HomeMy WebLinkAboutWPO201700052 Plan - VSMP 2021-07-14DUNLORA OVERLOOK79
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GENERAL NOTES
OWNER/APPLICANT. 06100-00-00-16500
DUNLORA INVESTMENTS, LLC
455 SECOND ST SE, SUITE 400
CHARLOTTESVILLE, VA 22902
ENGINEER: COLLINS ENGINEERING
200 GARRETT ST, SUITE K
CHARLOTTESVILLE, VA 22902
(434)293-3719
SURVEYOR: CARDINAL SURVEY
TAX MAP PARCEL: 06100-00-00-16500 (OB 4657 PG 413)
TOTAL PROJECT AREA: 8.62 ACRES TOTAL.
ZONING. R-4 RESIDENTIAL (BY -RIGHT) - NO PROFFERS
AIRPORT IMPACT AREA (AIA)
PROPOSED USE: 15 SINGLE FAMILY ATTACHED UNITS AND
14 SINGLE FAMILY DETACHED UNITS
REQUIRED DENSITY: 4 DU/AC
PROPOSED DENSITY: 29 00/8.62 AC = 3.36 UNITS/AC
OPEN SPACE.• REQ: 2.16 AC OF TOTAL DEVELOPMENT AREA &62 x 259,); AND
207 OF THE REQUIRED OPEN SPACE SHALL BE OUTSIDE OF CRITICAL
SLOPES AND THE SWM FACILITY
PROV: 3.20 AC TOTAL OPEN SPACE PROVIDED (379e)
1.47 AC PROVIDED OUTSIDE CRITICAL SLOPES AND THE SWM FACILITY
(46q OF THE REQUIRED OPEN SPACE)
THE OPEN SPACE WILL BE DEDICATED TO THE HOA.
BUILDING HEIGHTS: MAXIMUM BUILDING HEIGHTS SHALL NOT EXCEED 35 FEET
NON-INFILL SETBACKS: FRONT: 5' MIN AND 25' MAX
SIDE. • 10' BUILDING SEPARATION
REAR. 20' MIN AND NO MAX
SITE AMENITIES 2.63 ACRES OPEN SPACE (PASSIVE RECREATION AREA)
SUBDIVISION STREETS: CURB & GUTTER (PARKING ON ONE SIDE ONLY)
WATERSHED: THIS PARCEL IS NOT IN A WATER SUPPLY PROTECTED AREA - SITE
DRAINS TO MEADOW CREEK (UPPER RIVANNA WATERSHED)
AGRICULTURAL/ FORESTAL DISTRICT: NONE
TOPO & SURVEY. ON -GROUND SURVEY PROVIDED BY CARDINAL SURVEY IN SEPTEMBER 2016, AND
FROM DEEDS AND PLANS OF RECORD.
DATUM: NAD 83
EXISTING VEGETATION: PAR77ALLY WOODED WITH EXISTING RESIDENCE STRUCTURES
CRI77CAL SLOPES. MANAGED AND PRESERVED STEEP SLOPES ARE SHOWN AND LABELED.
LIGHTING: NO LIGH77NG IS PROPOSED
PHASING: 517E TO BE DEVELOPED IN A MINIMUM OF ONE PHASE.
UTILITIES PUBLIC WATER AND SEWER
FIRE & RESCUE. • AS REQUIRED, ALL FIRE FLOWS WITHIN THE DEVELOPMENT SHALL BE A MINIMUM
OF 1000 GPM AT 20 PSI. ADDIT70NALLY, FIRE HYDRANTS SHALL BE PROVIDED
ALONG THE ROADWAYS FOR FIRE PREVENTION AT A MAXIMUM SPACING OF 500
FT PER TRAVEL WAY.
