20061214 Ver 2_Stormwater Info_20071001

WITHERS ~ RAVENEL
ENGINEERS I PLANNERS I SURVEYORS
September 28, 2007
NC-Division of Water Quality
Attn: Ms. Cyndi Karoly
2321 Crabtree Blvd.; Suite 250
Raleigh, North Carolina 27604
Re: Woodcreek - Tract F Phase -Stormwater Management Plan
W&R Project #: 02040232.55
DWQ Project #: 06-1214 ~ 2
Dear Ms. Karoly,
~~ ~~~~~', '1
~~ ~~
SGT 0 1 2007
t?ENR -WATER G3UAL; TY
PUN~~S ANp ~ MWATER BRANCH
As a condition of our4ol Certification, we are providing the Stormwater Management
Plan for the Woodcreek - Tract F Phase for your review and approval. Specifically, the
plans include the design of three BMPs required to treat Stormwater run-ofF. The
applicant will provide extended detention wetlands fortreatment. The signed 0 and M
agreements and the DWQ stormwaterworksheets are included with the attachments. We
are in the process of submittingthe plans to the Town of Holly Springs as well.
Please feel free to call if you have questions or require additional information to complete
your review.
Sincerely,
WITHERS &RAVENEL, INC.
C. Heath Wadsworth, PE
Attachments:
1) Signed 0 and M agreements (BMP #1, #2, and #3)
2) DWQ Stormwater worksheets (BMP #1, #2, and #3)
3) Stormwater Management Report (2 copies)
4) BMP design details in Report
5) Drainage Map in Report
iii MacKenan Drive i Cary, NC z75ii i tel: [phone] i fax: [phone] i www.withersraveneLcom
7040 Wrightsville Avenue i Suite lol i Wilmington, NC 28403 i tel: [phone] i fax: [phone]
1027 Sabbath Home Rd, SW i Supply, NC 28462 i tel: [phone] i fax: [phone]

DWQ Project No. O(p ~ ~ 2 1 ~'~' V 2
DIVISION OF WATER QUALITY - 401 EXTENDED DETENTION (and POCKET*) WETLAND WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name: WODDGR£~K. - ""fSZEk-T' ~ P(`t~SE
Contact Person: (' tiER~TN V-/A~DSWOZTFF Phone Number:
For projects with multiple basins, specify which basin this worksheet applies to: _]~
Permanent Pool Elevation 3 3 S ft. (elevation of the orifice invert out)
Temporary Pool Elevation 33Co•5 ft. (elevation of the outlet structure invert in)

Permanent Pool Surface Area S. 99 S sq. ft. (water surface area at permanent pool elevation)
Drainage Area S o I ac. (on-site and off-site drainage to the basin)
Impervious Area Co ac. (on-site and off-site drainage to the basin)
Forebay Surface Area 8 sq. ft. (at permanent pool elevation approximately 15%)*
Marsh 0"-9" Surface Area 2~ D°I $ sq. ft. (at permanent pool elevation approximately 35%)*
Marsh 9"-18" Surface Area Z, pq Q sq. ft. (at permanent pool elevation approximately 35%)*
Micro Pool Surface Area $ °Iq• 5 sq. ft. (at permanent pool elevation approximately 15%)*

Temporary Pool Volume 1D.T S~ cu. ft. (volume detained on top of the permanent pool)
SAIDA used 2. 1 D (surface area to drainage area ratio)*
Diameter of Orifice 2.O in. (draw down orifice diameter)
II. REQUIRED ITEMS CHECKLIST
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
~~ft/ The temporary pool controls runoff from the 1 inch rain.
GtFI~ The basin side slopes are no steeper than 3:1.
G/is/ A planting plan for the marsh areas with plant species and densities is provided.
1/rr,~ Vegetation above the permanent pool elevation is specified.
G~-An emergency drain is provided to drain the basin.
L },{~ The temporary pool draws down in 2 to 5 days.
L1h~ Sediment storage is provided in the permanent pool.
LNr~ A sediment disposal area is provided.
GJ~f+~/ Access is provided for maintenance.
Lflr/ A site specific, signed and notarized operation and maintenance agreement is provided.
