SSW-SuppEZ-20170329-DEMLR-SW

BIORETENTION CELL
Trip) Cottages Phase 2
THE DRAINAGE AREA
7
Drainage area number
1
Break down of BUA in the drainage area (both new and existing):
Total coastal wetlands area (sq ft)
sf
- Parking / driveway (sq ft)
18970 sf
Total surface water area (sq ft)
sf
- Sidewalk (sq ft)
6671 sf
Total drainage area (sq ft)
217600 sf
- Roof (sq ft)
38720 sf
BUA associated with existing development (sq ft)
sf
- Roadway (sq ft)
36304 sf
Proposed new BUA (sq ft)
100665 sf
- Other, please specify in the comment box below (sq ft)
sf
Percent BUA of drainage area
46%
Total BUA (sq ft)
100665 sf
COMPLIANCE WITH THE APPLICABLE STORMWATER PROGRAM
Design rainfall depth (in)
1.0 in
Stormwater program(s) that apply (please specify):
Design rainfall depth (in)
1.0 in
GENERAL MDC FROM 02H.1050
Minimum volume required (cu ft)
Design volume of SCM (cu ft)
8349 cf
8523 cf
GENERAL MDC FROM 02H.1050
Yes
#7 If applicable, with the SCM be cleaned out after construction?
Yes
41 Is the SCM sized to treat the SW from all surfaces at build -out?
Yes
#7 If applicable, with the SCM be cleaned out after construction?
Yes
#2 Is the SCM located on or near contaminated soils?
No
#8 Does the mainetenance access comply with General MDC (8)?
Yes
43 What are the side slopes of the SCM (H:V)?
3:1
#9 Does the drainage easement comply with General MDC (9)?
Yes
#3 Does the SCM have retaining walls, gabion walls or other engineered side slopes?
Yes
#10 if the SCM is on a single family lot, does the plat comply with General MDC (10)?
Yes
#4 Are the inlets, outlets, and receiving stream protected from erosion (10 -year storm)?
Yes
#11 Is there an O&M Agreement that complies with General MDC (11)?
Yes
#5 Is there a a bypass for flows in excess of the design flow?
No
#12 Is there an O&M Plan that complies with General MDC (12)?
Yes
#6 What is the method for dewatering the SCM for maintenance?
Other
#13 Was the SCM designed by an NC licensed professional?
Yes
BIORETENTION CELL MDC FROM 02H .7052
#6 Percentage of medium to coarse washed sand by volume
88%
#1 SHWT elevation (fmsl)
587 ft
#6 Percentage of medium to coarse washed sand by volume
88%
#1 Bottom of the bioretention cell (fmsl)
591 ft
#6 Percentage of fines (silt and clay) by volume
8%
#1 Distance from bottom to SHWT (feet)
11793 sf
#6 Percentage of organic matter by volume
4%
#2 Surface area of the bioretention cell (square feet
11414 sf
#6 Type of organic material
mulch
#2 Design volume of the bioretention cell (cubic feet)
9230 cf
#7 Phosphorus Index (P -Index) of media (unitless)
25
#2 Ponding depth of the design storm (inches)
8 in
#8 Will compaction be avoided during construction?
Yes
#3 Is the bioretention cell used for peak attenuation?
Yes
#9 Will cell be maintained to a one inch/hour standard?
Yes
#3 Depth of peak attenuation over planting surface in
24 in
#10 Describe the planting plan:
#3 Height of peak attenuation outlet above the planting surface (in)
#4 Infiltration rate of the in situ will inch/hour
#4 Diameter of the underdrain pipes (it applicable)
8 in
2.0 in/hr
6 in
A combination of trees, shrubs, and herbaceous species to be used.
#4 Does the design include Internal Water Storage (IWS)?
Yes
#11 Depth of mulch, 'rf applicable (inches)
3 in
#4 if so, elevation of the top of the IWS (fmsl)
594 ft
#11 Type of mulch, if applicable
shredded hardwood
#4 Elevation of the planting surface (fmsl)
596 ft
#12 How many clean out pipes are being installed?
multiple
#5 Will the cell contain trees and shrubs?