RECREATION: NOT APPLICABLE/NOT REQUIRED
PARKING: 2 OFF-STREET PARKING SPACES SHALL BE PROVIDED FOR EACH DWELLING UNIT
+ 4 ON -STREET GUEST SPACES (MIN) FOR THE ATTACHED UNITS. 6 ON -STREET
GUEST SPACES SHALL BE LOCATED ALONG THE ROADWAYS WHERE MARKED.
BUILDING SITES: PARCELS 1-29 MAY NOT BE FURTHER DIVIDED. ONLY (1) DWELLING UNIT PER
LOT SHALL BE ALLOWED.
BURIAL SITES: NONE
STREAM BUFFERS/FLOODPLAIN. THERE IS A POR77ON OF A WPO STREAM BUFFER LOCATED AT THE
SOUTHEAST CORNER OF THE SITE. THERE IS NO 100-YEAR FLOODPLAIN LIMITS
ON THE SUBJECT PARCEL, PER FEMA MAP 51003CO229D; FEBRUARY 4, 2005.
OFFSITE DISTURBANCE: NO OFFSITE DISTURBANCE IS PROPOSED WITH THIS PLAN, EXCEPT FOR THE
TIE-IN CONNEC77ON TO THE SANITARY SEWER WITHIN EXISTING U77LITY EASEMENT.
LANDSCAPING. ALL PROPOSED ROADWAYS SHALL HAVE STREET TREES IN ACCORDANCE WITH
ALBEMARLE COUNTY REQUIREMENTS, PER SECTION 32.7.9 OF THE ZONING
ORDINANCE.
RETAINING WALLS: THREE SEGMENTAL RETAINING WALLS WERE ORIGINALLY APPROVED.
SIGNAGE.• NO SIGNAGE CURRENTLY PROPOSED.
TRASH COLLECTION: TRASH RECEPTACLES SHALL BE MAINTAINED ON EACH INDIVIDUAL LOT. ALL
TRASH SHALL BE COLLECTED BY A DRIVING DUMPSTER SERVICE.
DAM INUNDATION: THIS SITE IS NOT WITHIN A DAM INUNDATION ZONE.
un
STORMWAIER MANAGEMENT. STORMWATER WILL BE CONVEYED TO A �E;EE—N— olG�,FA L--FE,4—..�,TTu 1�
DOWNSTREAM DETENTION BASIN ""'^ " ^R" ^"`VTGN A&W SEE SWM PLAN
FOR DETAILS
IMPERVIOUS AREAS. SEE PROPOSED & APPROVED SWM SHEETS
LAND AREAS:
OPEN SPACE.• 3.20 AC. (31%)
LOTS 4.26 AC. (559e)
ROW DEDICATION. 1.16 AC. (14%)
TRAFFIC GENERATION: TRIP GENERATION BASED ON /IF GENERA7ON MANUAL (87H EDITION)
29 SINGLE FAMILY UNITS (CODE 210)
278 VPD (139 EN7ER/139 EXIT)
AM PEAK. 22 (6 ENTER/16 EXIT)
PM PEAK: 29 (19 ENTER/10 EXIT)
LEFT/RIGHT LANE TURN WARRANT ANALYSIS•
DUNLORA ADT = 2300 ADT
VPH = 2300 / 12 hrs X 2 = 400 VPH (WORST CASE)
NOTE: THE LOCATION OF THIS ENTRANCE IS BETWEEN (2) ENTRANCES INTO DUNLORA, ONE
ENTRANCE FROM RIO ROAD/PARK STREET, AND THE OTHER ENTRANCE FROM RIO ROAD/✓OHN
WARNER PARKWAY. WITH THE (2) ENTRANCES SPLIT77NG THE APPROACHING TRAFFIC AND
TRAFFIC LEAVING DUNLORA, THE VPH WILL ALSO BE LESS AT THIS ENTRANCE LOCATION.
