20070327 Ver 1_More Info Received_20070521

Weirbridge Village -Phase 1
Commercial Construction
Stormwater BMP Worksheets &
Calculations
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DENR -WATER QUALITY
WETLANDS AND SIURMWATER BRANCH

Project No. DWQ
(to be provided by DWQ)
DIVISION OF WATER QUALITY - 401 WET DETENTION BASIN WORKSHEET
DWQ Stormwater Management Plan Review:
A complete stormwater management plan submittal includes a wet detention basin worksheet for each basin, design
calculations, plans and specifications showing all basin and outlet structure details, and a fully executed operation
and maintenance agreement. An incomplete submittal package will result in a request for additional information and
will substantially delay final review and approval of the project.
L PROJECT INFORMATION (please complete the following information):
Project Name : Weirbridg_e Village -Phase 1 (Commercial Outlot #1) Asheville, North Carolina
Contact Person: Jeffrey L. Young , PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to:_Commercial-Outlot #1
Basin Bottom Elevation 2209 ft. (average elevation of the floor of the basin)
Permanent Pool Elevation 2212 ft. (elevation of the orifice invert out)
Temporary Pool Elevation 2217 ft. (elevation of the outlet structure invert in)
Permanent Pool Surface Area 2,688 sq. ft. (water surface area at permanent pool elevation)
Drainage Area 0.98 ac. (on-site and off-site drainage to the basin)
Impervious Area 0.78 ac. (on-site and off-site drainage to the basin)
Permanent Pool Volume 5 832 cu. ft. (combined volume of main basin and forebay)
Temporary Pool Volume 21 240 cu. ft. (volume detained on top of the permanent pool)
Forebay Volume 3 110 cu. ft.

SA/DA used 3.36 (surface area to drainage area ratio)
Diameter of Orifice 1_0 in. (draw down orifice diameter)
II. REQUIRED ITEMS CHECKLIST
The following checklist outlines design requirements per the Stormwater Best Management Practices manual
(N.C. Department of Environment, Health and Natural Resources, November 1995) and Administrative Code
Section: 15 A NCAC 2H .1008. Initial in the space provided to indicate the following design requirements have
been met and supporting documentation is attached. If a requirement has not been met, attach an explanation of
why.
Annlicants Initials
JLY The temporary pool controls runoff from the 1 inch storm event.
JLY The basin length to width ratio is greater than 3:1.
'The basin side slopes are no steeper than 3:1.
JLY A submerged and vegetated perimeter shelf at less than 6:1 is provided.
Vegetation to the permanent pool elevation is specified.
An emergency drain is provided to drain the basin.
JLY T'he permanent pool depth is between 3 and 6 feet (required minimum of 3 feet).
JLY The temporary pool draws down in 2 to 5 days.
JLY The forebay volume is approximately equal to 20% of the total basin volume.
JLY Sediment storage is provided in the permanent pool.
JLY Access is provided for maintenance.
A minimum 30-foot vegetative filter is provided at the outlet.
A site specific operation and maintenance (O&M) plan is provided.
A vegetation management/mowing schedule is provided in the O&M plan.
Semi-annual inspections are specified in the O&M plan.
A debris check is specified in the O&M plan to be performed after every storm event.
A specific sediment clean-out benchmark is listed (elevation or depth) in O&M plan.
A responsible party is designated in the O&M plan.
FORM SWG100 09/97 Page 1 of 1

Weirbridge Village -Phase 1 (Commercial Outlot #1)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Stormwater Wet Pond Calculations
Permanent pool depth = 3.0 feet
Impervious percentage (I): 80%
SA/DA ratio = 3.36
Drainage area (A): 0.98 ac (outlot #1)
SA = (3.36 / 100) " 0.98 ac = 0.032 ac (1434 sf) min.
Surface dimensions: 44 ft X 132 ft
Runoff coefficient (Rv) = 0.05 + (0.009 * 80) = 0.77
Design storm: 25-year, 24hour
Rainfall depth = 5.79 inches
Volume of runoff (V) = Rv * A'` (P/12)
_ (0.77)*(0.98 ac)*(43560 sf/ac)"(5.79 in)"(1in/12 in/ft)
= 15,860 cf
Forebay volume = 3,180 cf
Temporary pool surface area = 5,808 sf
Temporary pool depth = 5.0 ft
Permanent pool surface area = 2,688 sf
Permanent pool depth = 3.0 ft
Total wet pond depth = 8.0 feet
Orifice Design
Orifice Diameter = 1 inch (0.083 feet)
Orifice coefficient (C) = 0.60

g = 32.2 ft/sec2
Orifice Discharge Volume Drawdown Time
Discharge @ 5.0 feet of head (full pool) = 0.06 cfs 5,808 cf (24.8 hours)
Discharge @ 4.0 feet of head = 0.05 cfs 5,120 cf (28.4 hours)
Discharge @ 3.0 feet of head = 0.05 cfs 4,460 cf (24.8 hours)
Discharge @ 2.0 feet of head = 0.04 cfs 3,840 cf (26.7 hours)
Discharge Cad 1.0 feet of head = 0.03 cfs 3.248 cf (30.0 hours)
TOTAL DRAWDOWN TIME = 134.7 HOURS (5.6 DAYS)

