SW3191105_Millbridge Phase 7E State Stormwater Wet Detention Basin Supplement_12/3/2019

SUPPLEMENT-EZ FORM COVER PAGE
Please indicate the types, quantities and locations of SCMs that will be used on this project:
Quantity
Location(s)
Infiltration System
0
Bioretention Cell
0
Wet Pond
3
Stormwater Wetland
0
Permeable Pavement
0
Sand Filter
0
Rainwater Harvesting
0
Green Roof
0
Level Spreader -Filter Strip
0
Disconnected Impervious Surface
0
Treatment Swale
0
Dry Pond
1 0
Designer information for this project:
Name and Title:
Organization:
Street address:
City, State, Zip:
Phone number(s):
Email:
Designer
Weston Boles, PE
WK Dickson & Co. Inc.
616 Colonnade Drive
Charlotte, NC 28205
704.334.5348
[e-mail]
Signature of Designer
Date
Applicant:
NEB
Project Name:
Millbridge Phase 7E
Address
City i Town
Waxhaw, North Carolina
Company:
Landeavor, LLC
Contact:
Brad Heavner
Mailing Address:
9101 Southern Pine Blvd. Suite 210
City, State, Zip:
Charlotte, NC 28273
Phone number(s):
704.525.5998
Email:
[e-mail]
Certification Statement:
I certify, under penalty of law: that this Supplement-EZ form and all supporting
information were prepared under my direction or supervision;
- that the information provided in the form is, to the best of my knowledge
and belief, true, accurate, and complete; and
- that the engineering plans, specifications, operation and maintenance
agreements and other supporting information are consistent with
the information provided here.
I am aware that there are significant penalties for submitting false
information including the possibility of fines and imprisonment for knowing
violations as well as a report being made to my professional board.
Cover Page 1 4:34 PM 11/12/2019

WET POND
Millbridge Phase 7E
THE DRAINAGE AREA
Drainage area number
1
Break down of BUA in the drainage area (both new and existing):
Total coastal wetlands area (sq ft)
00 sf
Parking / driveway (sq ft)
Total surface water area (sq ft)
00 sf
Sidewalk (sq ft)
Total drainage area (sq ft)
565206 sf
Roof (sq ft)
BUA associated with existing development (sq ft)
00 sf
Roadway (sq ft)
Proposed new BUA (sq ft)
56643 sf
Other, please specify in the comment box below (sq ft)
Percent BUA of drainage area
1 10.02 %
ITotal BUA (sq ft)
56643 sf
COMPLIANCE WITH THE APPLICABLE STORMWATER PROGRAM
Stormwater program(s) that apply (please specify):
Design rainfall depth (in)
1.0 in
Phase II Post -Construction Stormwater
Minimum volume required (cu ft)
6603 cf
Design volume of SCM (cu ft)
6603 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
#2 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
#3 Does the SCM have retaining walls, gabion walls or other engineered side slopes?
No
#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
#5 Is there a a bypass for flows in excess of the design flow?
Yes
1#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?
Pump (preferred)
1#13 Was the SCM designed by an NC licensed professional?
Yes
WET POND MDC FROM 02H .1053
#1 Method used
SA/DA
#6 Width of the vegetated shelf (feet)
6 It
#1 Surface area of the main permanent pool (square feet)
10333 sf
#6 Location of vegetated shelf
@ Normal Pool
#1 Volume of the main permanent pool (cubic feet)
56038 cf
#6 Elevation of top of shelf (fmsl)
567.00 ft
#2 Average depth of the main pool (feet)
5.0 It
#6 Elevation of bottom of shelf (fmsl)
566.00 ft
#2 Was the vegetated shelf included in the calculation of average depth?
Yes
#6 Slope of vegetated shelf (H:V)
6:1
#2 Elevation of the bottom of the permanent pool (fmsl)
558.00 ft
#7 Diameter of drawdown orifice (inches)
1.75 in
#2 Elevation of the top of the permanent pool (fmsl)
566.50 ft
#7 Drawdown time for the temporary pool (hours)
72 hrs
#2 Elevation of the top of the temporary pool (fmsl)
566.61 ft
#7 Does the orifice drawdown from below the top surface of the permanent pool?
No
#3 Depth provided for sediment storage (inches)
12 in
#8 Does the pond minimize impacts to the receiving channel from the 1-yr, 24-hr storm?