RIGHT TURN WARRANT.- PEAK PM IS THE HIGHEST TRIP PER HOUR WITH 21 ENTERING THE SITE
BASED ON THE CHART IN THE VDOT MANUAL ON PAGE F-96, 21 CARS AN HOUR ENTERING 774E SITE
WITH AN APPROACHING TRAFFIC VOLUME OF 400 VPH DOES NOT WARRANT A RIGHT 77JRN LANE OR
FULL TAPER. A 4: 1 TAPER INTO THE DEVELOPMENT HAS BEEN PROVIDED.
LEFT TURN WARRANT.' BASED ON THE CHART IN THE VDOT MANUAL ON PAGE
F-78, A VOLUME OF 400 VPH ADVANCING VOLUME AND 400 VPH OPPOSING
VOLUME DOES NOT WARRANT A LEFT TURN LANE. THESE VPH VOLUMES ARE A
WORST CASE SCENARIO AND DO NOT TRIGGER THE REQUIREMENTS FOR A LEFT
TURN LANE.
NOTE. EACH LOT AS SHOWN HEREIN SHALL CONTAIN A BUILDING SITE WHICH MEETS THE REQUIREMENTS
OF SECT70N 4.2.2(b)l (18-520)
VSMP AMENDMENT #3
WPO 201700052
(AMENDMENT #3 TO WPO 201600058)
RIO MAGISTERIAL DISTRICT ALBEMARLE COUNTY, VIRGINIA
SCALE: 1"=60'
OWNER
DUNLORA INVESTMENTS, LLC
455 SECOND STREET SE, SUITE 400
CHARLOTTESVILLE, VA 22902
ENGINEER
COLLINS ENGINEERING
200 GARRETT STREET, SUITE K
CHARLOTTESVILLE, VA 22902
VSMP AMENDMENT #3 PROPOSED CHANGES:
, THE PREVIOUSLY APPROVED BIORETENTION BASIN HAS BEEN REMOVED WITH THIS
AMENDMENT AND WATER QUALITY REQUIREMENTS WILL NOW BE MET WITH A NUTRIENT
CREDIT PURCHASE. THE BIOFILTER's PREVIOUSLY APPROVED DETENTION CELL HAS ALSO BEEN
RECONFIGURED WITH THIS AMENDMENT AND NOW MORE CLOSELY MIMICS THE APPROVED /
ASBUILT EROSION & SEDIMENT CONTROL BASIN. UTILIZING THE OUTLET STRUCTURES AND THE
MAJORITY OF THE ASBUILT GRADING WILL MINIMIZE ADDITIONAL DISTURBANCES. THE
DETENTION BASIN WILL CONTINUE TO PROVIDE WATER QUANTITY TREATMENT.
APPROVED
by the Albemarle County
Communit�yy Developpment Department
Date 7l14/2011
I�If��JI I�Yllli r[IIIII1tY�
Amendment #3
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JOB NO.
122071
SCALE
AS NOTED
SHEET NO.
1
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POST -DEVELOPMENT SCENARIO &BEST MANAGEMENT PRACTICE PRESERVATION EASEME T ( A E OF 11,
—-�APPROVED Tc= 0.18 hrs. MANAGED SLOPES `TC-D
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STORMWATER MANAGEMENT NARRATIVE: I////.! 1D0 OF OLF W/ A LLLV.-3.5 .1H hrs.) PRESERVED SLOPES ,,,,j,TH 0
PROPOSED
LORA LOTS P AN SEPARATE REVIEW).
THE PROVIDES STORMWATER
TREATMENT
PHPART FOR T
RTH CONSTRUCTION
O � � ..�// - �♦I — 1 1 87 OF CF W/ A ELEV.
DUN=S (TC i 0.01 hrs.) STREAM BUFFER
REQUIREMENTS FOR STORMWATER MANAGEMENT. THE SUBMITTAL PACKAGE DOCUMENTS ��. / 47J OF CF @ I4 tt/S �TC i 0.01 hrs.)
