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HomeMy WebLinkAboutWPO201300032 Plan - VSMP 2021-06-18r GIOv¢ C° u"p 9 R4rf.'mRd TT: � Owe P¢h 4 �144 e V, w, .cowtlr �QC FtllYna - µdo WeV e o� a4 `E VSMP AMENDMENT #2 FOR WP0201300032 CASCADIA -BLOCKS 4 - 7 TIM 62, PARCEL 25 TM 78, PARCELS 59 & 59A TM 78E, PARCEL H1 RIVANNA DISTRICT, ALBEMARLE COUNTY, VIRGINIA q4 oa " xtlmwd Rd 9 P ��4 •� r }a HansenRd d .? ol= R.yvd Cmiepe Ch Cmtlo. RiverbeM�4 HN CaMM c¢rao. Mav Rd rylaa 0ele ®3012 Garyle- EEX In Aoagk4 COUNTY ENGINEER Curve Radius Tangent Length Delta Chard Chord Bear. C1 17500 9.6519.2968 56 19..2.8 S 26101 23 W 3 33.50 5.4 87.22 915C2 20'5255 E C3 540.0056. 113.12 2'00 1291 7'0351 W C4 35.00 29.63 49.18 8N 523 N'630702 E C5 225.01 12.41 24.79 1647 478 N'260124 E C6 3 121454 314.16 N 13'3420 E Course Beoring Distance L1 S 76'09 34 E 11.47 L2 N 821849 E 1&27 L3 N 55'4711 E 24.40 L4 N 54'3417 E 51.77 L5 N 6T5310 E 24.62 I N 78'35 38 E 53.53 L7 S 88'54 21 E 14.91 L8 S 5C53 41 E 54.57 L9 S 43'0813 E 141.55 L10 S 53'42 27 E 102.87 L11 S 1 T4615 E 166.27 L12 S 10'3018 W 81.51 L13 S 26'34 07 E 85.75 L14 S 1111 50 E 193.39 L15 S 425815 E 44.97 Lib S 03'2749 W 97.27 L17 S 3513 55 E 69.16 L18 S 20'38 22 E 65.59 L19 S 0T4516 W 89.84 00 S 39'49 04 E 53.80 L21 S 39'49 04 E 1170 Lz2 S 25'01 39 W 266.18 L23 N 6458 21 W 192.44 L24 N 64'58 21 W 347.14 L25 S 49'20 31 W 113.71 L26 S 2T51 58 W 53.92 L27 N 225158 E R.25 L28 N 1312 43 E 64.09 L29 N 6458 21 W 322.64 L30 7401 58 E 53.79 91 N 38'2458 E 181.21 92 N 07'0910 E 108.09 L33 -IT 419 04 E 88.36 TMP 78E-H FONTANA LAND TRUST 20' RWSA ESMT: DB 859 PG 53 DB 742 PG 195, 197 PLAT TMP 78-57A KMH PROPERTIES LLC. DB 3222 PC 519 u141111111111111P11 NEW PERMANENT - DRAIN. EASEMENT .pB 2436 PG 623 TMP 62-25C TMP 62-25C1 BROADUS MEMORIAL BAPTIST CHURCH DB 1109 PC 353 DB 1078 PC 97 10' PRIVATE EASEMENT TO BROADUS CHURCH PROPERTY DB 3662 PG 444 20' SANITARY SEWER EASEMENT DB 3662 PG 444 NAIL SET IN WOOD BRIDGE TMP 62-25 CASCADIA DEVELOPMENT, LLC "PARCEL TWO" TMP 78-59 TMP 78-59A TMP 62-25 DB 4209 PC 088 55.266 ACRES (TOTAL) TMP 78-59 L111S011a TMP 78-59A 20' SANITARY SEWER EASEMENT DB 3662 PG 444 NF @ 18" TMP 62-26 CASON, WILLIAM DB 793 PC 106 TMP 78-57 PANTOPS-LAKERIDCE LLC. DB 2805 PC 70 CASCADIA DEVELOPMENT, LLC y591, "PARCEL ONE" W 210560, TMP 78E-H1 (TDTAC) n DB 4209 PC 088 �¢ `Jry N 5.506 ACRES TMP 78E-H N n FONTANA LAND >-0B 41 TRUST I?3 �S9 CAA CL `VTgN9 rri p,9� >26 j N 7/y TMP 78E-C TMP 78E- FONTANA LAND FONTANA OWNERS TRUST 18967ON 'ZZ PONT9NA SN DB PC 281 SU Sp ��IpISI ACg A 100' VIRGINIA ELECTIRC & DN Z1 POWER CO EASEMENT AN9Sc ��0 284Y 2g SEE ALSO DB 867 PG 337 ,�i�yTH Oy plc o Dustin E. Greene LiC. N0. 