HomeMy WebLinkAboutWPO201200086 Plan - VSMP 2021-09-16GENERAL 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, S C OTT S V I L L E DISTRICT
EMAIL: SCOTT®COLLINS—ENGININEERING.COM
TAX MAP NO.: 09400-00-00-01500, 94-1581, 94-1582, 94-1583, & 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 94-1684) 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 IS BEING ASSIGNED TO LOT 5. THE AGGREGATE ACREAGE OF LOTS 1 2 3 4 AND
5, IS 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 SERWCED 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 ORGINIA
DEPARTMENT OF TRANSPORTATION OR THE COUNTY OF ALBEMARLE.
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LEGEND
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EXISTING CULVERT
EARTH DITCH
CULVERT
DRIVEWAY CULVERT
0
DROP INLET &STRUCTURE N0.
BENCH MARK
CURB
CLEARING LIMITS
CURB & GUTTER —
— — — —
PROPOSED PAVEMENT
-w-
VDOT STANDARD STOP SIGN
EC-3A DITCH - -
- -200- - -
- EXISTING CONTOUR
6"
DEPTH OF EC-3A DITCH
PROPOSED CONTOUR
20o
EC-2 DITCH
240.55
PROPOSED SPOT ELEVATION
TBC DENOTES TOP/BACK OF CURB
g"
DEPTH OF EC-2 DITCH
TAB 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
T�7
SP-2006-031CONDITIONS OF APPROVAL:
VICINITY MAP
SCALE: 1" = 2000'
No
SCOTT/R. C$L]
No. 35791
A 08/14/21
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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.
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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
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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.
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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.
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SHEET INDEX
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TITLE SHEET
TITLE SHEET 1
STORMWATER MANAGEMENT PLAN 2
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STORMWATER MANAGEMENT DETAILS & CALCULATIONS 3
TOTAL SHEETS 3
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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.
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PRE -DEVELOPMENT — / — — / / / / — —
POST-DEVE LOPMENTz�_��G — — —
Cover description
Soil name and
Drainage Area
(Covertype,treatment, and hydrologic condition;
Area
hydrologic group
Description
percent impervious; unconnected/ connected
(Acres)
(Appendix A)
impervious area ratio)
DA W
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 W
B
Woods in Good Condition (75%+/-)
0.00
(Developed)
Lawns in Good Condition (25%+/-)
20.63
Outflow Summary: (1-Year Storm Event)—
/ Pre -Development Post -Development
DA'A' 1.90 cfs 0.71 cfs _
(Routed)
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Outflow Summary: (2-Year Storm Event)
Pre -Development Post -Development /
DA W 5.85 cfs 5.25 cfs
(Routed)
Outflow Summary: (10-Year Storm Event)
Pre -Development Post -Development
DA'A' 27.25 cfs 27.18 cfs
\ I \ \ \ \ \ / '/ \ — I III I I I I I I I I \ \ / (Routed) /010
/V
General construction notes for Stormwater Management plans CIL):No.
/ �i. All dams and constructed fill to be within 95%of maximum dry density / H p�Ot;and 2%Of optimum moisture content. All fill material to be approved bya geotechnical engineer. A geotechnical engineer isto be present during
construction of dams. R. LINSZ 35791z. Pipe and riserjoints are to be watertight within stormwatermanagement facilities. 14/21�3. For temporary sediment traps or basins which are to be converted to �1ONAL S"'oti
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.
