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HomeMy WebLinkAboutSDP000000107 Calculations 2001-05-15 Short Version BMP Computations For Worksheets 2 -6 Albemarle County Water Protection Ordinance: Modified Simple Method Plan: Townwood Mobile Home Park Water Resources Area: Development Area Preparer: Kurt M. Gloeckner, P.E.,P.L.S. Date: 15-May-01 Project Drainage Area Designation DA#1 L storm pollutant export in pounds, L=[P(Pj)Rv/12][C(A)2.72] Rv mean runoff coefficient, Rv=0.05+0.009(1) Pj small storm correction factor,0.9 percent imperviousness P annual precipitation,43"in Albemarle A project area in acres in subject drainage area, A= 5.60' C pollutant concentration, mg/I or ppm target phosphorus f factor applied to RR ✓ required treatment volume in cy,0.5"over imperv.area= A(I)43560(0.5/12)/27 RR required removal, L(post)-f x L(pre) %RR removal efficiency, RR100/L(post) Impervious Cover Computation(values in feet&square feet) Item pre-development Area post-development Area Roads Length Width subtotal Length Width subtotal 300, 25 7500 300 25i 7500 0 0 0 1150 201 23000 0 0 00 0 7500 0 30500 Driveways Length Width no. subtotal Length Width no. subtotal and walks 1450 10 1 14500 1450 10 11 14500 0 0 0 0 0 0 0 0 0 14500 0 14500 Parking Lots 1 2 3 4 1 2 3 4 Gravel areas Area 36250 Area 24000 x 0.70= 25375 x 0.70= 16800 Structures Area no. subtotal Area no. subtotal 900 46 41400 900 611 54900 0 00 0 0€ 0 0 ..,... 0 41400 0 54900 Actively-grazed pasture& Area Area yards and cultivated turf 0 x 0.08= 0 0 x 0.08= 0 Active crop land Area Area 0x0.25= 0 x0.25= 0 Other Impervious Areas 0 0 Impervious Cover 36% 0 . I(pre) l(post) I :.::::::: (P ) Rv(post) V 0.48 180.1 New Development(For Development Areas,existing impervious cover<=20%) C f I(pre)* Rv(pre) L(pre) L(post) RR %RR Area Type Wai070 W M41 , 20%; 0.38 12.98 16.52 3.54 21%, Development Area £)35 `f00 0% 0.38 6.49 8.26 1.77 ••••:•.•:21° Drinking Water Watersheds j fa., 0.38 7.42 9.44 2.02 , 21°/0 Other Rural Land *min.values ».y Redevelopment(For Development Areas,existing impervious cover>20%) C f I(pre)* Rv(pre) L(pre) L(post) RR % RR Area Type O10 0 90 % 0.38 12.98 16.52 4.84 29%.: Development Area ,. 