55833 b� 6118121 ti}y �9SIONAL SI SW 1 Cover Sheet 2 viations, & Legend SW3 Existing Conditions SW4 Subdivision Overview SW5 Erosion and Sediment Control Phase 3 Plan Overview SW6 Erosion and Sediment Control Phase 3 Plan SW7 Erosion and Sediment Control Phase 3 Plan SW8 Erosion and Sediment Control Phase 3 Plan SW9 Erosion and Sediment Control Phase 3 Plan SW 10 Sediment Basin Details SW 1 1 Sediment Basin Details SW 12 Sediment Trap Details SW13 E&SC Details SW 13A Stormwater Management Plan - Final Grading ¢ al Grading W 14 Stormwater Management Plan/Details 2 SW1 als SW 16 Stream Buffer Mitigation Plan SW 17 Pre -Development Drainage Areas SW 18 Post -Development Drainage Areas SW 19 Storm Sewer Profiles SW20 Storm Sewer Profiles SW21 Storm Sewer Profiles SW22 Storm Sewer Profiles SW23 Storm Sewer Profiles and Details SW24 Storm Sewer Calculations SW25 Storm Sewer Calculations VSMP AMENDMENT #2 FOR WP0201300032 THIS AMENDMENT IS TO CONVERT THE SEDIMENT BASIN FACILITY IMMEDIATELY ADJACENT TO ROUTE 20 NORTH INTO THE PERMANENT WET POND FACILITY THAT WILL PROVIDE STORMWATER MANAGEMENT WATER QUANTITY AND QUALITY CONTROL FOR THE 60.77 ACRE CASCADIA SUBDIVISION. THE NORTHEASTERN PORTION OF THE POND BOTTOM AND THE EASTERN 2:1 POND UPLAND SLOPE WAS LOCATED IN CUT WITH DEPTHS OF UP TO 30. SIGNIFICANT ROCK WAS ENCOUNTERED IN THESE LOCATIONS AT THE POND ELEVATIONS, WHICH WAS FAIRLY HARD ROCK, BUT WAS ALSO FAIRLY RIPPABLE. THE CONTRACTOR RIPPED AS MUCH OF THE ROCK AS FEASIBLE USING A HOE RAM BUT ENCOUNTERED REFUSAL AT BEDROCK. FOR THIS REASON, THE PROVIDED POND VOLUME IS APPROXIMATELY 90% OF THE ORIGINALLY APPROVE PLANS. THE PERMANENT POOL HAS BEEN LOWERED AND THE OUTLET STRUCTURES HAVE BEEN UPDATED SO THAT THE STORMWATER FACILITY PERFORMS WITH THE INTENT OF THE ORIGINAL APPROVED PLANS AND CALCULATIONS. PLEASE SEE SHEET 14 FOR THE UPDATED DESIGN DETAILS AND THE H&H CALCULATIONS FOR COMPLIANCE WITH THE ORIGINAL APPROVED PLAN. 11 a �2 *o x N Cn 00) 2 1 W W Na E-, Z Q� ZO 2 aD O� x LLU > 0 Q•,Lz V1 QW J JJ U� 42 at,W W Q W LI Ootor V,K l ON w pR Urn N Wg O� Q� QLL 4W Wjj IK to p CO W o I� % a REVISIONS EROSION STABILIZATION AREA ADDED AUG. 22, 2018 COUNTY COMMENTS OCT. 2, 2018 VSMP AMENDMENT FEB 19, 2021 COUNTY COMMENTS APR. 2, 2021 COUNTY COMMENTS MAY 6, 2021 DATE APR. 17, 2014 SCALE AS SHOWN O LL �i z z �� iz Z O 0 W Z W J m _ � W T_ Q Q w m a W W W O U Q Pr Q U0 G Q Q U'- Ir FILE NUMBER 12.0065 SHEET SW1 ction Compacted Soil / First lntercontist Chu a Broadus B Pwith PY0 0� Riprap Class 1A / accordance _ _ _'.'.'.' O Emer enc Spillway = 355.93' / - nb 4712 & C'r O O , , Filter Cloth and riprapI I" MjNI O O p' to be keyed into �2 25' MIN embankment 9" =III_ Tie riprap into the top edge of the existing riprap ditch for a smooth transition for flow 3.0' MIN / 58� '--/--_ /" O 8 MODIFIED PERMANENT DIVERSION DIKE DD SW14 NOT TO SCALE i 55.3 / / 11 TIE INTO EXISTIN� , ; - _-r_ / / I% I / f / / ^\\ , EMERGENCY / � I � I I � � ��� I � / / 1 / � //I // j/I I / I � /�'// / //'/ /% V •/i // _/ \ A SPILLWAY�� K I I /I / / / / / ;/r ' cc OCP raiser \ � I 1A � \ I I /J / \ Iz 1 I \ / II I II II III I I I II Ma nt�na@c II I I I I I I I I I I II \ II \ i \ MEase(nelnt 1 I I I I 12:11 I\ \ \ \ I \ DB 14712 1PG 104 V I II I II I II I I II 11 II it \ \ A v \ qB 4732 �G16/I �l -17 Pbnd 3 \\ \ I \ 3o I 606 \ �.