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�.A. TO SWM BASIN \ \ \ / / 1 / / / / / �I \ \ — \ \ \ \ \ Ilk
Tc=o.23hrs\`�
CN=56 \ \ \ \ \ \ ` I I _ _ / f l l l / / / // // I (•�\\ — 1/ D.A.TOSWMBASIN
22.12 ac. A \
TAc= \0.23\hrs
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APPROVED TIME OFCONCENTRATIONAPPROVED TIME F�COJCENTRATI N
SHEET FLOWTc = o.16 SHEET FLOW, Tc=o.i6
CHANNEL FLOW, Tc = oCHANNEL FLOW,
POST -DEVELOPMENT Tc=o.23 \
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\� \ \ \ \ \ \ \ \ / \ I f POST-DEVELOPMENTTc=o.a3
ILOTI7 I I 1 \ \ \ 1 \ \ \/ \ \ 1 I I / \ /
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I I I u I I / I I I \ \ \ -� � — — \ \ ✓ � I I U I I / Y 1 I 1 � \ � -� VARIDTH
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PROPOSED AMENDMEN SHALL \ = i / 1 396 \ \\ \
\ \ J ( ` I ` \ \ \ T / \ J gg GREY HERON \\ \PROPOSED AMENDMEN SHALL
� \ \ INCLUDE A LEVEL I WET POND TO � \ � ;: \ INCLUDE A LEVEL I WET POND TO
\ \ \ '-REPLACE THE APPROVED / ROgp \ �� \ 'REPLACE THE APPROVED
\ \\\\ \\ -EXTENDED DETENTION \\\ \� _ /_ \ — 96 3 6 \\ -EXTENDED DETENTION
\ ` 1 \ \ �S 1 ORMWATER MANAGEMENT \ \ / / \ 0 _ _ \ �STORMWATER MANAGEMENT
/ \ \ \ BASIN. THE NEW WET POND SHALL \\ — _ \ 11 \ _ _ — — \ ` 3 \BASIN. THE NEW WET POND SHALL \\ _
\\ MAINTAIN THE EXISTING RISER \ \ \ \ \ \ \I \ I \ \ \MAINTAIN THE EXISTING RISER \ \ \ _� \
AMENDMENT NARRATIVE /SWM PROPOSED CHANGES: \ / \ \ `AND THE EXISTING BARREL \ \ \ 0 \ \ \ I \ \ \ AND THE EXISTING BARREL \ \
\OVERVIEW: \DESIGN. MODIFICATIONS SHALL BE \ 1 — \ I \\ \ \ ^ \� — — — ` \ \ \ 3y ?94 ESIGN. MODIFICATIONS SHALL BE \ \
Sf \ \ MADE TO THE RISER RIM & \ ^� \ \ \ \ — G \ MADE TO THE RISER RIM & \
THE PRESERVE AT GLENMORE IS A LARGE SUBDIVISION CONSISTING MOSTLY OF 0� \ \ 1 1 \ \ \\ \ \ \ 4� / ORIFICES TO MEET SWM \ \ 1 \ \ \ / \\ ORIFICES TO MEET SWM \
UNDEVELOPED AREAS. THE DEVELOPER WISHES TO CONVERT THE EXISTING \ �. I \ \
SEDIMENT BASIN TO A LEVEL I WET POND, IN LIEU OF THE EXTENDED DETENTION \ QUANTITY, CHANNEL, AND FLOOD \ \ \ \ I (� \ \ \ ` — \ QUANTITY, CHANNEL, AND FLOOD \
\BASIN APPROVED FOR THE SITE. PLEASE SEE BELOW FOR A DETAILED SUMMARY OF ` _ \ \PROTECTION RE UIREMENTS. \ \ \ \ \ \ \ \ \ \ I \ \ I — — ` _ I R T CTION RE UIREMENTS. \ \ \ \ \ \ \ \