Project No. DWQ
(to be provided by DWQ f
DIVISION OF WATER QUALITY - 401 WET DETENTION BASIN WORKSHEET
DWQ Stormwater Management Plan Review:
A complete stormwater management plan submittal includes a wet detention basin worksheet for each basin, design
calculations, plans and specifications showing all basin and outlet structure details, and a fully executed operation
and maintenance agreement. An incomplete submittal package will result in a request for additional information and
will substantially delay final review and approval of the project.
I. PROJECT INFORMATION (please complete the following information):
Project Name :_Weirbrid eg Village -Phase 1 (Commercial Outlot #2) Asheville, North Carolina
Contact Person: Jeffrey L. Young , PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Commercial-Outl_ot #2
Basin Bottom Elevation 2217 ft. (average elevation of the floor of the basin)
Permanent Pool Elevation 2220 ft. (elevation of the orifice invert out)
Temporary Pool Elevation 2225 ft. (elevation of the outlet structure invert in)
Permanent Pool Surface Area 2,688 sq. ft. (water surface area at permanent pool elevation)
Drainage Area 0.96 ac. (on-site and off-site drainage to the basin)
Impervious Area 0.77 ac. (on-site and off-site drainage to the basin)
Permanent Pool Volume 5 832 cu. ft. (combined volume of main basin and forebay)
Temporary Pool Volume 21,240 cu. ft. (volume detained on top of the permanent pool)
Forebay Volume 3 I1~ 0_ cu. ft.
SA/DA used 3.36 (surface area to drainage area ratio)
Diameter of Orifice 1.0 in. (draw down orifice diameter)
II. REQUIRED ITEMS CHECKLIST
The following checklist outlines design requirements per the Stormwater Best Management Practices manual
(N.C. Department of Environment, Health and Natural Resources, November 1995) and Administrative Code
Section: I S A NCAC 2H .1008. Initial in the space provided to indicate the following design requirements have
been met and supporting documentation is attached. If a requirement has not been met, attach an explanation of
why.
Annlicants Initials
JLY The temporary pool controls runoff from the 1 inch storm event.
JLY The basin length to width ratio is greater than 3:1.
The basin side slopes are no steeper than 3:1.
JLY A submerged and vegetated perimeter shelf at less than 6:1 is provided.
Vegetation to the permanent pool elevation is specified.
An emergency drain is provided to drain the basin.
JLY The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet).
JLY The temporary pool draws down in 2 to 5 days.
JLY The forebay volume is approximately equal to 20% of the total basin volume.
JLY Sediment storage is provided in the permanent pool.
JLY Access is provided for maintenance.
A minimum 30-foot vegetative filter is provided at the outlet.
A site specific operation and maintenance (O&M) plan is provided.
A vegetation management/mowing schedule is provided in the O&M plan.
Semi-annual inspections are specified in the O&M plan.
A debris check is specified in the O&M plan to be performed after every storm event.
A specific sediment clean-out benchmark is listed (elevation or depth) in O&M plan.
A responsible party is designated in the O&M plan.
FORM S WG 100 09/97 Page 1 of 1

Weirbridge Village -Phase 1 (Commercial Outlot #2)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Stormwater Wet Pond Calculations
Permanent pool depth = 3.0 feet
Impervious percentage (I): 80%
SA/DA ratio = 3.36
Drainage area (A): 0.96 ac (outlot #2)
SA = (3.36 / 100) * 0.96 ac = 0.032 ac (1405 sf) min.
Surface dimensions: 44 ft X 132 ft
Runoff coefficient (Rv) = 0.05 + (0.009 * 80) = 0.77
Design storm: 25-year, 24hour
Rainfall depth = 5.79 inches
Volume of runoff (V) = Rv'` A " (P/12)
_ (0.77)*(0.96 ac)*(43560 sf/ac)"(5.79 in)*(1 in/12 in/ft)
= 15,536 cf
Forebay volume = 3,110 cf
Temporary pool surface area = 5,808 sf
Temporary pool depth = 5.0 ft
Permanent pool surface area = 2,688 sf
Permanent pool depth = 3.0 ft
Total wet pond depth = 8.0 feet
Orifice Design
Orifice Diameter = 1 inch (0.083 feet)
Orifice coefficient (C) = 0.60
g = 32.2 ft/sec2
Orifice Discharge Volume Drawdown Time
Discharge @ 5.0 feet of head (full pool) = 0. 06 cfs 5,808 cf (24.8 hours)
Discharge @ 4.0 feet of head = 0.05 cfs 5,120 cf (28.4 hours)
Discharge @ 3.0 feet of head = 0.05 cfs 4,460 cf (24.8 hours)
Discharge @ 2.0 feet of head = 0.04 cfs 3,840 cf (26.7 hours)
Discharge a 1.0 feet of head = 0.03 cfs 3,248 cf (30.0 hours)
TOTAL DRAWDOWN TIME = 134.7 HOURS (5.6 DAYS)

Project No. DWQ
(to be provided by DWQ~
DIVISION OF WATER QUALITY - 401 WET DETENTION BASIN WORKSHEET
DWO Stormwater Management Plan Review:
A complete stormwater management plan submittal includes a wet detention basin worksheet for each basin, design
calculations, plans and specifications showing all basin and outlet structure details, and a fully executed operation
and maintenance agreement. An incomplete submittal package will result in a request for additional information and
will substantially delay fmal review and approval of the project.
I. PROJECT INFORMATION (please complete the following information):
Project Name : Weirbrid eg Village -Phase 1 (Commercial Outlot #3) Asheville, North Carolina
Contact Person: Jeffrey L. Young , PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Commercial-Outlot #3
Basin Bottom Elevation 2223 ft. (average elevation of the floor of the basin)
Permanent Pool Elevation 2226 ft. (elevation of the orifice invert out)
Temporary Pool Elevation 2231 ft. (elevation of the outlet structure invert in)
Permanent Pool Surface Area 1,456 sq. ft. (water surface area at permanent pool elevation)
Drainage Area 0.8 ac. (on-site and off-site drainage to the basin)
Impervious Area 0.64 ac. (on-site and off-site drainage to the basin)
Permanent Pool Volume 2,460 cu. ft. (combined volume of main basin and forebay)
Temporary Pool Volume _ 14,180 cu. ft. (volume detained on top of the permanent pool)
Forebay Volume 2 590 cu. ft.

SA/DA used 3.36 (surface area to drainage area ratio)
Diameter of Orifice 1_0 in. (draw down orifice diameter)
II. REQUIRED ITEMS CHECKLIST
The following checklist outlines design requirements per the Stormwater Best Management Practices manual
(N.C. Deparhnent of Environment, Health and Natural Resources, November 1995) and Administrative Code
Section: 15 A NCAC 2H .1008. Initial in the space provided to indicate the following design requirements have
been met and supporting documentation is attached. If a requirement has not been met, attach an explanation of
why.
Annlicants Initials
JLY The temporary pool controls runoff from the 1 inch storm event.
JLY The basin length to width ratio is greater than 3:1.
The basin side slopes are no steeper than 3:1.
JLY A submerged and vegetated perimeter shelf at less than 6:1 is provided.
Vegetation to the permanent pool elevation is specified.
An emergency drain is provided to drain the basin.
JLY The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet).
JLY The temporary pool draws down in 2 to 5 days.
JLY The forebay volume is approximately equal to 20% of the total basin volume.
JLY Sediment storage is provided in the permanent pool.
JLY Access is provided for maintenance.
A minimum 30-foot vegetative filter is provided at the outlet.
A site specific operation and maintenance (O&M) plan is provided.
A vegetation managemenbmowing schedule is provided in the O&M plan.
Semi-annual inspections are specified in the O&M plan.
A debris check is specified in the O&M plan to be performed after every storm event.
A specific sediment clean-out benchmark is listed (elevation or depth) in O&M plan.
A responsible party is designated in the O&M plan.
FORM SWG100 09/97 Page 1 0l?'1