-'n. Q z ah o \ \\ \\ 1 \\ I \\ 1 \I\,,\\III I I I \ 45 \ \\ I\ \\ \\ \ \\\\ 1 \ \ \ \ \ I \ \ \ \ \ \ \\\ \ \ \ lice Ith I\ \ V I T I td. 05 \ \ 1 A V v \ V 11 VAI\11 s Existll \V�mp \ 1 \ 1 Constwl \ DB 55WW Fq I \\ V X 5 o �P / \ \ 3 v / / V. 0 Fo ebeY \ I A V 1 (\ I Sedimefit �V A 1 \\ \\ V/Ok \� \\ \ \ A v v v THI \V LIN INDICATES v THE\SEPA ATION \ v ®ET%N SWM-2 AND \\ v\ SDP2 4000h, v \ / o m�J \ v A V v v \ a I 30 \ \ 0 3b \, 60 90\ SCALE: 1 _ 1 / X / / 1 '- 1 / I O / � / I to - \ \ MATCH EXISTING \ RIP RAP CLASS IA I Weir Report Hydm=EWm EMenebnfpr Autotlask®Aub MCNiil 3M by Aurotleek, Inc. Wetlneelay. Me 132014 SWM-1 Sediment Forebay Trapezoidal Weir Highlighted Crest = Sharp Depth (ft) = 1.85 Bottom Length (ft) = 14.00 Q (cfs) = 131.26 Total Depth (ft) = 2.00 Area (sqft) = 32.74 Side Slope (z:1) = 2.00 Velocity (ft/s) = 4.01 Top Width (ft) = 21.40 Calculations Weir Coeff. Gw = 3.10 Compute by: Known Q Known Q (cfs) = 131.26* Depth (ft) SWM-1 Sediment Forebay Depth (ft) 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.00 -1.00 0 - Weir 5 10 - W.S. -1.00 15 20 25 30 35 40 Length (ft) * 10-Year flow rate of 131.26 cfs from Hydrologic and Hydraulic calculations for SWM-1. 1 ) SWM-1 SEDIMENT FORBAY SPILLWAY V1 4 NOT TO SCALE Yr. Elev=356.99' Embankment Elev.=358.00' 40' 2 Riprap Weir class 1A Weir Elev.=355.93' (Outfalls Into class 1A, Rip -Rap Channel 16' wide section) EMERGENCY SPILLWAY DETAIL 3 SECTION B-B SW14 NOT TO SCALE Note: Clear and maintain the emergency spillway free of vegetative growth. Top of Dam Elev = 352.25 Forebay Bottom = 346.0 SWM-1 FOREBAY DETAIL 6 SECTION B-B SW14 HORIZ. SCALE: 1`12' VERT. SCALE: 1"=6' 7 SWM-1 DETAIL SW14 HORIZ. SCALE: VERT. SCALE: 1"=6' 1"=T ex 75° V-NOTCH WEIR. Elev. 354.00' 10quctic Bch nch 3.0" Orifice*, Elev. 349.60' p Elev. = 348.60' Bottom Elev Pond 1 = 344.0'P�J ' 8'4x1.5' Concrete Base ShortVersion BMP Computations For Worksheets 2 - 6 Albemarle County Water Protection Ordinance: Modified Simple Method Plan: Cascadia -Pondt Water Resources Area: Development Area Prepares. Dominion Engineering Date: 1/31/2D13 Project Drainage Area Designation Pond-1 L storm pollutant expo t in pounds, L = [P(Pj)RW12 ] [ C(A)2.72 ] Rv mean mooffcoefticiem, Rv=0,05+0.0090) Pi small shame correction factor, 0.9 I cement imperviousness P annual precipitation, 4Y in Albemarle A project area in acres in subject damage area, I A = - C pollutant concentration, mgA or ppm target phosphorus f factor applied to RR v required treatment volume in cy, 0.5" over imperv. area = A0)4356O(0.5H2y27 RR required removal, L(post) -fx L(pre) °/d2R removal