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HomeMy WebLinkAboutWPO201200086 Plan - VSMP 2021-11-30GENERAL NOTES OWNER: IMP 09400-00-00-01500 SANSOVICH DEVELOPMENT, LLC THE PRESERVE AT GLENMORE CONTACT NEAL SANSOVICH 2000 RED HILL ROAD CHARLOTTESVILLE, VA 22903 434-962-2150 -WP0201200086AMENDMENT #2 ENGINEER: COLLINS ENGINEERING 200 GARRETT STREET SUITE K VSMP CHARLOTTESVILLE, VA 22902 TELEPHONE.- (434)293-3719 FAX. • (434) 293-2813 CONTACT: SCOTT COLLINS, P.E. SCOTTSVILLE DISTRICT EMAIL: SCOTT©COLLINS—ES—ENGINEERING.COM TAX MAP NO.: 09400-00-00-01500, 94-1581, 94-1582, 94-15B3, & 94-1584 ALBEMARLEAREA: 144.78 AC. C 0 U N TY VIRGINIA ZONING: RA NOTE: LOTS 1-4 WERE RECENTLY RECORDED AT DB 4138 PG 339 ON FEBRUARY 24, 2012. USE: SINGLE—FAMILY RESIDENTIAL SUBDIVISION STREETS: PAVED ROADWAY WITH ROADSIDE DITCH TOPOGRAPHY. TOPOGRAPHY PROVIDED BY LICENSED LAND SURVEYORS, COMMONWEALTH LAND SURVEYING, LLC IN AUGUST 2012. BOUNDARY INFORMATION PROVIDED BY COMMONWEALTH LAND SURVEYING IN 2011. VEGETATION: ROLLING GRASS FIELD WITH EXISTING TREES WATERSHED: MIDDLE RIVANNA RIVER WATERSHED UTILITIES: THESE PARCELS ARE LOCATED OUTSIDE OF THE ACSA JURISDICTIONAL AREA. WATER SHALL BE PROVIDED BY PRIVATE WELLS AND PRIVATE SEPTIC SYSTEMS SHALL BE PROVIDED ON INDIVIDUAL LOTS. WELLS AND SEPTIC SYSTEMS SHALL BE DESIGNED AND APPROVED PRIOR TO FINAL PLAT APPROVAL. THIS PROPERTY IS NOT LOCATED WITHIN AN AGRICULTURAL —FORESTAL DISTRICT. NORTH ARROW DETERMINATION: NAD 83 DENSITY: PROPOSED: 13 LOTS/ 144.78 AC. = 0.09 DUA MAXIMUM ALLOWED: 0.5 DUA SETBACKS: FRONT (INTERNAL PRIVATE ROAD) 25' SIDE: 25' REAR: 35' MAXIMUM STRUCTURE HEIGHT: 35' STREAM BUFFER: 100' STREAM BUFFER(S) SHOWN HEREON SHALL BE MANAGED IN ACCORDANCE WITH THE ALBEMARLE COUNTY WATER PROTECTION No tes: ORDINANCE. 1.) LOTS 1-13 EACH CONTAIN A BUILDING SITE THAT COMPLIES WITH SECTION 4.2.1 OF THE ALBEMARLE COUNTY ZONING ORDINANCE. 2.) NOTE ORIGINAL TAX MAP 94 PARCELS 15 AND 16 EACH HAD 5 DEVELOPMENT RIGHTS BASED ON 1980 BOUNDARIES. WITH SUB-2010-154 RECORDED AT DEED BOOK 4138, PAGE NUMBER 339, NEW LOTS 1(TAX MAP 94-16Bl), 2(TAX MAP 94-16B2), 3(TAX MAP 94-16B3), AND 4(TAX MAP 94-16B4) WERE EACH ASSIGNED A DEVELOPMENT RIGHT FROM THE ORIGINAL (5) DEVELOPMENT RIGHTS THAT BELONGED TO THE ORIGINAL TAX MAP 94 PARCEL 16, AND MAY NOT BE FURTHER DIVIDED. THE REMAINING DEVELOPMENT RIGHT ON ORIGINAL TAX MAP 94 AND PARCEL 16 /S BEING ASSIGNED TO LOT 5. THE AGGREGATE ACREAGE OF LOTS 1 2 3 4 AND 5 /S LESS THAN 31 ACRES. ORIGINAL TAX MAP 94 PARCEL 15 HAD 5 DEVELOPMENT RIGHTS , , WHICH WERE ASSIGNED TO REVISED TAX MAP 94 PARCEL 15 AT D. B. 3863 PAGES 363-378. NEW LOTS 6, 7, 8, 9, AND 10, WILL EACH BE ASSIGNED A DEVELOPMENT RIGHT FROM THE REMAINING 5 DEVELOPMENT RIGHTS AND MAY NOT BE FURTHER DIVIDED. A MINIMUM OF 2 ACRES FROM NEW LOT AGGREGATE ACREAGE OF LOTS 6 7 8 9 AND 10 IS LESS THAN 31 ACRES. NEW LOTS 11, 12, AND 13 ARE EACH GREATER THAN 21 ACRES AND WILL NOT REQUIRE THE USE OF A DEVELOPMENT RIGHT. NO DEVELOPMENT RIGHTS REMAIN. 3.) LOT 6 CONTAINS 2.06 ACRES LOCATED WITHIN IMP 94-15 WHICH MEETS THE REQUIREMENT FOR A DEVELOPMENT RIGHT LOCATED IN IMP 94-15. A BOUNDARY LINE ADJUSTMENT WILL BE PROCESSED WITH THE FINAL SUBDIVISION PLAT FOR THE CREATION OF LOT 6, WITH A MINIMUM ACREAGE OF 2 ACRES FROM IMP 94-15, AS SHOWN. 4.) CONCEPTUAL LOCATIONS OF STORMWATER MANAGEMENT FACILITIES ARE SHOWN. FINAL DESIGN SHALL BE INCLUDED WITH FINAL ROAD PLANS, PRIOR TO FINAL PLAT APPROVAL. 5.) ALL LAND WITHIN THE SUBDIVISION SHALL BE CONTAINED WITHIN LOTS OR WITHIN THE PRIVATE RIGHT OF WAY. LOT ACREAGE: 143.48 AC. PRIVATE R/W ACREAGE. 1.27 AC. 6.) NO LOCATION OF ANY GRAVES OR OBJECTS OR STRUCTURES MARKING A PLACE OF BURIAL ARE KNOWN AT THIS TIME TO BE LOCATED ON THE PROPERTY. 7.) CRITICAL SLOPES ARE SHOWN ON THE PLAN IN ACCORDANCE WITH THE COUNTY GIS MAPPING AND COUNTY TOPOGRAPHY. NO IMPACTS TO THE CRITICAL SLOPES ARE PROPOSED WITH THE DEVELOPMENT PLAN. 8.) THE LOTS SHALL BE SERVICED BY ON —SITE WELLS AND ON —SITE SEPTIC FIELDS. FINAL APPROVAL OF THE WELLS AND SEPTIC FIELDS WILL BE APPROVED BY THE VIRGINIA HEALTH DEPARTMENT PRIOR TO THE APPROVAL OF THE FINAL SUBDIVISION PLAT. 9.) THE PROPOSED STREET IN THIS DEVELOPMENT PLAN SHALL BE A PRIVATE STREET, BUT BUILT TO VDOT STANDARDS, IN ACCORDANCE WITH THE GUIDELINES AND REQUIREMENTS OF ALBEMARLE COUNTY. THE STREET DOES NOT QUALIFY FOR A PUBLIC ROAD BECAUSE IT DOES NOT MEET ALL THE STANDARDS FOR ACCEPTANCE OF THE ROADWAY INTO THE SECONDARY SYSTEM OF STATE HIGHWAYS AND THEREFORE WILL NOT BE MAINTAINED BY THE VIRGINIA DEPARTMENT OF TRANSPORTATION OR THE COUNTY OF ALBEMARLE. IN QR �IA'Nm E \ \ 3. E VI 811 PROFITT, STERLING C OR LOUISE C 2.634 ACRES ZONE: RA D.B./PG. L—A�/�� 756/74�3 \II `I 1t 11 1\ I \ GLErV ORES^ S 41E�{ ITE\ —�HI N" D \\ \� =a.Bao Ys \� V LOT 5 V II�I��AA�VA\\V�VA\�vvwvXxr\ xx VAVA\ \ \ 1 1� SA S VIC D V LOT? 1\ \\�� \\ \ \ \ \ \ �� \� \ \ \ 144 7 \ \ 9 C \ �- / i \ 17 \ I / \\� �Y \ \ \ /.B.PN :RA \ \ \�\\\ \\� \ ANSO�VICH DEVELOPMENT, LC\ \ \\ \ \\ \ \ \\\ I ? _� \ \ \ TMP 94 15B4 / \ � 5.01 AC 1 / 1 E: RA, LOT1 \ (I I /� \�/\\/ III \\ \IVI �� (7ts'- NI W \� T)���l��� LEGEND EXISTING CULVERT ,,,y... EARTH DITCH CULVERT DRIVEWAY CULVERT DROP INLET & STRUCTURE NO. BENCH MARK CURB CURB & GUTTER — — — — — CLEARING LIMITS PROPOSED PAVEMENT T VDOT STANDARD STOP SIGN EC-3A DITCH — — — —200— — — — EXIS77NG CONTOUR DEPTH OF EC-3A DITCH 20o PROPOSED CONTOUR EC-2 DITCH 240.55 PROPOSED SPOT ELEVATION TBC DENOTES TOP/BACK OF CURB DEPTH OF EC-2 DITCH T/B DENOTES TOP OF BOX SHEET LAYOUT SCALE: 1" = 150' CURRENT OWNER SANSOVICH DEVELOPEMENT, LLC 2000 RED HILL ROAD CHARLOTTESVILLE, VA 22103 ENGINEER COLLINS ENGINEERING 200 GARRETT STREET, SUITE K CHARLOTTESVILLE, VA 22902 434.293.3719 APPROVED by the Albemarle County Community Development Department Date 11 /30/2021 htlf-��i�l I�Ylli HIITITIT:T� - Amendment 2 0] SP-2006-031CONDITIONS OF APPROVAL: m VICINITY MAP SCALE: 1" = 2000' DSO SCOTT/R. C$Ll No. 35791 po 08/14/21 &' ,_ONAL J Ln z z J W 0 .. 0 V V, oc m N z Z Z 0 z 0 z g o o a of (H� r/ W .. W H ` oc 1) 2) THE STREAM CROSSING SHALL BE BUILT IN ACCORDANCE WITH THE PLAN TITLED "SP 06-31 APPLICATION PLAN, "REVISED "AUGUST 01, 2007," AND PREPARED BY ROUDABUSH, GALE, & ASSOCIATES, INC. ANY SUBDIVISION ON THE PORTION OF THE PROPERTY DESIGNATED AS RURAL AREAS IN THE COMPREHENSIVE PLAN SHALL BE DESIGNED IN GENERAL ACCORD WITH THE PLAN TITLED GLENOAKS, DATED "8/1/07", AND PREPARED BY "KG ASSOCIATES." THE DEVELOPMENT LOTS EAST OF LIMESTONE CREEK AND LOT 26 SHALL BE DEVELOPED AS RURAL PRESERVATION DEVELOPMENT IN ACCORD WITH SECTION 10.3.3.3 OF THE ZONING ORDINANCE, WITH LOT 26 AS THE PRESERVATION TRACT. AS PART OF THE SAME SUBDIVISION, THE APPLICANT SHALL CONVEY TO THE COUNTY A PORTION OF LOT 10 (WHOSE BOUNDARIES ARE APPROVED BY PARKS AND RECREATION DEVELOPMENT) FOR USE AS GREENWAY. L9 3) THE DAM SHALL ALLOW FOR CONTINUATION OF THE BASE FLOW IN THE STREAM; AND 4) THE FOLLOWING CONDITIONS SHALL BE MET PRIOR TO ISSUANCE OF A GRADING PERMIT TO ALLOW INSTILLATION OF THE STREAM Z CROSSING OR SUBMITTAL OF THE FINAL SUBDIVISION PLAT, WHICHEVER COMES FIRST. A) THE APPLICANT MUST OBTAIN A MAP REVISION, LETTER OF REVISION, OR A LETTER OF AMENDMENT AS REQUIRED FROM THE FEDERAL EMERGENCY MANAGEMENT AGENCY (FEMA) AND COPY THE COUNTY ENGINEER ON ALL CORRESPONDENCE BETWEEN THE APPLICANT AND FEMA. B) COUNTY APPROVAL OF AN EROSION AND SEDIMENT CONTROL PLAN FOR THE STREAM CROSSING. C) COUNTY APPROVAL OF THE FINAL LANE CONFIGURATION OVER THE STREAM CROSSING WITH THE FINAL ROAD PLANS. D) NATURAL RESOURCES MANAGER APPROVAL OF A STREAM BUFFER MITIGATION PLAN IN GENERAL ACCORD WITH THE CONCEPTUAL PLAN SHOWN ON THE PLAN TITLED "SP 06-31 APPLICATION PLAN," REVISED "AUGUST 01 2007 " AND PREPARED BY ROUDABUSH, GALE & ASSOCIATED, INC. E) COUNTY APPROVAL OF FINAL DESIGN PLANS AND HYDROLOGIC/HYDRAULIC COMPUTATIONS FOR THE STREAM CROSSING. F) ARMY CORP OF ENGINEERS, VIRGINIA DEPARTMENT OF ENVIRONMENTAL QUALITY, AND OTHER NECESSARY STATE AND FEDERAL AGENCY APPROVALS MUST BE OBTAINED PRIOR TO ISSUANCE OF GRADING PERMITS, AND G) APPROVAL OF THE FINAL DESIGN OF THE DAM BY THE DEPARTMENT OF CONSERVATION AND RECREATION, AS NECESSARY. 5) PRIOR TO FINAL PLAT APPROVAL OF THE PRIVATE ROAD ACROSS THE CREEK, THERE SHALL BE A PRIVATE ROAD MAINTENANCE AGREEMENT THAT INCLUDES PROVISIONS FOR MAINTENANCE REPAIR AND FUTURE REPLACEMENT OF DAM WHEN NECESSARY IN A FORM ACCEPTABLE TO THE COUNTY AS APPROVED BY THE COUNTY ATTORNEY. ALL COSTS OF THIS MAINTENANCE OR REPAIR AGREEMENT SHALL BE PRIVATELY FUNDED. THE LANDOWNER'S PRIVATE RESPONSIBILITY FOR DAM MAINTENANCE OR REPAIR SHALL BE STATED IN EVERY DEED TRANSFERRING OWNERSHIP OF THE LOTS SERVED BY THIS CROSSING IN A STATEMENT APPROVED IN FORM AND CONTENT BY THE COUNTY ATTORNEY. THE COUNTY SHALL NOT BE RESPONSIBLE FOR ANY COSTS OF THE MAINTENANCE, REPAIR, OR FUTURE REPLACEMENT OF THE PRIVATE ROAD OR DAM. * THE GLEN OAKS STREAM CROSSING IS NOT BEING PURSUED, THEREFORE THESE CONDITIONS ARE NO LONGER APPLICABLE. z SHEET INDEX W TITLE SHEET TITLE SHEET 1 STORMWATER MANAGEMENT PLAN 2 Ul STORMWATER MANAGEMENT DETAILS & CALCULATIONS 3 TOTAL SHEETS 3 z APPROVALS DATE DEPARTMENT OF COMMUNITY DEVELOPMENT PLANNER/ZONING ENGINEER INSPECTIONS ARB DEPARTMENT OF FIRE RESCUE ALBEMARLE COUNTY SERVICE AUTHORITY VIRGINIA DEPARMENT OF TRANSPORTATION HEALTH DEPARTMENT COLLINS ENGINEERING IS NOT RESPONSIBLE OR LIABLE FOR ANY CONSTRUCTION OR DAMAGES TO THIS PROJECT PRIOR TO ALL FINAL PLAN APPROVALS. J J U oo� �o N N r� 00 w CT M r z CT N LCU M G I N W N N Q CL F_ W LU w Lu O O V / W 1f' \`y Z t- LU H � V 1 w P4� V / W w 10— IW I I O O W W a M 112054 SCALE AS NOTED SHEET NO. 1 o � a� 0 0 o � J p� J E3 O �E3 o � T 0 0 U U 0 0 a0 N 0 N U ° 0 U x L 00 C °a E U , O �n U � U 0� U � PRE -DEVELOPMENT V - — — POST-DEVELOPMENT�!