HomeMy WebLinkAboutStormwater - D53 - BIORETENTION POND (PDF) -1.CONTRACTOR SHALL INSTALL BIORETENTION BASINS ACCORDING TO THE APPROVED PLANS AND/OR
CONSTRUCTION SPECIFICATIONS.
2.PRE-CONSTRUCTION
2.1.CONTRACTOR SHALL AVOID COMPACTION OF THE BIORETENTION BASIN AREA TO PRESERVE EXISTING
INFILTRATION RATES.
2.2.CONTRACTOR SHALL CALL FOR CITY INSPECTIONS AT THE INTERVALS STIPULATED IN THE "DURING
CONSTRUCTION INSPECTION CHECKLISTS".
3.DURING CONSTRUCTION:
3.1.CONTRACTOR SHALL PROVIDE CONSTRUCTION OBSERVATION DURING CONSTRUCTION OF THE BIORETENTION
BASIN TO ENSURE COMPLIANCE WITH THE APPROVED PLANS AND DESIGN SPECIFICATIONS.
3.2.LOOSE MATERIALS SHALL NOT BE STORED ON THE BIORETENTION AREA.
3.3.THE CONTRACTOR SHALL, AT ALL TIMES DURING AND AFTER SYSTEM INSTALLATION, PREVENT SEDIMENT,
DEBRIS AND DIRT FROM ANY SOURCE FROM ENTERING THE BIORETENTION SYSTEM.
4.GEOTEXTILE LINERS:
4.1.WHERE USED, GEOTEXTILE LINERS (PERMEABLE OR IMPERMEABLE AS PER PLAN) SHALL BE INSTALLED ALONG
PERIMETER OF CROSS-SECTION OF THE BIORETENTION CELL.
4.2.WHERE USED, GEOTEXTILE LINERS SHALL BE PLACED IN ACCORDANCE WITH MANUFACTURER'S STANDARDS AND
RECOMMENDATIONS. ALL SEAMS AND OPENINGS IN THE LINER SHALL BE SEALED ACCORDING TO
MANUFACTURER'S RECOMMENDATIONS AND SPECIFICATIONS.
4.3.WHERE USED, IMPERMEABLE GEOMEMBRANE SHEET / LINER SHALL BE 40 MIL THICK, HIGH-DENSITY
POLYETHYLENE DESIGNED SPECIFICALLY FOR FLEXIBLE GEOMEMBRANE APPLICATIONS. ADJACENT STRIPS OF
IMPERMEABLE LINER SHALL OVERLAP A MINIMUM OF 18", OR PER MANUFACTURER'S SPECIFICATION.
4.4.WHERE USED, CONTRACTOR TO PLACE LINER IN A WAY THAT ENSURES ENOUGH SLACK IN THE LINER TO ALLOW
FOR BACKFILL AND SETTLING WITHOUT TEARING THE LINER.
5.AGGREGATES AND BSM:
5.1.ALL AGGREGATES SHALL BE ANGULAR, CRUSHED, WASHED ROCK, CLEAN OF DEBRIS AND WITH NO MORE THAN
1% FINES.
5.2.RESERVOIR AGGREGATE SHALL BE GRADATION ASTM #57 OR #67.
5.3.DIAPHRAGM AGGREGATE SHALL BE "PEA GRAVEL", WITH GRADATION ASTM #8, #89 OR #9.
5.4.THE BIORETENTION SOIL SHALL MEET THE CITY BIORETENTION SAND MEDIA ("BSM") SPECIFICATION FOUND
AT:https://www.fcgov.com/utilities/business/builders-and-developers/development-forms-guidelines-regulations/
NOTES:
12" MAX1
MAXIMUM ALLOWABLE
PONDING DEPTH IS 12"
FROM THE TOP OF THE
MULCH
4 MAX
PONDING DEPTH MUST
NOT EXCEED FLOWLINE
ELEVATION OF ADJACENT
GUTTER8" MIN DEPTH THICKENED
CURB ADJACENT TO
VEHICULAR PAVEMENTS
OVERFLOW
RISER OPTION
(AS PER PLAN)
8" MIN DEPTH
THICKENED CURB
ADJACENT TO
VEHICULAR
PAVEMENTS
STANDARD CROSS-SECTION
1
2
WALLED CROSS-SECTION
PONDING DEPTH MUST
NOT EXCEED FLOWLINE
ELEVATION OF ADJACENT
GUTTER
18" MIN
4"
12" MAX
30" MIN
36" MIN
BASIN WIDTH
COVER PLATE
8"
SIDEWALK CHASE
18" MIN
OVERFLOW RISER
OPTION (AS PER PLAN)
REINFORCED
CONCRETE WALLS (AS
PER PLAN)
4" MIN DEPTH OF
DIAPHRAGM AGGREGATE
8" MIN DEPTH OF
RESERVOIR AGGREGATE
18" MIN DEPTH OF
BIORETENTION SAND MEDIA
MAXIMUM ALLOWABLE
PONDING DEPTH IS 12"
FROM THE SURFACE OF
THE MULCH
4" MIN DIAMETER
PERFORATED PVC
UNDERDRAIN
6.UNDERDRAIN:
6.1.UNDERDRAIN PIPE TO BE PERFORATED OR SLOTTED. PERFORATIONS OR SLOTS TO BE SMALLER THAN SURROUNDING AGGREGATE TO ENSURE AGGREGATE DOES NOT FALL INTO OR
CLOG THE OPENINGS.
