Loading...
HomeMy WebLinkAboutWPO201700071 Plan - VSMP Minor Amendment 2018-08-28I SITE DATA OWNER % DEVELOPER: PLAN PREPARER: TAX MAP PARCEL No: PARCEL AREA: ZONING: USE.° MARCH MOUNTAIN PROPERTIES LLC 1005 HEATHERCROFT CIRCLE, SUITE 400 CROZET, VA 22932 ROUDABUSH, GALE, & ASSOCIATES 914 MONTICELLO ROAD CHARLOTTESVILLE, VA. 22902 (434)-977-0205 55E-01-22-0 12.02 ACRES CONTACT. DAVE BROCKMAN CELL: (702)-985-9088 dave©oldtrail village. com NEIGHBORHOOD MODEL DISTRICT IN ACCORDANCE WITH PROFFERS OF ZMA 2015-00001 APPROVED FEBRUARY 1, 2016 SINGLE FAMILY ATTACHED UNITS GROSS RESIDENTIAL DENSITY: 3.8 UNIT/ACRE MAGISTERIAL DISTRICT: WHITE HALL MAGISTERIAL DISTRICT STORMWATER MANAGEMENT - WA TERSHED: ANAGEMENT.° WATERSHED: TOPOGRAPHY: BENCHMARK - DA TUM: ENCHMARK:DATUM: CRITICAL SLOPES: FLOODPLAIN: LANDSCAPING: AS DEFINED BY THE OVERALL STORMWATER MASTER PLAN, APPROVED 4/25/2016 WPO2015600009 LICKINGHOLE CREEK LOUISA AERIAL SURVEYS, AUGUST 2012 ROUDABUSH GALE & ASSOC. TOPOGRAPHIC FIELD SURVEY FROM JUNE 2015 STORM SEWER INLET TOP = 695.13 0 LD TRAI L V1 LLAG E BLOCK 22 STORMWATER MANAGEMENT & EROSION CONTROL PLAN VERTICAL - NAVD 88, HORIZONTAL - NAD 83 CRITICAL SLOPES EXIST WITHIN THE PROPERTY LIMITS, BUT OUTSIDE OF THE PROJECT LIMITS THIS PROJECT IS LOCATED WITHIN 'ZONE X" AS SHOWN ON FLOOD INSURANCE RATE MAP. COMMUNITY PANEL NUMBER 510003C 0237 D. EFFECTIVE DATE. • FEBRUARY 4. 2005. SEE LANDSCAPING PLAN FOR PLANTINGS, SCHEDULE AND SPECIFICATIONS, NOTES AND DETAILS NO EVIDENCE OF A BURIAL SITE WAS FOUND ON THIS PORTION OF PARCEL A 1, THE STREAM BUFFER(S) SHOWN HEREON SHALL BE MANAGED IN ACCORDANCE WITH THE THE ALBEMARLE COUNTY WATER PROTECTION ORDINANCE. THIS SITE IS NOT LOCATED WITHIN AN AGRICULTURAL -FORESTAL DISTRICT. THIS SITE IS LOCATED WITHIN THE WATERSHED OF A PUBLIC WATER SUPPLY RESERVOIR. GENERAL EROSION CONTROL NOTES WORK AREA PROTECTION & MAINTENANCE 1. ALL FENCES REQUIRED TO BE REMOVED OR DISTURBED BY CONSTRUCTION SHALL BE SALVAGED, STORED, PROTECTED AND RE -INSTALLED BY CONTRACTOR AT THE DIRECTION OF AND LOCATION DESIGNATED BY THE PROJECT MANAGER. IF SUCH FENCE MATERIAL CANNOT BE REUSED DUE TO DAMAGE CAUSED BY CONTRACTOR, CONTRACTOR SHALL INSTALL NEW FENCE OF THE SAME TYPE OF MATERIAL. TEMPORARY FENCING REQUIRED BY PRIVATE PROPERTY OWNERS SHALL BE PROVIDED BY 'CONTRACTOR. CONTRACTOR IS ADVISED TO CONTACT PROPERTY OWNERS AT LEAST FORTY-EIGHT (48) HOURS IN ADVANCE OF REMOVING ANY FENCE IN ORDER TO COORDINATE RELOCATION AND/OR PROTECTION OF ANY ANIMALS, AND TO ESTABLISH AND CONFIRM WITH THE OWNER THE PRE -CONSTRUCTION CONDITION OF ANY FENCE TO BE REMOVED, DISTURBED OR REPLACED. 2. CONTRACTOR IS PERMITTED TO WORK IN THE PUBLIC RIGHT-OF-WAY (FOLLOWING ISSUANCE OF VDOT APPROVAL) AND ANY TEMPORARY OR PERMANENT EASEMENT (FOLLOWING VERIFICATION OF EXISTENCE OF EASEMENT) SHOWN ION THE PLANS. HOWEVER, CONTRACTOR SHALL NOTIFY PROPERTY OWNER(S) FORTY-EIGHT (48) HOURS PRIOR TO WORKING ON ANY PRIVATE PROPERTY TO GAIN AND COORDINATE ACCESS AND TO DETERMINE A STORAGE AREA FOR MATERIALS IF NEEDED. COORDINATION OF ACCESS TO PUBLIC RIGHT-OF-WAY AND STORAGE OF MATERIALS THEREON SHALL BE COORDINATED WITH VDOT AND THE PROJECT MANAGER. CONTRACTOR'S FAILURE TO SO NOTIFY AND COORDINATE WITH PROPERTY OWNERS AND/OR THE PROJECT MANAGER MAY RESULT IN DELAYS. 3. CONTRACTOR SHALL, AT HIS EXPENSE, MAINTAIN THE WORK SITE IN A CLEAN AND ORDERLY APPEARANCE AT ALL TIMES. ALL DEBRIS AND SURPLUS MATERIAL COLLECTED SHALL BE DISPOSED OF OFF THE WORK SITE BY CONTRACTOR, AT HIS EXPENSE. 4. EXISTING LAWNS, TREES, SHRUBS, FENCES, UTILITIES, CULVERTS, WALLS, WALKS, DRIVEWAYS, POLES, SIGNS, RIGHT-OF-WAY MONUMENTS, MAILBOXES AND THE LIKE SHALL BE PROTECTED FROM DAMAGE DURING THE WORK. ANY DAMAGE CAUSED TO SUCH ITEMS SHALL BE REPAIRED OR REPLACED BY CONTRACTOR AT NO ADDITIONAL COST. PROPERTY PINS DISTURBED BY CONTRACTOR THAT ARE NOT SHOWN ON THE PLANS TO BE DISTURBED SHALL BE RESTORED BY A LICENSED SURVEYOR AT CONTRACTOR'S EXPENSE. 5. CONTRACTOR SHALL EMPLOY EROSION CONTROL DEVICES AND METHODS AS REQUIRED TO MEET THE REQUIREMENTS AND INTENT OF THE LOCAL EROSION CONTROL ORDINANCE. CONTRACTOR SHALL PROVIDE THE NECESSARY DIVERSION DITCHES, DIKES OR TEMPORARY CULVERTS REQUIRED TO PREVENT MUD AND DEBRIS FROM BEING WASHED ONTO THE: STREETS OR PROPERTY. CONTRACTOR'S VEHICLES SHALL BE KEPT CLEAN TO PREVENT MUD OR DUST FROM BEING DEPOSITED ON STREETS. NO AREA SHALL BE LEFT DENUDED FOR MORE THAN SEVEN (7) CALENDAR DAYS. VEGETATION 1. PRIOR TO REMOVING ANY VEGETATION, CONTRACTOR SHALL MEET WITH THE PROPERTY OWNERS AIND THE PROJECT MANAGER TO REVIEW THE LIMITS OF CONSTRUCTION AND OBTAIN PERMISSION TO REMOVE VEGETATION REQUIRED TO DO THE WORK. 2. TREE AND PLANT ROOTS OR BRANCHES THAT MAY INTERFERE WITH THE WORK SHALL BE TRIMMED OR CUT ONLY WITH THE APPROVAL OF THE PROJECT MANAGER. ANY TREES OR PLANTS WHICH ARE SHOWN TO REMAIN THAT DO NOT INTERFERE WITH THE WORK, BUT ARE DAMAGED BY CONTRACTOR OR HIS SUBCONTRACTORS, SHALL BE REPAIRED OR REPLACED BY CONTRACTOR AT NO ADDITIONAL COST. 3. CONTRACTOR SHALL CLEAN UP, RESTORE, SEED AND MAINTAIN ALL DISTURBED AREAS IMMEDIATELY UPON COMPLETION OF WORK ON EACH SITE. TOPSOIL, SEED, FERTILIZER AND MULCH SHALL BE PLACED IN ACCORDANCE WITH ESC AUTHORITY STANDARDS ON ALL DISTURBED AREAS. A PERMANENT STAND OF GRASS ADEQUATE TO PREVENT EROSION SHALL BE ESTABLISHED PRIOR TO FINAL ACCEPTANCE. 4. THE ACT OF RESEEDING SHALL NOT QUALIFY AS "STABILIZED". THE CONTRACTOR SHALL BE RESPONSIBLE TO ESTABLISH VEGETATION, NOT SIMPLY APPLY SEED AND MATERIALS. ES -1: UNLESS OTHERWISE INDICATED, ALL VEGETATIVE AND STRUCTURAL EROSION AND SEDIMENT CONTROL PRACTICES WILL BE CONSTRUCTED AND MAINTAINED ACCORDING TO MINIMUM STANDARDS AND SPECIFICATIONS OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK AND VIRGINIA REGULATIONS VR 625-02-00 EROSION AND SEDIMENT CONTROL REGULATIONS. ES -2: THE PLAN APPROVING AUTHORITY MUST BE NOTIFIED ONE WEEK PRIOR TO THE PRE -CONSTRUCTION CONFERENCE, ONE WEEK PRIOR TO THE COMMENCEMENT OF LAND DISTURBING ACTIVITY, AND ONE WEEK PRIOR TO THE FINAL INSPECTION. ES -3: ALL EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE PLACED PRIOR TO OR AS THE FIRST STEP IN CLEARING. ES -4: A COPY OF THE APPROVED EROSION AND SEDIMENT CONTROL PLAN SHALL BE MAINTAINED ON THE SITE AT ALL TIMES. ES -5: PRIOR TO COMMENCING LAND DISTURBING ACTIVITIES IN AREAS OTHER THAN INDICATED ON THESE PLANS (INCLUDING, BUT NOT LIMITED TO, OFF-SITE BORROW OR WASTE AREAS), THE CONTRACTOR SHALL SUBMIT A SUPPLEMENTARY EROSION CONTROL PLAN TO THE OWNER FOR REVIEW AND APPROVAL BY THE PLAN REVIEWING AUTHORITY. ES -6: THE CONTRACTOR IS RESPONSIBLE FOR INSTALLATION OF ANY ADDITIONAL EROSION CONTROL MEASURES NECESSARY TO PREVENT EROSION AND SEDIMENTATION AS DETERMINED BY THE PLAN REVIEWING AUTHORITY. ES -7: ALL DISTURBED ARES ARE TO DRAIN TO APPROVED SEDIMENT CONTROL MEASURES AT ALL TIMES DURING LAND DISTURBING ACTIVITIES AND DURING SITE DEVELOPMENT UNTIL FINAL STABILIZATION HAS BEEN ACHIEVED. ES -8: DURING DEWATERING OPERATIONS, WATER WILL BE PUMPED INTO AN APPROVED FILTERING DEVICE. ES -9: THE CONTRACTOR SHALL INSPECT ALL EROSION CONTROL MEASURES PERIODICALLY AND AFTER EACH RUNOFF -PRODUCING RAINFALL EVENT. ANY NECESSARY REPAIRS OR CLEANUP TO MAINTAIN THE EFFECTIVENESS OF THE EROSION CONTROL DEVICES SHALL BE MADE IMMEDIATELY. VIc;iNIi i Y MAV SCALE: 1"= 1000 FEET SHEET INDEX SHEET 1 - COVER SHEET SHEET 2 EXISIIING CONDITIONS/SOILS MAP SHEET 3 EROSION CONTROL PHASE 1 SHEET 4 EROSION CONTROL PHASE 2 SHEET 5 OVERALL DRAINAGE MAP SHEET 6 EROSION CONTROL NARRATIVE & DETAILS SHEET 7 EROSION CONTROL NOTES & DETAILS SHEET 8 BMP CONVERSION NOTES & DETAILS SHEET 8 ADEQUATE OUTFALL ANALYSIS/SWM NOTES & DETAILS SHEET 10 LANDSCAPE PLAN/NOTES SHEET 11 MITIGATION PLANMOTES GENERAL CONSTRUCTION NOTES FOR EROSION AND SEDIMENT CONTROL PLANS 1. THE PLAN APPROVING AUTHORITY MUST BE NOTIFIED ONE WEEK PRIOR TO THE PRE -CONSTRUCTION CONFERENCE, ONE WEEK PRIOR TO THE COMMENCEMENT OF LAND DISTURBING ACTIVITY, AND ONE WEEK PRIOR TO THE FINAL INSPECTION. 2. ALL EROSION AND SEDIMENT CONTROL MEASURES WILL BE CONSTRUCTED AND MAINTAINED ACCORDING TO MINIMUM STANDARDS AND SPECIFICATIONS OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK AND VIRGINIA REGULATIONS yr 625-02-00 EROSION AND SEDIMENT CONTROL REGULATIONS. 3. ALL EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE PLACED PRIOR TO OR AS THE FIRST STEP IN CLEARING. A. A COPY OF THE APPROVED EROSION AND SEDIMENT CONTROL PLAN SHALL BE MAINTAINED ON THE SITE AT ALL TIMES. 5. PRIOR TO COMMENCING LAND DISTURBING ACTIVITIES IN AREAS OTHER THAN INDICATED ON THESE PLANS (INCLUDING, BUT NOT LIMITED TO, OFF-SITE BORROW OR WASTE AREAS),THE CONTRACTOR SHALL SUBMIT A SUPPLEMENTARY EROSION CONTROL PLAN TO THE OWNER FOR REVIEW AND APPROVAL BY THE PLAN APPROVING AUTHORITY. 