— — Cover description Soil name and Drainage Area (Covertype, treatment, and hydrologic condition; Area Description hydrologic group percent impervious; unconnected/ connected (Acres) (Appendix A) impervious area ratio) DA'A' Impervious Areas 0.37 B Woods in Good Condition (75%+/-) 20.80 (Present) Lawns in Good Condition (25%+/-) 0.95 Impervious Areas 1.49 DA'A' B Woods in Good Condition (75%+/-) 0.00 (Developed) Lawns in Good Condition (25%+/-) 20.63 - _- /X%/\ / Outflow Summary: (1-Year Storm Event)— / Pre -Development Post -Development 'FDA 'A' 1.90 cfs 0.71 cfs (Routed) / / — r i / / // j /, Outflow Summary: (2-Year Storm Event) ' \ Pre -Development Post -Development / / DA'A' s.sss 5.25 cfs (Routed) / //Z' / Outflow Summary: (10-Year Storm Event) / / / / / Pre -Development Post -Development / / � _/j DA W 27.25 cfs 27.18 cfs I I IIII I I I I I I I I I \ \ \ / \ V ` (Routed) / / �A\� \�\ General construction notes for Stormwater Management plans CNo.35791 / /1. All dams and constructed fill to be within 95%of maximum dry density /T and 2%Of optimum moisture content. All fill material to be approved by��a geotechnical engineer. A geotechnical engineer is to be present during construction of dams.NS'Z!n2. Pipe and riserjoints are to be watertight within stormwatermanagement facilities. w�\3. For temporary sediment traps or basins which are to be converted to permanent stormwater management facilities; conversion is not to take \ ` place until the site is stabilized, and permission has been obtained from the County erosion control inspector. '\ > / `fil IIIIIIIIII II11�\ \\\�/ o OPI If ou\ Q\ _ g \ \ \ \ Z w Z o Z o co = J W Z < < > Z W z ---% % \�\moo-- �r� \\ --- I I // / /// I ( // �� �� \� `4O / /��vv� //I I I �II����� �vv v � 4oTYo -i / �✓ i l I I v v 'b.A. TO SWM BASIN — 22.12 ac. \ / / _ \ \ \ \, \ � Tc = 0.23 hrs / ��� CN = 56 \ \ V A I I / / / / / / / �l l l I �� \\ — 1 D.A. O SWM BASIN \ 11 \ 22.12 ac. \ , Tc=0.23hrs APPROVED TIME OFiCOtJCE� TRATI�N � � V A \ \ � � � \ � A V A \ \ V A V A \ \ � I � — — � � � � I � � � � � ��� \ � CN = 63 — — SHEET FLOW Tc = o.i6 \ / \ V A \ — APPROVED TIIv7E F OtJCENTRATI N I / CHANNEL FLOW Tc=o.o A VA — — I CHANNEL FLOW Tc=o.oSHEET FLOW, Tc - 6� A VA \ �� POST-DEVELOPMENTTc=o.z3 \ \ V� A \ V A \ \ V A A — — I / 3 \ �� / I I I \ \ \ \ \ \ \ \ \ ` / / POST-DEVELOPMENTTc=o.z \ \ \ I Ji III 1 \ \ \ \ \ \ \ \ \ la,� v�vvvv // ILor 7 III \ — — LTA Q, % I v I I AA \ ✓ I I VARI�LE WIDTH VA V 1c' SWM EASEMENT I I I III I //��vv� � � �T I I I — o406 n / I I I I I 1 11 �� \\ v vv _ ��� / l I 4o�� I>r 1 1 V AI �� v A J/ \\ \ \ \ PROPOSED AMENDMENT SHAL400 L \I / / I PROPOSED AMENDMEN SHALL � � � \� � / \ � � � INCLUDE A LEVEL I WET POND TO \ \ _ _ / / \ - _ \ \\ \ \ � \ \ INCLUDE A LEVEL I WET POND TO gg GREY HERON ROgp \ \ REPLACE THE APPROVED \ �REPLACETHE APPROVED � \\ � / l � / _ -39 _ 396 ~�\ \ \ � EXTENDED DETENTION VA V /� V — 3 f� A V -EXTENDED DETENTION / -STORMWATER MANAGEMENT 0 _ _ \ \\ --STORMWATER MANAGEMENT \ \ \ I I \ \ \ \ \ \\ \ BASIN. THE NEW WET POND SHALL \\\ \ \ �� MAINTAIN THE EXISTING RISER \ \ _ \ \ \ \ \ I \ — — — — \ 39� ��MAINTAIN THE EXISTING RISER \ \ AMENDMENT NARRATIVE / SWM PROPOSED CHANGES: \ \ SAND THE EXISTING BARREL \ \ ra \ \ \ ^ \ AND THE EXISTING BARREL \OVERVIEW: \ / \ \ — \ \ \I'I — 96�9 \ \\ \ \ \ DESIGN. MODIFICATIONS SHALL BE \ 1 I \ \ � � � \ 3 4� ESIGN. MODIFICATIONS SHALL BE \ \ 400, — \� MADE TO THE RISER RIM & \ by \ \ \ \ \ — ` \ \ MADE TO THE RISER RIM & THE PRESERVE AT GLENMORE IS A LARGE SUBDIVISION CONSISTING MOSTLY OF \ \ I I \ \ \\ \ \ � \ 4� / \ ORIFICES TO MEET SWM \ \ \ \ \ / \� ORIFICES TO MEET SWM UNDEVELOPED AREAS. THE DEVELOPER WISHES TO CONVERT THE EXISTING \ \ \ SEDIMENT BASIN TO A LEVEL I WET POND, IN LIEU OF THE EXTENDED DETENTION �_ \ QUANTITY , CHANNEL, AND FLOOD \ \ \ I I — \ \ \\ \\ l \ I — — — ,� \ QUANTITY, CHANNEL, AND FLOOD \BASIN APPROVED FOR THE SITE. PLEASE SEE BELOW FOR A DETAILED SUMMARY OF ` — \ \PROTECTION REQUIREMENTS. _ R T iTION REQUIREMENTS. \ \ ft THIS \ PLAN'S PROPOSED CHANGES TO THE APPROVED STORMWATER MANAGEMENT— -490— II V I/moo— PLAN. —41 V o \ \ 1I II I I I ��A\ / WATER QUALITY: \ \ \ LOT 1 T, THIS PLAN WAS APPROVED IN 2012, USING THE iggg VIRGINIA STORMWATER \ i I I I I I c� I I I \ \ �\ \� �� \ \ I \ I P I LOT 5 MANAGEMENT HANDBOOK (VSMH), WHICH WAS THE GOVERNING DOCTRINE AT THE y / \ io' A\ C\ SS PATH \ \ \\ \ \ \\\ \\ \ LIMITS OAF \ 1 \ I I \ ` ( / \\ \ C E\\ LIMITS OF\ TIME OF THIS PLAN'S APPROVAL. THE APPROVED PLAN REQUIRED 2.52 LB/YEAR \ � ` I I I \ \ \ WPO BUFFER / ,) � / I I I / / j WPO BUFFER \ PHOSPHORUS REMOVAL FOR THE SITE (APPROVED Lpre-i7.85 LB/YEAR AND \ \ GRADE SHALL - I \ \ \ \ / I L / ' ` \ NOT EXCEED io% \\ \ \ \ \ APPROVED Lpost=zo.36 LB/YEAR). THE APPROVED PLAN PROVIDED AN EXTENDED \ ` I I \ \\ �\ \\\\ \ \\\\\ \ \ \ \ \ \ / / / I I _ \ VAR. WIDTH \ �� \ \ DETENTION FACILITY WITH 3S% PHOSPHORUS REMOVAL RATE. \ I I \ \ \ / / \ I / m \ \ y \ \ \\ /THIS PROPOSED STORMWATER MANAGEMENT AMENDMENT FOLLOWS THE \ V A V / \ \ �\ V \ VA \\ \VAVA \� \ \ V A\ / / / IIII — — — V A \ \ A \ ADRAINAGE & SWMCCESS EASEMENT \x�� \V�� � \\ iVIRGINIA RUNOFF REDUCTION METHOD zozi BMP STANDARDS. THE PROPOSED \ — I \ ` \ \ \\ \ \ \ \ \\ \\ \ \\\ \\ \ \ \ \ \ / / I I I III — — — \ \ \ I \ \\ \ C \ T \ \\\ < \ AMENDMENT IMPROVES UPON THE APPROVED PLAN WATER QUALITY STRATEGY. \ \ \ \ \ IT PROPOSES A LEVEL I WET POND TO REPLACE THE EXTENDED DETENTION FACILITY. THE WET POND PROVIDES A 5o% PHOSPHORUS REMOVAL RATE, WHICH RESULTS IN A 6.31 LB/YEAR PHOSPHORUS REMOVAL FOR THE SUBAREA IMPROVING UPON THE APPROVED PLAN'S 2.53. LB/YEAR REMOVAL. WATER QUANTITY: AMENDMENTTHE PROPOSED STORMWATER MANAGEMENT PROVIDES WATER QUANTITY PROTECTION IN POST -DEVELOPMENT FLOW REDUCTION, / \ \\\ L — — — \ / \\\ L T 6 I \ \ \ \ \ \ \ \ \ CHANNEL PROTECTION, AND FLOOD PROTECTION. THE i, 2, io, AND ioo YEAR STORM FLOWS ARE DETAINED AND PRODUCE POST -DEVELOPMENT OUTFLOWS I \ \\ \ _LESS THAN THE PRE -DEVELOPMENT CONDITION. CHANNEL PROTECTION IS / — \ �\ \\ \ > \ I I I \ \ \\\ \ I — \ \ \ / \ �� \\ \ I ) I I LOT 12I \ \ \\\ ACHIEVED WITH A 1-YEAR FLOW MEETING THE REQUIREMENT OF SECTION B.3.A. FLOOD PROTECTION IS MET WITH PER g VAC 25-870-66 SECTION C.2.B. IN WHICH THE io-YEAR POST DEVELOPMENT FLOW DOES NOT EXCEED THE PRE -DEVELOPMENT // / \\ \\ \\ \ \ \ \ \ \ / I / / / \ \ \ \ \ \\\\ \ ///I FLOW. THE TR-55 ANALYSIS IS PROVIDED IN THE CALCULATIONS PACKET ACCOMPANYING THIS PLAN. A SUMMARY OF PRE AND POST -DEVELOPMENT FLOWS / \\ \\ \ \ \ \ \ \ / I I l l / \ \ \\ / ( — — — \ \ \ / / j \\ \\ \ \ \ \ \ \ / / l l / / \ \ \\ IS PROVIDED ON THIS SHEET. / \ \ \ / / / / / \ \ \ \\ I 1 — L-0T�\ \ V / \ \ \ / / G APIC/ SC LE \ \ \ \\ \\\ ' ea <o as/ so 1\\\ \ / \ \ jam/\\\\\ \\\ \ �\� PLEASE NOTE THE SOIL AROUND THE SPILLWAYS ARE TO BE AT 95%COMPACTION WITH AN IMPERVIOUS CORE AND CUT-OFF TRENCH. THE EMERGENCY SPILLWAY SHAL— I EEARTHEN. EBAY SPILLWAY SHALL BE CONSTRUCTED �OF GA� BION ( IN F T i80 /) ftLOT13 i/ch\BASKETS WITH gSTONE ON THE UPHILL SIDE OF THE WEIR. L v M oD c N N \ n 00 L9C7� N -� M M 7 _ N w M o W W � � N WN Q z a Z � � z > > w W LU Q Z 01 O `,I," w W z U J � (D Ul'0 I IaI v , W Z J L� w l� J w O C_� LU LU O U 0 w d W 112054 SCALE 1"=80' SHEET NO. 2 of =J "0 U a 6 ° a" � o 0 C w �a E e U . o " a U 6.1 0 U t"n o WET POND CONSTRUCTION NOTES: FACILITY PLANTING SPECIFICATIONS: 1. THE CONTRACTOR SHALL ESTABLISH AND MAINTAIN A VEGETATIVE COVERAGE IN THE POND AND ITS BUFFER. 2. THE CONTRACTOR SHALL ALSO INSTALLANY WETLAND SHELF AND AQUATIC BENCH PLANTINGS, AS REQUIRED, AND USE NUTRIENT RICH SOIL IN THESE AREAS TO PROMOTE HEALTHY GROWTH AND ROOT DEVELOPMENT. 3. PLANT SELECTION SHALL PROMOTE DIVERSE WILDLIFE AND WATERFOWL USE WITHIN THE STORMWATER WETLAND, AQUATIC BENCH AND BUFFERS. 4. WOODY VEGETATION MAY NOT BE PLANTED OR ALLOWED TO GROW WITHIN 15 FEET OF THE TOE OF THE EMBANKMENT NOR WITHIN 25 FEET FROM THE PRINCIPAL SPILLWAY STRUCTURE. 5. A VEGETATED BUFFER SHALL BE PROVIDED THAT EXTENDS AT LEAST 25 FEET OUTWARD FROM THE MAXIMUM WATER SURFACE ELEVATION OF THE WET POND. PERMANENT STRUCTURES (E.G., BUILDINGS) SHALL NOT BE CONSTRUCTED WITHIN THE BUFFER AREA. EXISTING TREES SHALL BE PRESERVED IN THE BUFFER AREA DURING CONSTRUCTION IF POSSIBLE. 6. THE SOILS IN THE STORMWATER BUFFER AREA ARE OFTEN SEVERELY COMPACTED DURING THE CONSTRUCTION PROCESS, TO ENSURE STABILITY. THE DENSITY OF THESE COMPACTED SOILS CAN BE SO GREAT THAT IT EFFECTIVELY PREVENTS ROOT PENETRATION AND, THEREFORE, MAY LEAD TO PREMATURE MORTALITY OR LOSS OF VIGOR. AS A RULE OF THUMB, PLANTING HOLES SHALL BE THREE TIMES DEEPER AND WIDER THAN THE DIAMETER OF THE ROOT BALL FOR BALL -AND -BURLAP STOCK, AND FIVE TIMES DEEPER AND WIDER FOR CONTAINER -GROWN STOCK. 7. AVOID SPECIES THAT REQUIRE FULL SHADE, OR ARE PRONE TO WIND DAMAGE. EXTRA MULCHING AROUND THE BASE OF TREES AND SHRUBS IS STRONGLY RECOMMENDED AS A MEANS OF CONSERVING MOISTURE AND SUPPRESSING WEEDS. CONTRACTOR REQUIREMENTS: 1. THE CONTRACTOR SHALL BE RESPONSIBLE FOR LAYOUT OF ALL WORK COVERED UNDER THESE PLANS. 