Weirbridge Village -Phase 1 (Commercial Outlot #3)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Stormwater Wet Pond Calculations
Permanent pool depth = 3.0 feet
Impervious percentage (I): 80%
SA/DA ratio = 3.36
Drainage area (A): 0.8 ac (outlot #3)
SA = (3.36 / 100) " 0.8 ac = 0.027 ac (1170 sf) min.
Surface dimensions: 34 ft X 124 ft
Runoff coefficient (Rv) = 0.05 + (0.009 * 80) = 0.77
Design storm: 25-year, 24hour
Rainfall depth = 5.79 inches
Volume of runoff (V) = Rv * A * (P/12)
_ (0.77)*(0.8 ac)*(43560 sf/ac)*(5.79 in)"(1in/12 in/ft)
= 12,950 cf
Forebay volume = 2,590 cf
Temporary pool surface area = 4,216 sf
Temporary pool depth = 5.0 ft
Permanent pool surface area = 1,456 sf
Permanent pool depth = 3.0 ft
Total wet pond depth = 8.0 feet
Orifice Design
Orifice Diameter = 1 inch (0.083 feet)
Orifice coefficient (C) = 0.60

g = 32.2 ft/sec2
Orifice Discharge Volume Drawdown Time
Discharge @ 5.0 feet of head (full pool) = 0.06 cfs 4,216 cf (19.5 hours)
Discharge @ 4.0 feet of head = 0.05 cfs 3,600 cf (20.0 hours)
Discharge @ 3.0 feet of head = 0.05 cfs 3,016 cf (16.7 hours)
Discharge @ 2.0 feet of head = 0.04 cfs 2,464 cf (17.1 hours)
Discharge (a7 1.0 feet of head = 0.03 cfs 1.944 cf (18.0 hours)
TOTAL DRAWDOWN TIME = 91.3 HOURS (3.8 DAYS)

Project No. DWQ
(to be provided by DWQ)
DIVISION OF WATER QUALITY - 401 WET DETENTION BASIN WORKSHEET
DWQ Stormwater Management Plan Review:
A complete stormwater management plan submittal includes a wet detention basin worksheet for each basin, design
calculations, plans and specifications showing all basin and outlet structure details, and a fully executed operation
and maintenance agreement. An incomplete submittal package will result in a request for additional information and
will substantially delay fmal review and approval of the project.
L PROJECT INFORMATION (please complete the following information):
Project Name : Weirbrid eg Village -Phase 1 (Commercial Outlot #4) Asheville, North Carolina
Contact Person: Jeffrey L. Young , PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Commercial-Outlot #4
Basin Bottom Elevation 2225 ft. (average elevation of the floor of the basin)
Permanent Pool Elevation 2228 ft. (elevation of the orifice invert out)
Temporary Pool Elevation 2233 ft. (elevation of the outlet structure invert in)
Permanent Pool Surface Area 2,688 sq. ft. (water surface area at permanent pool elevation)
Drainage Area 1.2 ac. (on-site and off-site drainage to the basin)
Impervious Area 0.96 ac. (on-site and off-site drainage to the basin)
Permanent Pool Volume 5 800 cu. ft. (combined volume of main basin and forebay)
Temporary Pool Volume 22 475 cu. ft. (volume detained on top of the permanent pool)
Forebay Volume 3 900 cu. ft.

SA/DA used 3.36 (surface area to drainage area ratio)
Diameter of Orifice 1.0 in. (draw down orifice diameter)
II. REQUIRED ITEMS CHECKLIST
The following checklist outlines design requirements per the Stormwater Best Management Practices manual
(N.C. Department of Environment, Health and Natural Resources, November 1995) and Administrative Code
Section: 15 A NCAC 2H .1008. Initial in the space provided to indicate the following design requirements have
been met and supporting documentation is attached. If a requirement has not been met, attach an explanation of
why.
ADnlicants Initials
JLY The temporary pool controls runoff from the 1 inch storm event.
JLY The basin length to width ratio is greater than 3:1.
The basin side slopes are no steeper than 3:1.
JLY A submerged and vegetated perimeter shelf at less than 6:1 is provided.
Vegetation to the permanent pool elevation is specified.
An emergency drain is provided to drain the basin.
JLY The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet).
JLY The temporary pool draws down in 2 to 5 days.
JLY The forebay volume is approximately equal to 20% of the total basin volume.
JLY Sediment storage is provided in the permanent pool.
JLY Access is provided for maintenance.
A minimum 30-foot vegetative filter is provided at the outlet.
A site specific operation and maintenance (O&M) plan is provided.
A vegetation managemendmowing schedule is provided in the O&M plan.
Semi-annual inspections are specified in the O&M plan.
A debris check is specified in the O&M plan to be performed after every storm event.
A specific sediment clean-out benchmark is listed (elevation or depth) in O&M plan.
A responsible party is designated in the O&M plan.
FORM SWG100 09/97 Page 1 of 1

Weirbridge Village -Phase 1 (Commercial Outlot #4)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Stormwater Wet Pond Calculations
Permanent pool depth = 3.0 feet
Impervious percentage (I): 80%
SA/DA ratio = 3.36
Drainage area (A): 1.2 ac (outlot #4)
SA = (3.36 / 100) " 1.2 ac = 0.04 ac (1760 sf) min.
Surface dimensions: 44 ft X 132 ft
Runoff coefficient (Rv) = 0.05 + (0.009'` 80) = 0.77
Design storm: 25-year, 24hour
Rainfall depth = 5.79 inches
Volume of runoff (V) = Rv * A " (P/12)
_ (0.77)*(1.2 ac)"(43560 sf/ac)*(5.79 in)`(1 in/12 in/ft)
= 19,420 cf
Forebay volume = 3,900 cf
Temporary pool surface area = 5,808 sf
Temporary pool depth = 5.0 ft
Permanent pool surface area = 2,688 sf
Permanent pool depth = 3.0 ft
Total wet pond depth = 8.0 feet
Orifice Design
Orifice Diameter = 1 inch (0.083 feet)
Orifice coefficient (C) = 0.60

g = 32.2 ft/secZ
Orifice Discharge Volume Drawdown Time
Discharge @ 5.0 feet of head (full pool) = 0.06 cfs 5,808 cf (24.8 hours)
Discharge @ 4.0 feet of head = 0.05 cfs 5,120 cf (28.4 hours)
Discharge @ 3.0 feet of head = 0.05 cfs 4,460 cf (24.8 hours)
Discharge @ 2.0 feet of head = 0.04 cfs 3,840 cf (26.7 hours)
Discharge Cad 1.0 feet of head = 0.03 cfs 3.248 cf (30.0 hours)
TOTAL DRAWDOWN TIME = 134.7 HOURS (5.6 DAYS)

Weirbridge Village -Phase 2
Residential Construction
Sto rmwate r B M P Worksheets &
Calculations