6. THE CONTRACTOR IS RESPONSIBLE FOR INSTALLATION OF ANY ADDITIONAL EROSION CONTROL MEASURES NECESSARY TO PREVENT EROSION AND SEDIMENTATION AS DETERMINED BY THE PLAN APPROVING AUTHORITY. 7. ALL DISTURBED AREAS ARE TO DRAIN TO APPROVED SEDIMENT CONTROL MEASURES AT ALL TIMES DURING LAND DISTURBING ACTIVITIES AND DURING SITE DEVELOPMENT UNTIL FINAL STABILIZATION IS ACHIEVED. B. DURING DEWATERING OPERATIONS, WATER WILL BE PUMPED INTO AN APPROVED FILTERING DEVICE. 9. THE CONTRACTOR SHALL INSPECT ALL EROSION CONTROL MEASURES PERIODICALLY AND AFTER EACH RUNOFF PRODUCING RAINFALL EVENT. ANY NECESSARY REPAIRS OR CLEANUP TO MAINTAIN THE EFFECTIVENESS OF THE EROSION CONTROL DEVICES SHALL BE MADE IMMEDIATELY. 10. ALL FILL MATERIAL TO BE TAKEN FROM AN APPROVED, DESIGNATED BORROW AREA. 11. ALL WASTE MATERIALS SHALL BE TAKEN TO AN APPROVED WASTE AREA. EARTH FILL SHALL BE INERT MATERIALS ONLY, FREE OF ROOTS, STUMPS, WOOD, RUBBISH, AND OTHER DEBRIS. 12. BORROW OR WASTE AREAS ARE TO BE RECLAIMED WITHIN 7 DAYS OF COMPLETION PER ZONING ORDINANCE SECTION 5.1.28. 13. ALL INERT :MATERIALS SHALL BE TRANSPORTED IN COMPLIANCE WITH SECTION 13-301 OF THE CODE OF ALBEMARLE. 14. BORROW, FILL OR WASTE ACTIVITY INVOLVING INDUSTRIAL -TYPE POWER EQUIPMENT SHALL BE LIMITED TO. THE HOURS OF 7:00 AM TO 9:00 PM. 15. BORROW, FILL OR WASTE ACTIVITY SHALL BE CONDUCTED IN A SAFE MANNER THAT MAINTAINS LATERAL SUPPORT, OR ORDER TO MINIMIZE ANY HAZARD TO PERSONS, PHYSICAL DAMAGE TO ADJACENT LAND AND IMPROVEMENTS, AND DAMAGE TO ANY PUBLIC STREET BECAUSE OF SLIDES, SINKING, OR COLLAPSE. 16, THE DEVELOPER SHALL RESERVE THE RIGHT TO INSTALL, MAINTAIN, REMOVE OR CONVERT TO PERMANENT STORi WATER MANAGEMENT FACILITIES, WHERE APPLICABLE, ALL EROSION CONTROL MEAS,URES`RREQUIRED BY THIS PLAN REGARDLESS OF THE SALE OF ANY LOT, UNIT, BUILDING OR OTHER PORTION OF THE PROPERTY. 17. TEMPORARY STABILIZATION SHALL BE TEMPORARY SEEDING AND MULCHING. SEEDING IS TO BE AT 75 LBS/ACRE, AND IN THE MONTHS OF SEPTEMBER TO FEBRUARY TO CONSIST A 50/50 MIX OF ANNUAL RYEGRASS AND CEREAL WINTER RYE, OR IN MARCH AND APRIL TO CONSIST OF ANNUAL RYE, OR MAY THROUGH AUGUST TO CONSIST OF GERMAN MILLET. STRAW MULCH IS TO BE APPLIED AT 80 LBS/100SF. ALTERNATIVES ARE SUBJECT TO BE APPROVED BY THE COUNTY EROSION CONTROL INSPECTOR. 18. PERMANENT STABILIZATION SHALL BE LIME AND FERTILIZER, PERMANENT SEEDING, AND MULCH. AGRICULTURAL GRADE LIMESTONE SHALL BE APPLIED AT 90 LBS/1000SF. INCORPORATED INTO THE TOP 4-6 INCHES OF SOIL. FERTILIZER SHALL BE APPLIED AT 1000 LBS/ACRE AND CONSIST OF A 10-20-10 NUTRIENT MIX. PERMANENT SEEDING SHALL BE APPLIED AT 180 LBS/ACRE AND CONSIST of 115% KENTUCKY 31 OR TALL FESCUE AND 0-5% PERENNIAL RYEGRASS OR KENTUCKY BLUEGRASS. STRAW MULCH IS TO BE APPLIED AT 80 LBS/100SF. ALTERNATIVES ARE SUBJECT TO BE APPROVED BY THE COUNTY EROSION CONTROL INSPECTOR. 19. MAINTENANCE: ALL MEASURES ARE TO BE INSPECTED WEEKLY AND AFTER EACH RAINFALL. ANY DAMAGE OR CLOGGING TO STRUCTURAL MEASURES IS TO BE REPAIRED IMMEDIATELY. SILT TRAPS ARE TO BE CLEANED WHEN 50% OF THE WET STORAGE VOLUME IS FILLED WITH SEDIMENT. ALL SEEDED AREAS ARE TO BE RESEEDED WHEN NECESSARY TO ACHIEVE A GOOD STAND OF GRASS. SILT FENCE AND DIVERSION DYKES WHICH ARE COLLECTING SEDIMENT TO HALF THEIR HEIGHT MUST BE CLEANED AND REPAIRED IMMEDIATELY. 20. ALL TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE REMOVED WITHIN 30 DAYS OF FINAL SITE STABILIZATION, WHEN MEASURES ARE NO LONGER NEEDED, SUBJECT TO APPROVAL BY THE COUNTY EROSION CONTROL INSPECTOR. GENERAL CONSTRUCTION NOTES FOR STORMWATER MANAGEMENT PLANS 1. ALL DAMS AND CONSTRUCTED FILL TO BE WITHIN 95% OF MAXIMUM DRY DENSITY 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. 2. PIPE AND RISER JOINTS ARE TO BE WATERTIGHT WITHIN STORMWATER MANAGEMENT FACILITIES. 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. APPROVED i 0K., County ,)npai'tmeni yTH 0 jN1 4,, raqqart )ilmY 0 _22841 �Av' OA ��SSIONAL E��� APPROVALS DATE PLANNING moi! s a w � O REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE October 5, 2017 SCALE 1 "=1000' CONTOUR INTERVAL N/A W V Z �g z WN�J� W CV - > _�e()> oc U w j o w00Qui >� a OM 2 �--Lu Q w o J 0 FILE NUMBER 8053 SHEET 1 Of 11 s a w � O 0`0 _ 2 N Q QQ. 0Er Q rxW Q@ ? OU Q.Zwo wM Q0� UQ �w W 0 °� UN a � (� 0 � co (00 �ZLL 0cr � J� Lu Cm �Q z ti W �W Q� �t W 0r Z W O a REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE October 5, 2017 SCALE 1 "=1000' CONTOUR INTERVAL N/A W V Z �g z WN�J� W CV - > _�e()> oc U w j o w00Qui >� a OM 2 �--Lu Q w o J 0 FILE NUMBER 8053 SHEET 1 Of 11 i REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE October 5, 2017 SCALE 1"=40' CONTOUR INTERVAL 2 FT (. CQ G U) W J 0 z g Z �Np.—�� ZN -> p�0 0 oO�Q� z� �< Om�E-m V a wo p J Z 0 X W FILE NUMBER 8053 SHEET 2 OF 11 � w o U wN m too Z ®� (t Lu >O � a2 �z CC Lb, Q Q00 T OJN W J2 2�� 0 � �W(D 2 OR O� v, O� Vcc GO w ctN aWZO9 Q� SCP WT- rr2W V CD 2 OW i REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE October 5, 2017 SCALE 1"=40' CONTOUR INTERVAL 2 FT (. CQ G U) W J 0 z g Z �Np.—�� ZN -> p�0 0 oO�Q� z� �< Om�E-m V a wo p J Z 0 X W FILE NUMBER 8053 SHEET 2 OF 11 yj- - .... . .. . .... .. .... ..... . ........... ... . . .. .... ..... .... . ..... 001, IV V PAY SPECIAL RF _ _ LINE ENS IRE AR� . . ..... ..... .......... haj . ....... . .. ..... . ....... DRAINAGE AREA FROMAPPROVEDsVvMMASTER PLAN DRAINAGE AREA TO PROPOSED BIOFILTER S-4 v 4 43 z if 0 C.) N cloc) D co CL 41 04 41C < z:01 T) cc Lu 5� o �O�/�g 00 U4 z U, z , X -Y 0 W 0 Z wo co U'. 0S. 9 Lu r LL, V I z 0 Lu z . ....... . .. ..... . ....... DRAINAGE AREA FROMAPPROVEDsVvMMASTER PLAN DRAINAGE AREA TO PROPOSED BIOFILTER S-4 v REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28,2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE \October 5, 2017, SCALE 1"=40' CONTOUR INTERVAL 2 FT FILE NUMBER 8053 SHEET 5 OF11 0 C.) N cloc) D co CL 41 04 41C < z:01 T) cc Lu 5� o �O�/�g 00 U4 z U, z 0 W 0 Z wo co U'. 0S. 9 Lu r LL, V I z 0 Lu z 0 O . ... ...... Z (L REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28,2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE \October 5, 2017, SCALE 1"=40' CONTOUR INTERVAL 2 FT FILE NUMBER 8053 SHEET 5 OF11 F, EROSION CONTROL NARRATIVE PRIOR TO CONSTRUCTION 1. OWNER SHALL POST SURETY BONDS FOR CONSTRUCTION, AND EROSION & SEDIMENT CONTROL/SWM. 2. CONTRACTOR SHALL OBTAIN PERMITS TO WORK WITHIN STATE RIGHT-OF-WAY (VDOT LAND -USE PERMIT). BONDING FOR WORK WITHIN THE VDOT RIGHT-OF-WAY MAY BE REQUIRED TO OBTAIN THE PERMIT. 3. CONTRACTOR SHALL COORDINATE WITH OWNER TO MEET VSMP REQUIREMENTS, INCLUDING PERMITS AS REQUIRED BY THE STATE DEPARTMENT OF ENVIRONMENTAL QUALITY (DEQ) OR LOCAL VSMP AUTHORITY (ALBEMARLE CO.). 4. CONTRACTOR SHALL OBTAIN LAND DISTURBANCE PERMIT FROM THE COUNTY OF ALBEMARLE PRIOR TO BEGINNING CONSTRUCTION. 5. A PRE -CONSTRUCTION MEETING WITH THE ENGINEER, THE CERTIFIED LAND DISTURBER, AND THE ENVIRONMENTAL INSPECTOR MAY ALSO BE REQUIRED. ALLOW 72 HOURS FOR COORDINATION AND SCHEDULING OF PRE -CONSTRUCTION MEETING. PROJECT DESCRIPTION THE PURPOSE OF THIS PROJECT IS TO CONSTRUCT BLOCK 22 AS PART OF THE ONGOING DEVELOPMENT WITHIN OLD TRAIL VILLAGE. THE BMP FACILITY WILL SERVE AS PART OF THE ORIGINAL APPROVED STORMWATER MASTER PLAN (WP0201600009) FUNCTIONING AS A BIORETENTION FACILITY. THE LIMITS OF DISTURBANCE INCLUDES APPROXIMATELY 5.87 ACRES OF LAND DISTURBING ACTIVITIES. EXISTING SITE CONDITIONS THE PROJECT AREA IS CURRENTLY BEING USED AS AN EROSION AND SEDIMENT CONTROL PLAN (WP0201600049) FOR THE TEMPORARY STOCKPILING OF TOPSOIL AND FILL MATERIALS BEING USED FOR OTHER DEVELOPMENT WITHIN OLD TRAIL. THE PROPOSED MEASURES TO CAPTURE THE SITE'S RUNOFF DURING THE CONSTRUCTION OF THE PATH WILL BE SUPER SILT FENCE. INSTALLATION AND MAINTENANCE OF THE PERIMETER CONTROLS THROUGHOUT CONSTRUCTION IS CRITICAL TO PREVENTING SEDIMENT LATENT RUNOFF FROM EXITING THE SITE. ADJACENT AREAS OLD TRAIL DRIVE FORMS THE WESTERN BORDER, LICKINGHOLE CREEK LIES TO THE NORTHEAST, WHILE GOLF DRIVE FRONTS THE NORTH OF THE PROJECT SITE. OFF-SITE AREAS NO CONSTRUCTION OUTSIDE THE LIMITS OF DISTURBANCE SHOWN IS REQUIRED. ANY SURPLUS OR SHORTAGE OF EARTHWORK SHALL BE BROUGHT TO OR OBTAINED FROM A SITE WITH APPROVED AND ADEQUATE EROSION CONTROL PROTECTION. CRITICAL AREAS CRITICAL AREAS EXIST WITHIN THE PROPOSED BLOCK DEVELOPMENT AND ARE IDENTIFIED ON THE PLANS. THESE AREAS SHALL BE EXAMINED AND IDENTIFIED BY THE CONTRACTOR WITH EXTREME CAUTION. SOILS 25B - DYKE SILT LOAM (2% TO 7%) SOIL IS DEEP, GENTLY SLOPING AND WELL -DRAINED, AND IS IN HYDROLOGIC GROUP B. PERMEABILITY AND WATER CAPACITY ARE MODERATE. SURFACE RUNOFF IS MEDIUM AND EROSION HAZARD IS MODERATE. 