ASSOCIATED WITH THIS PLAN SHOW WATER QUALITY COMPLIANCE BEING • \ ♦ \ SCOTT R. LLINS'Z
SOC O G .�� ♦�
THE BEST MANAGEMENT PRACTICE OF OPEN SPACE PRESERVATION, AND 1 i
NUTRIENT CREDIT PURCHASE. THIS PLAN ALSO COMPLIES WITH PART IIB R � - — — �• - ♦ - L.� Lie. NO. 035791
THE ATTENUATION OF FLOWS IN THE DETENTION BASIN. PLEASE SEE THE ATTACHED Is \ --- - ♦ 1 APPROVED A
STORMWATER MANAGEMENT CALCULATIONS PACKET FOR THE FULL DETAILS OF PLAN -�- — f LIMITS OF TREE �iO 05/31/21
1 COMPLIANCE. � I � \ � �� — — — —s I ♦ � � - CLEARING (TYP.)
♦ I �♦ - �,
Watershed Summary � � �♦ � � ', -- — ♦ �
APPROVED Pre -Development ♦� \ 1 /
CN Area, 1-year 2-year 10-year � / ♦♦ A —� — — � �
ac. Flow, cfs Flow, cfs Flow, cfs vv y / ♦♦ A — _ _ A
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DA'A' 1 62 4.17 2.41 2.88 7.70 VARICK STREET, MARIN COURT, AND THE �� I, � � � � v \ ♦ A I � � �� ♦, SURROUNDING LOTS ARE NOT PART OF
♦ X�.
APPROVED Post- Development V ♦ A \
\ \ ` •. ♦ \ \ \ \ � \' THIS SET OF PLANS. THE PROPOSED SWM
/ —� \
CN Area, 1-year 2-year 10 year I — - ♦ \ \ \ \ \ v� \ \` FACILITIES &BEST MANAGEMENT
ac. Flow, cfs Flow, cfs Flow, cfs / �� ♦♦ V A A� \ \ /� /� \ A PRACTICES ARE PROPOSED WITH THIS
DA A 80 4.17 0.70 1.15 7.42
' ' ' � `� • ♦A A A A ' � � SET OF PLANS &PROVIDE TREATMENT � o
/ / \ ♦I9* \\ \, FOR THE FUTURE ROADWAYS AND w a
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Area, 1-year 2-year 10-year / \ �� \ \ \\ A �1♦A % / ) \\ AV ` Q p O
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wo General Construction notes for Stormwater Management Plans
i. All dams and constructed fill to be within %of maximum dry density and z0/o of V / A _ / ♦ \ \ A -�
optimum moisture content. All fill material to be approved by a geotechnical engineer. A Q / ♦ / / \ A �\ \ ♦*Lu
geotechnical engineer is to be present during construction of dams. V A A VA ♦,� �j\ �, A \ VA \ j
z. Pipe and riserjoints are to be watertight within stormwater Management facilities. _ / ♦ _ \ A` \ \ \\\ w -\, / \ \ \ \ w m
3. For temporary sediment traps or basins which are to be converted to permanent �� / ♦ / _ \ \ �C)VED DA A \ \� / \ \\ \ ��/� /` �� A 'V'�E�- _ ) �\\�VA V� \ \ w
stormwater management facilities; conversion is not to take place until the site is Q 3 �� \V \ ♦ �. . A V A
stabilized, and permission has been obtained from the County erosion control inspector. / / \ \ \ 4-2, dL. \ \ \ \ ♦ \ - � ` •.� \\ \ \ \ ` LU0�
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A �� r ` , A A VA \ \
Total Onsite Impervious Areas (Water Quality) /Ce
Roadway z9,60o sf /; / \ \ �� TC=�.i8 h r v V ` \ \ V— ♦♦ \ VAA- \� A VA V A \
Sidewalks & Driveways 22110 sf / / / / ♦ A A� A ♦♦ �• \
Buildings 65700 sf ♦ — — A V V ♦ ` \ \ V� �V A V A
Total= 117,410sf /'// / ♦ v v �� v ♦♦♦ `� \ VAA`••� A�\\\V A A