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STORMWATER MANAGEMENT SYSTEM -PRELIMINARY SITE MAP ~~ ~~
Horse Shoe, North Carolina 28742-6739 BIORETENTION AREAS 8 WET DETENTION POND
~ PHONE: [phone] FAX: [phone] Hendersoville Roed, Asheville, North Caroline 28803 NOTTO~ ~~ ~+aor

Project No. DWQ
DIVISION OF WATER QUALITY - 401 WET DETENTION BASIN WORKSHEET
DWQ Stormwater Management Plan Review:
A complete stormwater management plan submittal includes a wet detention basin worksheet for each basin, design
calculations, plans and specifications showing all basin and outlet structure details, and a fully executed operation
and maintenance agreement. An incomplete submittal package will result in a request for additional information and
will substantially delay final review and approval of the project.
(to be provided by DWQ)
I. PROJECT INFORMATION (please complete the following information):
Project Name : Weirbrid eg Village -Phase 2 (Residential Component) Asheville, North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Residential-Phase 2
Basin Bottom Elevation 2210 ft. (average elevation of the floor of the basin)
Permanent Pool Elevation 2213 ft. (elevation of the orifice invert out)
Temporary Pool Elevation 2224 ft. (elevation of the outlet structure invert in)
Permanent Pool Surface Area 25 300 sq. ft. (water surface area at permanent pool elevation)
Drainage Area 15.5 ac. (on-site and off-site drainage to the basin)
Impervious Area 10.85 ac. (on-site and off-site drainage to the basin)
Permanent Pool Volume 24 300 cu. ft. (combined volume of main basin and forebay)
Temporary Pool Volume 196,090 cu. ft. (volume detained on top of the permanent pool)
Forebay Volume cu. ft.
SA/DA used
Diameter of Orifice
(surface area to drainage area ratio)
in. (draw down orifice diameter)
II. REQUIRED ITEMS CHECKLIST
The following checklist outlines design requirements per the Stormwater Best Management Practices manual
(N.C. Department of Environment, Health and Natural Resources, November 1995) and Administrative Code
Section: 15 A NCAC 2H .1008. Initial in the space provided to indicate the following design requirements have
been met and supporting documentation is attached. If a requirement has not been met, attach an explanation of
why.
Annlicants Initials
JLY The temporary pool controls runoff from the 1 inch storm event.
JLY The basin length to width ratio is greater than 3:1.
JLY The basin side slopes are no steeper than 3:1.
JLY A submerged and vegetated perimeter shelf at less than 6:1 is provided.
Vegetation to the permanent pool elevation is specified.
An emergency drain is provided to drain the basin.
JLY The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet).
JLY The temporary pool draws down in 2 to 5 days.
JLY The forebay volume is approximately equal to 20% of the total basin volume.
JLY Sediment storage is provided in the permanent pool.
JLY Access is provided for maintenance.
A minimum 30-foot vegetative filter is provided at the outlet.
A site specific operation and maintenance (O&M) plan is provided.
A vegetation management/mowing schedule is provided in the O&M plan.
Semi-annual inspections are specified in the O&M plan.
A debris check is specified in the O&M plan to be performed after every storm event.
A specific sediment clean-out benchmark is listed (elevation or depth) in O&M plan.
A responsible party is designated in the O&M plan.
FORM SWG100 09/97 Page 1 of 1

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Stormwater Wet Pond Calculations
Permanent pool depth = 3.0 feet
Impervious percentage (I): 70%
SA/DA ratio = 2.88
Drainage area (A): 15.5 ac (phase 2 -residential)
SA=(2.88/100)*15.5ac=0.45ac
Forebay area = 0.45 ac * 0.20 = 0.09 ac (3920 sf)
Runoff coefficient (Rv) = 0.05 + (0.009 " 70) = 0.68
Design storm: 25-year, 24hour
Rainfall depth = 5.79 inches
Volume of runoff (V) = Rv * A * (P/12)
_(0.68)'`(15.5 ac)*(43560 sf/ac)*(5.79 in)"(1in/12 in/ft)
= 221,500 cf
Area treated by bioretention areas = 7.0 acres (304,920 sf)
Volume treated by bioretention areas = (304,920 sf)*(1 in / 12 in/ft) = 25,410 cf
Volume entering wet pond (25-year, 24-hour storm) = 221,500 cf - 25,410 cf = 196,090 cf
Temporary pool volume = 196,090 cf
+ Permanent pool volume = 24.300 cf
Total pond volume = 220390 cf
Forebay volume = 44,000 cf
Temporary pool surface area = 25,300 sf (0.58 ac)
Temporary pool depth = 11.0 ft
Permanent pool surface area = 10,100 sf (0.23 ac)
Permanent pool surface depth = 3.0 ft
Total wet pond depth = 14.0 feet
Orifice Design
Orifice Diameter = 3 inches (0.25 feet)
Orifice coefficient (C) = 0.60

g = 32.2 ft/secZ
Orifice Discharge Volume Drawdown Time
Discharge @ 11.0 feet of head (full pool) = 0.78 cfs 25,300 cf (9.0 hours)
Discharge @ 10.0 feet of head = 0.75 cfs 24,000 cf (8.9 hours)
Discharge @ 9.0 feet of head = 0.71 cfs 22,700 cf (8.9 hours)
Discharge @ 8.0 feet of head = 0.67 cfs 21,400 cf (8.9 hours)
Discharge @ 7.0 feet of head = 0.62 cfs 20,200 cf (9.0 hours)
Discharge @ 6.0 feet of head = 0.58 cfs 19,000 cf (9.1 hours)
Discharge @ 5.0 feet of head = 0.53 cfs 17,700 cf (9.3 hours)
Discharge @ 4.0 feet of head = 0.47 cfs 16,600 cf (9.8 hours)
Discharge @ 3.0 feet of head = 0.41 cfs 15,400 cf (10.4 hours)
Discharge @ 2.0 feet of head = 0.33 cfs 14,300 cf (12.0 hours)
Discharge t'c.~ 1.0 feet of head = 0.24 cfs 13.250 cf (15 3 hours)
TOTAL DRAWDOWN TIME = 110.6 HOURS (4.6 DAYS)