THIS PLAN'S PROPOSED CHANGES TO THE APPROVED STORMWATER MANAGEMENT— � \ \ \ \ I I I I I \ \\ \ \ \ \ \ \\ \ I I — \
I v \ \ Aso— — ♦ W v
\PLAN. ICAO— — �`\ 1 11 I 1 I (III I I �\\\\\ \\ \ \ \ \ \\� \ I I , , / I
\WATER QUALITY:
THIS PLAN WAS APPROVED IN 2012, USING THE iggg VIRGINIA STORMWATER �♦% I I I I I I \ \\\ \\ \\ \\ \ \ _ \ \ \ \ \\ I P I LOT 5 1\ \
MANAGEMENT HANDBOOK (VSMH), WHICH WAS THE GOVERNING DOCTRINE AT THE \ \ \ \\ � \ \ / \ \ \ \ A C\\ LIMNS OF
TIME OF THIS PLAN'S APPROVAL. THE APPROVED PLAN REQUIRED 2.51 LB/YEAR \ \ ` I I I ( I \ \ \ \ \\ \ LIMNS O� \ > 1 \ \ I I I / \ ( I ( I \ \ 'ACCESS PAT I H\\
REMOVAL FOR THE SITE (APPROVED Lpre=17.85 LB/YEAR AND \ I I I I \ \ \ \ \\ \ \\ WPO BUFFER \ \ // , / / I I / \ i \ \ GRADE SHALL WPO BUFFER \ \
APPROVED Lpost=2o.36 LB/YEAR). THE APPROVED PLAN PROVIDED AN EXTENDED \ \ ` I I 1 �\ \\ \\\ \ \\\\ i NOT EXCEED io%
,,DETENTION FACILITY WITH 3S% PHOSPHORUS REMOVAL RATE. \ \ \ = I I \ \ \ \\
VAR. WIDTH \
\\ \ \ \ / \ \ \ \\ \ \ \ \ \\ \\ \ \\\ \\ \ \ \ \\ / / / III \
THIS PROPOSED STORMWATER MANAGEMENT AMENDMENT FOLLOWS THE — DRAINAGE & SWIM
_ ACCESS EASEMENT
-VIRGINIA RUNOFF REDUCTION METHOD 2oii BMP STANDARDS. THE PROPOSED \ — I \ \ ♦ \ \ \\ \ \ \ \ \\ \\ \ \\\ \\ \ \ \ \\ \ / / I I I III \ \ \ \ �\ I \ \ \\ \ C AMEN \ \\ \\\\\\ \ \ \\ \
AMENDMENT IMPROVES UPON THE APPROVED PLAN WATER QUALITY STRATEGY. \ f I L
IT PROPOSES A LEVEL I WET POND TO REPLACE THE EXTENDED DETENTION \ \ \ — \ \ \ ` \ \ \ \ \ \ \ \ \\ \\ \ \\\ \\ l \ / I �= _ \ \ \ \ \ \ \ \ ♦ \ \ \ / \ \ \ \ \\ \ \ \
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:
THE PROPOSED STORMWATER MANAGEMENT AMENDMENT TO THE SITE PROVIDES
WATER QUANTITY PROTECTION IN POST -DEVELOPMENT FLOW REDUCTION, / \ \ I L / — _ / \\\ � L T 6
CHANNEL PROTECTION,
POST-DEVELOPMENT
I \ \ \ \ \ \ 1 \
STORM FLOWS ARE DETAND FLOOD PROTECTION. THE 1, 2, io, AND ioo YEARAINED AND PRODUCE POST DEVELOPMENT OUTFLOWS � \ �_ _\\ I \ � \ \ � I \ \ I 1 � I I I I I I � \� \� � \\ \ � I / 1 / _ � _ \ \ \ / \ I
_LESS THAN THE PRE -DEVELOPMENT CONDITION. CHANNEL PROTECTION IS / / — \ \\ \\ \ \ _ > \ I J I I ` \ \ \\\ \ \ / I II / _ \ \ \ ✓ / / t— \ \\ \\ \ \ I J I I LOT 12� \ \ \\\ \ \
ACHIEVED WITH A 1-YEAR FLOW MEETING THE REQUIREMENT OF SECTION B.3.A.