0 30 0 80 X% 0.38 6.49 8.26 2.74 33% DrinkingWater Watersheds 040BEZWOUNgtreginEnvimpi 0.38 7.42 9.44 3.14 • 33%`Other Rural Land Interim Manual, Page 70 rev. 16 Feb 1998 GEB Short Version BMP Computations For Worksheets 2-6 Albemarle County Water Protection Ordinance: Modified Simple Method Plan: Townwood Mobile Home Park Water Resources Area: Development Area Preparer: Kurt M. Gloeckner, P.E.,P.L.S. Date: 15-May-01 Project Drainage Area Designation DA#2 L storm pollutant export in pounds, L=[P(Pj)Rv/12][C(A)2.72] Rv mean runoff coefficient, Rv=0.05+0.009(1) Pj small storm correction factor, 0.9 I percent imperviousness P annual precipitation,43"in Albemarle A project area in acres in subject drainage area, i A= !.-..6.97' C pollutant concentration, mg/I or ppm target phosphorus f factor applied to RR ✓ required treatment volume in cy,0.5"over imperv. area= A(1)43560(0.5/12)/27 RR required removal, L(post)-f x L(pre) %RR removal efficiency, RR100/L(post) Impervious Cover Computation(values in feet&square feet) Item pre-development Area post-development Area Roads Length Width subtotal Length Width subtotal 0 0 0 900 20 18000 0 0 0 100 201 2000 0 0 0 0 O 0 0 20000 Driveways Length Width no. subtotal Length Width no. subtotal and walks 900 10 1 9000 20 1080 16000 0 0 0 0 0 0 0 0 O 9000 0 16000 Parking Lots 1 2 3 4 1 2 3 4 0 0 4200 0 4200 Gravel areas Area 22500 Area 0 x0.70= 15750 x0.70= 0 Structures Area no. subtotal Area no. subtotal 900 27 24300 900 42 37800 00 0 0 0` 0 ....._ . O._ 0 ... , .._� . 0 24300 0 37800 Actively-grazed pasture& Area Area yards and cultivated turf 0 x 0.08= 0 0 x 0.08= 0 Active crop land Area Area 0 x0.25= 0 x0.25= 0 Other Impervious Areas 00 Impervious Cover 16% • 26/°..6o. £ I(pfe) ((post)'...,.,., Rv(post) V 0.28 120.4 New Development(For Development Areas,existing impervious cover<=20%) C f I(pre)* Rv(pre) L(pre) L(post) RR % RR [Area Type 0 100 20%; 0.23 9.84 12.03 2.19 18°/d Development Area 035 100 0% 0.20 4.18 6.02 1.84 31% Drinking Water Watersheds 040 100 1`36:. 0.20 4.78 6.88 2.10E _. 31%.:i•Other Rural Land *min.values Redevelopment(For Development Areas,existing impervious cover>20%) C i f I(pre)* Rv(pre) L(pre) L(post) RR .% RR Area Type 0 70 0€30 ` 20% 0.23 9.84 12.03 3.18 26%1 Development Area iiiiiiigOOSM:.(I$ 0°g 0.20 4 18 6 02 2.46 41%s Drinking Water Watersheds .... 