36C - HAYESVILLE CLAY LOAM (7% TO 15%, SEVERELY ERODED) SOIL IS DEEP, MODERATELY STEEP AND WELL -DRAINED, AND IS IN HYDROLOGIC GROUP B. PERMEABILITY AND WATER CAPACITY ARE MODERATE. SURFACE RUNOFF IS RAPID AND EROSION HAZARD IS SEVERE. STRUCTURAL PRACTICES 1. TEMPORARY CONSTRUCTION ENTRANCE (3.10) - A TEMPORARY CONSTRUCTION ENTRANCE SHALL BE INSTALLED AT SITE ENTRANCE OFF OF OLD TRAIL DRIVE. 2. SILT FENCE BARRIER (3.10) - SILT FENCE BARRIERS WILL BE INSTALLED TO FILTER RUNOFF FROM SHEET FLOW AS INDICATED ON THE EROSION AND SEDIMENT CONTROL PLAN. 3. SUPER SILT FENCE BARRIER - WIRE -REINFORCED SILT FENCE BARRIER WILL BE INSTALLED TO FILTER RUNOFF FROM SHEET FLOW AS INDICATED ON THE EROSION AND SEDIMENT CONTROL PLAN. VEGETATIVE PRACTICES 1. SURFACE ROUGHENING (3.29) - ALL AREAS WITH A GRADE STEEPER THAN 3:1 SHALL BE STAIR -STEP GRADED OR GROOVED (PLATE 3.29-4) TO AID IN GRASS ESTABLISHMENT, INCREASE INFILTRATION, AND TO SLOW RUNOFF VELOCITIES. 2. TOPSOILING & STOCKPILING (3.30) - TOPSOIL WILL BE STRIPPED FROM AREAS TO BE GRADED AND STOCKPILED FOR LATER USE. STOCKPILES ARE TO BE STABILIZED WITH TEMPORARY VEGETATION OR TO HAVE SILT FENCE INSTALLED ALONG THE LOWER PERIMETER TO PROTECT DOWNSTREAM AREAS. 3. TEMPORARY SEEDING (3.31) - AREAS NOT BROUGHT TO FINAL GRADE FOR A PERIOD OF MORE THAN 14 DAYS SHALL BE STABILIZED WITH A TEMPORARY SEED MIXTURE ACCEPTABLE FOR THAT TIME OF YEAR. CRIMPING, PUNCH ROLLER -TYPE ROLLERS, OR TRACK WALKING MAY BE USED TO INCORPORATE STRAW MULCH INTO THE SOIL ON SLOPES IF STRAW IS TO BE USED. 4. PERMANENT SEEDING (3.32) - AREAS BROUGHT TO FINAL GRADE OR THOSE CONSTRUCTION AREAS THAT WILL REMAIN DORMANT FOR YEAR OR MORE SHALL BE STABILIZED WITH A PERMANENT SEED MIXTURE ACCEPTABLE TO THAT TIME OF YEAR. PREPARE SURFACE WITH APPROVED TREATMENT AND ADDITIVES PRIOR TO APPLYING SEED. 5. MULCH (3.35) - PLANT RESIDUES OR OTHER SUITABLE MATERIALS SHALL BE APPLIED TO DISTURBED SURFACES TO PREVENT EROSION AND REDUCE OVERLAND FLOW VELOCITIES. THIS PRACTICE SHOULD BE APPLIED TO ALL SEEDING OPERATIONS, OTHER PLANTER MATERIALS WHICH DO NOT PROVIDE ADEQUATE SOIL PROTECTION BY THEMSELVES, AND BARE AREAS WHICH CANNOT BE SEEDED DUE TO THE SEASON BUT WHICH STILL NEED PROTECTION TO PREVENT SOIL LOSS. CRIMPING, PUNCH ROLLER -TYPE ROLLERS, OR TRACK WALKING MAY BE USED TO INCORPORATE STRAW MULCH INTO THE SOIL ON SLOPES IF STRAW IS TO BE USED. 6. DUST CONTROL (3.39) - DUST CONTROL METHODS MUST BE USED TO REDUCE THE AMOUNT 1OF AIRBORNE DUST DURING ALL PHASES OF CONSTRUCTION WHERE SOIL IS EXPOSED OR DISTURBED. MANAGEMENT STRATEGIES 1. CONSTRUCTION WILL BE SEQUENCED SO THAT GRADING OPERATIONS CAN BE SEQUENCED, AND ALSO BEGIN AND END AS QUICKLY AS POSSIBLE. 2. THE CONSTRUCTION ENTRANCE AND PERIMETER EROSION CONTROL MEASURES SUCH AS SILT FENCE SHALL BE INSTALLED AS THE FIRST STEP OF DISTURBANCE. 3. TEMPORARY SEEDING OR OTHER STABILIZATION METHODS, SUCH AS BASE AGGREGATE WILL FOLLOW IMMEDIATELY AFTER REACHING FINAL GRADES. ALL SEEDED AREAS WILL BE CHECKED REGULARLY TO ENSURE THAT A GOOD STAND IS MAINTAINED. AREAS SHOULD BE FERTILIZED AND RE -SEEDED AS NEEDED TO ESTABLISH GROWTH. IF GROWTH IS NOT PRESENT AFTER A PERIOD OF SUCCESSIVE ATTEMPTS, ALTERNATIVE MEASURES SHOULD BE TAKEN TO STABILIZE THE AREA SUCH AS BLANKET MATTING OR SOD. 4. THE JOB SUPERINTENDENT SHALL BE RESPONSIBLE FOR THE INSTALLATION AND MAINTENANCE OF ALL EROSION AND SEDIMENT CONTROL PRACTICES. 5. AFTER BEING NOTIFIED BY THE EROSION AND SEDIMENT CONTROL ADMINISTRATOR, THE TEMPORARY EROSION AND SEDIMENT CONTROLS CAN BE CLEANED UP OR REMOVED, AND THE SEDIMENT TRAPS CAN BE FILLED IN AND SEEDED, THEREBY REDIRECTING DRAINAGE TO THE PERMANENT FACILITIES. PERMANENT STABILIZATION ALL AREAS DISTURBED BY CONSTRUCTION SHALL BE STABILIZED WITH STRAW & SEED IMMEDIATELY FOLLOWING FINISHED GRADE. SEEDING SHALL BE DONE WITH KENTUCKY 31 TALL FESCUE IN ACCORDANCE TO STANDARD AND SPECIFICATION 3.32, PERMANENT SEEDING, OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK. ANY FERTILIZER AND LIME APPLICATIONS SHALL BE IN ACCORDANCE WITH SOIL TEST RESULTS. ALL SEEDED AREAS WILL BE STRAW MULCHED TO PROTECT AGAINST RILL EROSION AND TO PRESERVE SOIL MOISTURE THAT WILL ENHANCE SEED GERMINATION. CRIMPING, PUNCH ROLLER -TYPE ROLLERS, OR TRACK WALKING MAY BE USED TO INCORPORATE STRAW MULCH INTO THE SOIL ON SLOPES IF STRAW IS TO BE USED. EROSION CONTROL MAINTENANCE 1. IN GENERAL, ALL EROSION AND SEDIMENT CONTROL MEASURES SHALL BE CHECKED DAILY AND AFTER EACH SIGNIFICANT RAINFALL. THE FOLLOWING ITEMS WILL BE CHECKED IN PARTICULAR: 2. THE CONSTRUCTION ENTRANCE SHALL BE CHECKED DAILY FOR SOIL BUILDUP. IF THE ENTRANCE BECOMES CLOGGED WITH SOIL AND FAILS TO PREVENT TRANSPORTATION OF SOIL ONTO THE ROADWAY, ADDITIONAL STONE, REPLACEMENT OF STONE, OR A WASH -RACK MAY BE REQUIRED. 3. SILT FENCE SHALL BE INSPECTED IMMEDIATELY AFTER EACH RAINFALL AND AT LEAST DAILY DURING PROLONGED RAINFALL. CLOSE ATTENTION SHALL BE PAID TO THE REPAIR OF DAMAGED SILT FENCE RESULTING FROM END RUNS AND UNDERCUTTING. SHOULD THE FABRIC ON A SILT FENCE DECOMPOSE OR BECOME INEFFECTIVE PRIOR TO THE END OF THE EXPECTED USABLE LIFE AND THE BARRIER STILL BE NECESSARY, THE FABRIC SHALL BE REPLACED PROMPTLY. SEDIMENT DEPOSITS SHOULD BE REMOVED AFTER EACH STORM EVENT. THEY MUST BE REMOVED WHEN DEPOSITS REACH APPROXIMATELY ONE-HALF THE HEIGHT OF THE BARRIER. ANY SEDIMENT DEPOSITS REMAINING IN PLACE AFTER THE SILT FENCE IS NO LONGER REQUIRED SHALL BE DRESSED TO CONFORM WITH THE EXISTING GRADE, PREPARED, AND SEEDED. 4. STORMWATER CONVEYANCE CHANNELS: 4.1.RIPRAP-LINED CHANNELS - RIPRAP LINED CHANNELS SHOULD BE CHECKED PERIODICALLY TO ENSURE THE SCOUR IS NOT OCCURRING BENEATH FABRIC UNDERLINING OF THE RIPRAP LAYER. THE CHANNEL SHOULD ALSO BE CHECKED TO DETERMINE THE STONES ARE NOT DISLODGED BY LARGE FLOWS. 4.2.SEDIMENT DEPOSITED IN A RIPRAP CHANNEL SHOULD BE REMOVED WHEN IT REDUCES THE CAPACITY OF THE CHANNEL. 5. THE EARTHEN EMBANKMENTS SHALL BE CHECKED REGULARLY TO ENSURE THAT IT IS STRUCTURALLY SOUND AND HAS NOT BEEN DAMAGED BY EROSION OR CONSTRUCTION EQUIPMENT. 6. ALL SEEDED AREAS WILL BE CHECKED REGULARLY TO ENSURE THAT A GOOD STAND IS MAINTAINED. ARFAC SHnul n RF FFRTII 17F0 AND RE -SEEDED AS NEEDED. SEQUENCE OF CONSTRUCTION Maintenance Fertilization for Permanent Seedings Use Soil Test Recommendation or Rates Shown Below Seeding Mixture PERMANENT SEEDING MIXTURES 1. AFTER OBTAINING ALL REQUIRED PERMITS, THE CONTRACTOR SHALL COORDINATE APRE-CONSTRUCTION Lbs. per Time 2. MEETING, ALLOWING 72 HOURS FOR ITS COORDINATION. PS FOR THE PIEDMONT AREA J 3. CONTRACTOR SHALL INSTALL ALL PERIMETER CONTROLS (SUPER SILT FENCE, THE RECEIVING SEDIMENT 1000 sf Lbs/1000 BASIN, AND THE CONSTRUCTION ENTRANCE) AS FIRST STEP IN CONSTRUCTION. TABLE 25 TOTAL LBS. PER ACRE 4. CONTRACTOR SHALL COORDINATE INSPECTIONS ACCORDINGLY, AS REQUIRED BY THE COUNTY OF J` 11.5 ALBEMARLE. *Not closer than 3" up 70% or more 5. AFTER RECEIVING AUTHORITY APPROVAL, BEGIN CLEARING, GRUBBING AND FINE GRADING OPERATIONS AS MINIMUM CARE LAWN - COMMERCIAL OR RESIDENTIAL 175-200 LBS. NECESSARY TO ACHIEVE FINAL GRADES FOR THE STORMWATER MANAGEMENT MEASURES. - KENTUCKY 31 OR TURF -TYPE TALL FESCUE %95-100% 6. CONSTRUCT THE TEMPORARY SEDIMENT BASIN ALONG WITH DIVERSION DIKES TO ENSURE PROPER DESIGN - IMPROVED PERENNIAL RYE GRASS 0-5% - DRAINAGE. INSTALL RISER STRUCTURE, BARREL PIPE, TRASH RACK, ANTI VORTEX DEVICE, AND DEWATERING - KENTUCKY BLUEGRASS o 0-/5 ORIFICE AS PART OF THE TEMPORARY SEDIMENT BASIN. THE STRUCTURES SHALL REMAIN IN PLACE WITH ..: r 4/30 SUBTLE CHANGES AS PART OF BMP CONVERSION TO STORMWATER MANAGEMENT. ALL MEASURES SHALL BE Do not mow 7 CONSTRUCTED IN ACCORDANCE WITH APPROVED PLANS. 