FLOOD PROTECTION IS MET WITH PER 9 VAC 2S-870-66 SECTION C.2.13. IN WHICH THE
io-YEAR POST DEVELOPMENT FLOW DOES NOT EXCEED THE PRE -DEVELOPMENT / /
FLOW. THE TR-55 ANALYSIS IS PROVIDED IN THE CALCULATIONS PACKET / \ \ \ / / \ \ \ \\ I _ _ \ \ \ \ \ \ I
ACCOMPANYING THIS PLAN. A SUMMARY OF PRE AND POST DEVELOPMENT FLOWS / \\ ^ / /
IS PROVIDED ON THIS SHEET. ' / \ \ \ / / / / / \ \ \ \\ k�T�\ \ \ / \ \ \ / / ° / G AP�1(/ SC LE \ \ \ \ \\\\
0 \
/ // \ \ / \ \ \ \ \ \ \ \ \ 80 / / ` 40 80 / 160 \ \ \
\PLEASE NOTE THE SOIL AROUND THE SPILLWAYS ARE TO BEAT 95%COMPACTION
WITH AN IMPERVIOUS CORE AND CUT-OFF TRENCH. THE EMERGENCY SPILLWAY \ \ / \ \ / \ \ \ // 1 I I \ \ \ _
\ I 1 I I I \ \ \ J / / / / / / \ \ \ I \ \ I I I I I \ \ \ \ / I / ( IN F ET )
SHALL BE EARTHEN. THE FOREBAY SPILLWAY SHALL BE CONSTRUCTED OF GABION / / I \ — � _ ) I I \ \ �i / I I I 1 \ 1 — �O� �
\BASKETS WITH Ya" STONE ON THE UPHILL SIDE OF THE WEIR. I \ \ / / / / — \ \. �I L I I I I I I \ \ I \ \ / LOT 13 1ch ao /ft
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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 INSTALL ANY 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.
10.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.
a
16.THE CONTRACTOR SHALL MAINTAIN A ONE 1 CALENDAR YEAR 90k 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 IS DONE, THE VOLUME SHALL BE BASED
ON THE MORE STRINGENT SIZING RULE (EROSION AND SEDIMENT CONTROL REQUIREMENT VS. WATER QUALITY TREATMENT REQUIREMENT).
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 REQ UI RED TO TH E DESI RED SU B-GRADE.
5. THE CONTRACTOR SHALL INSTALL E&5 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.
S. 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 Liner Specifications
Property
Test Method
Unit
Specification
Permeability
ASTM D-2434
Cmtsec
1 x 10
Plasticity Index of Gay
ASTM D423/424
%
Not less than 15
Liquid Limit of Clay
ASTM D-2216
%
Not less than 30
CWy Particles Passing
ASTM D-422
%
Not less than 30
Clay Compaction
ASTM D-2216
%
95% of standard proctor deris-
Source- Virginia Stormwaler Management Handbook (1999)
AMENDED v v v v v v v v-
LEVEL 1 WET PQND v v v v v v v v v v
SCALE. 1` 20' / v 26v v A A A A
FA- PLANT TURF\q ROV D ED D AND RECOR VAR.THE \ \ \ \ \
/ WITHNNET PON LEVEL1Fg TQBF RFS SqN�/NS W DTH SWFACILITY EASEMENT \ \36,9 SEDIDURMENT BASIN TO A WMCONVERSION FACILITY, THE CONTRACTOR ROM\ \
\\ \ FRVFO \ \ \ \ \ ALL
REMOVE UNSUITABLE SOIL AND \ \
ENSURE FACILITY IS BUILT IN
\3 \ \ ACCORDANCE WITH THESE PLANS \ \
360 \ \ \ MIN. WATER'VOLUME \ \
\ 3S \ \ \ \ REQUIRED=20,13. cf.
