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HomeMy WebLinkAboutSW1210902_Plansheet - SCM Detail_20211124J w Q w z CD w m m Q L2 N 0 N 0 z w �w zz oQ Q:5 �m mw O�_ wQ z3: m O of wo 0 w Q 0 cn 1 0 r m w z CD w Q ry . I- DA 8 L CD A 1 I uuuuuuuu DA 3 SAND FILTER DA= 6.27 AC AUNUIN I E UI�IVL� 60' R/W AND VARIABLE WIDTH R/W DRAINAGE AREA MAP SCALE: 1 "=80' DA 7 DITCH CALCULATIONS DITCH DIMENSIONS Q10 (CFS) V (FT/S) DEPTH (FT) STABILIZATION SHAPE: TRAPEZOIDAL DITCH-1A BOTTOM WIDTH=2' 2.67 1.51 0.37 SOD MIN. VERT. DEPTH=1.0' SHAPE: TRAPEZOIDAL DITCH-1 B BOTTOM WIDTH=2' 6.33 2.30 0.68 SOD MIN. VERT. DEPTH=2.0' SHAPE: TRAPEZOIDAL DITCH-1 C BOTTOM WIDTH=2' 5.90 2.34 0.68 SOD MIN. VERT. DEPTH=3' SHAPE: TRAPEZOIDAL DITCH-2 BOTTOM WIDTH=2' 24.76 5.92 1.03 SOD MIN. VERT. DEPTH=3 SHAPE: TRIANGULAR EXISTING DIVERSION DITCH MIN. VERT. DEPTH=1.2' 24.76 7.21 1.07 N/A AVE. SIDE SLOPE=3:1 DRAINAGE AREA TABLE DA RECIEVING STORM SYSTEM ON -SITE AREA (AC) OFF -SITE AREA (AC) TOTAL AREA (AC) CN ToC (MIN) Q10 (CFS) Q25 (CFS) DA-1 TRENCH DRAIN 0.13 0.00 0.13 98.00 5.00 0.90 1.07 DA-2 CI-2.4 0.99 0.00 0.99 96.00 5.00 7.35 8.70 DA-3 CI-2.3 0.51 0.00 0.51 92.00 5.00 3.61 4.32 DA-4 DITCH-1 C 1.77 0.00 1.77 80.00 19.10 5.90 7.49 DA-5 DITCH-1 B 1.59 0.00 1.59 82.00 14.70 6.33 7.99 DA-6 D ITCH-1 A 0.47 0.00 0.47 87.00 7.10 2.67 3.27 DA-7 EXIST. 18" CMP 0.00 25.20 25.20 62.00 33.90 26.41 38.85 DA-8 EXISTING DRAINAGE DITCH 0.67 25.20 25.87 62.00 33.90 24.76 36.90 DA-9 EXISTING STREAM 0.20 26.50 26.70 61.00 37.90 24.52 36.57 Know what's below. Call before you dig. ;Gi No, 1405Vz. w o$ t SW 36" INV=20 Fw RIM =2059.53 � SW 18" INV=2049.26I S 10" INV=2057.00 E 24" INV=2049.22 0 Ln J PROPOSED IMPACTS - STREAM 1 (88.4 LF/0.006 AC)� 78 LF OF 36" HDPE_ N-12 WT ST ® 2.15% HW-1- NE 36" INV=2051.28 FES-1 W 24" INV=2049.00 �Fw Fw 44 LF OF 24" HDPE N-12 WT ST ® 0.50% ` 6 LF OF 10" HDPE N-12 WT ST ® 2.00\/% / 0' �TIR(ELHIDRAIN IISEE NCDOT DETAIL 840.30 I ON SHEET C2.4. II ,� 2060 58 LF OF 18" HDPE N-12 WT ST ® 0.50% 205 I I I I I ! I I' I I BENCHED FILL SLOPE. 2:1 MAX. SEED AND STABILIZE AS SPECIFIED. EXISTING BYPASS SWALE, TO REMAIN. ENLARGED VIEW: TRUCK ENTRANCE SCALE: 1 "=20' STUB 4" SCH. 40 PVC UNDERDRAIN INTO OUTLET CONTROL STRUCTURE. 