2. LANDSCAPE CONTRACTOR SHALL REFER TO THE STANDARDIZED LANDSCAPE SPECIFICATIONS FOR THE STATE OF VIRGINIA FOR ADDITIONAL INFORMATION. THE CONTRACTOR SHALL ABIDE BY ITS CONTENTS; HOWEVER ANY NOTES OR SPECIFICATIONS ON THE PLANS SHALL SUPERSEDE THOSE OUTLINED IN THE SPECIFICATIONS MANUAL COPIES ARE AVAILABLE FOR A FEE FROM THE VIRGINIA CHAPTER OF THE AMERICAN SOCIETY OF LANDSCAPE ARCHITECTS, VIRGINIA NURSERYMEN'S ASSOCIATION, INC. AND THE VIRGINIA SOCIETY OF LANDSCAPE DESIGNERS). 3. ALL PLANT MATERIAL SHALL MEET THE MINIMUM SPECIFICATIONS AND STANDARDS DESCRIBED IN THE CURRENT ISSUE OF THE AMERICAN STANDARD FOR NURSERY STOCK, PUBLISHED BY THE AMERICAN ASSOCIATION OF NURSERYMEN, 1250 STREET, NW, SUITE 500, WASHINGTON, DC 20005. 4. THE CONTRACTOR SHALL VERIFY ALL DIMENSIONS IN THE FIELD AND NOTIFY THE DESIGNER OF ANY VARIANCE FROM THE PLAN. S. THE LANDSCAPE CONTRACTOR IS RESPONSIBLE FOR VERIFYING THE LOCATION OF ANY ONSITE UTILITIES (CALL MISS UTILITY 1-800-552-7001 BEFORE ANY EXCAVATION). 6. REFER TO THE APPROVED CONSTRUCTION PLANS FOR ANY DETAILED SITE INFORMATION. 7. ALL WORK SHALL BE COORDINATED WITH OTHER PARTIES. 8. PLANTS WILL BE PREPARED FOR SHIPMENT IN A MANNER THAT WILL NOT CAUSE DAMAGE TO THE BARK BUDS BRANCHES STEMS OR OVERALL SHAPE OF THE STOCK. CONTAINER GROWN PLANTS WILL BE TRANSPORTED IN THE CONTAINERS IN WHICH THEY HAVE BEEN GROWN. 9. ALL PLANT MATERIAL UNLESS OTHERWISE SPECIFIED SHALL BE UNIFORMLY BRANCHED AND HAVE A VIGOROUS ROOT SYSTEM. PLANT MATERIAL SHALL BE HEALTHY, VIGOROUS, AND FREE FROM DEFECTS, DECAY, DISEASES, INSECT PEST EGGS, AND ALL FORMS OF INFESTATION. ALL PLANT MATERIAL SHALL BE FRESH, FREE FROM TRANSPLANT SHOCK OR VISIBLE WILT. PLANTS DEEMED UNHEALTHY WILL BE REJECTED. 1O.ALL CONTAINER STOCK SHALL HAVE BEEN PROPAGATED IN A CONTAINER LONG ENOUGH FOR THE ROOT SYSTEM TO HAVE DEVELOPED SUFFICIENTLY TO HOLD ITS SOIL. CONTAINER STOCK WITH POORLY DEVELOPED ROOT SYSTEMS WILL NOT BE ACCEPTED. 11.PLANTS NOT INSTALLED ON THE DAY OF ARRIVAL ON SITE SHALL BE STORED AND PROTECTED BY THE CONTAINER. OUTSIDE STORAGE AREAS WILL BE SHADED AND PROTECTED FROM THE WIND AND SUN. PLANTS STORED ON SITE SHALL BE PROTECTED FROM ANY DRYING AT ALL TIMES BY COVERING THE BALLS OR ROOTS WITH MOIST SAWDUST, WET BURLAP, WOOD CHIPS, SHREDDED BARK, PEAT MOSS, OR OTHER SIMILAR MULCHING MATERIAL. 12.THE OWNER RESERVES THE RIGHT TO SUBSTITUTE PLANT MATERIAL TYPE, SIZE AND/OR QUANTITY. ANY SUBSTITUTIONS MUST BE APPROVED BY THE DESIGNER. 13.MINOR FIELD ADJUSTMENTS MAY BE NECESSARY DUE TO SITE CONDITIONS (EX: ROOTBALL AND UTILITY CONFLICT). MAJOR ADJUSTMENTS MUST BE APPROVED BY THE DESIGNER. 14.NO PLANTING SHALL OCCUR WHEN THE SOIL IS FROZEN. 15.PLANT MATERIAL SHALL BE PLACED IN EXISTING SOIL WITH EACH PLANTING PIT EXCAVATED TO A SIZE SUFFICIENTTO CONTAIN THE ENTIRE ROOT BALL OR ROOT MASS, WITHOUT CRAMPING ROOT STOCK. 16.THE CONTRACTOR SHALL MAINTAIN A ONE 1 CALENDAR YEAR 90% CARE AND REPLACEMENT WARRANTY FOR ALL PLANTINGS. THE PERIOD OF CARE AND REPLACEMENT SHALL BEGIN AFTER INSPECTION AND APPROVAL OF THE COMPLETE INSTALLATION OF ALL PLANTS AND CONTINUE FOR ONE CALENDAR YEAR. 17.THE CONTRACTOR IS RESPONSIBLE FOR REMOVAL AND DISPOSAL OF TRASH AND DEBRIS WITHIN THE LIMITS OF THE PLANTING ON A DAILY BASIS. 18.THE CONTRACTOR WILL NOT BE RESPONSIBLE FOR PLANT MATERIAL THAT HAS BEEN DAMAGED BY VANDALISM, FIRE, OR OTHER ACTIVITIES BEYOND THE CONTRACTOR'S CONTROL. FACILITY CONSTRUCTION: 1. THE CONTRACTOR SHALL USE THE WET POND AS AN E&S CONTROL STRUCTURE IF SHOWN IN THIS MANNER ON THE APPROVED ESC PLANS. IF APPLICABLE THE WET POND SHALL SERVE AS A SEDIMENT BASIN DURING PROJECT CONSTRUCTION. IF THIS 15 DONE THE VOLUME SHALL BE BASED ON THE MORE STRINGENT SIZING RULE EROSION AND SEDIMENT CONTROL REQUIREMENT VS. WATER QUALITY TREATMENT REQUIREMENT). ( Q Q Q ) INSTALLATION OF THE PERMANENT RISER SHALL BE INITIATED DURING THE CONSTRUCTION PHASE, AND DESIGN ELEVATIONS SHALL BE SET WITH FINAL CLEANOUT OF THE SEDIMENT BASIN AND CONVERSION TO THE POST -CONSTRUCTION WET POND IN MIND. THE BOTTOM ELEVATION OF THE WET POND SHALL BE LOWER THAN THE BOTTOM ELEVATION OF THE TEMPORARY SEDIMENT BASIN. APPROPRIATE PROCEDURES SHALL BE IMPLEMENTED TO PREVENT DISCHARGE OF TURBID WATERS WHEN THE BASIN IS BEING CONVERTED INTO A WET POND. 2. WET PONDS SHALL ONLY BE CONSTRUCTED AFTER THE CONTRIBUTING DRAINAGE AREA TO THE POND IS COMPLETELY STABILIZED. IF THE PROPOSED POND SITE WILL BE USED AS A SEDIMENT TRAP OR BASIN DURING THE CONSTRUCTION PHASE, THE CONTRACTOR SHALL DE -WATER, DREDGE AND RE -GRADE THE SEDIMENT CONTROL FACILITY TO DESIGN DIMENSIONS AFTER THE ORIGINAL SITE CONSTRUCTION IS COMPLETE. 3. THE CONTRACTOR SHALL ASSEMBLE CONSTRUCTION MATERIALS ON -SITE, MAKING SURE THEY MEET DESIGN SPECIFICATIONS AND ARE PREPARED AT STAG ING AREAS WHEN POSSIBLE. 4. THE CONTRACTOR SHALL CLEAR AND STRIP THE PROJ ECT AREA I F REQUI RED TO TH E DESI RED SU B-GRADE. 