I \ 8 \ \WATER QUALITY VOLUME
I \ \ \ \ \\ PROWEI\20,247 cf Qa ELEV\/. 353-5 \
3S6 \\ \ \ \
3 \ \
S4 4•1
• I\\ \\ 3535 \ \ EX�TING 042" CL. III RCP MULTI -STAGE to
\ \ RISER MODIFIED \
PROPOSED FLOW PATH > 2:1 \ / 3S0 RIM rLEV. = g 15'
MID -FL W ORIFICES 2-016", ELF S.37'
\ FLOVd LENGT 1=i43' �We=29' \ \ l \ \ \ Li9W-FLOW ORIFICE i,5", ELEV.=353-50' -
\ \ _ 9 \ \
\ \ \ \ \\ d \ d 350.00 \ \ \ \ \
"56, \W�1+0,2s0 MIDPOND \ \__E TING'12' EMERRGENEY-GRASS
SPIL "Y WEIR w/3:1 SIDE
I SLOPES ATEJ EV.\9.0
AT RISE \ -
EXISTINNN6CRITICAL� \ \\ I // / \
SLOPES�O� MAIN
PROPO EDGABI BASKE�WEIRW/4NOTCHAT \
\ ELE�ATION035�. .WEIR SHALL HAVFe VDOT 03 \\
\ COARSEA�GREGAT ONTHE4PHILLSID`�(�FTHE
WEER Be CLASS I RIPRAP ON THE DOWNHILL SIDE OF
\ T WEIR. (FOTEXTIL FILTER F� IC
UNDERLAYME T SHALL INSTAL�D.
\ MIN. F6E\ B \ MBINER D= ,o17cf.TFOREAY VOLUME PROVIDED=)ocf \� \
\
\ \ \ \ \ EXISTING V60T STD. i& CL. PpII,'
\ TYPE B RIPRAP w/ GE TTILE
\ \ FILT FABRICUNDERL YMENT
\W \
-'o (Wl-- ,75r W2- .25',- L-21', D -
_2" . I
EXI�lING V �OT STD. @S 1 @S 1 \
GRAPHIC \SCALk \ I I
I
I
\ inch =\ 20 ft\
9. EXCAVATION AND GRADING TO THE APPROPRIATE ELEVATIONS AND DESIRED CONTOURS SHALL BE ACHIEVED FOR THE BOTTOM AND SIDE SLOPES
OFTHE POND.
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 INSTALLTHE 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 FOREBAY.
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. INSPECTTHE 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 - twiceayear
Quarterly or after major stoma
•
Remove debris and blockages
(>1 inch of rainfall)Ited,
Repair undercut, erodand bare soil areas
•
Mowing
Twice a year
•
Shoreline cleanup to remove trash, debris and
floatables
•
A full maintenance inspection
Annually
•
Open up the riserto access and lest the valves
to
Repair broken mechanical components, if needed
one time during the
•
Pond buffer and aquatic bench reinforcement plantings
second year following construction
•
FSediment Removal
Every 5 to 7 years
•
r er and 'I hatal as deeded
R iareba rise
Film 5 to 25 years
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-VORTEX 7RASHRACK
I I
OF RE AY
/1
EXIS77NG TOP OF DAM
ELEV.= 360.00
EXISTING 12' WDE GRASS WEIR
OUTFALL CHANNEL W1 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 Lv
COMPLETELY DRAINED. THE
APPROVING AUTHORITY SHALL BE
NOTIFIED BEFORE DRAINING THIS
POND. RISER FOOTING
EXISTING PRINCIPAL SPILLWAY
( Ulu rl L T J Oz 1(11V1 1 V DTJ 1V1 V1J1C1T lJ,
ADDITION O 'ANTI -SEEP COLLARS)
(NOT TO SCALE)
-EXISTING 36" CL. III RCP BARREL
98 LF 0 19
INV. IN= 350.00'
INV. OUT= 349.00'
INSTALL 2-6 x6' AN77 SEEP
COLLARS PER CALCULA77ONS
BELOW
AN77-SEEP COLLARS CALCULA77ON
L s= Y(Z+4)+[ 1 +(S1(0.25-S)))
Y=7.15;- Z=4, S=0.0102
Ls=59.6'
FROM PLATE 3.14-12, 2 COLLARS REQUIRED
WTH 6'x6' DIMENSIONS SPACED AT
2xP=2x1.5=3' FROM RISER, AND
14xP=14x1.5=21' FROM FIRST COLLAR
/;7 \ /
/ g6
PROPOSED BAFFLE
I EXISTINT, 10' WDEFLAT BENCH AT THE
TOP OF THE EMBANKMENT SHALL
SERVE AS A STORMWATER
MANAGEMENT ACCESS&
MAINTENANCE PATH
\ 1 EXISTING 6" CL. III RCS BARREL
V
h�
`5 re
`rY
\ EXISTING VDOT STD. EC-1 CL. II
\
TYPE B RIPRAP w GEOTEXTILE
I� /
FILTER FABRIC UNDERLAYMENT.