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #1
Permanent Pool Elevation
Temporary Pool Elevation
2230.0 ft.
2230.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
1200 sq. ft.
0.26 ac.
0.26 ac.
0.95
10
5.1 fps
4 in.
>6.0 ft.
2.0 in./hr
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #1 Stormwater Bioretention Calculations
Drainage area (A): 11,365 sf (roof only)
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 " I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
_ (1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv'` A'` (P/12)
_ (0.95)*(11,365 sf)*(1in/12 in/ft)
= 900 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (900 cf)/(0.75 ft) = 1200 sf
Percentage of bioretention area to drainage area: 1200 sf / 11365 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C "` I * A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.26 acres
Q =(0.95)"(7.4 in/hr)*(0.26 ac)
Q = 1.8 cfs
Inlet pipe size: 8-inches (diameter)
cross-sectional area
= rr(radius)2
= 3.14"(4 in/12 in/ft) 2
= 0.35 sf
Inlet velocity: Q = V * A
1.8 cfs = V '` (0.35sf)
V = 5.1 fps
Rain garden dimensions: 80 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville, North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: !_828) 606-3480
For projects with multiple basins, specify which basin this worksheet applies to: Building #2 and Parking Lot
Permanent Pool Elevation
Temporary Pool Elevation
2234.0 ft.
2234.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
2090 sq. ft.
0.45 ac.
0.45 ac.
0.95
10
4.1 fps
4 in.
>6.0 ft.
2.0 in./hr
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #2 ~ Parking Lot Stormwater Bioretention Calculations
Drainage area (A): 19,800 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 * I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + ((% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A * (P/12)
_ (0.95)*(19,800 sf)*(1 in/12 in/ft)
= 1, 567 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (900 cf)/(0.75 ft) = 2,090 sf
Percentage of bioretention area to drainage area: 2090 sf / 19800 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C * I * A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.45 acres
Q = (0.95)*(7.4 in/hr)*(0.45 ac)
Q = 3.2 cfs
Inlet pipe size: 12-inches (diameter)
cross-sectional area
= rr(radius)Z
= 3.14*(6 in/12 in/ft) z
= 0.78 sf
Inlet velocity: Q = V * A
3.2 cfs = V * (0.78sf)
V = 4.1 fps
Rain garden dimensions: 70 feet x 30 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building#3
Permanent Pool Elevation
Temporary Pool Elevation
2243.0 ft.
2243.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
1200 sq. ft.
0.26 ac.
0.26 ac.
0.95
10
5.1 fps
4 in.
>6.0 ft.
2.0 in./hr
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a -equirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in~situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #3 Stormwater Bioretention Calculations
Drainage area (A): 11,365 sf (roof only)
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 * I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A * (P/12)
_ (0.95)*(11,365 sf)*(1in/12 in/ft)
= 900 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (900 cf)/(0.75 ft) = 1200 sf
Percentage of bioretention area to drainage area: 1200 sf / 11365 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C " I " A
C = 0.95
1 = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.26 acres
Q = (0.95)*(7.4 in/hr)*(0.26 ac)
Q=1.8cfs
Inlet pipe size: 8-inches (diameter)
cross-sectional area
= rr(radius)2
= 3.14'(4 in/12 in/ft) 2
= 0.35 sf
Inlet velocity: Q = V * A
1.8 cfs = V '' (0.35sf)
V = 5.1 fps
Rain garden dimensions: 40 feet x 30 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville North Carolina
Contact Person: Jeffrey L. Young. PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #4
Permanent Pool Elevation
Temporary Pool Elevation
2246.0 ft.
2246.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
1200 sq. ft.
0.26 ac.
0.26 ac.
0.95
10
5.1 fps
4 in.
>6.0 ft.
2.0 in./hr
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 inlhr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #4 Stormwater Bioretention Calculations
Drainage area (A): 11,365 sf (roof only)
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 * I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + ((% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A * (P/12)
_ (0.95)*(11,365 sf)*(1in/12 in/ft)
= 900 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (900 cf)/(0.75 ft) = 1200 sf
Percentage of bioretention area to drainage area: 1200 sf / 11365 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C * I * A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.26 acres
Q = (0.95)*(7.4 in/hr)*(0.26 ac)
Q = 1.8 cfs
Inlet pipe size: 8-inches (diameter)
cross-sectional area
= rr(radius)2
= 3.14*(4 in/12 in/ft) 2
= 0.35 sf
Inlet velocity: Q = V * A
1.8 cfs = V * (0.35sf)
V = 5.1 fps
Rain garden dimensions: 80 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #4 Parking
Permanent Pool Elevation
Temporary Pool Elevation
2240.0 ft.
2240.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
633 sq. ft.
0.14 ac.
0.14 ac.
0.95
10
5.0 fps
3 in.
>6.0 ft.
2.0 in./hr
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mourn