085 1 a 0.20 4.78 6.88 2.81 : 41%,Other Rural Land Interim Manual, Page 70 rev. 16 Feb 1998 GEB C_o \ %A-) 1-A \ATCDO i\Att) te< - us 44F._ aptRA\ki \ c `A-.)Cr± C:)`3 \ cr v-7-0 Itzt AT\ 014 TIl 0-4 oF S 7 A K10 -Dr_mAt443 -1-4A1.4 az/0 ce -At-sc sz* F- • .r-0vJ GIA 7-0 .a5ar_. cmi AA 1-4 C.= Ns , 3 111,,m,A 1,1 C--- C_ 0 A 1c3c5 -17-\'0L)T k V-170 .5/77/0 C:"--7- 1C C4 cvu),:\ woc5-12:) '(\014.4z._ -4R.A.. ;1A, c_.0,),e:R.s. A A- „), G .°17 A 1 i\A FE.. 'D US = 2.6)/ Pc 0. z6 c.`'17 A C,. - \ , , \ S VV PST - .4:55G‘4, Z ')e (y: z(--sH2-8 -7- c 's70 Un-15- m ► rJ i tLA J 6 •1 #6 L- VC)L 1 C U e..-1z> 1., t0 = ` � , 374 c (as70 _ i Z( Goo) AcLuz) ujoke%_ - r� oz CDRr a Q• 0 4-� �. e 0, 5 C� i��, o4 � z (5z` Z (05-19 Te. \(Di 9 6 '5 0 . 19,8 • Gc, 04P Walk elt-1r-k T r Z 4-6c) of 4 z 57 A.Ac, • `.3 , Q ‘7 c.- c = 0, 5 (4--.3s4,13 -- 54k- al cP tZ tS �7 L o TR:), ►A • '1)t Z ' o C3 . 1 "7 k .-Tr , X GO) 'Z oa=J Co, 0 02.2 432.., 2)(3, 7:0 ,10-jei a F ► o , <, 6. ~3 "a..5 4- C:c A t-L-o SAM C4 t Z(3Goo' - --- s'4- gsst ,a M' • _ - r 5 0 to mf � d 3 " Colv►1' iNv=C Cid t�vi -""506 ; o tJ 4t301/4)-"C \0 '1 '_ ra-"'C' cnA T o a C��' �co Z o c7 ':s ---�o 54 Ac. 0 ,5C, 5 00 6 D 1'5 Q.}LeV- ' RC ' Se - Soca toP Co z- �z. Oc o9G77 GRADING QUANTITIES PROJECT : 0viM \JOC`)-� 0e-,1FILE ' tC\—O 7--00 DESCRIPTION: 1 Q v T T1O�•.� ( ,�CT�t�('Dc1J i2-►\r __ AW � SHEET ‘, OF X- SECT AVG. AREA V 0LUME STATION DIST Aroa,s.f. s'f. c.f. cat-E.4 sobI 75, 1 I z I x 3c I 732- SOS I6s5 ha l x ( 544 30PiS ►© 12433 I x 3o 7 :3,057 I3. G2I 1 1 I x 44 a 5k2. 153 I I 1 x - cF. I j I Ix I Ix x I Ix I Ix I Ix Ix I Ix x x j I Ix �...�.....1...x.1 x i GLOECKNER ENGINEERING/SURVEYING, INC. Charlottesville, Virginia . l � � F.xcv_.._11 N` . '.1 .r--1-e---1-VT\cq--.\-\ �a �� �� iz-A4 PERIOD INTENSITY PEAK FLOW TIME OF CONCENTRATIONMIN ( YEAR� H|< ) ( IN/ ) ( CF5 ) C-FACT0R= ' O56O - 5 ------- --------- AHEA= 6 '65 i:•:-:V1-IR E-3..; � 5 '40 l9 .U4 5 5 '36 23 '33 10 7 - 10 26 '06 25 3 '00 29 .39 5O 8 '90 32 '70 100 9 -50 35 '27 HYDRUGRAPH TIME OF CONCENTRATION = 6 '0 MIN STORM DURATION = 6 '0 MIN TIME 02 05 QlO 025 O50 0100 ( MIN ) ( CFS ) ( CFS ) ( CFS ) ( CFS ) ( CF5 ) { L:PS ) -_-_- --- __ ---- 0 'O 0 '00 0 .00 0 .00 0 .0O 000 0 0( 1 '0 � '97 4 -67 5 .22 5 .88 6 'S4 / ' vD 2 '0 7 .93 9 '33 10 .43 11 '76 l30G 14 lu 3 '0 11 '90 14 '00 15 .66 l7 '6J l9 '32 2I ^l � 4 .0 15 .87 18 .66 20 .0/ 23 .61 25 , 15 28 ,21 u 5 .0 19 '84 23 '33 26 .08 29239 32 '7O Jb 'r 6 '0 17 '46 20 '63 22 '96 25 .87 28 ^ /G 31 7 .0 16 .09 17 � 19 .84 22 _35 24 'G5 26 '82 ^v1/ .1/ ..74-8 .0 12 .. /1 14 '95 15 .71 13 .83 2O '95 22 ^50 9 '0 10 '33 12 . 