0.0000 107.30 0.0000 109.90 0.0000 102.20 0.0000 104.80 0.0000 107.40 0.0000 110.00 0.0000 102.30 0.0000 104.90 0.0000 107.50 0.0000 102.40 0.0000 105.00 0.0000 107.60 0.0000 102.50 0.0000 105.10 0.0000 107.70 0.0000 4/30/98 7 : 33 : 51 am A.D.A. Engineering page 5 BELFAIR SAND AND GRAVEL ACTIVE MINING PERIOD 25 YR STORM ZERO DISCHARGE LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- -PEAK- STORAGE <--------DESCRIPTION---------> (cfs) (cfs) --id- --id- <-STAGE> id VOL (cf) ABDMINE 25YR ................. 0.00 14.90 ST02 DIS2 108.20 10 6 ac-ft 4/28/98 9: 48: 6 am A.D.A. Engineering page 9 BELFAIR SAND AND GRAVEL ACTIVE MINING PERIOD 25 YR STORM ZERO DISCHARGE --------------------------------------------------------------------- --------------------------------------------------------------------- LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> STORAGE <--------DESCRIPTION---------> (cfs) (cfs) --id- --id- <-STAGE> id VOL (cf) ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- CMINE 25YR ................... 0.00 4.74 ST03 DIS3 105.91 11 80838.14 cf