4" STUB SERVES AS CONTROL ORIFICE. INV. ELEV = 2056.50 COMPACTED SUBGRADE Fw � FES-2 SW 24" INV=2052.00i 12' WIDTH RIP -RAP EMERGENCY SPILLWAY. D50=8". INSTALL TO 16" DEPTH OVER MIRAFI 140N EC FABRIC. 64 LF OF 24" HDPE -12WTST® 2.00% _� OLpZ LO 5 co N co 2070.00 0 0 FG OCS-2.1 RIM=2062.50 2070 SE 4" INV=2056.50 NE 24" INV 20 3.28 SANDFILTER. SEE DETAIL BELOW 1,823 SF. MIN. 090Z / 10' MIN. WIDTH ACCESS / / MAINTENANCE BERM. \ ggpZ 2065.00 FG 2065.00 �n65 • � (I1 �rff �rf1 �I�����j�+� I��%'�I A 206�.4� I \ / I 2064.0 272 LF OF 18" HDPE J 2064.07 N-12 WT ST @ 0.50% - 2:1 SIDE SLOPES. STABILIZE _ CI-2.3 W/ SOD, CONTINUOUS AROUND - SIDES & TOP OF BERM. RIM=2064.07 = NW 18" INV=2059.57 �ssoz- SW 15" INV=2059.59 / AF NE 24" INV=2059.55 _ ENLARGED VIEW: SAND FILTER SCALE: 1 "=20' SAND FILTER DETAIL SCALE: NOT TO SCALE - LINE BOTTOM AND SIDES OF SAND FILTER CHAMBER AND RIP -RAP FOREBAY W/ NON -WOVEN SOIL SEPARATING FABRIC. 6" DEPTH J" WASHED STONE W/ 4" SLOTTED PVC UNDER -DRAIN CENTERED W/N STONE BED. SEE PLAN. PROVIDE TEE SECTION AND CLEANOUT STANDPIPES AT THE END OF EACH RUN. UALITY CONTROL CALCS. RV = 0.05 + 0.9 X IA WHERE RV = RUNOFF COEFFICIENT (STORM RUNOFF (IN) / STORM RAINFALL (IN)), UNITLESS IA = IMPERVIOUS FRACTION (IMPERVIOUS PORTION OF DRAINAGE AREA (AC) / DRAINAGE AREA (AC)) DRAINAGE AREA AT BUILD -OUT: RV=0.05+0.9 (5.13/6.27) RV = 0.786 AND WQV = 3630 X RD X RV X A WHERE WQV = FILTRATION VOLUME (CUBIC FEET) RD = DESIGN STORM RAINFALL DEPTH (IN) 1.0 FOR MILLS RIVER A = WATERSHED AREA (AC) DRAINAGE AREA: WQV = 3630 X 1.00 X 0.786 X 6.27 WQV = 17.889 CF ADJUSTMENT FOR SAND FILTER = WQV X 0.75 = 13.417 CF SURFACE AREA REQUIREMENT AT 4' AVG. DEPTH = 3,354 SF. PROPOSED = 3,646 SF. (1,823 FOREBAY & 1,823 SAND FILTER) Q Q Q m N N N O O O N N N N � o � � N ro \N 0 0-)o ��O\ I O O - z z Q w w :5 m :2 :2 z o U U w 1i � - 3: 3: : w w w O U Q:� __Uw � � 3: 0 w ow� U U j O w D m 0 0 co U) 0 w O m O O w 0 0 0 3: U U U cnzzz N N N N \ \ \ \ w o O � r- _- ����o o 0 CO L N > w O LL CD N � Cl N o Z E 00ID N N C Z J L Y � � m m -> n o 3 N 2 Z = 00 0 Ln¢000 3 LO W !- V Z I� W E Z z p� 0 11.4 CO r::l Q W Z 0 w anzz rp � C) O� I--M--I W M� W Q0 U Q Q cn II REVIEW 10/08/21 RDH w REVIEW 11/15/21 RDH z O n Q O m JOB NO. MNK2001 .01 A SHEET E C2.2 0