16 13 ..59 15 .31 l7 'O3 10 .3Y 10 '0 7596 9 .36 10 .45 11 - 79 13 . 12 14 11 .0 S S8 6 ' 57 7 .34 8 '27 9 'ZO 9 ' �� 12 '0 3 '21 3 '77 4 .22 4 ''75 5 '29 G ' r� l3 ' ' .0 O '8� 0 98 1 D9 l '�3 ' ' ' « l 37 1 4G �*********************************************-'x******* �-**********�. ****** r .'.t-. n ROUT VERSION 6 '2 ** PROJECT : TOWNW0OO-EXT 2Y ` ***** ***** ***********************************************�*DATE � +0�-l7_�U0l* �� ����� T>K*:r* **�� STRUCTURE l STRUCTURE 2 STRUCTURE 3 __________- l ' TYPE --- ' 3 : RISER WElR : 2 : ELEVATION ( FT ) 0 '00 0 .00 0 _00 3 : LENGTH ( FT ) 0 '00 0 'OO O 'O0 , 4 : COEFFICIENT 0 '00 D ' 0O O 'OO RISER : 5 : ELEVATION ( FT ) 611 .50 D ^00 0 '0O 6 : DIAMETER ( IN ) 60 .00 0 '00 0 .00 7 :*. ORIFICE ELEVATION ( FT ) 506 .00 O 'OO U 'O0 8z ORIFICE DIAMETER ( IN ) 2 .00 U 'O0 0 ^0O 9 : ORIFICE ELEVATION ( FT ) 0 '00 O ^O0 O 'Q0 10: ORIFICE DIAMETER ( IN ) 0 '00 O 'O0 0 „00 11 � ORIFICE ELEVATION ( ET ) 0 .00 0 'O0 O 'OO pTpE _ 3 12 � ORIFICE DIAMETER ( IN ) 0 .00 0 ^ 00 O .:00 ' l143: INVERT ELEVATION ( /T ) 506 .00 O ~'OO O ''O0 , l4DIAMETER ( IN ) 36 .00 000 DOO 15 ':, ORIFICE DIAMETER ( IN ) 36 '00 O '00 O '00 16 . LENGTH ( FT ) 6� 00 0 ' 00 - n.� 17 .. MANNlNG 'b N .016 UD0 00� ' ( t�^) 18 : SLOPE ( FT/FT ) .09/ ' . ^�� 197 ENTRANCE LOSS COEFFICIENT 'S ^UOO .00O SURFACE 20 : INITIAL. ELEVATION ( FT ) 50600 O 'O STORAGE POND CHARACTERISTICS '.: SECTION ELEVATION ARLA ( FT ) ( SO FT ) --------------------------- -- 1 505 .74 0 .00 ( CALCW-ATLD ) 2 606 .00 76 '00 3 500 '00 665 '00 4 510 .00 2 ,403 .00 H 611 '00 3 ,681 .00 6 512 ,00 5 ,3I2 00 CONTROL : RW = RISER ACTING AS A WEIR RU = RISER ACTING AS AN ORIFI[E PI = HORIZONTAL PIPE IN INLET CONTROL PO = HORIZONTAL PIPE IN OUTLET CONTROL. TIME INFLOW RISER TOTAL ELEV STORAGE ( MIN ) ( CFS ) ( CF5 ) ( CFS ) ( FT ) ( CU FT ) 0 0 '00 O 'O 0 .00 506 .00 0 .00 1 3 .97 0 . 1 0 . 