D.A. 'A' Post -Development Impervious Areas (Water Quantity) g /� / / / \ / �� � A A� �� A / �� V `.♦♦ �� A OVA F0 E§T&OPENSPACE
Roadway 29,600 sf / %") / /\ / / i / A \ \ �\ \ \ ��� / \ L A� - ♦j♦- A� EMENf(DB 04967, PG
♦- ♦♦ /A -�� i �i/;, �� \ EASEMENT ENT IS A BEST & Driveways 19300 sf 1�3�23 NAMNE&46650 sf ♦♦Buildin �BITS FUTURE MTotal= 95,550 sf it \
b LOPMENT& rj oo Le)
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GRAPHIC SCALE — _ __ JOB No
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„o 122071
SWM FOREST& OPEN SPACE SCALE
EASEMENT (DB 04967, PG 133-134) \ \ \
IN FEET) COINCIDES WITH PROPERTY LINE \ \ \ - g 1rr=30'
1 inch = 30 ft. \
AMENDED SWM FACILITY TO TREAT \ SHEE
( r No.
\ ` WATER QUANTITY NOT QUALITY . EXIST�NG��EV€D \
) STEEP SLOPE�(TYP.)�
BASIN NOTES:
1. STATE APPROVED TRASH RACKS SHALL BE INSTALLED ON ALL ORIFICE OPENINGS.
2. A CONCRETE FOUNDATION SHALL BE INSTALLED ON THE RISER AS SHOWN & MEETING THE MINIMUM SPECIFICATIONS SET FORTH IN THE VESCH SPEC. #3.14.
3. CONTRACTOR AND CONSTRUCTION SHALL ADHERE TO ALL OSHA REQUIREMENTS. ADDITIONALLY, SPECIAL ATTENTION SHALL BE GIVEN TO THE CONSTRUCTION
BASIN's CONVERSION TO A PERMANENT SWM FACILITY. CONTRACTOR SHALL ENSURE THE PERMANENT SWM FACILITY HAS A STABILIZED GROUNDCOVER, SUCH AS
435 435
CONTRACTOR SHALL MAKE THE FOLLOWING MODIFICATIONS TO THE RISER:
1. PLUG THE 04" ESC DEWATERING ORIFICE WATERTIGHT (INV.=4o6.83 AB)
2. DRILL ONE (1) NEW 03.5" LOW -FLOW SWM ORIFICE (INV: 402.00)
3. DRILL FOUR (4) NEW 012" MID -FLOW SWM ORIFICES (INV.=4o8.25)
4. INSTALL A WEIR PLATE OVER THE TOP HALF OF THE BARREL'S OPENING
5. INSTALL TRASHRACKS ON THE LOW -AND MID -FLOW ORIFICES. SEE DETAIL
430
ON THIS SHEET, OR EQUIVALENT.
430
APPRO
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425
425
420
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ASBUILT
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'
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405
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TfENSUME
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=39.90')
395
APPROVED
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FABI
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392
ASBUILT
S:L=16.5,W1=7.4',W2=18.9'
392
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PROFILE SCALES
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DETENTION BASIN CONSTRUCTION NOTES:
FACILITY PLANTING SPECIFICATIONS:
1. THE DETENTION BASIN SHALL HAVE TURF GROUND COVER, SUCH AS GRASS OR SOME OTHER FORM OF A VEGETATIVE
GROUNDCOVER. LANDSCAPING BEYONDTHIS ISOPTIONALAND IS NOTREQUIRED.
2. THE PROPOSED SIDE SLOPES OF THE BASIN SHALL BE A MAXIMUM OF 2:1 TO REDUCE THE RISK OF EROSION. THE PROPOSED
FLOOR SLOPES SHALL BE G RADED TO PROVIDE POSITIVE DRAINAGE AT ALL TIMES TO THE RISER STRUCTURE.