I
3 hit \ (W1=7.5', W2=18', L=16', D =2')
I X
\I EXISTING:o'TOP6F �3
DAM ELEVV�36o.00 � 16,
LEVEL I WET POND PLANTING PLAN
SYM
BOTANICAL
COMMON NAME
SIZE
SWM FACILITY
QUANTITY
COVERAGE (sf)
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 ELEVA770N=
360.00
WEIR COEFF.= 33
EMERGENCY _J
SPILLWAY GRASS LINED SPILLWAY
ELEVATION=
359.0'
APPROVED EMERGENCY
SPILLWAY
NTS
FIGURE 3.01 - la
Homogeneous Embankments w/Seepage Controls
omogeneous fill
F- -----�
I
4' min _ I_
'"scut off trench-4' below suitable)
I material I
Soil or rack L-----------J
TYPICAL HOMOGENEOUS
EMBANKMENT
�T-ration fill
ock or gravel
t:;j'Pipe outlet Coarse filt
oroun s o
Perforated collector
Foundation drain 4BI.nket drain
FOUNDATION DRAIN BLANKET DRAIN
_Tmnsltlon filter
CHIMNEY DRAIN
r.\3_01-1a
Source: SCS Engineering Field Manual
Standard Dimensions
24
!3(3/2
48
58
M
1�41
27
80
72
37112
226
30
37
60
72
41
2.25
36
4,
60
72
48
222
42
51
72
86
55
3.16
48 -
58
84
100
52
427
54
68"/1
B4
ion
711/e
420
80
72
96
114
78
5.48
88
BD'/2
96
114
Ill
5.39
72
BE
108
128
90
6.83
78
94 / S
126
147
91 / Y
8.97
ad
105
126
147
1oa
e.90
m
atlN
Rack or gravel
-Rxk toe o�o,r; drain
Tmnsilion filter
TOE DRAIN
Cold in Top Slab plan VIEW V V
h And-Voriwr
FI F Cc O.D.
ai.
Nod, Diameler f
full
(1.) AntWoNx devim (Cep and Riser) Mabu aired In
o.dunce calm ASTM C476.
Omenel[ns nub ectm rmleaibk vedatlonc or Asn4 C47e.
(2) 1 �
inlatmu Area between aehce l.D. nine deer o.D. i. ra.mr
(3) awn met am. (Am afdeer l.D.) ) 9
4. Slab remrorcement to be ASTM MIS to ban Q e'E.W.
Cecume6MemdHm A. • t ®a.150
Wixv2.5 Fmlaun.
Mateerm:fc=4,000 p.s.i., f,=BWpei. Cmxae
mvarport.-41arl. Concrete cwerwer nlMorwmanl
(ccea)= t•, unless rx4ed.
(5.) DI-1 Frzne 8 Grate Is avallabla Mda' LD. rirers and larger
Precast Anti -Vortex Device (Cap and Riser)
MIN. FOREBAY COMBINED VOLUME
REQ'D= 3,017cf. TOTAL FOREBAY
VOLUME PROVIDED= 3,790cf
BOTTOM OFF
FOREBAY
ELEV. 3535
PROPOSED GABION BASKET WEIR W140'
NOTCH AT ELEVA77ON 357.5. WEIR
SHALL HAVE VDOT #3 COARSE
AGGREGATE ON THE UPHILL SIDE OF
THE WEIR & CLASS I RIPRAP ON THE
DOWNHILL SIDE OF THE HEIR.