14 506 '60 lI4 ''32 3 7 .93 0 .2 0 ' 19 607 '33 45622 3 11 '90 0 '2 0 '22 508 '03 l ,004 ''99 4 15 '87 0 .3 0 '25 608 ' 73 1 ,85029 5 19 .84 0 .3 0 .28 509 '41 2 ,902 ^ 10 6 17 .46 0 '3 0 '31 509 '98 3 ,999 '20 7 15 '09 0 '3 O .33 510 .42 4 ,96O '' 72 8 12 ' 71 0 -3 0 .34 510 -76 .5 ,777 .26-26 9 10 '30 0 .4 0 .35 511 '02 6 ,46080 10 7 .96 0 .4 0 .36 511 '21 6 ,9GU ~99 11 5 '58 0 .4 0 .36 311 '35 7 ,367 ' 2S l2 ] .21 0 '4 0 .37 511 .43 7 ,6O9 ^79 13 0 '83 O '4 O '37 511 .46 ~/ 7 .709 ' 06 `--~ 0 4 Q ) ' , r N1 b b �v17.ia-v-1 01-1 PERIOD INTENSITY PEAK FLOW TIME OF CONCENTRATION= 5 MIN ( YEARS ) ( IN/HR ) ( CFS ) C.-FACTOR=0 ..560 ' ------- --------- --------- AREA 6 .56 ACRES 5 .40 19 .84 5 6 .35 23 .33 10 7 . 10 26 .08 25 8 .00 29 .39 50 8 .90 32 .70 100 9 .60 35 .27 HYDR0GRAPH TIME OF CONCENTRATION = 5 .0 MIN STORM DURATION = 5 .0 MIN TIME 02 05 010 025 050 0100 ( MIN ) ( CFS ) ( CFS ) ( CFS ) ( CFS ) ( CFS ) ( CFS ) ----- 0 .0 0 .00 0 .00 0 .00 0 .00 0 .00 0 .00 1 .0 3 .97 4 .6/ 5 .22 5 .88 6 .54 _, 5 2 .0 7 .93 9 .33 10 .43 11 .76 :13 .08 14 . 11 3 .0 11 .90 14 .00 15 .65 17 .63 19 .62 4 .0 15 .87 21 . 1618 .66 20 .87 23 .51 26 . 16 28 .21 5 .0 19 .84 23 .33 26 .08 29 .39 32 .70 35 .27 6 .0 17 .46 20 .53 22 .96 25 .87 28 .78 31 .04 7 .0 15 .09 17 .74 19 .84 22 .35 24 .86 26 .82 8 .0 12 .71 14 .95 16 .71 18 .83 20 .95 22 .60 9 .0 10 .33 12 . 15 13 .59 15 .31 17 .03 18 .37 10 .0 7 .96 9 .36 10 .46 11 .79 13 . 12 14 . 15 11 .0 5 .58 6 .57 7 .34 8 .27 9 .20 9 .93 12 .0 3 .21 3 .77 4 .22 4 .75 5 .29 5 .70 13 .0 0 .83 0 .98 1 .09 1 .23 1 .37 1 .48 ******************************************************* :******* ********:;***** : * ROUT VERSION 5 .2 ** PROJECT : TOWNWOOD/EXT-DET ** DATE: 03-09-2001* *********************************************************** :****************** STRUCTURE 1 STRUCTURE 2 STRUCTURE 3 WEIR : 1 : : _ 2: ELEVATION ( FT ) RISER __ ____. ----------- 0 .00 0 .00 0 .00 3: LENGTH ( FT ) 0 .00 0 .00 0 .00 4 : COEFFICIENT 0 .00 RISER: 5: ELEVATION ( FT ) 0 .00 0 .00 51.1 .50 0 .00 0 .00 6 : DIAMETER ( IN ) 60 .00 0 .00 0 .00 7: ORIFICE ELEVATION ( FT ) 505 .00 0 .00 8 : ORIFICE DIAMETER ( IN ) 2 .00 0 .00 0 .00 0 .00 9: ORIFICE ELEVATION ( FT ) 0 .00 0 .00 10: ORIFICE DIAMETER ( IN ) 0 .00 0 .00 11 : ORIFICE ELEVATION ( FT ) 0 .00 0 ,00 0 .00 12: ORIFICE DIAMETER ( IN ) 0 .00 0 .00 PIPE: 13 : INVERT ELEVATION ( FT ) 506 ,00 0 .00 0 .00 ()0 0 .r)0 14 : DIAMETER ( IN ) 36 .000 0 .00 0 .00 15 : ORIFICE. DIAMETER ( IN ) 36 :,00) 0 .00 0 .00 11 : MANNING 'S N ,.024 .000 .000 6) Ag' 18 : SLOPE ( FT/FT ) .097 .000 .000 19 : ENTRANCE LOSS COEFFICIENT 