Yes
#12 Briefly describe the pretreatment that will be used:
#5 Media depth 'inch I
36 in
Irock lined forebays
ADDITIONAL INFORMATION IF
I
review:
Please use this space to provide an additional information about this bioretention cell that you think
is relevant to the
review:
THE DRAINAGE AREA
2
Drainage area number
2
Break down of BUA in the drainage area (both new and existing):
Total coastal wetlands area (sq ft)
sf
- Parking / driveway (sq ft)
16233 sf
Total surface water area (sq ft)
sf
- Sidewalk (sq ft)
4773 sf
Total drainage area (sq ft)
200885 sf
- Roof (sq ft)
38720 sf
BUA associated with existing development (sq ft)
sf
- Roadway (sq ft)
32554 sf
Proposed new BUA (sq ft)
92280 sf
- Other, please specify in the comment box below (sq ft)
sf
Percent BUA of drainage area
46%
Total BUA (sq ft)
92280 sf
COMPLIANCE WITH THE APPLICABLE STORMWATER PROGRAM
Stormwater program(s) that apply (please specify):
Design rainfall depth (in)
1.0 in
Minimum volume required (cu it)
Design volume of SCM (cu ft)
7681 cf
GENERAL MDC FROM 02H.1050
#1 Is the SCM sized to treat the SW from all surfaces at build -out?
Yes
#7 If applicable, with the SCM be cleaned out after construction?
Yes
42 Is the SCM located on or near contaminated soils?
No
#8 Does the mainetenance access comply with General MDC (8)?
Yes
#3 What are the side slopes of the SCM (H:V)?
3:1
#9 Does the drainage easement comply with General MDC (9)?
Yes
43 Does the SCM have retaining walls, gabion walls or other engineered side slopes?
Yes
#10 If the SCM is on a single family lot, does the plat comply with General MDC (10)?
#4 Are the inlets, outlets, and receiving stream protected from erosion (10 -year storm)?
Yes
#11 Is there an O&M Agreement that complies with General MDC (11)?
Yes
45 Is there a a bypass for flows in excess of the design flow?
Yes
#12 Is there an O&M Plan that complies with General MDC (12)?
Yes
46 What is the method for dewatering the SCM for maintenance?
other
#13 Was the SCM designed by an NC licensed professional?
Yes
BIORETENTION CELL MDC FROM 02H.1052
#1 SHWT elevation (fmsl)
#6 Percentage of medium to coarse washed sand by volume
88%
#1 Bottom of the bioretention cell (fmsl)
587 ft
#6 Percentage of fines (silt and clay) by volume
8%
#1 Distance from bottom to SHWT (feet)
#6 Percentage of organic matter by volume
4%
#2 Surface area of the bioretention cell(square feel
11793 sf
#6 Type of organic material
mulch
#2 Design volume of the bioretention cell (cubic feet)
#7 Phosphorus Index (P -Index) of media (unitless)
25
#2 Ponding depth of the design storm (inches)
7 in
#8 Will compaction be avoided during construction?
Yes
#3 Is the bioretention cell used for peak attenuation?
Yes
#9 Will cell be maintained to a one inch/hour standard?
Yes
#3 Depth of peak attenuation over planting surface in
24 in
#10 Describe the planting plan:
#3 Height of peak attenuation outlet above the planting surface (in)
A combination of trees, shrubs, and herbaceous species to be used.
#4 Infiltration rate of the in situ soil inch/hour
#4 Diameter of the underdrain pipes (it applicable)
#4 Does the design include Internal Water Storage (IWS)?
#11 Depth of mulch, if applicable (inches)
3 in
#4 if so, elevation of the top of the IWS (fmsl)
M36in
#11 Type of mulch, if applicable
shredded hardwood
#4 Elevation of the planting surface (fmsl)
#12 How many clean out pipes are being installed?
multiple
#5 Will the cell contain trees and shrubs?
#12 Briefly describe the pretreatment that will be used:
#5 Media depth (inches)
rock lined forebay
ADDITIONAL INFORMATION
Please use this space to provide any additional information about this bioretention cell that you think is relevant to the
review:
Bioretention 1 9:32 AM 11/3/2017