5. THE CONTRACTOR SHALL INSTALL E&S CONTROLS PRIOR TO CONSTRUCTION, INCLUDING TEMPORARY DE -WATERING DEVICES AND STORMWATER DIVERSION PRACTICES. ALL AREAS SURROUNDING THE POND THAT ARE GRADED OR DENUDED DURING CONSTRUCTION MUST BE PLANTED WITH TURF GRASS, NATIVE PLANTINGS, OR OTHER APPROVED METHODS OF SOIL STABILIZATION. 6. THE CONTRACTOR SHALLALSO EXCAVATE THE CORE TRENCH AND INSTALLTHE SPILLWAY PIPE. 7. THE RISER AND APPLICABLE OUTFLOW STRUCTURES SHALL BE INSTALLED, AND THE CONTRACTOR SHALL ENSURE THE TOP INVERT OF THE OVERFLOW WEIR IS CONSTRUCTED LEVEL ATTHE DESIGN ELEVATION. 8. THE CONTRACTOR SHALL CONSTRUCT THE EMBANKMENT AND ANY INTERNAL BERMS IN 8-TO 12-INCH LIFTS, COMPACTION SHALL BE COMPLETED IN LIFTS WITH APPROPRIATE EQUIPMENT. THE CONTRACTOR SHALL ALSO ADHERE TO THE CLAY LINER SPECIFICATIONS OUTLINED IN TABLE 14.4 BELOW: Table 14.4. Clay Layer Speci(carions Pro rt Test Method Unk Specification Permeability ASTM D-2434 Cm/sec 1 x 10 Plasticity Index of Gay ASTM D-4231424 % Not less than 15 Liquid Limit of Clay ASTM D-2216 % Not less than 30 Clay Particles Passing ASTM D-422 % Not less than 30 Clay Compaction ASTM D-2216 % 95% of standard prWor derrifty Source- Virginia Stormwaler Management Handbook (1999) AMENDED v v v v v LEVEL 1 WET POND \ SCALE. • I' 20' /261 v \ \ FA- PLANT TURF �Sg�O' Nq IV' VA \ WITHNNELEVEL T PON 1 �OBF RFS S� ��/NS APPROVED A RECORDED VAR. \ 368\ SSEDIDURIMENT BASIIN TO A SONVERSIWMNGTHECROM\ Nl WIDTH-SWM FACILITY EASEMENT �\ FRS \ \ FACILITY, THE CONTRACTOR SHALL \ \ \ \ FD \ \ --f.EMOVE UNSUITABLE SOIL AND _\ \ ENSURE FACILITY IS BUILT IN V A \ v36\ ACCORDANCE WITH THESE PLANS \ 4 \ \ \ \ \ 360 v \ MIN. WATER QUALITY VOLUME REQUIRED=20,11b{f. 3S8 I \ -WATER QUALITY VOLUME \ \ \ \ \ \\ \\ PROVMED= 20,247 cf Qa ELC`. 353-5 3S6 \\ \ \ \ \ \ \ \ \ 3 •1 � S4 4 • ., EXISTING 042" CL. III RCP MULTI -STAGE x / 3S RIS R M'ODIFIED PROPOSED FLOW PATH > 2:1 \\ 3S0 \ \ RIM ELEV. = g 15' \ FLOW\LENGT� -'143' �We-49' \ \ \MID-FLpW ORIFICES z-0i6", ELECT.-3�37' \ =2.9 \ \ 'OW ORIFICE 1,5", ELEV.=353-5 ' \ \ \ d \ W 350.00 \ \ \ \ 4JD W Sp MIDPOND S� Ws S2 \ \ XLSTING 1z' EMERRZiENCY-_GR-ASS \ SPILZWAY WEIR w/ 3:1 SIDE SLOPES AT ELEV.= 359.o \ \ \ \ O \\ 7 \ \ AT RISE •\ - \ EXISTI iG CRITICAL\ SLOPES\fvO REMAIN PROPOSED BAFFLE \ PROPO \ r>h 1b ED GABI BASKET WEIR Wil40 l NOTCH At \ \ ELE�ATION035/. WEIR SHALL HAVE VDOT #3 \ \\ \ C\OARSEA%GREGAT ON THE UPHILL SIDE <OFTHE WEER & CLASS I RIPRAP ON THE DOWNHILL SIDE OF \ T WEIR. CiFOTEXTIL FILTER FA IC \ \ \ UN RLAYMENT SHALL BE INSTAL�D. \ \\ \ \ \ \ \ Wrn\ tP \ \ MIN. FQREBAY CCMBINER VOLUM REQ'D= ,o17cf. \\ \ TOTAL BAY VOLUME PROVIDED= OCf 3r 9 \ v v v � 7 v� \ \ \ \ EXTING VDOT STD. EC- CL. II,' \ TYPE B RIPRAP w/ GEOTEXTILE \ \ FILTEFABRI UNDERLAYMENT. 04 W1= . Wz= .z ' L=21' D=z ( 75t 5 , t �. I O EXISTING V�OT STD. ES 1 \ GRAPHIC \SCALk I I A inch = 20 ft\ 9. EXCAVATION AND GRADING TO THE APPROPRIATE ELEVATIONS AND DESIRED CONTOURS SHALL BE ACHIEVED FOR THE BOTTOM AND SIDE SLOPES OFTHEPOND. 10.THE EMERGENCY SPILLWAY SHALL BE CONSTRUCTED IN CUT WHERE POSSIBLE, OR IN STRUCTURALLY STABILIZED SOILS. 11.THE OUTLET PIPES, INCLUDING DOWNSTREAM RIP -RAP APRON PROTECTION, SHALL BE INSTALLED. 12.EXPOSED SOILS SHALL BE STABILIZED WITH TEMPORARY SEED MIXTURES APPROPRIATE FOR THE POND BUFFER. ALL AREAS ABOVE THE NORMAL POOL ELEVATION SHALL BE PERMANENTLY STABILIZED BY HYDROSEEDING OR SEEDING OVER STRAW. 13.THE POND BUFFER AREA SHALL BE PLANTED WITH A VEGETATIVE GROUND COVER AND THE CONTRACTOR SHALL THEN INSTALL THE APPROPRIATE BASIN LANDSCAPING IN ACCORDANCE WITH THE APPROVED PLANS. 14.ALL CONSTRUCTION SHALL ADHERE TO THE VIRGINIA DEQ POST CONSTRUCTION BMP CLEARINGHOUSE REQUIREMENTS SET FORTH IN DESIGN SPECIFICATION NUMBER 14. FACILITY MAINTENANCE: MAINTENANCE OF THE WET POND(S) IS DRIVEN BY ANNUAL INSPECTIONS THAT EVALUATE THE CONDITION AND PERFORMANCE OF THE POND. DURING THESE INSPECTIONS THE FOLLOWING TASKS SHALL BE PERFORMED BY THE CONTRACTOR IN THE FIRST YEAR FOLLOWING INSTALLATION, AND THE OWNER THEREAFTER: 1. MEASURE SEDIMENT ACCUMULATION LEVELS IN THE FQREBAY. 1. MONITOR THE GROWTH OF WETLANDS, TREES AND SHRUBS PLANTED, AS APPLICABLE. RECORD THE SPECIES AND THEIR APPROXIMATE COVERAGE, AND NOTE THE PRESENCE OF ANY INVASIVE PLANT SPECIES, AS APPLICABLE. 2. INSPECT THE CONDITION OF STORMWATER INLETS TO THE POND FOR MATERIAL DAMAGE, EROSION OR UNDERCUTTING. 3. INSPECT THE BANKS OF UPSTREAM AND DOWNSTREAM CHANNELS FOR EVIDENCE OF SLOUGHING, ANIMAL BURROWS, BOGGY AREAS, WOODY GROWTH, OR GULLY EROSION THAT MAY UNDERMINE EMBANKMENT INTEGRITY. 4. INSPECT POND OUTFALL CHANNEL FOR EROSION, UNDERCUTTING, RIP -RAP DISPLACEMENT, WOODY GROWTH, ETC. 5. INSPECT CONDITION OF PRINCIPAL SPILLWAY AND RISER FOR EVIDENCE OF SPALLING, JOINT FAILURE, LEAKAGE, CORROSION OR OTHER FAILURES. 