Yes
#4 Are the inlet(s) and outlet located in a manner that avoids short-circuiting?
Yes
#9 Are fountains proposed?
No
#4 Describe any measures, such as berms or baffles, that will be taken to improve the flow path:
#9 If yes, is documentation provided per Wet Pond MDC (9)?
Forebay Berm Provided
#10 Is a trash rack or other device provided to protect the outlet system?
Yes
#5 Volume of the forebay (cubic feet)
10529
#11 Are the dam and embankment planted in non -clumping turf grass?
Yes
#5 Is this 15-20% of the volume in the main pool?
Yes
#11 Species of turf that will be used on the dam and embankment
Bermuda
#5 Depth of forebay at entrance (inches)
54 in
911 Describe the planting plan for the vegetated shelf:
#5 Depth of forebay at exit (inches)
54 in
See planting details in construction documents prepared by W.K. Dickson and Company.
#5 Does water flow out of the forebay in a non -erosive manner?
Yes
#5 Clean -out depth for forebay (inches)
12 in
#5 Will the forebay be cleaned out when the depth is reduced to less than the above?
Yes
ADDITIONAL INFORMATION
Please use this space to provide any additional information about this wet pond that you think is relevant to the review:
Wet Pond 2 4:34 PM 11/12/2019

WET POND
Millbridge Phase 7E
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)
00 sf
Parking / driveway (sq ft)
Total surface water area (sq ft)
.00 sf
Sidewalk (sq ft)
Total drainage area (sq ft)
421172 sf
Roof (sq ft)
BUA associated with existing development (sq ft)
00 sf
Roadway (sq ft)
Proposed new BUA (sq ft)
196324 sf
Other, please specify in the comment box below (sq ft)
Percent BUA of drainage area
146.61 %
ITotal BUA (sq ft)
196324 sf
COMPLIANCE WITH THE APPLICABLE STORMWATER PROGRAM
Stormwater program(s) that apply (please specify):
IDesign rainfall depth (in)
1.0 in
Phase II Post -Construction Stormwater
IMinimurn volume required (cu ft)
16479 cf
Design volume of SCM (cu ft)
16479 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
#2 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
#3 Does the SCM have retaining walls, gabion walls or other engineered side slopes?
No
#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
#5 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
#6 What is the method for dewatering the SCM for maintenance?
Pump (preferred)
1#13 Was the SCM designed by an NC licensed professional?
Yes
WET POND MDC FROM 02H .1053
#1 Method used
SA/DA
#6 Width of the vegetated shelf (feet)
6 It
#1 Surface area of the main permanent pool (square feet)
7384 sf
#6 Location of vegetated shelf
@ Normal Pool
#1 Volume of the main permanent pool (cubic feet)
26958 cf
#6 Elevation of top of shelf (fmsl)
559.00 ft
#2 Average depth of the main pool (feet)
3.50 ft
#6 Elevation of bottom of shelf (fmsl)
558.00 ft
#2 Was the vegetated shelf included in the calculation of average depth?
Yes
#6 Slope of vegetated shelf (H:V)
6:1
#2 Elevation of the bottom of the permanent pool (fmsl)
553.00 ft
#7 Diameter of drawdown orifice (inches)
2.50 in
#2 Elevation of the top of the permanent pool (fmsl)
558.50 ft
#7 Drawdown time for the temporary pool (hours)
48 hrs
#2 Elevation of the top of the temporary pool (fmsl)
559.05 ft
#7 Does the orifice drawdown from below the top surface of the permanent pool?
No
#3 Depth provided for sediment storage (inches)
12 in
#8 Does the pond minimize impacts to the receiving channel from the 1-yr, 24-hr storm?
Yes
#4 Are the inlet(s) and outlet located in a manner that avoids short-circuiting?
Yes
#9 Are fountains proposed?
No
#4 Describe any measures, such as berms or baffles, that will be taken to improve the flow path:
#9 If yes, is documentation provided per Wet Pond MDC (9)?
Forebay Berm Provided
#10 Is a trash rack or other device provided to protect the outlet system?
Yes
#5 Volume of the forebay (cubic feet)
5030
#11 Are the dam and embankment planted in non -clumping turf grass?
Yes
#5 Is this 15-20% of the volume in the main pool?