3. WOODYVEGETATION SHALL NOT BE PLANTED OR ALLOWED TO GROW WITHIN 15 FEETOFTHETOEOFTHE EMBANKMENTNC
WITHIN 25 FEET OF THE PRINCIPAL SPILLWAY STRUCTURE.
4. A VEGETATED BUFFER SHALL BE PROVIDED THAT EXTENDS AT LEAST 25 FEETOUTWARD FROM THE BASIN TOP OF DAM
ELEVATION. PERMANENT STRUCTURES (E.G., BUILDINGS, SHEDS, etc.) SHOULD NOT BE CONSTRUCTED WITHIN THE BUFFER AR
EXISTING TREES SHALL BE PRESERVED IN THE BUFFER AREA DURING CONSTRUCTION IF AT ALL POSSIBLE.
S. 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 SHOULD BE THREE TIMES DEEPER AND WIDER THAN THE DIAMETER OF THE ROOTBALL FOR BALL -AND -BURLAP STOCK,
AND FIVE TIMES DEEPER AND WIDER FOR CONTAINER -GROWN STOCK.
6. AVOID SPECIES THAT REQUIRE FULLSHADE,ORARE PRONE TO WIND DAMAGE. EXTRA MULCHING AROUND THE BASEOFTREE
AND SHRUBS IS STRONGLY RECOMMENDED ASA MEANS OF CONSERVING MOISTURE AND SUPPRESSING WEEDS.
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 MEETTHE 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 NOTIFYTHE 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 FINAL SITE PLANS FOR ANY DETAILED SITE INFORMATION.
7. ALL WORK SHALL BE COORDINATED WITH OTHER PARTIES.
B. 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 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 INSPECTOR INITIALLY, AND THEN 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 SUFFICIENT TO CONTAIN
THE ENTIRE ROOT BALL OR ROOT MASS, WITHOUT CRAMPING ROOTSTOCK.
16. THE CONTRACTOR SHALL MAINTAIN A ONE (1) CALENDAR YEAR 90% CARE AND REPLACEMENT WARRANTY FOR ALL PLANTINGS.
THE PERIOD OF CARE AND REPLACEMENT SHALL BEGIN AFTER INSPECTION AND APPROVAL OF THE COMPLETE INSTALLATION 01
ALL PLANTS AND CONTINUE FOR ONE CALENDAR YEAR.
17. THE CONTRACTOR IS RESPONSIBLE FOR REMOVALAND DISPOSAL OF TRASH AND DEBRIS WITHIN THE LIMITS OF THE PLANTING
ON A DAILY BASIS.
18. THE CONTRACTOR WILL NOT BE RESPONSIBLE FOR PLANT MATERIALTHAT HAS BEEN DAMAGED BY VANDALISM, FIRE, OR OTHEI
ACTIVITIES BEYOND THE CONTRACTOR's CONTROL.
FACILITY CONSTRUCTION
1. THE DETENTION BASIN MAY SERVE AS A SEDIMENT BASIN AND/OR TRAP DURING PROJECT CONSTRUCTION. IF THIS IS DONE, TH
VOLUME SHALL BE BASED ON THE MORE STRINGENT SIZING RULE (EROSION AND SEDIMENT CONTROL REQUIREMENTS VS.
STORMWATER TREATMENT REQUIREMENTS). 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 POND IN MIND. APPROPRIATE PROCEDURES SHALL BE IMPLEMENTED TO PREVENT
DISCHARGE OF TURBULENT WATERS WHEN THE BASIN IS BEING CONVERTED INTO AN DETENTION BASIN.