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #4 Parking Lot Stormwater Bioretention Calculations
Drainage area (A): 6,000 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 * I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A * (P/12)
_ (0.95)*(6,000 sf)*(1in/12 in/ft)
= 475 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (900 cf)/(0.75 ft) = 633 sf
Percentage of bioretention area to drainage area: 633 sf / 6000 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surtace layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C * I * A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.14 acres
Q = (0.95)*(7.4 in/hr)*(0.14 ac)
Q = 1.0 cfs
Inlet pipe size: 6-inches (diameter)
cross-sectional area
= rr(radius)2
= 3.14*(3 in/12 in/ft) z
= 0.20 sf
Inlet velocity: Q = V * A
1.o cfs = v * (o.2osfl
V = 5.0 fps
Rain garden dimensions: 45 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
1. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville North Carolina
Contact Person:_ Jeffrey L. Young, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #5
Permanent Pool Elevation
Temporary Pool Elevation
2246.0 ft.
2246.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
1200 sq. ft.
0.26 ac.
0.26 ac.
0.95
10
5.1 fps
4 in.
>6.0 ft.
2.0 in./hr.
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmgnt and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #5 Stormwater Bioretention Calculations
Drainage area (A): 11,365 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 * I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
_ (1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A " (P/12)
_ (0.95)*(11,365 sf)*(1in/12 in/ft)
= 900 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (900 cf)/(0.75 ft) = 1,200 sf
Percentage of bioretention area to drainage area: 1,200 sf / 11,365 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surtace layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C '` I " A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.26 acres
Q = (0.95)*(7.4 in/hr)'`(0.26 ac)
Q = 1.8 cfs
Inlet pipe size: 8-inches (diameter)
cross-sectional area
= rr(radius)Z
= 3.14*(4 in/12 in/ft)z
= 0.35 sf
Inlet velocity: Q = V " A
1.8 cfs = V " (0.35sf)
V = 5.1 fps
Rain garden dimensions: 80 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #5 & #6 Parking Lot
Permanent Pool Elevation
Temporary Pool Elevation
2236.0 ft.
2236.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
1200 sq. ft.
0.26 ac.
0.26 ac.
0.95
10
5.1 fps
4 in.
>6.0 ft.
2.0 in./hr
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at (east 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #5 ~ #6 Parking Lot Stormwater Bioretention Calculations
Drainage area (A): 11,215 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 " I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv'` A * (P/12)
_ (0.95)*(11,215 sf)*(1in/12 in/ft)
= 888 cf
Maximum storage depth within Bioretention area = 9 in (0.75 ft)
Bioretention area = (888 cf)/(0.75 ft) = 1,184 sf
Percentage of Bioretention area to drainage area: 1,184 sf / 11,215 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C * I " A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.26 acres
Q =(0.95)"(7.4 in/hr)*(0.26 ac)
Q=1.8cfs
Inlet pipe size: 8-inches (diameter)
cross-sectional area
= rr(radius)2
= 3.14*(4 in/12 in/ft)Z
= 0.35 sf
Inlet velocity: Q = V * A
1.8 cfs = V * (0.35sf)
V = 5.1 fps
Rain garden dimensions: 80 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville, North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #6
Permanent Pool Elevation
Temporary Pool Elevation
2232.0 ft.
2232.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
11. REQUIRED ITEMS CHECKLIST
1200 sq. ft.
0.26 ac.
0.26 ac.
0.95
10
5.1 fps
4 in.
>6.0 ft.
2.0 in./hr.
2.0-6.0 in./hr.
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The Bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6° ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the Bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #6 Stormwater Bioretention Calculations
Drainage area (A): 11,365 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 * I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv'` A * (P/12)
_ (0.95)*(11,365 sf)*(1in/12 in/ft)
= 900 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (900 cf)/(0.75 ft) = 1,200 sf
Percentage of bioretention area to drainage area: 1,200 sf / 11,365 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C * I " A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.26 acres
Q =(0.95)"(7.4 in/hr)`(0.26 ac)
Q = 1.8 cfs
Inlet pipe size: 8-inches (diameter)
cross-sectional area
= Tr(radius)Z
= 3.14*(4 in/12 in/ft)Z
= 0.35 sf
Inlet velocity: Q = V " A
1.8 cfs = V " (0.35sf)
V = 5.1 fps
Rain garden dimensions: 80 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
1. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville, North Carolina
Contact Person: Jeffrey L. Young. PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #7
Permanent Pool Elevation
Temporary Pool Elevation
2232.0 ft.
2232.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
11. REQUIRED ITEMS CHECKLIST
1200 sq. ft.
0.26 ac.
0.26 ac.
0.95
10
5.1 fps
4 in.
>6.0 ft.
2.0 in./hr.
2.0-6.0 in./hr.
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in wlsand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6° ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #7 Stormwater Bioretention Calculations
Drainage area (A): 11,365 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 " I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
_ (1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A * (P/12)
_ (0.95)*(11,365 sf)"(1in/12 in/ft)
= 900 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (900 cf)/(0.75 ft) = 1,200 sf
Percentage of bioretention area to drainage area: 1,200 sf / 11,365 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C " I * A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.26 acres
Q =(0.95)"(7.4 in/hr)*(0.26 ac)
Q = 1.8 cfs
Inlet pipe size: 8-inches (diameter)
cross-sectional area
= rr(radius)Z
= 3.14*(4 in/12 in/ft) 2
= 0.35 sf
Inlet velocity: Q = V * A
1.8 cfs = V * (0.35sf)
V = 5.1 fps
Rain garden dimensions: 80 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: j828) 606-3480
For projects with multiple basins, specify which basin this worksheet applies to: Building #7 Parking Lot
Permanent Pool Elevation
Temporary Pool Elevation
2231.0 ft.
2231.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
433 sq. tt.
0.09 ac.
0.09 ac.
0.95
10
3.0 fps
3 in.
>6.0 ft.
2.0 in./hr.
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #7 Parking Lot Stormwater Bioretention Calculations
Drainage area (A): 4,100 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 * I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
_ (1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv " A * (P/12)
_ (0.95)*(4,100 sf)*(1 in/12 in/ft)
= 325 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (325 cf)/(0.75 ft) = 433 sf
Percentage of bioretention area to drainage area: 433 sf / 4,100 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C " I * A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.09 acres
Q =(0.95)"(7.4 in/hr)*(0.09 ac)
Q = 0.6 cfs
Inlet pipe size: 6-inches (diameter)
cross-sectional area
= rr(radius)Z
= 3.14*(3 in/12 in/ft) z
= 0.20 sf
Inlet velocity: Q = V " A
0.6 cfs = V * (0.20sf)
V = 3.0 fps
Rain garden dimensions: 30 feet x 14 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville, North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #8 and Parking Lot
Permanent Pool Elevation
Temporary Pool Elevation
2230.0 ft.
2230.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
3068 sq. ft.
0.67 ac.
0.67 ac.
0.95
10
3.8 fps
6 in.
>6.0 ft.
2.0 in./hr.
2.0-6.0 in./hr.
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is speafied in plans.
JLY Planting soil meets minimum soil Specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #8 & Parking Lot Stormwater Bioretention Calculations
Drainage area (A): 29,065 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 " 1) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A " (P/12)
_ (0.95)*(29,065 sf)*(1 in/12 in/ft)
= 2, 300 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (2,300 cf)/(0.75 ft) = 3,068 sf
Percentage of bioretention area to drainage area: 3,068 sf / 29,065 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C * I '` A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.67 acres
Q =(0.95)`(7.4 in/hr)"(0.67 ac)
Q = 4.7 cfs
Inlet pipe size: 15-inches (diameter)
cross-sectional area
= rr(radius)Z
= 3.14*(7.5 in/12 in/ft)2
= 1.23 sf
Inlet velocity: Q = V " A
4.7 cfs=V*(1.23sf)
V = 3.8 fps
Rain garden dimensions: 205 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Comaonent) Asheville, North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: X828) 606-3480
For projects with multiple basins, specify which basin this worksheet applies to: Building #9 and Parking Lot
Permanent Pool Elevation
Temporary Pool Elevation
2230.0 ft.
2230.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
I1. REQUIRED ITEMS CHECKLIST
1880 sq. ft.
0.41 ac.
0.41 ac.
0.95
10
5.4 fps
4 in.
>6.0 ft.
2.0 in./hr
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requi-ement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is err®vided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #9 ~ Parking Lot Stormwater Bioretention Calculations
Drainage area (A): 17,800 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 * I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A * (P/12)
_ (0.95)*(17,800 sf)*(1in/12 in/ft)
= 1,409 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (1,409 cf)/(0.75 ft) = 1,880 sf
Percentage of bioretention area to drainage area: 1,880 sf / 17,800 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C * I * A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.41 acres
Q = (0.95)*(7.4 in/hr)*(0.41 ac)
Q = 2.9 cfs
Inlet pipe size: 10-inches (diameter)
cross-sectional area
= n(radius)2
= 3.14*(5 in/12 in/ft)2
= 0.54 sf
Inlet velocity: Q = V * A
2.9 cfs=V*(0.54sf)
V = 5.4 fps
Rain garden dimensions: 125 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville North Carolina
Contact Person: Jeffrey L. Young. PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #10 and Parking Lot
Permanent Pool Elevation
Temporary Pool Elevation
2226.0 ft.
2226.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
11. REQUIRED ITEMS CHECKLIST
1827 sq. ft.
0.40 ac.
0.40 ac.
0.95
10
5.2 fps
4 in.
>6.0 ft.
2.0 in./hr
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requin?ment has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #10 ~ Parking Lot Stormwater Bioretention Calculations
Drainage area (A): 17,300 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 * I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv " A * (P/12)
_ (0.95)*(17,300 sf)*(1in/12 in/ft)
= 1,370 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (1,370 cf)/(0.75 ft) = 1,827 sf
Percentage of bioretention area to drainage area: 1,827 sf / 17,300 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surtace Layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C " I * A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.40 acres
Q =(0.95)"(7.4 inlhr)"(0.40 ac)
Q = 2.8 cfs
Inlet pipe size: 10-inches (diameter)
cross-sectional area
= Tr(radius)2
= 3.14"(5 in/12 in/ft) 2
= 0.54 sf
Inlet velocity: Q = V * A
2.8 cfs = V * (0.54sf)
V = 5.2 fps
Rain garden dimensions: 122 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridae Village -Phase 2 (Residential Component) Asheville. North Carolina
Contact Person: Jeffrey L. Young. PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #11 and Parking Lot
Permanent Pool Elevation
Temporary Pool Elevation
2231.0 ft.
2231.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
11. REQUIRED ITEMS CHECKLIST
1552 sq. ft.
0.34 ac.
0.34 ac.
0.95
10
4.4 fps
4 in.
>6.0 ft.
2.0 in./hr
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An opAratiAn and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #11 ~ Parking Lot Stormwater Bioretention Calculations
Drainage area (A): 18,600 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009'` I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + ((% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv'` A'` (P/12)
_ (0.95)*(18,600 sf)*(1in/12 in/ft)
= 1,472 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (1,472 cf)/(0.75 ft) = 1,963 sf
Percentage of bioretention area to drainage area: 1,963 sf / 18,600 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C " I " A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.43 acres
Q =(0.95)"(7.4 in/hr)*(0.43 ac)
Q=3.Ocfs
Inlet pipe size: 12-inches (diameter)
cross-sectional area
= rr(radius)2
= 3.14*(6 in/12 in/ft)2
= 0.78 sf
Inlet velocity: Q = V * A
3.0 cfs = V " (0.78sf)
V = 3.8 fps
Rain garden dimensions: 130 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: (8281 606-3480
For projects with multiple basins, specify which basin this worksheet applies to: Buildin4 #12
Permanent Pool Elevation
Temporary Pool Elevation
2230.0 ft.
2230.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
1200 sq. ft.
0.26 ac.
0.26 ac.
0.95
10
5.1 fps
4 in.
>6.0 ft.
2.0 in./hr.
2.0-6.0 in./hr.
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #12 Stormwater Bioretention Calculations
Drainage area (A): 11,365 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 " I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A * (P/12)
_ (0.95)*(11,365 sf)*(1in/12 in/ft)
= 900 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (900 cf)/(0.75 ft) = 1,200 sf
Percentage of bioretention area to drainage area: 1,200 sf / 11,365 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C " I " A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.26 acres
Q = (0.95)*(7.4 in/hr)*(0.26 ac)
Q = 1.8 cfs
Inlet pipe size: 8-inches (diameter)
cross-sectional area = rr(radius)2
= 3.14"(4 in/12 in/ft) 2
= 0.35 sf
Inlet velocity: Q = V " A
1.8 cfs = V * (0.35sf)
V = 5.1 fps
Rain garden dimensions: 80 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville, North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #13
Permanent Pool Elevation
Temporary Pool Elevation
2236.0 ft.
2236.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
1200 sq. ft.
0.26 ac.
0.26 ac.
0.95
10
5.1 fps
4 in.
>6.0 ft.
2.0 in./hr.
2.0-6.0 in./hr.
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 inlhr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #13 Stormwater Bioretention Calculations
Drainage area (A): 11,365 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 * I) = 0.95
or
Rational Ccoefficient = ((% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv'` A * (P/12)
_ (0.95)*(11,365 sf)'`(1in/12 in/ft)
= 900 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (900 cf)/(0.75 ft) = 1,200 sf
Percentage of bioretention area to drainage area: 1,200 sf / 11,365 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C " I " A
C = 0.95
1 = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.26 acres
Q = (0.95)*(7.4 in/hr)*(0.26 ac)
Q = 1.8 cfs
Inlet pipe size: 8-inches (diameter)
cross-sectional area = ir(radius)Z
= 3.14*(4 in/12 in/ft) 2
= 0.35 sf
Inlet velocity: Q = V * A
1.8 cfs = V " (0.35sf)
V = 5.1 fps
Rain garden dimensions: 80 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville North Carolina
Contact Person: Jeffrey L. Youn4, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #14 and Parking Lot
Permanent Pool Elevation
Temporary Pool Elevation
2235.0 ft.
2235.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
1942 sq. ft.
0.42 ac.
0.42 ac.
0.95
10
5.4 fps
4 in.
>6.0 ft.
2.0 in./hr.
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that Under rains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #14 ~ Parking Lot Stormwater Bioretention Calculations
Drainage area (A): 18,400 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 " I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A " (P/12)
_ (0.95)"(18,400 sf)*(1 in/12 in/ft)
= 1,457 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (1,457 cf)/(0.75 ft) = 1,942 sf
Percentage of bioretention area to drainage area: 1,942 sf / 18,400 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C '` I " A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.42 acres
Q =(0.95)'`(7.4 in/hr)"(0.42 ac)
Q = 2.9 cfs
Inlet pipe size: 10-inches (diameter)
cross-sectional area
= Tr(radius)2
= 3.14*(5 in/12 in/ft)2
= 0.54 sf
Inlet velocity: Q = V * A
2.9 cfs = V '" (0.54sf)
V = 5.4 fps
Rain garden dimensions: 130 feet x 15 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville North Carolina
Contact Person: Jeffrey L. Younca. PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Building #15 and Parking Lot
Permanent Pool Elevation
Temporary Pool Elevation
2231.0 ft.
2231.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
1552 sq. ft.
0.34 ac.
0.34 ac.
0.95
10
4.4 fps
4 in.
>6.0 ft.
2.0 in./hr.
2.0-6.0 in./hr.
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. !f a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Building #15 8 Parking Lot Stormwater Bioretention Calculations
Drainage area (A): 14,700 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 " I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A * (P/12)
_ (0.95)*(14,700 sf)'`(1in/12 in/ft)
= 1,164 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (1,164 cf)/(0.75 ft) = 1,552 sf
Percentage of bioretention area to drainage area: 1,552 sf / 14,700 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C " I " A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.34 acres
Q = (0.95)*(7.4 in/hr)*(0.34 ac)
Q=2.4cfs
Inlet pipe size: 10-inches (diameter)
cross-sectional area
= rr(radius)2
= 3.14"(5 in/12 in/ft) z
= 0.54 sf
Inlet velocity: Q = V * A
2.4 cfs = V " (0.54sf)
V = 4.4 fps
Rain garden dimensions: 80 feet x 20 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 (Residential Component) Asheville, North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Clubhouse and Parking
Permanent Pool Elevation
Temporary Pool Elevation
2246.0 ft.
2246.75 ft.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
1340 sq. ft.
0.29 ac.
0.29 ac.
0.95
10
5.7 fps
4 in.
>6.0 ft.
2.0 in./hr
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Clubhouse and Parking Lot Stormwater Bioretention Calculations
Drainage area (A): 12,700 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009 * I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + [(% pervious area) x 0.25)]
=(1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv " A * (P/12)
_(0.95)"(12,700 sf)*(1 in/12 in/ft)
= 1005 cf
Maximum storage depth within bioretention area = 9 in (0.75 ft)
Bioretention area = (1005 cf)/(0.75 ft) = 1340 sf
Percentage of bioretention area to drainage area: 1340 sf / 12,700 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C * I * A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.29 acres
Q =(0.95)"(7.4 in/hr)*(0.29 ac)
Q = 2.0 cfs
Inlet pipe size: 8-inches (diameter)
cross-sectional area
= rr(radius)2
= 3.14*(4 in/12 in/ft)z
= 0.35 sf
Inlet velocity: Q = V * A
2.0 cfs = V " (0.35sf)
V = 5.7 fps
Rain garden dimensions: 90 feet x 15 feet with a forebay with energy dissipation
(two areas - 45 feet x 15 feet)
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