GEOTEX77LE FILTER FABRIC
UNDERLAYMENT SHALL BE INSTALLED.
2
Section A -AA -A
wialmensl tdbno en aibweEle
soxla'
Ecemn tmerexe
iii
VA 14.1 03-15-06 •°•Hanson
Technical Bulletin 7
Minimum Standard 3.02
no ^lei.a noox
�a m a/e' raaenx
e- ae, aav
eDPG etruclwa W nc wllh
O a-1/E" M,ee end ija' pieta
r OC) saw «ma wr,vue
i
0000
- ,. "im ,tenet w.•
root .u.
as a
e- - [�Pr eVuerunl uac MN ( nW w xw-r z-Ue• bat.• a , a•W .t•
Section / ,e.,t.,.,a ey �InaUo
s.mu"n• m�. or esaa
orin�•,11e� ElewaLion
PI.AS1yC i11 �" b'e
BMP DEBRIS CAGE IS01U470NS en a 4aVA re =sao-
INC. xt-xe-tee+
Vegetative Cover Slo eof Exit Channel Slo eof Exit Channel
0-sat. 5-10°h 0-5%e 5-JOY.
Bermuda Grass ft 1 7 1 6 1 5
R"A:a
Buffialogmss
Kentucky Bluegrass
Smooth Bromegrass
7
6
5
4
Tall Fescue
Reed Canary Grass
Sod komung Grass -Legume 5 1 4 1 4 3
Mixtures
Lespede2a
Weeping Lovegrass
Yellow Bluestem 3.5 3.5 2.5 2.5
Native Grass Mixtures
' USDA-NRCS TP-61
2 Increase values 25 percent when the anticipated average use of the spillway is not more
vent than once in 10 ears.
�9 Y
3
Thane with a high clay content and high plasticity.TYPice] soil textures are silty clay, sandy
clay, and clay
Those with a high content of fine sand or silt and lower plasticity or non -plastic. Typical soil
GENERAL SWM NOTES:
3. 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 .3. SPECIFICATIONS.
3 4
3 CONTRACTOR SHALL HIRE A THIRD PARTY GEOTECHNICAL ENGINEER TO
ENSURE THE EMBANKMENTS ARE 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.
MIN. WATER QUALITY VOLUME 1-YR W.S.E. =355.4
REQUIRED = 20,116 cf.. 2-YR W.S.E. =356.0
WATER QUALITY VOLUME 10-YR W.S.E. =357.6
PROVIDED = 20,247 cf AT 353.5 100-YR W.S.E. =359.0
CONCRETE
AN77-VORTEX
IRA SHRACK
_ _ [_ _ PROPOSED M_WSE=3535'
/ ORIFICE COEFF.= O.6J
PERMANENT POOL
DEPTH=3.5'
FLOOR ELEV.=350
CL. III RCP MUL77-STAGE
RISER. SEE THIS SHEET EXIS77NG
FOR DETAILS. 36" CL. At RCP BARREL
98 LF 0 1%
INV. IN= 350.00'
INV. OUT= 349.00'
AMENDED LEVEL I WET
POND
10' WIDE TOP OF DAM ELEV.=
360.00'
-WEIR ELEV.= 359.00
12' WIDE GRASS WEIR
OUTFALL CHANNEL W1 31
SIDE SLOPES.
MAX. EMBANKMENT
HL=10' (460-450)
MIN. 8' WIDE 0 TOP & 10'
DEEP IMPERVIOUS CORE &
CUTOFF TRENCH WITH 1:1 SIDE
SLOPES SEE DETAIL ON THIS
SHEET FOR ADDITIONAL
INFORMATION.
No. 35791 a
08/14/21 F41
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