6M~+/ The drainage area (including any offsite area) is delineated on a site plan.
L/~/L/ Access is provided for maintenance.
6<kJ Plan details for the wetland are provided .
L,t~lc,/ Plan details for the inlet and outlet are provided.
G,rft,/ A site specific operation and maintenance agreement, signed and notarized by the responsible parry is provided (see
http://h2o.ehnr.state.nc.us/ncwetland s/oand m.doc).
* Pocket Wetlands have different design parameters and are only assumed to remove 35% TSS -See pp. 19 and 20 of the NC DENR
stormwater BMP Manual, April 1999. 10% open water, 50% high marsh, 40% low marsh.
~ '>I~ W 14tr N'f~+F~D'~ R~E "DQ A-r N~ W >Ir 1~ TT u M f?

WETLAND DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT
- Woodcreek - Tract F Phase (BMP #1)
The wetland detention basin system is defined as the wetland detention basin, pretreatment including forebays
and the vegetated filter if one is provided.
Maintenance activities shall be performed as follows:
After every significant runoff producing rainfall event and at least monthly:
a. Inspect the wetland detention basin system for sediment accumulation, erosion, trash accumulation,
vegetated cover, and general condition.
b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within
2 to 5 days as designed.
2. Repair eroded areas immediately, re-seed as necessary to maintain good vegetative cover, mow
vegetative cover to maintain a maximum height of six inches, and remove trash as needed.
3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to
maintain proper functioning.
4. Remove accumulated sediment from the wetland detention basin system semi-annually or when depth is
reduced to 75% of the original design depth (see diagram below). Removed sediment shall be disposed
of in an appropriate manner and shall be handled in a manner that will not adversely impact water quality
(i.e. stockpiling near a wetland detention basin or stream, etc.).
The measuring device used to determine the sediment elevation shall be such that it will give an accurate
depth reading and not readily penetrate into accumulated sediments.
If the elevation of the marsh areas exceeds the permanent pool elevation, the sediment should be
removed to design levels. This shall be performed by removing the upper 6 inches of soil and stockpiling
it. Then the marsh area shall be excavated six inches below design elevations. Afterwards the stockpiled
soil should be spread over the marsh surface. The soil should not be stockpiled for more than two weeks.
When the permanent pool depth reads Z , Z S feet in the forebay and micro-pool, the sediment shall be
removed.
BASIN DIAGRAM
(fill in the blanks)
Permanent Pool Elevation 3 3 5
Sediment Removal EI.
--------------*--
Bottom E vation 33Z I ;
FOREBAY/ Micro-pool
75%
- - Sediment Removal Elevation N A 75%
------------------------------- ------
MAIN POND
5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These
plants shall be encouraged to grow along the vegetated shelf and forebay berm.
Page 1 of 2

5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These
plants shall be encouraged to grow along the vegetated shelf and forebay berm.
6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment
through the emergency drain shall be minimized to the maximum extent practical.
7. All components of the wet detention basin system shall be maintained in good working order.
8. Level spreaders or other structures that provide diffuse flow shall be maintained every six months. All
accumulated sediment and debris shall be removed from the structure, and a level elevation shall be
maintained across the entire flow spreading structure. Any down gradient erosion must be repaired and/or
replanted as necessary.
I acknowledge and agree by my signature below that I am responsible for the performance of the seven
maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any
changes to the system or responsible party.
Print name: Ginger Warner,
Title: Project Manager
Address: 140 Tower View Court
Phone: 91
Signature
Date: 9/2~/~,
Note: The legally responsible party should not be a homeowners association unless more than 50% of the
lots have been sold and a resident of the subdivision has been named the president.
I, ~~~e (`(~e~~ ~ , a Notary Public for the State of North Carolina, County of
Wake, do hereby certify that Ginger Warner personally appeared before me this 28th day of September, 2007
and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness
my hand and official seal,
111uuuull/
~~.~~`~~~\E MEN/q~''%,
~, gyp..,,......,. ,,
,~ ••. ,;
~pTAR y'
.... ~- _
~~~'%~,F ~OUN~y~~~~~
~~///fll n 11111\1
SEAL
My commission expiresT~ J c7 , 2d I [~
Page 2 of 2

DWQ Project No. C7 to ' l Z I `( Y ~..