11/15 5/31 7. PERMANENT SOIL STABILIZATION SHALL BE APPLIED TO ALL DENUDED AREAS WITHIN SEVEN DAYS AFTER 10/31 Service lespedeza FINAL GRADE IS REACHED ON ANY PORTION OF THE SITE. TEMPORARY SOIL STABILIZATION SHALL BE HIGH MAINTENANCE LAWN 200-250 LBS. APPLIED WITHIN SEVEN DAYS TO DENUDED AREAS THAT MAY NOT BE AT FINAL GRADE BUT WILL REMAIN - KENTUCKY 31 OR TURF -TYPE TALL FESCUE 100% DORMANT FOR LONGER THAN 30 DAYS. PERMANENT STABILIZATION SHALL BE APPLIED TO AREAS THAT ARE GENERAL SLOPE (3:1 OR LESS) BY TO BE LEFT DORMANT FOR MORE THAN ONE YEAR. - KENTUCKY 31 FESCUE 128 LBS. 8. CONSTRUCTION OF THE BIORETENTION AREA MAY ONLY BEGIN AFTER THE ENTIRE CONTRIBUTING DRAINAGE 2.5 bu. 2.80 AREA HAS BEEN STABILIZED WITH VEGETATION. IT MAY BE NECESSARY TO BLOCK CERTAIN CURB OR Not required. not Fairly uniform OTHER INLETS WHILE THE BIORETENTION AREA IS BEING CONSTRUCTED. THE PROPOSED SITE SHOULD BE - RED TOP GRASS 2 LBS. CHECKED FOR EXISTING UTILITIES PRIOR TO ANY EXCAVATION. - SEASONAL NURSE CROP* 20 LBS. 9. BOUNDARIES OF THE CONTRIBUTING DRAINAGE AREA SHOULD BE CHECKED AND THE ACTUAL INLET 500 TOTAL 150 LBS. ELEVATIONS BE EXAMINED TO ENSURE THEY CONFORM TO ORIGINAL DESIGN. STEEPER THAN 3:1MAINTENANCE SLOPE LOW- ( ) & service 10. PRIOR TO THE CONSTRUCTION OF THE BIORETENTION AREA, A BERM SHALL BE CONSTRUCTED SLIGHTLY - X UPGRADIENT OF THE AREA SO THAT ANY STORMWATER RUNOFF IS DIVERTED AWAY FROM THE desired, and then in lespedeza, or BIORETENTION AREA INTO THE EXISTING SEDIMENT BASIN UNTIL IT IS COMPLETED. SPECIAL PROTECTION - KENTUCKY 31 FESCUE 108 LBS. MEASURES SUCH AS EROSION CONTROL FABRICS MAY BE NEEDED TO PROTECT VULNERABLE SIDE SLOPES fall after seed has birdsfoot trefoil. FROM EROSION DURING THE CONSTRUCTION PROCESS. - RED TOP GRASS 2 LBS. 11. ANY PRE-TREATMENT CELLS SHOULD BE EXCAVATED FIRST AND THEN SEALED TO TRAP SEDIMENTS. - X 12. EXCAVATORS OR BACKHOES SHOULD WORK FROM THE SIDES TO EXCAVATE THE BIORETENTION AREA TO - X ITS APPROPRIATE DESIGN DEPTH AND DIMENSIONS. EXCAVATING EQUIPMENT SHOULD HAVE SCOOPS WITH _ SEASONAL NURSE CROP* 20 LBS. ADEQUATE REACH SO THEY DO NOT HAVE TO SIT INSIDE THE FOOTPRINT OF THE BIORETENTION AREA. CONTRACTORS SHOULD USE A CELL CONSTRUCTION APPROACH IN LARGER BIORETENTION BASINS, - CROWN VETCH** 20 LBS. WHEREBY THE BASIN IS SPLIT INTO 500 TO 1,000 SQ. FT. TEMPORARY CELLS WITH A 10-15 FOOT EART TOTAL 150 LBS. BRIDGE IN BETWEEN, SO THAT CELLS CAN BE EXCAVATED FROM THE SIDE. *USE SEASONAL NURSE CROP IN ACCORDANCE WITH SEEDING DATES AS STATED BELOW: 13. IT MAY BE NECESSARY TO RIP THE BOTTOM SOILS TO A DEPTH OF 6 TO 12 INCHES TO PROMOTE 500 11.5 GREATER INFILTRATION. occasional mowing is fairly uniform 14. PLACE GEOTEXTILE FABRIC ON THE SIDES OF THE BIORETENTION AREA WITH A 6 -INCH OVERLAP ON THE FEBRUARY 16TH THROUGH APRIL 30TH. , . . , , . , . . . . ANNUAL RYE SIDES. IF A STONE STORAGE LAYER WILL BE USED, PLACE THE APPROPRIATE DEPTH OF #57 STONE ON MAY 1ST THROUGH AUGUST 15TH . . . . . . . . . . . . . . FOXTAIL MILLET THE BOTTOM, INSTALL THE PERFORATED UNDERDRAIN PIPE, PACK #57 STONE TO 3 INCHES ABOVE THE AUGUST 16TH THROUGH OCTOBER 31ST. . . . < . . . , . , .ANNUAL RYE UNDERDRAIN PIPE, AND ADD APPROXIMATELY 3 INCHES OF CHOKER STONE/PEA GRAVEL AS A FILTER NOVEMBER 1ST THROUGH FEBRUARY 15TH . . . . . . . . . , ANNUAL RYE BETWEEN THE UNDERDRAIN AND THE SOIL MEDIA LAYER. IF NO STONE STORAGE LAYER IS USED, START X X WITH 6 INCHES OF #57 STONE ON THE BOTTOM, AND PROCEED WITH THE LAYERING AS DESCRIBED ** SUBSTITUTE SERICEA LESPEDEZA FOR CROWNVETCH EAST OF FARMVILLE, VA (MAY ABOVE. THROUGH SEPTEMBER USE HULLED SERICEA, ALL OTHER PERIODS, USE UNHULLED 15. INSTALL RISER STRUCTURE, BARREL PIPE, TRASH -RACK, ANTI VORTEX DEVICE, UNDER -DRAINS, AND SERICEA. ) Mow no closer than CLEANOUTS/OBERSERVATION WELLS AS PART OF THE CONVERSION FROM EROSION CONTROL TO STORMWATER MANAGEMENT. ALL MEASURES SHALL BE CONSTRUCTED IN ACCORDANCE WITH THE APPROVED IF FLATPEA IS USED IN LIEU OF CROWNVETCH, INCREASE RATE TO 30 LBS./ACRE. ALL PLANS. LEGUME SEED MUST BE PROPERLY INNOCULATED. WEEPING LOVEGRASS MAY BE ADDED 16. OBTAIN SOIL THE MEDIA FROM A QUALIFIED VENDOR, AND STORE IT ON AN ADJACENT IMPERVIOUS AREA TO ANY SLOPE OR LOW MAINTENANCE MIX DURING WARMER SEEDING PERIODS; ADD 10 - OR PLASTIC SHEETING. AFTER VERIFYING THAT THE MEDIA MEETS THE SPECIFICATIONS, APPLY THE MEDIA 20 LBS. ACRE IN MIXES. / - IN 12 -INCH LIFTS UNTIL THE DESIRED TOP ELEVATION OF THE BIORETENTION AREA IS ACHIEVED. WAIT A December, and closer than 3" FEW DAYS TO CHECK FOR SETTLEMENT, AND ADD ADDITIONAL MEDIA, AS NEEDED, TO ACHIEVE THE DESIGN 20-10-10 100 ELEVATION. Y Ma 20 -June -30, for fescue. 17. AFTER SITE IS STABILIZED AND PERMISSION IS OBTAINED FROM THE EROSION CONTROL AUTHORITY, X - REMOVE SILT FENCING AND OTHER ESC MEASURES SUCH AS THE TEMPORARY BERM, DIVERSION DIKES, if needed. - ETC. DRILL THE (3) 4" ORIFICES INTO THE EXTENDED DETENTION STRUCTURE AND REMOVE AND PATCH PERMANENT SEEDING - THE DEWATERING ORIFICE AS FINAL STAGE OF BMP CONVERSION. Millet42/ 50 lbs. Ps FERTILIZATION &MAINTENANCE �E CONSTRUCTION ENTRANCE X - - X - - X - Applicable on slopes of 3:1 or flatter M1I� °� Ali! ''., pkv t 2'1A A RO IL Q SECTION k_ PAVED HASH' RACK TABLE 24 Maintenance Fertilization for Permanent Seedings Use Soil Test Recommendation or Rates Shown Below Seeding Mixture Formulation Lbs, per Lbs. per Time 13111 11 :r"e Seedingzones and Seeding Date IV 9 J Acre 1000 sf Lbs/1000 Tail fescue makes 10-10-10 J` 11.5 Yearly, or as needed *Not closer than 3" up 70% or more or 2/1- .,, 8/15- IS iNCi of cover. 30-10-10 400 9.2 fall is desired. Crownvetclh r{ ..: r 4/30 Spring the year Do not mow 7 8/14 11/15 5/31 following establish - 10/31 Service lespedeza 0-20-0 400 9.2 .1 crownvetch Birdsfoot trefoil +i u, L; C rD't 'LL 'Jdl� i j0 BY O 11JGRESG >-.NrLt.lz.„.'SS 0 BY Barley 2.5 bu. 2.80 S�' PN'. Not required. not Fairly uniform SECTION k_ PAVED HASH' RACK TABLE 24 Maintenance Fertilization for Permanent Seedings Use Soil Test Recommendation or Rates Shown Below Seeding Mixture Formulation Lbs, per Lbs. per Time Mowing Seedingzones and Seeding Date IV 9 J Acre 1000 sf Lbs/1000 Tail fescue makes 10-10-10 500 11.5 Yearly, or as needed *Not closer than 3" up 70% or more or 2/1- 5/1- 8/15- if occasional mowing of cover. 30-10-10 400 9.2 fall is desired. Crownvetclh Ir � SAEASONAL NURSE CROP ** 4/30 Spring the year Do not mow 4/30 8/14 11/15 5/31 following establish - 10/31 Service lespedeza 0-20-0 400 9.2 ment and every 4-5 crownvetch Birdsfoot trefoil j0 BY years thereafter. 0 BY Barley 2.5 bu. 2.80 1-2 Not required. not Fairly uniform 10/15 X - Fall the year closer than 4" if stand of 'tall 5-10-10 500 11.5 followingestablish- s occasional mowing is & service - - X ment and every 4-5 desired, and then in lespedeza, or - - Rye -19j years thereafter. fall after seed has birdsfoot trefoil. X - X X - X X - X Barley or matured. W Not required. not weeping kovegrass Spring the year closer than 4" if & serice lespedeza 5-10-10 500 11.5 following establish- occasional mowing is fairly uniform X 10/15 X ment and every 3-4 desired, and fall plant distribution years thereafter. after sericea has X X X X X matured. X 20-10-10 250 5.8 September, Mow no closer than Red & chewings 30 days later 2" for red fescue fescue, Kentucky Weeping lovegrassA / 4 lbs. 0.09 and Ky bluegrass; bluegrass; hard X - - December, and closer than 3" fescue mixture: 20-10-10 100 2.3 Y Ma 20 -June -30, for fescue. 1 4 1 2 / - / X - 11 / if needed. - ssF SUPER SILT FENCE CONSTRUCTION OF A SILT FENCE (WITH WIRE SUPPORT) 1. SET THE STAKES, 2. EXCAVATE A 4"X 4" TRENCH UPSLOPE ALONG THE LINE OF STAKES. TEMPORARY SEEDING MIXTURES OTS FOR THE PIEDMONT AREA INFORMATION FROM TABLE 3.32-C OF THE VA TABLE 26 IS PROVIDED BELOW FOR SEEDING TEMPORARY SEEDINGS BY RATES, DEPTHS, AND DATES CD Seeding Rate Planting depth 36/ Seedingzones and Seeding Date IV 9 J Species Per Lbs/1000 7a and 7b 6b 6a and 5b 0-10% H acre Sq. ft (Inches) 2/1- 5/1- 8/15- 3/1- 5/1- 8/15- 3/15- 6/1- 8/1- RED TOP GRASS 20 LBS Ir � SAEASONAL NURSE CROP ** 4/30 8/14 11/30 4/30 8/14 11/15 5/31 7/31 10/31 Choose one: AUGUST 16TH THROUGH SEPTEMBER, OCTOBER ANNUAL RYE NOVEMBER THROUGH FEBRUARY WINTER RYE � , BY j0 BY 00w 0 BY Barley 2.5 bu. 2.80 1-2 X - 10/15 X - 10/15 X - 10/1 Oats 3 bu. 2.21 1-2 X - - X - - X - - Rye -19j 2.5 bu. 3.22 1-2 X - X X - X X - X Barley or W Rye Plus 150 lbs. 3.45 1 X X 10/15 X X 10/15 X X 10/1 Foxtail X X X X X X X X X mil Iet40 Weeping lovegrassA / 4 lbs. 0.09 1/4-1/2 - X - - X - - X - Annual ryegrasS 5 l 0 lbs. 1.15 1 4 1 2 / - / X - 11 / X - 11 1 / X - 8 151 / Millet42/ 50 lbs. 1.15 1/2 - X - - X - - X - Applicable on slopes of 3:1 or flatter 17 Refer to figure A -Adopted from USDA, ARS Miscellaneous Publication #1475, January 1990 IV Between fall and spring seeding dates, use mulch only if ground is frozen and reseed when thawed 39 May be used as a nurse crop for late fall/early winter permanent seedings, add 56 lbs/ac. to the permanent seeding mixture Maryland State Highway Administration Temporary Seed Mix AV May be used as a nurse crop for mid -summer permanent seedings. Add 2 lbs/ac Alz to permanent seed mix. May be used as a nurse crop for mid -summer permanent seedings. Add 10 lbs/ac. AV to the permanent seeding mix. INFORMATION FROM TABLE 3.32-C OF THE VA ESC HANDBOOK IS PROVIDED BELOW FOR SEEDING SELECTION CD TOTAL LBS. PER ACRE MINIMUM CARE LAWN 200-250 LBS J -COMMERCIAL OR RESIDENTIAL 90-100% KENTUCKY 31 OR TURF -TYPE TALL FESCUE 0-10% H IMPROVED PERENNIAL RYEGRASS 0-10% CO) � KENTUCKY BLUEGRASS � GENERAL SLOPE (3:1 OR LESS) 128 LBS � KENTUCKY 31 FESCUE 2 LBS F -•-i l RED TOP GRASS 20 LBS Ir � SAEASONAL NURSE CROP ** g Q a: Lu ** USE