2. THE DETENTION BASIN SHALL ONLY BE CONSTRUCTED AFTER THE CONTRIBUTING DRAINAGE AREA TO THE POND IS COMPLETEL
STABILIZED. IF THE PROPOSED POND SITE WILL BE USED AS A SEDIMENTTRAP OR BASIN DURING THE CONSTRUCTION PHASE,
THEN THE FACILITY WILL BE DEWATERED, DREDGED AND RE -GRADED TO DESIGN DIMENSIONS AFTER THE ORIGINAL SITE
CONSTRUCTION IS COMPLETE.
3. INSTALL E&S CONTROLS PRIOR TO CONSTRUCTION OF THE BASIN INCLUDING TEMPORARY DE -WATERING DEVICES AND
STORMWATER DIVERSION PRACTICES. ALL AREAS SURROUNDING THE BASIN THAT ARE GRADED OR DENUDED DURING
CONSTRUCTION SHALL BE PLANTED WITH TURF GRASS, NATIVE PLANTINGS, OR OTHER APPROVED METHODS OF SOIL
STABILIZATION.
4. CONTRACTOR SHALL EXCAVATE THE CORE TRENCH AND INSTALLTHE SPILLWAY PIPE DURING THE ESC PHASE.
S. CONTRACTOR SHALLALSO INSTALL THE RISER, OUTFLOW STRUCTURE AND/OR THE BARREL(s) DURING THE ESC PHASE TO ENSUI
THE TOP INVERT OF THE OVERFLOW WEIR IS CONSTRUCTED LEVEL AT THE DESIGN ELEVATION.
6. THE CONTRACTOR SHALL THEN CONSTRUCTTHE IMPERVIOUS CLAY CORE EMBANKMENT AND ANY INTERNAL BERMS IN 8 TO
12-INCH LIFTS AND COMPACT THE LIFTS WITH APPROPRIATE EQUIPMENT.
7. UPON COMPLETION OF THE EMBANKMENT GRADING, THE CONTRACTOR SHALL EXCAVATE/GRADE UNTILTHE APPROPRIATE
ELEVATION AND DESIRED CONTOURS ARE ACHIEVED FOR THE BOTTOM AND SIDE SLOPES OF THE BASIN.
8. CONTRACTOR SHALL THEN CONSTRUCT THE EMERGENCY SPILLWAY IN CUT OR STRUCTURALLY STABILIZED SOILS.
9. THE CONTRACTOR SHALL THEN FINISH CONSTRUCTION OF ALL OUTLET STRUCTURES, INCLUDING DOWNSTREAM RIP -RAP APROI
PROTECTION.
10. THE CONTRACTOR SHALL NEXT STABILIZE EXPOSED SOILS BY HYDROSEEDING OR SEEDING OVER STRAW.
11. THE CONTRACTOR SHALLTHEN INSTALL THE APPROPRIATE BASIN LANDSCAPING IN ACCORDANCE WITH THE APPROVED PLANS.
FACILITY MAINTENANCE:
MAINTENANCE OF THE DETENTION BASIN IS DRIVEN BY ANNUAL INSPECTIONS THAT EVALUATE THE CONDITION AND PERFORMANCE
OF THE FACILITIES. 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 BASIN.
2. MONITOR THE GROWTH OF THE GROUNDCOVER AND ANY TREES AND SHRUBS PLANTED, AS APPLICABLE. RECORD THE SPECIES
AND THEIR APPROXIMATE COVERAGE, AND NOTE THE PRESENCE OF ANY INVASIVE PLANT SPECIES, AS APPLICABLE.
3. INSPECTTHE CONDITION OF STORMWATER INLETS TO THE BASIN FOR MATERIAL DAMAGE, EROSION OR UNDERCUTTING.
4. 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.
5. INSPECT BASIN OUTFALL CHANNEL FOR EROSION, UNDERCUTTING, RIP -RAP DISPLACEMENT, WOODY GROWTH, etc.
6. INSPECT CONDITION OF PRINCIPAL SPILLWAY AND RISER FOR EVIDENCE OF SPALLI NG, JOINT FAILURE, LEAKAGE, CORROSION OR
OTHER FAILURES.