DWQ Project No.
DIVISION OF WATER QUALITY - BIORETENTION AREA WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: Weirbridge Village -Phase 2 {Residential Component) Asheville, North Carolina
Contact Person: Jeffrey L. Young, PE Phone Number: [phone]
For projects with multiple basins, specify which basin this worksheet applies to: Town Square
Permanent Pool Elevation
Temporary Pool Elevation
2242.0 tt.
2242.75 tt.
(elevation of the orifice invert out)
(elevation of the outlet structure invert in)
Bioretention Surface Area
Drainage Area
Impervious Area
Rational C Coefficient
Size
Inlet Velocity
Inlet flow depth
Depth to Ground Water
Planting Soil Infiltration Rate
In-Situ Soil Infiltration Rate
II. REQUIRED ITEMS CHECKLIST
1742 sq. ft.
0.38 ac.
0.38 ac.
0.95
10
5.0 fps
4 in.
>6.0 tt.
2.0 in./hr
2.0-6.0 in./hr
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(either 5% in w/sand under drain or 7% in w/o)
(the soil layer down to 4 feet)
(the soil layer below 4 feet or below the sand bed)
Initial in the space provided to indicate the following design requirements have been met and supporting documentation
is attached. If a requi-sment has not been met, attach an explanation of why. At a minimum, a complete stormwater
management plan submittal includes a worksheet for each BMP, design calculations, plans and specifications showing
all BMPs and outlet structure details, a detailed drainage plan and a fully executed operation and maintenance
agreement. An incomplete submittal package will result in a request for additional information and will substantially delay
final review and approval of the project.
Applicants Initials
JLY No vertical sand bed is proposed
JLY The bioretention area is at least 40 feet by 15 feet.
JLY Sheet flow is provided at inlet.
JLY Water table depth is greater than 6 feet.
JLY Minimum of 6" ponding is provided.
JLY The ponded area will draw down in less than 4 days.
JLY Planting soil infiltration rate is greater than 0.52 in/hr.
JLY The in-situ soil infiltration rate is greater than 0.2 in/hr.
A planting plan with species and densities is provided.
Mulch layer is specified in plans.
JLY Planting soil meets minimum soil specifications (NCDENR Stormwater Best Management
Practices Manual, April 1999)
JLY Plan details for the bioretention area provided.
JLY Plan details for the inlet and outlet are provided.
An operation and maintenance agreement signed and notarized by the responsible party is provided.
Please note that underdrains beneath the planting soil are acceptable in the Piedmont and Mountains