6. INSPECT CONDITION OF ALL TRASH RACKS OR FLASHBOARD RISERS FOR EVIDENCE OF CLOGGING, LEAKAGE, DEBRIS ACCUMULATION OR OTHER FAILURES. 7. INSPECT MAINTENANCE ACCESS TO ENSURE IT IS FREE OF WOODY VEGETATION, AND CHECK TO SEE WHETHER VALVES, MANHOLES AND LOCKS CAN BE OPENED AND OPERATED. 8. INSPECT INTERNAL AND EXTERNAL SIDE SLOPES OF THE POND FOR EVIDENCE OF SPARSE VEGETATIVE COVER, EROSION, OR SLUMPING, AND MAKE TRASH RACKS SHALL BE NEEDED REPAIRS IMMEDIATELY. INSTALLED ON ALL ORIFICES 9. REPAIR AND REPLACE AS NECESSARY. PER VSMH-SEE THIS SHEET 10. PLEASE SEETHE TABLE BELOW FOR ADDITIONAL MAINTENANCE MEASURES ABOVE AND BEYOND THOSE OUTLINED ABOVE: FOR DETAILS Table 14.6. Typical Wet Pond Maintenance Tasks and Frequency Maintenance Items Frequency • Mowing - twice a year Quarterly or after major storms • Remove debris and blockages (-I inch of rainfall) • Repair undercut eroded, and bare soil area • Mowing Twice a year • Shoreline cleanup to remove trash, debris and floatables • Mull maintenance inspection Annually • Open up the riserto access and lest the valves • Repair broken mechanical components, if needed One time �nqurio the • Pontl buffer and aquatic bench reinforcement plantings second ar101bXti CDrtsgucgm • Foreba Sediment Removal Every 5 to 7 years • Repar pipas,the riser and sollheianitas needed From 5 to 25 va2m FACILITY INSPECTION: MULTIPLE INSPECTIONS ARE CRITICAL TO ENSURE THE BASIN(S) ARE PROPERLY CONSTRUCTED. BECAUSE THE TIMING OF THE INSTALLATION IS DICTATED BY THE CONTRACTOR, THE CONTRACTOR SHALL BE RESPONSIBLE FOR CONTACTING THE ENGINEER AND INSPECTOR PRIOR TO INSTALLATION. MULTIPLE SITE VISITS AND INSPECTIONS ARE REQUIRED TO BE SCHEDULED BY THE CONTRACTOR, WITH THE ENGINEER AND INSPECTOR, DURING THE FOLLOWING STAGES OF THE EXTENDED DETENTION BASIN'S CONSTRUCTION PROCESS: 1. PRE -CONSTRUCTION MEETING 2. INITIAL SITE PREPARATION (INCLUDING INSTALLATION OF PROJECT E&S CONTROLS) 3. EXCAVATION/GRADING (E.G., INTERIM/FINAL ELEVATIONS) 4. WET POND INSTALLATION (E.G., INTERIM AND FINAL ELEVATIONS) S. INSTALLATION OF THE EMBANKMENT, THE RISER/PRIMARY SPILLWAY, AND THE OUTLET STRUCTURE(S). 6. PLANTING AND VEGETATIVE STABILIZATION PHASE (WITH AN EXPERIENCED LANDSCAPE ARCHITECT PRESENT) 7. FINAL INSPECTION (DEVELOP A PUNCH LIST FOR FACILITY ACCEPTANCE) EXISTING SPILLWAY CREST ELEVATION= 359.00 EXIS77NG HANSON CONCRETE AN77-VOR7EX TRASHRACK II OFF REB/�Y � I/ EXISTING TOP OF DAM ELEV.= 360.00 EXIS77NG 12' WIDE GRASS WEIR OUTFALL CHANNEL W/ 3: 1 SIDE SLOPES. EXISTING 042" CL. III RCP MULTI -STAGE RISER MODIFIED RIM ELEV. = 35Z15' MID -FLOW ORIFICES 2-016", ELEV.=355.37' LOW -FLOW ORIFICE 1-05". ELEV.=353.50' POND DRAIN PROVIDED AT ORIFICE COEFF.= 0.6 ELEV.=350 WITH ADJUSTABLE VALVE LOCATED ABOVE THE PERMANENT POOL AND WITHIN THE RISER. DRAIN SHALL ALLOW PERMANENT POOL TO BE COMPLETELY DRAINED. THE APPROVING AUTHORITY SHALL BE NOTIFIED BEFORE DRAINING THIS POND. RISER 10071NG EXISTING PRINCIPAL SPILLWAY (Mull' urJ Oz 1(11V1 1 V nz 1V1V1J1C1L'lJ, ADDITION OFANTI-SEEP COLLARS) (NOT TO SCALE) -EXIS77NG 36" CL. III RCP BARREL 98 LF ® IZ INV. IN= 350.00' INV. OUT= 349.00' INSTALL 2-6'x6' AN77 SEEP COLLARS PER CALCULA77ONS BELOW AN77-SEEP COLLARS CALCULATION Ls= Y(Z+4)*[1 +(S/(0.25-S))) Y=715',• Z=4,- S=0.0102 Ls=59.6' FROM PLATE 3.14-12, 2 COLLARS REQUIRED WITH 6'x6' DIMENSIONS SPACED AT 2xP=2xl.5=3' FROM RISER, AND 14xP=14xl.5=21' FROM FIRST COLLAR EXISTING-10' WIDE TLATBE CH AT THE / Top OFTHE EMBANKMENT SHALL. SERVE AS A STORMWATER I �60 _ �� MANAGEMENT ACCESS& �\ 1 MAINTENANCE PATH v / (\ EXISTING 36" CL. III RCP BARREL e / I N �`O \ EXISTING VDOT STD. EC-1, CL. II, \ god TYPE B RIPRAP Will GEOTEXTILE \ I \ FILTER FABRIC UNDERLAYMENT. \ h� (W1=7.5', W2=18', L=16', D =z') \ X EX15TING o' TOP � _ DAM ELEZ36o.00 ��� LEVEL I WET POND PLANTING PLAN SYM BOTANICAL COMMON NAME SIZE SWM FACILITY QUANTITY COVERAGE (so PLANTINGS FA FESTUCAARUNDINACEA TALL FESCUE TURF 19,500 2 & 10-YEAR STORM EVENTS DO NOT CREST THE EMERGENCY SPILLWAY 12 TOP OF DAM WIDTH= 10' AT AN ELEVAT70N= 360.00 WEIR COEFF. = 3.3 EMERGENCY _J SPILLWAY GRASS LINED SPILLWAY ELEVATION= 359.0' APPROVED EMERGENCY SPILLWAY NTS FIGURE 3.01 - la Homogeneous Embankments w/Seepage Controls omogeneous fli l --------� I 4' min _ I_ ut off trench-4' below suitable) material I Soil or rock L - - - - - - - - - - - J TYPICAL HOMOGENEOUS EMBANKMENT Transition Rockfill or grovel Pipe outlet Coarse filter oroun '4' o Perforated collector Foundation drain Blanket drain FOUNDATION DRAIN BLANKET DRAIN Transition filter CHIMNEY DRAIN ci�3_01-1a Source: SCS Engineering Field Manual Management Standard Dimensions 24 !30 48 58 M 1AB 27 /2 60 72 $7112 228 30 3i 60 72 41 2.M 36 41 60 72 48 222 42 51 72 86 55 3.16 48 - 58 84 100 62 427 54 66 "/2 8a 100 701/R 420 60 7; 96 114 78 5.48 66 BO'/ a 96 114 8A / z 6.39 72 8E 1a6 128 90 8.a3 78 94I/x 126 147 98t/z 8.97 84 100 IM 147 104 6.90 tr path > .ad outlet Rack or gravel -Rod Jae drain �_ Tmnsition filter TOE DRAIN Cast in Tau Slab V V P Plan View win-vmev Cap o.D. Mn-Vodm Cep I.D.