SEASONAL NURSE CROP IN ACCORDANCE WITH SEEDING DATES AS STATED BELOW: MARCH, APRIL THROUGH MAY 15TH ANNUAL RYE MAY 16TH THROUGH AUGUST 15TH FOXTAIL MILLET AUGUST 16TH THROUGH SEPTEMBER, OCTOBER ANNUAL RYE NOVEMBER THROUGH FEBRUARY WINTER RYE FERTILIZER (10-20-10 OR EQ) SHALL BE APPLIED AT THE RATE of 1100 LBS/ ACRE. AGRICULTURAL LIME SHALL BE APPLIED TO SEEDBEDS AT TTHE RATE of 110 LBS/ 1000 SQ. FT. SUGGESTED TEMPORARY SEEDING MIXTURE FERTILIZER: 10-20-10 1,000 LBS/ACRE SEPTEMBER -FEBRUARY 15: 50% ANNUAL RYE & 50% WINTER RYE 100 LBS/ACRE FEBRUARY 16 -APRIL 30: ANNUAL RYE 100 LBS/ACRE MAY -AUGUST: GERMAN MILLET 50 LBS/ACRE OTHER OPTIONS EXIST, SEE VA EROSION AND SEDIMENT CONTROL HANDBOOK. SUGGESTED PERMANENT SEEDING MIXTURE LIME: 2 TONS/ACRE FERTILIIZER: 10-20-10 1,000 LBS/ACRE MARCHI-MAY 15: KENTUCKY 31 FESCUE 200 LBS/ACRE, ANNUAL RYE 20 LBS/ACRE MAY 16 -AUGUST 15: KENTUCKY 31 FESCUE 200 LBS/ACRE, FOXTAIL MILLET 20 LBS/ACRE AUGUST 16 -OCTOBER: KENTUCKY 31 FESCUE 200 LBS/ACRE, ANNUAL RYE 20 LBS/ACRE NOVEMIBER- FEBRUARY: KENTUCKY 31 FESCUE 200 LBS/ACRE, WINTER RYE 20 LBS/ACRE SAFETY FENCE PERSPECTIVE VIEWFLOW di _ I SILT FENCE 3. STAPLE FILTER MATERIAL 4. BACKFILL AND COMPACT TO STAKES AND EXTEND THE EXCAVATED SOIL.IT INTO THE TRENCH. SF/STONE NOT REQUIRED AFTER SLOPES ARE STABILIZED DOWNSLOPE OF OUTFALL POINTS A SHOULD BE HIGHER THAN POINT B. DRAINAGEWAY INSTALLATION (FRONT ELEVATION) E: Adapted from Installation of Straw and Fabric Filter Barriers for Sediment Control,VA. DSNC PLATE. 3.10-2 )od and Wyant SHEET FLOW INSTALLATION (PERSPECTIVE VIEW) PERSPECTIVE VIEW PLASTIC FENCE SOURCE: CONWED PLASTICS VDOT ROAD AND BRIDGE STANDARDS VA. DSWC PERSPECTIVE VIEW METAL FENCE PLATE. 3.1-1 Aj,T H Op Dry Jimmy L. Taggart Lic. No. IL "d,,f, 22841 �sv� O�-YSIONAL I REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE October 5, 2017 SCALE N/A CONTOUR INTERVAL N/A r CD a J ..W O U H 1� W CO) � Uj � Q � 0�D N ao -:3 Z F -•-i l J Ir � V O g Q a: Lu >LL � ONS5;ZV0%Z az �z UQ � , j0 = 00w 0 0� y, UN O V Zm W2 OLL w 0 wa ' �- aW V N zQ I� W Qy �rz Z 2 WJ T LU Z 0 1. C W CD W 0 REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE October 5, 2017 SCALE N/A CONTOUR INTERVAL N/A FILE NUMBER 8053 SHEET 6of11 CD J LaL 1� W Uj � (jww ♦W J V0 ,QL W LUNWJa 1� Z ONS5;ZV0%Z Jv j0 0 00w _ Zm w 0 Z �- m U Ufa Z WJ 0 0 CD 0 �yrr � LL W FILE NUMBER 8053 SHEET 6of11 SOURCE: VA. DSWC PLATE. 3.14-2 1P INLET PROTECTION BL 0 CK & GRA VEL C URB INLE T SEDIMENT FIL TER CURB INLET WIRE SCREEN RUNOFF OVERFLOW WATER WITH SEDIMENT it Le it.���,� •,��UI►++rte- FILTERED WATER SEDIMENT WIRE SCREEN ` 2" X 4" WOOD STUD CURB INLET SPECIAL APPLICATION THIS METHOD OF INLET PROTECTION IS APPLICABLE AT CURB INLETS WHERE AN OVERFLOW CAPABILITY IS NECESSARY TO PREVENT EXCESSIVE PONDING IN FRONT OF THE STRUCTURE. GRAVEL SHALL BE VDOT #3, #357 OR #5 COARSE AGGREGATE PLATE. 3.14-4 oP OUTLET PROTECTION PIPE OUTLET CONDI TIONS A A PIPE OUTLET TO FLAT AREA WITH NO DEFINED CHANNEL PLAN VIEW L a 0 % -� d SECTION A -A FILTER CLOTH KEY IN 6"-9"; RECOMMENDED FOR ENTIRE PERIMETER A A ado (MIN.) d� PIPE OUTLET TO WELL DEFINED CHANNEL PLAN VIEW L a 0%� d SECTION A -A T FILTER CLOTH KEY IN 6"-9"; RECOMMENDED FOR ENTIRE PERIMETER NOTES: 1. APRON LINING MAY BE RIPRAP, GROUTED RIPRAP, GABION BASKET, OR CONCRETE. 2. La IS THE LENGTH OF THE RIPRAP APRON AS CALCULATED USING PLATES 3.18-3 AND 3.18-4. 3. d = 1.5 TIMES THE MAXIMUM STONE DIAMETER, BUT NOT LESS THAN 6 INCHES. SOURCE: VA. DSWC PLATE 3.07-8 Source: Va. DSWC EACH LIFT OF THE FILL IS COMPACTED, BUT THE OUTER FACE OF THE SLOPE IS ALLOWED TO REMAIN LOOSE SO THAT THE ROCKS, CLODS, ETC. REACH THE NATURAL ANGLE OF REPOSE. FILL SL OPE TREA TMENT SOURCE: VA. DSWC RANWE f •••36 •fa�� SAO x TRA CKING ,\ SOURCE: MICHIGAN SOIL EROSION AND SEDIMENTATION GUIDE PLATE. 3.29-3 Plate 3.18-1 STAIR STEPPING CUT SLOPES DEBRIS FROM SLO911= ABOVE IS CAUGHT III -I11- BY STEPS --,,,,,,,,I 0DRAINAGE 111- 40"-50" WATER, SOIL AND FERTILIZER ARE HELD BY STEPS - PLANTS CAN BECOME ESTABLISHED ON THE STEPS. SOURCE: VA. DSWC PLATE 3.29-1 GR 0 0 VING SLOPES 1=- Iil�llll-Ii�=1, �40 -III AD ill,�llll=l III -II-_ �-III-III GROOVING IS CUTTING FURROWS I -III-I ALONG THE CONTOUR OF A SLOPE. I I -I III IIII- IRREGULARITIES IN THE SOIL -IIIA SURFACE CATCH RAINWATER AND PROVIDE SOME COVERAGE OF LIME, FERTILIZER AND SEED. PLATE. 3.29-4 SOURCE: VA. DSWC .M 675 670 665 I 655 650 0+00 w TEMPORARY SEDIMENT BASIN .:• 675 670 665 ••0 655 650 +20 +40 +60 +80 1+00 +20 +40 +60 +80 2+00 +20 +40 +60 W0 -4 -NN 000 000Go NON ICOM Q 6o6r-� rMaO i`�"i4 �hIMT ONOf - Total Design Drainage Area= 4.71 acres 2 -YR 14.79 5.28 0 c� c0 0 c0 tC c0 c0 (0 t0 c0 to J 26.21 0 0 0 0 L� Wet Storage - Minimum Volume Req'd. = 67 cy * 4.71 acres = 316 cy 25 -YR 34.13 28.20 wp 617 O o: ccW >O a. ooW H BOLT TOGETHER W/GALVANIZED EVENTS FOR TEMPORARY SEDIMENT BASIN TEMPORARY SEDIMENT BASIN PARAMETERS EVENT INFLOW (CFS) ROUTED ELEVATION (FT) STORAGE (CUBIC YD) *PARAMTERS TO REM/A,IN FOR BMP CONVERSION TO EXTENDED DETENTION SEE SWM DETAILS a WELDED ATTACHMENT ,CFS) Total Design Drainage Area= 4.71 acres 2 -YR 14.79 5.28 665.14 475 Basin Design Volumes: 10 -YR 26.21 21.96 665.60 584 Wet Storage - Minimum Volume Req'd. = 67 cy * 4.71 acres = 316 cy 25 -YR 34.13 28.20 665.74 617 Available Basin Volume Prov'd. = 347 cy @ 664.60 Depth to Cleanout Elev. = 1.00 ft TOP OF EMBANKMENT=666.50 SCALE 1" = 5' VERTICAL Dry Storage- W.S.E. 25-YR=665.74 5 NF - Minimum Volume Req d. = 67 cy * 4.71 acres = 288 cy W.S.E. 10-YR=665.60 U Available Basin Volume Prov'd. = 320 cy © 665.95W.S.E.2-YR=665.14Dl��4" Dewatering Orifice Invert = 664.60 2.5��Cleanout Elev. = 663.60 Basin Design Elevations: \ 0Top of Dam = 666.50 \ ASSUMED PHREATIC LINE 4H:1V SCALE IN FEET artEmergency Spillway = 666,00 �w�Design High Water = 665.74 (25 -Year Storm) CRSssoo RE ^ SCALE 1" = 20' HORIZONTAL�1� Crest of 48" RCP Riser = 665.00 Toe of Dam = 661.50 _ _ PROJECTED SAT+S/0.25-S) E\MIEN a Ls=t30 \ ANTI -SEEP COLLARS 20 10 0 20 40 Principal Spillway Design: _ \ 2 -ANTI -SEEP COLLARS ® 3.5'X3.5' SCALE IN FEET RCP Riser Dia. = 48" Trash Rack Dia. = 72" Trash Rack Ht. 21 HP Barrel Length = 50.0' HP Barrel Dia. = 24" Inv. Out 24" HP Barrel = 655.00 HP Barrel Slope=13.00% OUTLET PROTECTION SPECIFICATIONS OPI CL 1-RIPRAP00La DEPTHLYING F.F APRON LENGTH = 10' �v DIVERSION DIVERSION 10% SETTLEMENT SEDIMENT BASIN/EXTENDED DETENTION OUTFLOW F 24" Q2 = 6 cfs (WORST CASE) PLATE 3.29-2 Source: Va. DSWC TYPICAL VEE -SHAPED DIVERSION Plate 3.12-1 (SEE DETAIL) HP BARREL (SEE DETAIL) OUTLET PROTECTION (SEE DETAIL) �- CUT OFF TRENCH EXCAVATED INTO SUITABLE MATERIAL WHERE APPLICABLE (TBD BY GEOTECH) CONCENTRIC TRASH RACK AND ANTI VORTEX DEVICE PARAMETERS N 0 C: M 0 c 0 I 0 (A SUPPORT ANGLES UPPER ANCHOR TABS O O a WELDED ATTACHMENT ..W PLAN VIEW O U D 'l 12" LOWER ANCHOR TABS I' TACKWELD Z ALL AROUND O 1.5•X1.5'X7.5' STEEL ANGLE ccW >O 2 0 90' APART(NOTCH 1 0 CENTER & ooW H BOLT TOGETHER W/GALVANIZED 3/8"X3/4^ BOLTS) UQ �W J Z U� MIN. O 18" LOWER ANCHOR TABS° . : -4 ' w2 BOLT TO RCP RISER °• v, O, �4) 1.5"X1.5"X8" ANGLE a 4 . • " ° (6 Q W (4) 3/8 X2" GALVANIZED BOLTS " ° G WQ� (8) 3/8• WASHERS Z #6 X 12^ ° SUPPORT BAR SIZE SPACER BAR (#6 REBAR MIN.) (TYPICAL) ° A .... a . W RISER DIAMETER SECTION A -A ISOMETRIC TOP STIFFENER (IF REQUIRED) IS -X -X- ANGLE WELDED TO TOP AND ORIENTED PER- PENDICULAR TO CORRUGATIONS. TOP IS -GAGE CORRUGATED METAL OR 1/8" STEEL PLATE. PRESSURE RELIEF HOLES MAY BE OMMITTED, IF ENDS OF CORRUGATIONS ARE LEFT FULLY OPEN WHEN THE TOP IS ATTACHED. CYLINDER IS GAGE CORRUGATED METAL PIPE OR FABRICATED FROM 1/8" STEEL PLATE. NOTES: 1. THE CYLINDER MUST BE FIRMLY FASTENED TO THE TOP OF THE RISER. 2. SUPPORT BARS ARE WELDED TO THE TOP OF THE RISER OR ATTACHED BY STRAPS BOLTED TO TOP OF RISER. REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT ,AUGUST 21, 2018 DATE October 5, 2017 SCALE AS SHOWN CONTOUR INTERVAL N/A W J � a w W Vl 0 c� Q �- N W J a ON p- > zV06> z JV�J0 O U �O�Q� ZZiLU O Q V UD z �J O W (n O O W FILE NUMBER 8053 SHEET 7 of 11 U w a ..W O U Z O Q ccW >O ooW Q UQ �W J Z U� O w2 0� v, O, VN v1 (6 Q W Z 9 WQ� 2°' Z W Q o a. 'V W REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT ,AUGUST 21, 2018 DATE October 5, 2017 SCALE AS SHOWN CONTOUR INTERVAL N/A W J � a w W Vl 0 c� Q �- N W J a ON p- > zV06> z JV�J0 O U �O�Q� ZZiLU O Q V UD z �J O W (n O O W FILE NUMBER 8053 SHEET 7 of 11 P. BIORETENTION FACILITIES WITH EXTENDED DETENTION �r V IVI/1nIIVIUIVI rUIVLJIIVV VCr I rl _ ........ _ _ 12 SCH 40 PVC OUTLET T ET _ _ ..... .......... _ __ (SEE DETAIL) _ 680 r /1 -,7 FI 1:1 11 1:1 - 12// SCH. 40 PVC SYSTEM ( P.) BIOFILTER CLEA - _ _ N WATER BYPASS YTEM TO _. ...... EXTENDED....DETENTION _POND_ 675 0 665 S TOP OFQ EMERGENCY ILLWAY=666.00 AM=667.UO SLUHE UK LOUIVALEN I / / . _ .... .. :1 3:1 1:1 :1 _ COF TO " NYLOPLAST It C4 N 2:1 -(TO BE LA DSCAPED) A - - __ _ . DRAINAGE BASIN _ W/ DOME GRATE to to (0 CO 0 1\ r - 12' SCH 40 PVC OUTLET t0�0 I-_ CDt0� t00� (0t0_j (0t0J (SEE DETAIL): A4 0 N O� a� THREADED LID COVERED WITH WIRE MESH 3" DOUBLE I Q J BOTTOM OF EXTENED PRETREATMENT BIORET NTION CELL 660 W •Y W W W •Y W W W W _561 5 Q// E)F MULCH LAYER WHERE APPLICABLE W W W W W W W W W W W W W W W W W W •Y .Y W W W � W W W W W W W W W W .4• •� � W W W N W � MAX. HORIZ. SPACING) III YVASHEB #57/ W W W W W W W W W `M - -__ •6• W W W W •Y W 3 SHREDDED MULCH GRAVEL TO INCLUDE NDERLYING OUTLET PROTECTI.O. ACCORDING TO DESIGNED TAKING INTO CONSIDERATION LOCAL SOIL CONDITIONS, 0� FILTER FABR C SEE DESIGN DETAILS FOer __ _ (3) VARIABLE SUMP DEPTH � DIMENSIONS ACCORDWG TO PLANS ...36"._ OF APPROVED 1.2" OF__#57 WASHED STONE .12'' SCH. 40 PVC _SYSTEM P. BLOFILTER EM 655 -,� (4) VARIOUS TYPES OF INLET &OUTLET ADAPTERS AVAILABLE:MA(NUFAC ING REQ.) _ BIORETENTION SOIL MEDIA BELOW CHOKER STONE LAYER ! CLEAN WATER BYPASS TO 6" CLEANOUTS .(TYP.)_ WITH THREADED LID LOCATED @ 50' APART. MAK. 01 ... ...... ..... � _ APPROX...-100' ..OF GRASS 2' HIGH TO CONVEY RUNOI BIOFILTER 675 12" OF #57 WASHED STONE 670 13ELOW CHOKER STONE LAYER -6" RIGGID SCH 40 PVC +40 +60 +80 6+00 NDERDRAIN OR EQUIVALENT _. RUGATED HDPE ©1.0% SLOPE .INCLUDE UNDERLYING FILTER o�� -ARRIC BETWEEN PV(- AND 665 CHOKER STONE 660 nqn 7OT Storage(CY) °- MN rqO� 000 It C4 N co_r� 2.066 Cq*N NI�� (0 U)- to to (0 CO 0 1\ r r n � r- t0�0 I-_ CDt0� t00� (0t0_j (0t0J (0(0:D A4 0 N O� a� THREADED LID COVERED WITH WIRE MESH 3" DOUBLE 0 Q J i (TOP TO BE 6" ABOVE I MAXIMUM PONDING AS NECESSARY (BEYOND) U POST BMP CONVERSION STAGE STORAGE Elev(Ft) Storage(CF) Storage(CY) 661.500 0.000 0.000 662.000 55.783 2.066 664.000 850.596 31.504 666.000 3482.473 128.980 668.000 8871.719 328.582 670.000 17531 .665 649.321 Area (SF) 49.904 186.577 754.705 1949.009 3472.167 5217.504 STORM EVENTS FOR BIORETENTION FACILTY EVENT INFLOW (CFS) ROUTED (CFS) 2 -YR 14.79 2.37 nqn `-Orn 0000000 0) N 00 (OtOF �tOJ U L� ��S TH OF P f4 Jimmy L. Taggart ASPHALT PAVEMENT Lic. No. 10 -YR 26.17 3.20 OR OTHER STRUCTURAL 22841 sv� 2 COMPONENTS / i�f / rONAL E��1 100 -YR 48.73 4.97 / / Trash Rack Dia. OPTIONAL 2"-3" STONE WITH FILTER FABRIC AROUND BOTTOM AND SIDES W W NYLOPLAST 18" DRAIN BASIN: 2818AG _ _ X W I W 21 " HP OUTLET PIPE (CONNECT TO I W W y SOD REQUIRED FOR FIRST ( (RECOMMENDED ADJACENT TO PAVEMENT W •6 ADEQUATE DRAINAGE SYSTEM 24" U F PLANTING YEAR) 1' MIN WIDTH, 1' MIN DEPTH) (1, 2) INTEGRATED DUCTILE IRON �S yFFi, � - o N FRAME & GRATE TO MATCH BASIN O.D. CLEANOUT WITH OVERFLOW OUTLET STRUCTURE 18" MIN WIDTH GUIDELINE A4 0 N O� a� THREADED LID COVERED WITH WIRE MESH 3" DOUBLE 0 Q J i (TOP TO BE 6" ABOVE I MAXIMUM PONDING AS NECESSARY (BEYOND) HAMMERED HARDWOOD OVERFLOW OUTLET STRUCTURE W W W W W W W W W W •Y W W W •Y W W W W ELEVATION, AT 100 FEET MULCH LAYER WHERE APPLICABLE W W W W W W W W W W W W W W W W W W •Y .Y W W W � W W W W W W W W W W .4• •� � W W W N W � MAX. HORIZ. SPACING) 2>_M,gX SOD ON SIDE -SLOPES AVAILABLE (ACCORDING TO RECOMMENDATION (5) ADAPTER W W W W W W W W W `M 4 W W W •V W W W W •6• W W W W •Y W b REQ. SAME AS MIN. SUMP) VARIABLE 0° -360° GUIDELINE PURPOSES ONLY. ACTUAL CONCRETE SLAB MUST BE 6" PONDING DEPTH - J• W A- 10 4 ' MIN. F G •.rS W W W W .Q WW W •r S W �i .O W 011 W W W W�W W W W W W 4 MIN. W W W W W W y U W W W W W W W W �/ •Y W W W W \ 0^ W W W W W W W W W W W W W W V W W W W ,.0.5% •=<-"``• '`, SLOPE F TLET PIPE MIN SLOPE f = PRETREATMENT AND ENERGY DISSIPATION (TYP. FOR BIORETENTION WITH EXTENDED DETENTION PARAMETERS Total Post Development Drainage Area- 4.48 acres Bioretention Design Volumes: Bioretention Surface Area Required= 4,150 SF Bioretention Surface Area Provided= 4,400 SF Extended Detention Design Elevations: Top of Dam = 667.00 Emergency Spillway = 666.00 Design High Water = 665.11(100 -Year Storm) Crest of 48" RCP Riser = 665.00 (1) 5" Low Flow Orifice = 661.75 Toe of Dam - 661.50 Extended Detention Principal SQillwav Desian: RCP Riser Dia. = 48" Trash Rack Dia. = 72" W W NYLOPLAST 18" DRAIN BASIN: 2818AG _ _ X W I W 21 " HP OUTLET PIPE (CONNECT TO I W W y = 50.0' HP W •6 ADEQUATE DRAINAGE SYSTEM 24" Inv. DOWNGRADIENT) Barrel = 655.00 HP (1, 2) INTEGRATED DUCTILE IRON = 13.00% 2311 FRAME & GRATE TO MATCH BASIN O.D. N CIO): m 18" MIN WIDTH GUIDELINE 0 N O� a� 0 Q J OCW OU >O z Zw 0 MINIMUM PIPE BURIAL 8" MIN THICKNESS GUIDELINE DEPTH PER PIPE (3) VARIABLE INVERT HEIGHTS MANUFACTURER 2 ('J v AVAILABLE (ACCORDING TO RECOMMENDATION (5) ADAPTER PLANS/TAKE OFF) (MIN. MANUFACTURING ANGLES TRAFFIC LOADS: CONCRETE SLAB DIMENSIONS ARE FOR V REQ. SAME AS MIN. SUMP) VARIABLE 0° -360° GUIDELINE PURPOSES ONLY. ACTUAL CONCRETE SLAB MUST BE 0¢ 0 L ^� ACCORDING TO DESIGNED TAKING INTO CONSIDERATION LOCAL SOIL CONDITIONS, 0� wo PLANS TRAFFIC LOADING, & OTHER APPLICABLE DESIGN FACTORS. co SEE DRAWING NO. 7001-110-111 FOR NON TRAFFIC INSTALLATION. MM W (3) VARIABLE SUMP DEPTH � ACCORDWG TO PLANS BASED (4) VARIOUS TYPES OF INLET &OUTLET ADAPTERS AVAILABLE:MA(NUFAC ING REQ.) 4" -18" FOR CORRUGATED HDPE (ADS N-12/HANCOR DUAL WALL, 4" MIN I IL O ADS/HANCOR SINGLE WALL), N-12 HP, PVC SEWER (EX: SDR 35), PVC DWV (EX: SCH 40), PVC C900/C905, CORRUGATED & RIBBED PVC THE BACKFILL MATERIAL SHALL BE CRUSHED STONE OR OTHER WATERTIGHT JOINT GRANULAR MATERIAL MEETING THE REQUIREMENTS OF CLASS I, (CORRUGATED HDPE SHOWN) CLASS II, OR CLASS III MATERIAL AS DEFINED IN ASTM D2321. BEDDING & BACKFILL FOR SURFACE DRAINAGE INLETS SHALL BE 1 - GRATES/SOLID COVER SHALL BE DUCTILE IRON PER ASTM A536 GRADE 70-50-05. PLACED & COMPACTED UNIFORMLY IN ACCORDANCE WITH ASTM D2321. 2 - FRAMES SHALL BE DUCTILE IRON PER ASTM A536 GRADE 70-50-05. 3- DRAIN BASIN TO BE CUSTOM MANUFACTURED ACCORDING TO PLAN DETAILS. RISERS ARE NEEDED FOR BASINS OVER 84" DUE TO SHIPPING RESTRICTIONS. SEE DRAWING NO. 7001-110-065. 4 - DRAINAGE CONNECTION STUB JOINT TIGHTNESS SHALL CONFORM TO ASTM D3212 FOR CORRUGATED HDPE (ADS N-12/HANCOR DUAL WALL), N-12 HP, & PVC SEWER. 5 - ADAPTERS CAN BE MOUNTED ON ANY ANGLE 0° TO 360°, TO DETERMINE MINIMUM ANGLE BETWEEN ADAPTERS SEE DRAWING NO. 7001-110-012. THIS PRINT DISCLOSES SUBJECT MATTER IN WHICH DRAWN BY EBC MATERIAL 3130 VERONA AVE NYLOPLAST HAS PROPRIETARY RIGHTS. THE RECEIPT vOBUFORD, GA 30518 OR POSSESSION OF THIS PRINT DOES NOT CONFER, DATE 04.03.06 '1� PHN (770) 932.2443 TRANSFER, OR LICENSE THE USE OF THE DESIGN OR Nyloplast" FAX (770) 9 TECHNICAL INFORMATION SHOWN HEREIN st-us www.nyloplast-us0.com REVISED BY NMH PROJECT NO.1NAME REPRODUCTION OF THIS PRINT OR ANY INFORMATION TITLE CONTAINED HEREIN, OR MANUFACTURE OF ANY DATE 03.14.16 18 IN DRAIN BASIN QUICK SPEC INSTALLATION DETAIL ARTICLE HEREFROM, FOR THE DISCLOSURE TO OTHERS IS FORBIDDEN, EXCEPT BY SPECIFIC WRITTEN PERMISSION FROM NYLOPLAST. 02013 NYLOPLAST DWG N0. 7001.110-191 REV E DWG SIZE A SCALE 1:30 SHEET 1 OF 1 6" PONDING DEPTH - J• W A- 10 4 ' MIN. F G •.rS W W W W .Q WW W •r S W �i .O W 011 W W W W�W W W W W W 4 MIN. W W W W W W y U W W W W W W W W �/ •Y W W W W \ 0^ W W W W W W W W W W W W W W V W W W W ,.0.5% •=<-"``• '`, SLOPE F TLET PIPE MIN SLOPE f = PRETREATMENT AND ENERGY DISSIPATION (TYP. FOR BIORETENTION WITH EXTENDED DETENTION PARAMETERS Total Post Development Drainage Area- 4.48 acres Bioretention Design Volumes: Bioretention Surface Area Required= 4,150 SF Bioretention Surface Area Provided= 4,400 SF Extended Detention Design Elevations: Top of Dam = 667.00 Emergency Spillway = 666.00 Design High Water = 665.11(100 -Year Storm) Crest of 48" RCP Riser = 665.00 (1) 5" Low Flow Orifice = 661.75 Toe of Dam - 661.50 Extended Detention Principal SQillwav Desian: RCP Riser Dia. = 48" Trash Rack Dia. = 72" Trash Rack Ht. = 21 " HP Barrel Length = 50.0' HP Barrel Dia. = 24" Inv. Out 24" HP Barrel = 655.00 HP Barrel Slope = 13.00% STORM EVENTS FOR EXTENDED DETENTION FACILITY EVENT INFLOW (CFS) ROUTED (CFS) ELEVATION (FT) STORAGE (CF) 2 -YR 2.37 2.57 664.89 2022 10 -YR 3.20 3.32 664.95 2100 100 -YR 4.97 4.97 665.11 2311 3" MULCH 2'-0" TO 4 '-0" LAYER FILTER MEDIA SEE BMP DESIGN MEDIA MANUAL FOR SOIL SURFACE AREA PARAMETERS. 1'-0" GRAVEL LAYER AROUND UNDERDRAIN ALL CONCENTRATED FLOW LOCATIONS- SEE DESIGN STORIM DRAINAGE UNDERDRAIN GRAVEL BED DETAILS AS LOCATION MAY VARY) EASEMENT (TYP) (#57 WASHED STONE) WITH PPLAN^' NON -WOVEN FILTER FABRIC LAN AROUND TOP, BOTTOM AND SECTION A - A SIDES, TVP. BIORETENTION PLAN NOT TO SCALE BIORETENTION CROSS-SECTION NOT TO SCALE DAM CONSTRUCTION NOTES: 1, GEOTECHNICAL CONSULTANT TO SPECIFY DAM EMBANKMENT MATERIAL, SEEPAGE CONTROL DEVICES, CUT-OFF TRENCH DESIGN, CULVERT BEDDING REQUIREMENTS, AND OTHER APPROPRIATE GEOTECHNICAL DESIGN REQUIREMENTS. 