5 0 {a SURFACE : 20 : INITIAL ELEVATION ( FT ) 506 .00 STORAGE POND CHARACTERISTICS: SECTION ELEVATION AREA ( FT ) ( SU FT 1 505 .74 0 .00 ( CALCULATED ) 2 506 .00 76 .00 3 508 .00 655 .00 4 510 .00 2 ,433 .00 5 511 .00 3 ,681 .00 6 5.1.2 .00 5 ,312 .00 CONTROL : RW RISER ACTING AS A WEIR RO = RISER ACTING AS AN ORIFICE PI = HORIZONTAL PIPE IN INLET CONTROL PO = HORIZONTAL PIPE IN OUTLET" CONTROL TIME INFLOW RISER TOTAL ELEV STORAGE ( MIN ) ( CFS ) ( CFS ) ( CFS ) ( FT ) ( CU FT ) - ----------------- -------- ---------------------- -- 0 0 .00 0 .0 0 .00 506 .00 0 .00 1 5 .22 0 .2 0 .15 506 .72 152 .84 2 10 .43 0 .2 0 .20 507 .55 609 .56 3 15 .65 0 .2 0 .24 508 .35 1 ,377 .01 4 20 .87 0 .3 0 .27 509 . 1.4 2 ,455 .33 5 26 .08 0 .3 0 .31 509 .91. 3 ,844 .65 6 22 .96 0 .3 0 .33 510 .56 5 ,293 .87 7 19 .84 0 .4 0 .35 511. .06 6 ,562 .21 8 16 .71 0 .4 0 .37 511 .44 7 ,647 .71 9 13 .59 4 ,8 RW 4 .75 511. .69 8 ,401 .97 10 10 .46 8 ,7 RW 8 .71. 511 .79 8 ,722 .82 11 7 .34 8 .9 RW 0 .87 511. .80 8 ,734 .49 12 4 .22 7 . 1 RW 7 .12 511 .76 8 ,600 .66 13 1 .09 4 .7 RW 4 .75 511. .69 8 ,401 .59 ' ,X1 o , r.i 40' 1/: MANNING 'S N .024 00 .000 18 : SLOPE ( FT/FT ) 097 .000 .000 19: ENTRANCE LOSS COEFFICIENT .5 .0 .0 SURFACE : 20 : INITIAL ELEVATION ( FT ) 506 .00 STORAGE POND CHARACTERISTICS : SECTION ELEVATION AREA ( FT ) ( SQ F=T ) I 505 .74 0 .00 ( CALCULATED ) 2 506 .00 76 .00 3 508 .00 655 .00 4 510 .00 2 ,433 .00 5 511 .00 3 ,681 .00 6 512 .00 5 ,312 .00 CONTROL : RW = RISER ACTING AS A WEIR RO = RISER ACTING AS AN ORIFICE PI = HORIZONTAL PIPE IN INLET CONTROL PO = HORIZONTAL PIPE IN OUTLET CONTROL TIME INFLOW RISER WEIR TOTAL ELEV STORAGE ( MIN ) ( CFS ) ( CFS ) ( CFS ) ( CFS ) ( FT ) ( CU FT ) 0 0 .00 0 .0 1 8 .85 0 .2 0 .0 0 .17 506 .98 260 .37 2 17 .70 0 .2 0 .0 0 .22 508 .05 1 ,045 .38 3 26 .55 0 .3 0 .0 0 .27 509 .07 2 ,350 .90 4 35 .40 0 .3 0 .0 0 .31 510 .07 4 ,190 .78 5 44 .24 0 .4 0 .0 0 .35 511 .05 6 ,554 . 12 6 38 .95 9 ,0 RW 0 .0 8 .99 511 .80 8 ,743 .46 7 33 .65 27 .0 RW 1 .4 28 .42 512 . 14 9 ,846 .99 8 28 .35 28 .8 RW 1 .8 30 .53 512 . 16 9 ,937 .82 9 23 .05 25 .5 RW 1 .0 26 .56 512 .11 9 ,765 .01 10 17 .75 21 .4 RW 0 .3 21 .70 512 .05 9 ,536 .47 11 12 .45 17 .0 RW 0 .0 17 .03 511 .97 9 ,275 .95 12 7 . 15 12 .4 RW 0 .0 12 .36 511 .87 8 ,978 .75 13 1 .85 7 .7 RW 0 .0 7 .65 511 .77 8 ,642 .81