Weirbridge Village -Phase 2 (Residential Component)
1741 Hendersonville Road, Asheville, NC 28803
Stormwater Management System
May 15, 2007
Town Square Stormwater Bioretention Calculations
Drainage area (A): 16,500 sf
Depth of storm captured (P): 1 in
Impervious percentage (I): 100%
Runoff coefficient (Rv) = 0.05 + (0.009'` I) = 0.95
or
Rational Ccoefficient = [(% impervious area) x 0.95] + ((% pervious area) x 0.25)]
_ (1.00x0.95)+(0x0.25)
= 0.95
Volume of runoff (V) = Rv * A " (P/12)
_ (0.95)*(16,500 sf)*(1in/12 in/ft)
= 1, 306 cf
Maximum storage depth within Bioretention area = 9 in (0.75 ft)
Bioretention area = (1306 cf)/(0.75 ft) = 1,742 sf
Percentage of Bioretention area to drainage area: 1,742 sf / 16,500 sf = 10%
In-situ Soil Data
Clifton Clay Loam (8 to 15% slopes)
Profile: 0-10 inches yellowish red clay loam
10-34 inches red clay loam
34-79 inches yellowish red fine sandy loam saprolite
Depth to groundwater: More than 6.0 feet
Permeability: Moderate in the surface layer and subsoil and moderately
rapid in the underlying material
Peak flow for design storm (25-year)
Rational Method: Q = C * I " A
C = 0.95
I = 7.4 inches/hour (25-year, 5-minute duration)
A = 0.38 acres
Q =(0.95)"(7.4 in/hr)"(0.38 ac)
Q=2.7cfs
Inlet pipe size: 10-inches (diameter)
cross-sectional area
= rr(radius)2
= 3.14'`(5 in/12 in/ft)2
= 0.54 sf
Inlet velocity: Q = V " A
2.7 cfs = V " (0.54sf)
V = 5.0 fps
Rain garden dimensions: 70 feet x 25 feet with a forebay with energy dissipation
Planting media: 12% fines (silt+clay), 82-85% sand, 3-6% organic

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