DIVISION OF WATER QUALITY - 401 EXTENDED DETENTION (and POCKET*) WETLAND WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name : In~pot, Gtz~EK - 'f~A~T' 1~ Pt{-~s>r
Contact Person: G. 1~'EA?N WA't>SWoZrH Phone Number: P°114) 23$-03 i
For projects with multiple basins, specify which basin this worksheet applies to: RM 1° #I< 3
Permanent Pool Elevation 32.5 ft. (elevation of the orifice invert out)
Temporary Pool Elevation _~, ft. (elevation of the outlet structure invert in)
Permanent Pool Surface Area
Drainage Area
Impervious Area
Forebay Surface Area
Marsh 0"-9" Surface Area
Marsh 9"-18" Surface Area
Micro Pool Surface Area
!o~ O $~q sq. ft.
if • y y ac.
~ ac.
O'•S sq. ft.
Z ~ t 21 sq. ft.
2~ 1 Z 1 sq. ft.
q O$• S sq. ft.
(water surface area at permanent pool elevation)
(on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
(at permanent pool elevation approximately 15%)*
(at permanent pool elevation approximately 35%)*
(at permanent pool elevation approximately 35%)*
(at permanent pool elevation approximately 15%)*
Temporary Pool Volume R, ~ Z7 cu. ft
SA/DA used Z . I $
Diameter of Orifice 2. o in.
II. REQUIRED ITEMS CHECKLIST
(volume detained on top of the permanent pool)
(surface area to drainage area ratio)*
(draw down orifice diameter)
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
Aoolicants Initials
L/b.J The temporary pool controls runoff from the 1 inch rain.
L11fW The basin side slopes are no steeper than 3:1.
GMv A planting plan for the marsh areas with plant species and densities is provided.
~.~,fr~ Vegetation above the permanent pool elevation is specified.
~k/ An emergency drain is provided to drain the basin.
/~ The temporary pool draws down in 2 to 5 days.
~/,k/ Sediment storage is provided in the permanent pool.
G}k/ A sediment disposal area is provided.
~1kJ Access is provided for maintenance.
h/t~ A site specific, signed and notarized operation and maintenance agreement is provided.
The drainage area (including any offsite area) is delineated on a site plan.
G/~/ Access is provided for maintenance.
1Nr/ Plan details for the wetland are provided.
GX~ Plan details for the inlet and outlet are provided.
L//d A site specific operation and maintenance agreement, signed and notarized by the responsible party is provided (see
http:l/h2o. eh nr.state. nc. us/ncwetland s/oand m.doc).
* Pocket Wetlands have different design parameters and are only assumed to remove 35% TSS -See pp. 19 and 20 of the NC DENR
stormwater BMP Manual, April 1999. 10% open water, 50% high marsh, 40% low marsh.

WETLAND DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT
- Woodcreek - Tract F Phase (BMP #3)
The wetland detention basin system is defined as the wetland detention basin, pretreatment including forebays
and the vegetated filter if one is provided.
Maintenance activities shall be performed as follows:
After every significant runoff producing rainfall event and at least monthly:
a. Inspect the wetland detention basin system for sediment accumulation, erosion, trash accumulation,
vegetated cover, and general condition.
b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within
2 to 5 days as designed.
2. Repair eroded areas immediately, re-seed as necessary to maintain good vegetative cover, mow
vegetative cover to maintain a maximum height of six inches, and remove trash as needed.
3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to
maintain proper functioning.
4. Remove accumulated sediment from the wetland detention basin system semi-annually or when depth is
reduced to 75% of the original design depth (see diagram below). Removed sediment shall be disposed
of in an appropriate manner and shall be handled in a manner that will not adversely impact water quality
(i.e. stockpiling near a wetland detention basin or stream, etc.).
The measuring device used to determine the sediment elevation shall be such that it will give an accurate
depth reading and not readily penetrate into accumulated sediments.