-� h- Noxh Marvin - I Oam (1.) A.Man D;1th (Cep eM Riam) Mandledund In eP»rdence wM ASiM C47e. (2.) Dlnlenams subject In parmlasible variations MASW C47e. InletArea betwaen device l.D. and deer O.D. realer �) Naarea fire. of Haar l.D.) 1 is 9 d. Slab rektlorcement m be AaTM M15#4 ban 0 e'E.W. D6cumrerential .5 WMF.hl . Ar • 1®0.150 2x6al pnx W2.6WMF m000p.s. cove,lpor.-4kil.c=4,000 P.s.i., fv=BO,Wa p.ai. Cmcrem (CCOR)=V=4kcl. Corcnte cwerwer nlMorwment (cccR)=t^, anleas mind. (6.) DI-1 Fiala & Gans Is avallabla mr*W' LD. risers and lagan Precast Anti -Vortex Device (Cap and Riser) MIN. FQREBAY COMBINED VOLUME REQ'D= 3,017cf. TOTAL FQREBAY VOLUME PROVIDED= 3,790cf BOTTOM OFF FOREBAY ELEV. 3535 PROPOSED GABION BASKET WEIR W/40' NOTCH AT ELEVA77ON 357.5. WEIR SHALL HAVE VDOT #J COARSE AGGREGATE ON THE UPHILL SIDE OF THE WEIR & CLASS l RIPRAP ON THE DOWNHILL SIDE OF THE WEIR. GEOTEX71LE FILTER FABRIC UNDERLAYMENT SHALL BE INSTALLED. --r-t--rj--r�r- Section AA ADscan_ Al dlnmslms subject to alb-ne w«erenon wmnr<a.. rrz an..r. are OW. 03-15-06 ' Hanson MIN. WATER QUALITY VOLUME REQUIRED = 20,116 cf. WATER QUALITY VOLUME PROVIDED = 20,247 cf AT 353.5 Technical Bulletin 7 Minimum Standard 3.02 "c ^wtsa n r. raxmx aePa etruGwal Bc wllh � 0 a-r/Y Mla..�a• par. 00 wa�u. i swee 0000 .,],:..: with eP41onJ PVb rpo1'r4i a1Fr .prvt B Ititt Sa1Pe uec wND ( ) w ' h.1-eat z-Ue• hoer a e a• LG Section Waa4arva er Wra,tc snlueon. tve. m eWtl / A' d Dels . - _______ Elevation _ PLA OILIF Oema 4 BMP DEBRIS CAGE TT1ieeMala 94 ae604 INC. wo-ree-la¢r ..wdw.-,a.u•,em Vegetative Cover Slo a of Ent Channel Slo a of Exit Chs•nel 0 5 0-SX Bermuda Grass ft 1 7 6 5 n.n:w Butfalogmss Kentucky Bluegrass Smooth Bromegrass 7 6 5 4 Tall Fescue Reed Camary Grass Sod Forming Urass-Legume S 4 4 3 Mixtures Lespedeia g WeeP in Love s t 3.5 3.5 2.5 2.5 Yellow Bluestein Native Grass Mixtures ' USDA-NRCS TP-61 z Increase values 25 percent when the anticipated average use of the spillway is not mare Pe P g P Y uent than once in 10 ears. �9 Y 3 Those with a high clay content and high plasticity. Typical soil textures are silty clay, sandy clay, and clay 4 Those with a high content of fine Sand or silt and lower plasticity or non -plastic. Typical soil GENERAL SWM NOTES: a. STATE APPROVED TRASH RACKS AND ORIFICES SHALL BE INSTALLED ON ALL ORIFICE OPENINGS. SEE DETAILS ON THIS SHEET, OR EQUIVALENT, FOR INSTALLATION. 2. CONCRETE FOUNDATIONS SHALL BE INSTALLED ON ALL RISER STRUCTURES MEETING MINIMUM VESCH .a SPECIFICATIONS. 3 4 3 CONTRACTORSHALL HIREATHIRD PARTY GEOTECHNICAL ENGINEER TO ENSURETHE EMBANKMENTSARE STRUCTURALLY SOUND. THE EMBANKMENTS SHALL HAVE A COMPACTED CLAY CORE WITH A CUTOFF TRENCH & BE IN ACCORDANCE WITH THE DETAILS SHOWN ON THIS SHEET. ALL EXISTING AND PROPOSED FILL MATERIAL AND PROPOSED CONSTRUCTION SHALL BE APPROVED BY AN ONSITE GEOTECHN ICAL ENGINEER PRESENT DURING THE CONSTRUCTION OF THE EMBANKMENTS AND FILL AREAS, AND PRESENT DURING THE CORE SAMPLING. 4. THE DOWNSTREAM EMBANKMENT SIDE SLOPES OF ALL PERMANENT FACILITIES SHALL HAVE A MAXIMUM 3:1 SLOPE. 5. A POND EMBANKMENT REPORT WILL BE REQUIRED PRIOR TO RELEASE OF THE LEVEL I WET POND FACILITY. 6. THE EXISTING VEGETATED SPILLWAY SHALL BE MAINTAINED WITH GRASSES FROM TABLE C-i ABOVE. 1-YR W.S.E. =355.4 2-YR W.S.E. =356.0 10-YR W.S.E. =357.6 100-YR W.S.E. =359.0 CONCRETE ANTI -VORTEX IRA SHRACK _ _ _ PROPOSED M_WSE=353.5' _ ORIFICE COEFF.= 0.6 PERMANENT POOL DEPTH=35' FLOOR ELEV.=350 CL. Ill RCP MUL77-STAGE RISER. SEE THIS SHEET EXIS77NG FOR DETAILS. 36" CL. N RCP BARREL 98 LF 0 1% INV. IN= 350.00' INV. OUT= 349.00' AMENDED LEVEL I WET D/l�►T$/l 10' WIDE TOP OF DAM ELEV.= 360.00' WEIR ELEV.= 359.00 12' WIDE GRASS WEIR OUTFALL CHANNEL W/ 31 SIDE SLOPES. MAX. EMBANKMENT HT=10' (460-450) W No. 35791 12�_ 08/14/21 F41 H � LU O J k w (^ o U Z to w to Z z i O z 5 a U 1 O Q a i > w K H Z LU ! w i H ram. > w L i Uj N Otter i MIN. 8' WOE ® TOP & 10' DEEP IMPERVIOUS CORE & CUTOFF TRENCH WITH 1:1 SIDE SLOPES. SEE DETAIL ON THIS SHEET FOR ADD177ONAL INFORMATION. O O .i N N N M O 7 1, 00 � N cen m Z W (!� Q I I- N z a W 0111 w N J N Q W 06 z a a � H LU Z OJ za O � � Z W x z w U U--� W J Q w (D z Q z w W J w 0 w LL O J 0c rre!l�� O V W o = o � U N C~J LU O w w C-1 _ CL to JOB NO. 112054 SCALE 1"=20' SHEET NO. 3 `o C O N nw c c ° _ U `o c � y 0 3 t 3 0 c � a a x U U ° m 0 0