7. INSPECT CONDITION OF ALL TRASH RACKS, REVERSE SLOPED PIPES OR FLASHBOARD RISERS FOR EVIDENCE OF CLOGGING,
LEAKAGE, DEBRIS ACCUMULATION OR OTHER FAILURES AS APPLICABLE.
8. 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.
9. INSPECT INTERNAL AND EXTERNAL SIDE SLOPES OF THE BASIN FOR EVIDENCE OF SPARSE VEGETATIVE COVER, EROSION, OR
SLUMPING.
10. OWNER OR CONTRACTOR SHALL MAKE NEEDED REPAIRS IMMEDIATELY.
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 CONTRACTO
WITH THE ENGINEER AND INSPECTOR DURING THE FOLLOWING STAGES OF THE 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. EXTENDED DETENTION BASIN INSTALLATION (e.g., INTERIM AND FINAL ELEVATIONS)
S. INSTALLATION OF THE EMBANKMENT, THE RISER/PRIMARY SPILLWAY, AND THE OUTLET STRUCTURE(s).
6. PLANTING PHASE (WITH AN EXPERIENCED LANDSCAPE ARCHITECT PRESENT/DIRECTING)
7. FINAL INSPECTION (DEVELOP A PUNCH LIST FOR FACILITY ACCEPTANCE) r JI
EMBANKMENT NOTES:
THE EMBANKMENT SHALL HAVE A COMPACTED CLAY CORE WITH A CUTOFF TRENCH & BE IN ACCORDANCE
WITH THE DETAILS SHOWN ON THIS SHEET. BERMS AND SPILLWAYS SHALL BE STABILIZED WITH EC-3 MATTING
& THE REMAINING DISTURBED SLOPES SHALL BE STABILIZED WITH EC-2 MATTING. ALL BERM FILL MATERIAL
SHALL CONSIST OF ML, CL, SC OR GC SOILS & BE FREE OF WOOD, ROOTS, ROCKS OR ANY OTHER NON
COMPACTING SOIL. COMPACTED FILL SHALL BE PROCTOR MAXIMUM DRY DENSITY ASTM D698 AND HAVE A
MINIMUM OF 9S% OF MAXIMUM DRY DENSITY AND 2%OF OPTIMUM MOISTURE CONTENT. ALL FILL
MATERIAL AND CONSTRUCTION SHALL BE APPROVED BY AN ONSITE GEOTECHNICAL ENGINEER PRESENT
DURING THE CONSTRUCTION OF THE EMBANKMENTS AND FILL AREAS.
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5/8" dia hole
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orifice
DEBRIS CAGE
STEEL WEIR PLATE TO BE -
FASTENED OVER THE 15"
OUTLET OPENING,
COVERING THE TOP HALF OF
THE OUTLET OPENING.
SEAL OPENINGS AROUND
THE PLATE WITH MORTAR
TO CREATE A WATER -TIGHT
PLATE OVER THE OPENING.
INSTALL STEPS IN EX. RISEF
STRUCTURE IF THE STEPS
HAVE NOT PREVIOUSLY
BEEN INSTALLED. '
48" RISER
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1/2" zinc plated hook
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N.T.S.
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HDPF sI.-eickirml pinsl.ic with
2-1/8" holes and 1/4' plate
manufactured by Plastic
Solutions Inc or equal
PLASTIC
SOLUTIONS
INC.
P.O. Box '1386
Caches., W 22604
877-877-5727
•ra.Phistw-Mohw.esom
Perforated
SECTION A-9: TYPICAL GRAPHICAL DETAILS
Homogeneous fill
4 ��CDt oft trench,-b' below suil4�lel
material
Soil air rock L - - _ - __ - - - - - - J
TYPICAL HOMOGENEOUS
EMBANKMENT
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CHIMNEY DRAIN
Transition fill
- Rock or gravel
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BLANKET DRAIN
Rode or gravel
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TOE DRAIN
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