2. IMPERVIOUS CORE SHALL EXTEND TO THE 10 -YR WATER SURFACE ELEVATION UNLESS OTHERWISE NOTED. 3. FOUNDATION AND ABUTMENT AREA EXTENDING 10' BEYOND DAMI FOOTPRINT SHALL BE CLEARED, GRUBBED AND STRIPPED OF ALL VEGETATION TOPSOIL AND/OR ORGANIC SOIL AND OTHER UNSUITABLE MATERIALS. 4. AFTER CLEARING, GRUBBING, STRIPPING, AND REMOVING ANY OTHER UNSUITABLE MATERIALS, THE SUBGRADE SHALL BE PROOF -ROLLED WITH COMPACTION EQUIPMENT UNDER THE OBSERVATION OF A QUALIFIED ENGINEER. THE COMPACTION EQUIPMENT SHALL CONSIST OF THE HEAVIEST POSSIBLE EQUIPMENT THAT WILL NOT CAUSE DISTURBANCE OF SUITABLE SUBGRADE SOILS. EXCESSIVELY SOFT OR UNSUITABLE MATERIALS SHALL BE REMOVED AND REPLACED WITH COMPACTED FILL. WHERE ROCK IS EXPOSED AFTER STRIPPING OR UNDERCUTTING, ALL LOOSE ROCK MATERIAL SHALL BE REMOVED PRIOR TO PLACING COMPACTED FILL. ROCK SUBGRADES SHALL BE INSPECTED AND APPROVED BY INSPECTOR OR ENGINEER PRIOR TO PLACEMENT OF FILL. 5. COMPACTED FILL SHALL NOT BE PLACED PRIOR TO PERFORMING THE REQUIRED FOUNDATION AND ABUTMENT PREPARATION, OR ON ANY FROZEN SURFACE. COMPACTED FILL SHALL EXTEND TO THE FILL LIMIT LINES AND GRADES INDICATED ON THE APPROVED CONSTRUCTION PLAN. COMPACTED FILL MATERIAL SHALL BE OF THE TYPE CLASSIFICATION SYMBOL SPECIFIED BY THE GEOTECHNICAL CONSULTANT, OR OF A BETTER QUALITY MATERIAL AS DEFINED BY THE UNIFIED SOIL CLASSIFICATION SYSTEM (USCS). RESTRICTIONS ON LIQUID LIMIT AND PLASTICITY INDEX OF MATERIAL MAY BE INCLUDED WHERE APPLICABLE. COMPACTED FILL SHALL CONSIST OF MATERIAL FREE OF ORGANIC MATTER, RUBBISH, FROZEN SOIL, SNOW, ICE, AND PARTICLES WITH SIZES LARGER THAN 3" OR ANY OTHER DELETERIOUS MATERIAL. 6. COMPACTED FILL SHALL BE PLACED IN HORIZONTAL LAYER of 10"-12" IN LOOSE THICKNESS. ACTUAL LIFT THICKNESS SHALL BE SPECIFIED BY THE GEOTECHNICAL CONSULTANT. THE MOISTURE CONTENT SHALL BE CONTROLLED SUCH THAT COMPACTION IS ACHIEVED WITHOUT YEILDING OF THE SURFACE. EACH LAYER SHALL BE UNIFORMLY COMPACTED WITH SUITABLE COMPACTION EQUIPMENT TO AT LEAST 95% OF STANDARD PROCTOR MAXIMUM DENSITY IN ACCORDANCE WITH ASTM D-698, AASHTO T-99, OR VDOT SPECIFICATIONS. ANY LAYER OF FINE GRAINED FILL WHICH BECOMES SMOOTH SHALL BE SACRIFICED TO A DEPTH OF 2" TO ALLOW ADEQUATE BONDING BETWEEN LAYERS. 7. COMPACTED FILL WITH A MOISTURE CONTENT WHICH WILL NOT PERMIT COMPACTION TO THE SPECIFIES DENSITY STANDARD SHALL BE SACRIFICED, DRIED, OR WETTED AS NECESSARY TO PERMIT PROPER COMPACTION. GENERAL BIORETENTION NOTES: 1. ALL DRAINAGE AREAS TO A BIORETENTION FACILITY ARE TO BE STABILIZED PRIOR TO INSTALLATION OF AMENDED SOILS, MULCH OR PLANTINGS. 2. AMENDED SOIL WILL ONLY BE PERMITTED WITH A VALID SOIL ANALYSIS REPORT. NO AMENDED SOIL SHALL BE ALLOWED ON THE SIDE SLOPES. 3. UNDERDRAIN PIPE SHOULD BE MIN. 6" PERFORATED SCHEDULE 40 PVC (PER AASHTO M278) OR DOUBLE WALL (HDPE (PER AASHTO M252). PERFORATIONS SHOULD BE 3/8" SPACED 6" ON CENTER ALONG 4 LONGITUDINAL ROWS SPACED 90' APART. 4. UNDERDRAIN CLEANOUTS SHOULD EXTEND A MIN. OF 6" ABOVE MAXIMUM PONDING ELEVATION. ONE CLEANOUT MAY BE FLUSH WITH TOP OF SURFACE TO ALLOW DRAWDOWN. 5. ONLY SMALL MATURING TREES ARE ALLOWED TO BE PLANTED IN THE AMENDED SOILS. 6. A PERMANENT MAINTENANCE ACCESS EASEMENT MUST BE PROVIDED AROUND THE PERIMETER OF ALL BMPS 'TO ALLOW FOR ADEQUATE MAINTENANCE AND REPAIR. 7. AMENDED SOIL WILL ONLY BE PERMITTED WITH A VALID SOIL ANALYSIS REPORT. 8. INSTALL WIRE SCREENING AS NECESSARY AROUND ALL OUTLET OPENINGS TO PREVENT LOSS OF MULCH. ANNUAL BMP MAINTENANCE REQUIREMENTS BIORETENTION N ON • MOWING OF GRASS FILTER STRIPS AND BIORETENTION TURF COVER AT LEAST 4 TIMES A YEAR • SPOT WEEDING, EROSION REPAIR, TRASH REMOVAL, AND MULCH RAKING TWICE DURING GROWING SEASON • ADD REINFORCEMENT PLANTING TO MAINTAIN DESIRED THE VEGETATION DENSITY AS NEEDED • REMOVE INVASIVE PLANTS USING RECOMMENDED CONTROL METHODS AS NEEDED • STABILIZE THE CONTRIBUTING DRAINAGE AREA TO PREVENT EROSION AS NEEDED • SPRING INSPECTION AND CLEANUP • SUPPLEMENT MULCH TO MAINTAIN A 3 INCH LAYER • PRUNE TREES AND SHRUBS • REMOVE SEDIMENT IN PRE-TREATMENT CELLS AND INFLOW POINTSONCE EVERY 2 TO 3 YEARS • REPLACE THE MULCH LAYER EVERY 3 YEARS EXTENDED DETENTION • MEASURE SEDIMENT ACCUMULATION LEVELS IN FOREBAY. • MONITOR THE GROWTH OF WETLANDS, TREES AND SHRUBS PLANTED. RECORD THE SPECIES AND THEIR APPROXIMATE COVERAGE, AND NOTE THE PRESENCE OF ANY INVASIVE PLANT SPECIES. • INSPECT THE CONDITION OF STORMWATER INLETS TO THE POND FOR MATERIAL DAMAGE, EROSION OR UNDERCUTTING. • 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. • INSPECT POND OUTFALL CHANNEL FOR EROSION, UNDERCUTTING, RIP -RAP DISPLACEMENT, WOODY GROWTH, ETC. • INSPECT CONDITION OF PRINCIPAL SPILLWAY AND RISER FOR EVIDENCE OF SPALLING, JOINT FAILURE, LEAKAGE, CORROSION, ETC. • INSPECT CONDITION OF ALL TRASH RACKS, REVERSE SLOPED PIPES OR FLASHBOARD RISERS FOR EVIDENCE OF CLOGGING, LEAKAGE, DEBRIS ACCUMULATION, ETC. • 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. • INSPECT INTERNAL AND EXTERNAL SIDE SLOPES OF THE POND FOR EVIDENCE OF SPARSE VEGETATIVE COVER, EROSION, OR SLUMPING, AND MAKE NEEDED REPAIRS IMMEDIATELY. , REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE October 5, 2017 SCALE AS SHOWN CONTOUR INTERVAL N/A J W W c J 06Q W E- Z ONp- > V065; 06 5 Z �z zowJ O0w,QLLI c�J0 �mZi-W m W V a Z WJ o O /U I.L M� W I FILE NUMBER 8053 SHEET 8of11 w a to U N CIO): m 0 N Q Z0. 0 Q J OCW OU >O z Zw 0 2 ('J v V W2 0¢ 0 L ^� 0� wo co VN 0 a; MM W Q � WT ? z IL O W REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE October 5, 2017 SCALE AS SHOWN CONTOUR INTERVAL N/A J W W c J 06Q W E- Z ONp- > V065; 06 5 Z �z zowJ O0w,QLLI c�J0 �mZi-W m W V a Z WJ o O /U I.L M� W I FILE NUMBER 8053 SHEET 8of11 e ss 400 CF EXISITNG TYPICAL CREEK PROFILE (PRE 655 650 DEVELOPMENT 660 655 650 645 �_ 1 645 0+00 O d - LO co +20 +40 +60 +80 1+00 +20 N O LO +40 400' OF EXISITNG TYPIC 660 655 650 +60 +80 2+00 +20 +40 +60 +80 Oq cD cD E�ED 3+00 O cD CREEK PROFILE (POST +20 +40 +60 +80 cD 00 d- cD 4+00 DEVELOPMENT 660 655 650 645 - I I 1645 0+00 O +20 +40 N d- cD +60 +80 TI'la2 lexisdua Erna; IraS. Ie£ISling_ _ False Iesrstiug Step 4 Determine the relative pre -development pollutant load (lyse). Based -on Existing lmoervious Cover 1 I pre(esistiu j - [0'05 ' ((),009 x 1 stin,}1 A /, 2,28 (Equation 5-16). inhere; Lpr-L� 1_t;,l ; _ relative pre-rrevelopmerat total piiosphoroits� load (pounds per year) lessein" _--isstiug.�te tmpaGieus mvar(p+sccuf e�,res szd in tn•hote.number>1 A7" = applicable area (acres) pre{esrsting} - [0.05 + (0.009 x 0% )l x 4.4?r0005 x 2.28 pounds per year 21 gxe(eatersaled) _ (0.05 - (0.009 v,li.aiar ei ], x A x 2.28. (Equation 546) rel zre. L pz.r;eE«an al relativepre- developurenttotal phosphorous load (pounds, peryear) IaGeisr,ed - �•<ra�tasd-mvzr camditiun for spr'�.x�atershza cr toyaliay^rt)x Chrsapta4e Sal^.si.Seult vatua cit l6a(pe[c.�nt_�.prasseiia'shottnurntxt>) A applic-ab le area (act es) Lpre(xatexshesry _ (fl.ti5 i (fl.fl04-% 16?0. }l x. 4.4801105 x 2.22 1 8 pounds peryear Std Determine the relative post -development pollutant load (i a eS )• I pest [0:05 T (0 009 x 1p_)] x, A x 2.28 (Equation 5-21) where: Lpa,t = relative post -development total phosphorous load (potinds per year) 1pa c = post -development firpenious cover (percent e-gressed it whole ranitbers) A = applicable area (acres) L,A = [0.05 +. (0,009,N 85% }l x 4.480005 .x 2.25 poundsperyear Step 6 Determine the relative pollutant removal requirement (RR). RR - Lp.,r (0.9 x L Y I 1 [:lQij RR 8:3 3.`+ RR= Z.t37 pounds per year or RR- - Lp u - I:prr(:�aYei;hrc; RR = 83 2.0 RR= 6:35 pounds per year Use RR= 6,35 (lesserwtine) Step 7 Identit best management practice (BMP) for the site. 1. Determine the required pollutant r'emoval.efiiciency° for floe site: E)~`F' = (RR +Lpo,,, ) x 100 (Equation 5 -?2) wtere: EFF = required pollutant temomal ef6-iency RR = pollutant removal r• qui emera (,pounds per year) relative post -development total phosphorous load.. Equation 5-21 (pounds per year)) EFF = 6.35 8. 3x 100= 76% 2, Select B fl?(s) from Table 5-14 and locate on the :site: Drainage Impervious Type Effc7oncy Area (,3 } Area 01) Description: B -NIP 1• sioretentten` _00 '18 77-165966'B10PA BlIP2. Ekfetdedi)eten'€on 1 181}774 0, BMP B. BtIP3 84r1P C BMP4 BttP ria. 131IP5: BMP E 1+00 +20 +40 +60 +80 2+00 +20 +40 to to O NO cLOD EXISTING CREEK CHANNEL TYPICAL CROSS-SECTION ,3r TI !IIr NTS "5 10 10 YR WSE I N 2 . 2 YR WSE - - I I 1 N4.5 FT egmlto the average land coli condition(lwatersh4) and the pooposed inprouerncnts vvilicreate a totalpercent +60 +80 3+00 +20 +40 O U') d d +60 2U -7 Identify best management practice (BLIP) for the site. L Deteriniae the regt>ited pollutant reahm-al eflicienc} for the site. E,FI?