efficiency, RR700/L(post) Impervious Cover Computation (values in feet & square feet) hem predevelopment Area postdevelopment Area Roads & Parkm9 Length Width subtotal Length Width subtotal 0 0 101059 0 0 101059 0 0 0 0 0 10890 0 0 0 0 0 701059 0 1 Driveways Length Width no. subtotal Length Width nl subtotal and walks 0 0 0 0 0 0 0 0 of o 0 0 0 0 0 0 0 0 ul 0 0 - 1 2 3 4 1 2 3 4- 0 0 Gravel areas Area Am x 0.70= 0 4356x 0.70= 3 structures Am no. subtotal Am '10, sublevel 1 0 0 435601 1 01 0 43560 and cultivated tuff I 152460 x 0.08 = 1 12196.81 1 217800 x 0.08 - _yards Active crop land Am Am x0.25Other mp vious Areas -----is0.25- J Impervious Cover I(pre) Rv(pos0 V 024 2813 New Development (For Development Areas, tied all his I mpervlous cover <= 20W C f I (pre) Rv(pre) Liam) L(post) RR %RR Area Type 070 1,000000.. 0��23 28.58 29.361 0.78 i DevebPmem Ante--- ��20% 035 L"� 21 ffi.05 74.88 7.83 Dnnkirg Water Wetershnds OAO 1. 021 14.92 16.78 I 1.86 Other Rural Land ' m in values Re barelopment [Far Development Areas, existing Impervious cover> MY4 C 1 I (l Rvgue) L28.) LIPart) RR %RR Area Type 2056 29W 364 Devebpmem Area 070 090 023 0 35 0 85 U 21 13 M 14 66 1 3.59 Dnnkirg Water Watersheds 040 OM, 021 14W 16781 4.In-Other Rural Land Imenm Manual, Page 70 rev 16 Feb 1998 OLD Embankment Elev.=352. rvicee ucv. wv.v EMERGENCY SPILLWAY DETAIL !:)(SECTION A -A) SW14 NOT TO SCALE 2 15' Aquatic Bench s Core* *Impervious core shown for informational purposes only. Final design to be provided by geotechnical engineer. FAI Inv= 346.57 -Embed 6" in Concrete Elev. = 348.6 SWM-1 Bottom = 344.0 Top of Dam Elev = 358.00 66.0'-30" HDPE 2.83% Cutoff Trench* inn v_ Short Version BMP Computations For Worksheets 2 -6 Albemarle Courtly Water Protection Ordinance Modified Simple Method Plan: Casuain subdivision Water Resources Area: Deem proem Area Prepares: Dominion Engineening Date: ti/13YL014 Project Drainage Area Designation DA D2PCSTDEVELOPMENT L storm pollutant export in pounds, L= [Pfl)Rv/12 ] [ CtA)2.72 ] Rv mean mnoff coefficient, Rv=0,05+000N) P small storm correction factor, 0.9 ) Ipercent impetuousness P annual precipitation, 43" in Alternate A project area in acres in subject drainage ama, A = C pollutant concentration, mg4 or ppm target phosphorus / factor applied to RR V required treatment volume in cy, 0.5" over imperv. area = AON3560(0. 5/12y27 RR required removal, L(post) -fx Lima) 'ARR removal efficiency RR1001-post) Impervious Cover Computation (values in feet & square bet) Item predevelopmem Area poetdevelopment Area Roads & Parking Length Width subtotal Length Width subtotal 0 0 0 0 01 152460 0 0 0 0 0 0 o D o 0 ul 0 0 152460 Dnveways Length Wdlh no. subtotal Length Width nl subtMel and walks 0 0 0 0 0 0 0 58806 0 0 0 0 0 0 0 23958 -1 0 0 01 0 82764 - - 1 2 3 4 1 2 3 4 0 0 0 Gravel areas Am Area x 0.70 = 0 x 0.70 = 3049.2 4356 Structures Area