Yes
#11 Species of turf that will be used on the dam and embankment
Bermuda
#5 Depth of forebay at entrance (inches)
54 in
#11 Describe the planting plan for the vegetated shelf:
#5 Depth of forebay at exit (inches)
54 in
See planting details in construction documents prepared by W.K. Dickson and Company.
#5 Does water flow out of the forebay in a non -erosive manner?
Yes
#5 Clean -out depth for forebay (inches)
12 in
#5 Will the forebay be cleaned out when the depth is reduced to less than the above?
I Yes
ADDITIONAL INFORMATION
Please use this space to provide any additional information about this wet pond that you think is relevant to the review:
Wet Pond 3 4:34 PM 11/12/2019

WET POND
Millbridge Phase 7E
THE DRAINAGE AREA S
Drainage area number
3
Break down of BUA in the drainage area (both new and existing):
Total coastal wetlands area (sq ft)
00 sf
Parking / driveway (sq ft)
Total surface water area (sq ft)
00 sf
Sidewalk (sq ft)
Total drainage area (sq ft)
300642 sf
Roof (sq ft)
BUA associated with existing development (sq ft)
.00 sf
Roadway (sq ft)
Proposed new BUA (sq ft)
132885 sf
Other, please specify in the comment box below (sq ft)
Percent BUA of drainage area
14420 %
jTotal BUA (sq ft)
132885 sf
COMPLIANCE WITH THE APPLICABLE STORMWATER PROGRAM
Stormwater program(s) that apply (please specify):
IDesign rainfall depth (in)
1.0 in
Phase II Post -Construction Stormwater
IMinimurn volume required (cu ft)
11219 cf
Design volume of SCM (cu ft)
11219 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
#2 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
#3 Does the SCM have retaining walls, gabion walls or other engineered side slopes?
No
#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
#5 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
#6 What is the method for dewatering the SCM for maintenance?
Pump (preferred)
1#13 Was the SCM designed by an NC licensed professional?
Yes
WET POND MDC FROM 02H .1053
#1 Method used
SA/DA
#6 Width of the vegetated shelf (feet)
6 It
#1 Surface area of the main permanent pool (square feet)
7151 sf
#6 Location of vegetated shelf
@ Normal Pool
#1 Volume of the main permanent pool (cubic feet)
23357 cf
#6 Elevation of top of shelf (fmsl)
569.00 ft
#2 Average depth of the main pool (feet)
3.50 ft
#6 Elevation of bottom of shelf (fmsl)
568.00 ft
#2 Was the vegetated shelf included in the calculation of average depth?
Yes
#6 Slope of vegetated shelf (H:V)
6:1
#2 Elevation of the bottom of the permanent pool (fmsl)
564.00 ft
#7 Diameter of drawdown orifice (inches)
2.00 in
#2 Elevation of the top of the permanent pool (fmsl)
568.50 ft
#7 Drawdown time for the temporary pool (hours)
48 hrs
#2 Elevation of the top of the temporary pool (fmsl)
568.94 ft
#7 Does the orifice drawdown from below the top surface of the permanent pool?
No
#3 Depth provided for sediment storage (inches)
12 in
#8 Does the pond minimize impacts to the receiving channel from the 1-yr, 24-hr storm?
Yes
#4 Are the inlet(s) and outlet located in a manner that avoids short-circuiting?
Yes
#9 Are fountains proposed?
No
#4 Describe any measures, such as berms or baffles, that will be taken to improve the flow path:
#9 If yes, is documentation provided per Wet Pond MDC (9)?
Forebay Berm Provided
#10 Is a trash rack or other device provided to protect the outlet system?
Yes
#5 Volume of the forebay (cubic feet)
4341
#11 Are the dam and embankment planted in non -clumping turf grass?
Yes
#5 Is this 15-20% of the volume in the main pool?
Yes
#11 Species of turf that will be used on the dam and embankment
Bermuda
#5 Depth of forebay at entrance (inches)
54 in
#11 Describe the planting plan for the vegetated shelf:
#5 Depth of forebay at exit (inches)
54 in
See planting details in construction documents prepared by W.K. Dickson and Company.
#5 Does water flow out of the forebay in a non -erosive manner?
Yes
#5 Clean -out depth for forebay (inches)
12 in
#5 Will the forebay be cleaned out when the depth is reduced to less than the above?
Yes
ADDITIONAL INFORMATION
Please use this space to provide any additional information about this wet pond that you think is relevant to the review:
Wet Pond 4 4:34 PM 11/12/2019