6.2.DO NOT WRAP UNDERDRAIN WITH GEOTEXTILE OR SOCK.
6.3.UNDERDRAIN PIPE MUST OUTFALL BY GRAVITY AND MUST TIE INTO A STORMWATER PIPE, INLET OR SYSTEM AND THE LOCATION MUST BE APPROVED BY THE CITY. THE UNDERDRAIN
TIE-IN SHALL MEET ALL REQUIRED PIPE SIZE, TYPES, AND COVER REQUIREMENTS THAT MAY APPLY TO PIPING THAT EXTENDS BEYOND THE LIMITS OF THE BIORETENTION CELL AND
ENCROACHES INTO PUBLIC RIGHT-OF-WAY OR OTHER PROPERTY.
7.OVERFLOW INLET:
7.1.A 100-YEAR OVERFLOW SPILLWAY OR INLET MUST BE PROVIDED.
7.2.ALL OVERFLOW INLETS SHALL BE CAPPED WITH A DOME-SHAPED GRATE, OR PER PLAN.
7.3.IN ALL CASES, AN EMERGENCY OVERFLOW ROUTE SHALL BE PROVIDED AND THE LOCATION SHALL BE IDENTIFIED ON THE PLANS (THIS MAY BE COINCIDENT WITH THE 100-YEAR
OVERFLOW SPILLWAY).
8.CLEANOUTS:
8.1.PROVIDE CLEANOUTS (AS PER PLAN) TO ALLOW INSPECTION (BY CAMERA) OF THE UNDERDRAIN SYSTEM DURING AND AFTER CONSTRUCTION.
8.2.CLEANOUTS SHALL BE PROVIDED AT EACH BEND GREATER THAN OR EQUAL TO 90° AND EVERY 100' ALONG A STRAIGHT RUN. CLEANOUT SHALL BE INSTALLED PER THE APPROVED
PLANS.
8.3.CLEANOUTS SHALL BE A SOLID WALL PVC STRUCTURE FOR ALL VERTICAL SECTIONS WITH FITTINGS TO CONNECT TO DISTRIBUTION AND UNDERDRAIN PIPING MATERIALS, AS
REQUIRED.
9.FOREBAY:
9.1.THE FOREBAY SHALL BE EASILY ACCESSIBLE WITH A HARD SURFACED BOTTOM FOR MAINTENANCE PURPOSES.
9.2.THE FOREBAY SHOULD NOT EXTEND INTO THE SAND MEDIA TO PREVENT ANY SETTLING OF THE FOREBAY.
10.LANDSCAPE MATERIALS
10.1.CONTRACTOR SHALL NOT PLACE WEED BARRIER ANYWHERE WITHIN THE BIORETENTION BASIN. IF MULCH IS PLACED IN THE BIORETENTION BASIN, IT MUST BE NON-FLOATABLE.
10.2.IF MULCH OR COBBLES ARE PLACED IN THE BIORETENTION BASIN, THE MAXIMUM ALLOWABLE WATER DEPTH OF 12" AND REQUIRED BASIN VOLUME MUST BE MEASURED FROM THE
TOP SURFACE OF THE MULCH OR COBBLE.
10.3.ROLLED TURF OR SOD IS NOT AN ALLOWABLE LANDSCAPE MATERIAL FOR BIORETENTION BASINS. LOW WATER CONSUMPTION LANDSCAPE PLANTINGS ARE PREFERRED FOR
BIORETENTION BASINS.
10.4.LANDSCAPE PLANTINGS SHALL NOT BE PLACED TO IMPEDE DRAINAGE INTO OR OUT OF THE BIORETENTION BASIN.
10.5.TEMPORARY IRRIGATION MAY BE INSTALLED TO ESTABLISH LANDSCAPING OR SEED IN THE BIORETENTION BASIN.2" MIN
8" MIN
4"
FLAT
FOREBAY IS REQUIRED TO
BE PLACED AT
CONCENTRATED INFLOW
LOCATIONS; PER PLANS
AND SITE SPECIFIC
DETAILS
LANDSCAPING TO BE
INSTALLED PER
APPROVED
LANDSCAPING PLAN
6"-12"
4" MIN DEPTH OF
DIAPHRAGM AGGREGATE
8" MIN DEPTH OF
RESERVOIR AGGREGATE
8" MIN 4" MIN DIAMETER
PERFORATED PVC
UNDERDRAIN
2" MIN
30" MIN
GEOTEXTILE
FABRIC OR LINER
(AS PER PLAN)18" MIN DEPTH OF
BIORETENTION SAND
MEDIA
NATIVE SOIL
ZONE
RUNDOWN OR SCOUR
PROTECTION NEEDED
ON SLOPES
8"
FLAT AREA - SEE DESIGN
PLANS FOR EXTENTS OF
BIORETENTION FLAT
SURFACES
APPROVED:
DRAWN BY:DETAILS
CONSTRUCTION DATE REVISED:
DETAILSTORMWATER
BIORETENTION
JUNE 2023
SAA
D-53