no. ad Ante W. subtotal _btotel 21780 124 0 U� 0 0 21780 210003 Activelyyrazed pasture 8 Area Am yetis and cultivated turf 982676 x 0.Do - 77014.08 644801 x 0.08 = 5156808 Active crop lend Area Am x 0.25= 0 x0.25= 0 Other Impervious Areas (Future Development `Tarn" Phase) 0 300000 Impervious Cover 4D% I(pn) I(post) Wiliest) V 0.41 1234.3 New Development For Development v Amos existing Impervious cover <=20%d P g De C T I (pre)' Win.) L(prt) L[posq RR % RR Area Type 0.70 100 20% 023 64.30 11543 5113 44% Development Am 0.35 100 0% Om 13.25 57.71 44.466-17% Drinking WaterWatemheds 040 100 1% Om 15.15 65.96 50.81 Other Rural Lend ' min. values Retlevelopre end (For Development Area; existing impervious cover> MW C f I (pre)' Wbanal Liters) L[posg RR %RR Area Type 070 U 023 8430 11543 s156 Development Area 0 35 0 to ' 0 m 13 25 Sf 11 4645 - until Water Watersheds 040 Out Om 15.15 65.96 Sus Other Rural Land btedm Manual, Page 70 rev 16 Feb 1998 OLD 2 BMP CALCULATIONS SW14 SCALE: 1"=100' s � ar �m. •••••••�c•• •••.•••.1111 i gal ••••••••+•• •4.4.4.4.4.141+141+1411 d•It 50'ddO+Y+' ,,,' 111 : j F ;?� •0'J0; •S'Jtt!01 ••//111/1111 �;; � � a LD (TYP.) 1/2• x 1 1/2- x 1/4" STEEL ANGLE (TYP.) 11/2- x 1/4' STEEL - 3- - 3 STOCK MELDED TO M3BASE AS SHOWN GENERAL NOTES FOR TRASH RACK 1. STEEL TO CONFORM TO ASTM A-36. ev. - 349.E 2. ALL SURFACES OF TRASH RACK(S) MUST BE HOT DIPPED GALVANIZED AFTER FABRICATION. 3. TRASH RACK(S) TO BE FASTENED TO WALL WITH 1/2" MASONRY ANCHORS. TRASH RACK(S) TO BE REMOVABLE. 4. TRASH RACK(S) TO BE CENTERED HORIZONTALLY OVER THE OPENING. 5. FABRICATOR MAY MODIFY COMPONENTS OF TRASH RACK FRAME TO IMPROVE CONSTRUCTABILITY OF TRASH RACK. MODIFICATIONS MUST BE APPROVED BY MCDPS PRIOR TO FABRICATION. Emeraen mpervious Core** * DETAIL TAKEN FROM MONTGOMERY COUNTY, MARYLAND WATER RESOURCES SPECIFICATIONS. = 355.93' 5 ORIFICE TRASH RACK SW14 NOT TO SCALE *Trash rack to be installed on orifice as sh on detail 5/SW14 or approved equal. **Impervious core and cutoff trench shown for informational purposes only. Final design to be provided by geotechnical engineer. ayTs of dr�c 44 f1 o 7 Is, Dustin nEE.`.GGreene Lic. No. ti 4 55833 ` �O�r 8/18/EIo1$4r 93ZONAL So 1.5 yr. Elevation = 354.03' 2 yr. Elevation = 354.23' 10 yr. Elevation = 355.75' 100 yr. Elevation = 356.99' Inv = 344.70 ES-1 n h W G rn 0 C\1 Do DO W W W Na Z ao 2 z0 �i oab 0 > O LL W CC 4J 2 0 %" Q > Q co 2i W L[ [ XJ V -a O N (t_ U rn -ail O �) u±, Wd 2 Q 0� f� a� IA. O fr xQ 0 l ¢ CC �W I wo Q� Ho y, pq W W Or 2 �'T lL O � O a REVISIONS EROSION STABILIZATION AREA ADDED AUG. 22, 2018 COUNTY COMMENTS OCT. 2, 2018 VSMP AMENDMENT FEB 19, 2021 COUNTY COMMENTS APR. 2, 2021 COUNTY COMMENTS MAY 6, 2021 / DATE APR. 17, 2014 SCALE AS SHOWN U) J W r LL Z l tF3 2 z Q C/) Y > d 0 ? o � U W m ir w CW G I W Q Q Q k Q WIr Q U C Q ~ 11 W Q U� Cl i_ a z � U� o FILE NUMBER 12.0065 SHEET SW14