` = (Pit , Lq_, ) x 10o (Equation 5-22) where: �F = required pollutant removal efficiency ncy 1Z = pollrnrait removal requirement (pounds per year). TLvo n = rehtive post-devek-)ptuent total phosphorous load, Equation 5-21 (pounds per .,'ear) EFF = 6.41 531 x l 00= 77;0 2: SelectBTAP(s) liornTable 5-14 and locate on the site: Dain e € s r Ina tvou. 9e p Type Efficiency Area (s f) Area (s.f.) Description: I3 SP1: B'4IP2: BMP 3s. BYIP4:. B3IP 5: B€tiretent€on q0 188)774,' 1S`9fi(r Extended Detention 15 j 1a077i; a Channel Type: Rectangular Channel Type: Rectangular Dimensions: Dimensions: •. Base Dimension: 4.50 ft Base Dimension: 4.50 ft BMP A BMIP a BMP c BMP D BMP E 3. Determine the pollutant load entering the proposed BNIP(s):. LB up [0,05:+ (0:009 t 13bra)]x AP,.rai fP X 2.28 (Equation 5-23) where: La ,tP _ relativz post-dexelopnxnt total phosphoroLis load entering proposed BMP (pvtaxls per year) I5z&fp = post-developniont percent invenious cotter to proposed WNW (percent expressed in whole nuai Qrs) 4,preprhmp = drainage area to proposed Bit1P (acres) Lhorp, = [{1.05 ' (0,009 x 92% )l: x 4.15 x.2.28 829 potutds per year LB,,,, _ [0.05 _ (0.009 x. 01"tjl x 4.15 ,x 2.28 - 0.47 pounds per year Lihh1p3 = [o. 05 + (0.009 x 0% A x 0.00 .X.2:28. 0)o pounds per year L11MP4 = [0.ra5 + (0'()09 x oeE A x 0,00 x 228 0.08 pounds per year L-B_re5 = [0.05 = (0.009 x 0% }j x 0.00 ir 2.28 0.00 pounds per year 4. Calculate the pollutant laid reni'med by the proposed 13NIP(:s): Lre;_d = Efku_,tp x L3,�rP (Equation 5-24) post -development total phosphorous load renhoved by proposed B1sfR (potnrds per -ear). Eff , = art eratovileffieietrc a:,#P p olltu. � r } of B:alP (e-Vressed nit des;iuntl f0rtn) La�jp = nelative post-deveWnhent total phosphorous load enteTing pibposed BiN P, Equation 5-23 (pounds-peryear) I ren nse4tBttP€ = 7.46 Pounds per year removiced reuweedfB.liP2= 0,47 Pounds per year retnoved I"i:egio}ed,`$EtP3= O.GtJ Pounds per yearremowd. Lrew o�ed�sitpa- = 0:013 Pounds, per year <emoved EYemor?a/Stir's _. ly- Pounds per year temoved- 5. Calculate the tectal polhaaut load removed by dna BNIP(s ): Lt'eruese$.ko ssf - Lrcinoc•c�.Ii`iP t-'-Lrenevz&Bir?"' ' Lramotec B'arPi ,.(Equation. 5-25) total polkaarat load removed lit proposed BNIPs (pounds per year) L:t„ _ a3, Pr =pollutant lead removed by proposed BMP No, 1, Equaucnt 5-24 Lre,a d Bc Q = pollutant load removed ora proposed B -NIP No. 2, Equation 5-24 = portant load removed by proposed BNIP No. 3, Equatrena 5-24 LY,,.Q.&1sl=P4 = P9lkitant load remmcd by proposed BMP Ns o: 4, Equation 5-24 L: rl a'as=a; =polltaint load rer m,Qd by proposed 1331-41? No. 5; Equation 5-24 Eremoceditonl = 7:53 Total Pou€1ds. peryearrernoved 6, Cl?r1phance: Lre _,rtotat c RR. L;emerza so[ai 7.53 Total Poundsper year removed- Req'd Removal= 6.41 Total Pounds per year retrieved OK, Removal Rate Exceaded- ps 4+00 2 YEAR PRE -DEVELOPMENT STORM EVENT 10 YEAR PRE -DEVELOPMENT STORM EVENT EXISTING CHANNEL PARAMETERS (ERODIBLE) EXISTING CHANNEL PARAMETERS (ERODIBLE) w a Channel Type: Rectangular Channel Type: Rectangular Dimensions: Dimensions: •. Base Dimension: 4.50 ft Base Dimension: 4.50 ft Wetted Perimeter: 5.03 ft Wetted Perimeter: 5.58 ft Area of Wetted Area of Wetted Cross Section: 1.18 ft2 Cross Section: 2.44 ft2 Channel Slope. 1.5000 % Channel Slope. 1.5000 Manning's n rcW Manning's n of Channel: 0.0275 of Channel: 0.0275 Discharge: 2.99 cfs (10 -YR PRE) Discharge: 9.30 cfs (10 -YR PRE) Depth of Flow: 0.26 ft Depth of Flow: 0.54 ft Velocity: 2.52 fps Velocity: 3.81 fps Channel Lining: Earth, F. Uniform,Weeds/Grass Channel Lining: Earth, F. Uniform,Weeds/Grass Freeboard: Variable Freeboard: Variable Depth: Variable -Consistent 2.00 ft Depth: Variable -Consistent 2.00 ft 2 YEAR POST -DEVELOPMENT STORM EVENT 10 YEAR -POST DEVELOPMENT STORM EVENT EXISTING CHANNEL PARAMETERS (ERODIBLE) EXISTING CHANNEL PARAMETERS (ERODIBLE) Channel Type: Rectangular Channel Type: Rectangular Dimensions: Dimensions: Base Dimension: 4.50 ft Base Dimension: 4.50 ft Wetted Perimeter: 4.98 ft Wetted Perimeter: 5.06 ft Area of Wetted Area of Wetted Cross Section: 1.08 ft2 Cross Section: 1.26 ft2 Channel Slope: 1.5000 % Channel Slope: 1.5000 Manning's n Manning's n of Channel: 0.0275 of Channel: 0.0275 Discharge: 2.57 cfs (10 -YR POST) Discharge: 3.32 cfs (10 -YR POST) Depth of Flow: 0.24 ft Depth of Flow: 0.28 ft Velocity: 2.39 fps Velocity: 2.62 fps Channel Lining: Earth, F. Uniform,Weeds/Grass Channel Lining: Earth, F. Uniform,Weeds/Grass Freeboard:: Variable Freeboard: Variable Depth: Variable -Consistent 2.00 ft Depth: Variable -Consistent 2.00 ft 9VAC25-870-97 STREAM CHANNEL EROSION. b. Adequacy of alll channels and pipes shall be verified in the following manner: (2) (a) Natural channels shall be analyzed by the use of a two-year storm to verify that stormwvater will not overtop channel banks nor cause erosion of channel bed or banks. Q2YR PRE -DEVELOPMENT = 2.99 CFS Q2YR POST -DEVELOPMENT = 2.57 CFS Q2YR POST- DEVELOPMENT = 2.57 CFS 5 Q2YR PRE -DEVELOPMENT = 2.99 CFS 9VAC25-870-98 FLOODING. A. Downstream properties and waterways shall be protected from damages from localized flooding due to changes in runoff rate of flow and hydrologic characteristics, including, but not limited to, changes in volume, velocity, frequency, duration, and peak flow rate of stormwater runoff in accordance with the minimum design standards set out in this section. B. The 10 -year p(ostdeveloped peak rate of runoff from the development site shall not exceed the 10 -year predevelolped peak rate of runoff. Q10YR PRE -DEVELOPMENT = 9.30 CFS Q10YR POST -DEVELOPMENT = 3.32 CFS Q10YR POST -DEVELOPMENT = 3.32 CFS S Q10YR PRE -DEVELOPMENT = 9.30 CFS STREAM CHANNEL EROSION & FLOODING ANALYSIS A portion of the exisitng creek that will receive site runoff was visually inspected by Roudabush obtain Gale & Assoc. in order to I aln design information to evaluate existing conditions, as well as post -development conditions. The following observations/evaluations were made: 1. The creek appeared to be a rectangular channel with moderate to steep side slope banks. The banks varied in height but showed consistency of 2 feet or more. Water was present in the channel with a gentle flowing depth of 3-3.5 inches. The width of the creek channel varied between 4-5 feet. The creek appeared in good health and lined with natural' earthen cover with some tall grass and weeds present. Soils appeared to be clay loalm with natural erosion. 2. Calculations were run using the pre -development and post development conditions for the two and ten year storm events and were evaluated as such. 3. The bmp measures put forth for the proposed development provide a reduction in the runoff velocity exiting the site for both the two and ten year storm events. Projected values for the flow depth in the channel were obtained by forecasted linear trend methods and appear to show no threat of overtopping the banks of the existing channel. By reducing the velocity exiting the site, the measures will be providing additional relief of natural erosion of the exisiting channel banks, thus satisfying 9VAC25-870-97. 4. While the volume of flow will increase naturallty due to the project development, the rounoff from the site will be routed through multiple, complex design measures that will react to the increased volume and account for the peak intensity the hydrograph produces from the two and ten year storm events. No localized flooding is visually present at this time in the existing channel. The bmp measures will decrease the rate of flow than is exiting the site, reduce the velocity, and spread the peak intensity over a longer duration during a storm event, thus decreasing localized flooding satisfying 9VAC25-870-98. A1,T H Op vj+P Jimmy L. Taggart Lic. No. 22841ISI SIONAL St - 1+00 t. J REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE October 5, 2017 SCALE AS SHOWN CONTOUR INTERVAL NA C!) U. J 0 'W W LU V O � Z LQL r Z �NWJ0 CO N C > cnVC> Z JVJU zOWW �Q_J QJ0�� amZ � Ufa v O WJ W n W Q FILE NUMBER 8053 SHEET 9 of 11 i s T w a •. W 0 U W a (2 J Q. N_ Z= O q rcW >0 �I 0U dZ � 0J az Q WW U� W C. o 20 ULOC6 N ; W, q. <S2 r� W2 0 L, 0� � t wo w ( cc rt aW U O P q Q T LU Q� w O Z CL ® W REVISIONS COUNTY COMMENTS MARCH 5, 2018 AMENDMENT JUNE 28, 2018 AMENDMENT AUGUST 6, 2018 AMENDMENT AUGUST 21, 2018 DATE October 5, 2017 SCALE AS SHOWN CONTOUR INTERVAL NA C!) U. J 0 'W W LU V O � Z LQL r Z �NWJ0 CO N C > cnVC> Z JVJU zOWW �Q_J QJ0�� amZ � Ufa v O WJ W n W Q FILE NUMBER 8053 SHEET 9 of 11