If the elevation of the marsh areas exceeds the permanent pool elevation, the sediment should be
removed to design levels. This shall be performed by removing the upper 6 inches of soil and stockpiling
it. Then the marsh area shall be excavated six inches below design elevations. Afterwards the stockpiled
soil should be spread over the marsh surface. The soil should not be stockpiled for more than two weeks.
When the permanent pool depth reads Z.2 ~ feet in the forebay and micro-pool, the sediment shall be
removed.
BASIN DIAGRAM
(fill in the blanks)
Permanent Pool Elevation 3 3~• 5
Sediment moval EI. 33oz 75%
- Sediment Removal Elevation '~ 75%
--------------- -
Bottom E vation 3Z .5 5%
ly o
FOREBAY/ Micro-pool MAIN POND
5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These
plants shall be encouraged to grow along the vegetated shelf and forebay berm.
Page 1 of 2

5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These
plants shall be encouraged to grow along the vegetated shelf and forebay berm.
6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment
through the emergency drain shall be minimized to the maximum extent practical.
7. All components of the wet detention basin system shall be maintained in good working order.
8. Level spreaders or other structures that provide diffuse flow shall be maintained every six months. All
accumulated sediment and debris shall be removed from the structure, and a level elevation shall be
maintained across the entire flow spreading structure. Any down gradient erosion must be repaired and/or
replanted as necessary.
I acknowledge and agree by my signature below that I am responsible for the performance of the seven
maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any
changes to the system or responsible party.
Print name: Ginger Warner.
Title: Project Manager
Address: 140 Tower View Court
Phone: 91
Signature:
Date: 9/22siu r
Note: The legally responsible party should not be a homeowners association unless more than 50% of the
lots have been sold and a resident of the subdivision has been named the president.
I, K ~~ ~ ~~,~~G , a Notary Public for the State of North Carolina, County of
Wake, do hereby certify that Ginger Warner personally appeared before me this 28th day of September, 2007
and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness
my hand and official seal,
`~~\\tlulunllllli%
~NorgAy~•
~z~
q~' UBLIG :`v.
''%, OOUN~~ ~ ,~~`~
////1111111111\\`
SEAL
My commission expires 1"f"D>1 I 10 ~ 2 0 l a
Page 2 of 2

DWQ Project No. O jp - ~ Z 1 `~ y
DIVISION OF WATER QUALITY • 401 EXTENDED DETENTION (and POCKET*) WETLAND WORKSHEET
I. PROJECT INFORMATION (please complete the following information):
Project Name : o o £ ~. - ~eFtvi' F PifASE-
Contact Person: G. }~A~T1~ wA~Swea-'~'~ Phone Number: (°l lq) Z3 $ -D3
For projects with multiple basins, specify which basin this worksheet applies to: ~3~'rl r'' t~ Z
Permanent Pool Elevation 3 3 3 ft. (elevation of the orifice invert out)
Temporary Pool Elevation 3 3'•1'."1 ft. (elevation of the outlet structure invert in)
Permanent Pool Surface Area Z 3Z sq. ft. (water surface area at permanent pool elevation)
Drainage Area ! Z. I S ac. (on-site and off-site drainage to the basin)
Impervious Area ac. (on-site and off-site drainage to the basin)
Forebay Surface Area 1 ~ sq. ft. (at permanent pool elevation approximately 15%)*
Marsh 0"-9" Surface Area 3.2 32 sq. ft. (at permanent pool elevation approximately 35%)*
Marsh 9"-18" Surface Area 3. Z~ Z. sq. ft. (at permanent pool elevation approximately 35%)*
Micro Pool Surface Area ~. 3~d `F sq. ft. (at permanent pool elevation approximately 15%)*
Temporary Pool Volume ~' / ~ S cu. ft. (volume detained on top of the permanent pool)
SA/DA used ~• lD3 (surface area to drainage area ratio)*
Diameter of Orifice Z• 5• in. (draw down orifice diameter)
II. REQUIRED ITEMS CHECKLIST
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
L.rft/ The temporary pool controls runoff from the 1 inch rain.
~~k/ The basin side slopes are no steeper than 3:1.
lN1J A planting plan for the marsh areas with plant species and densities is provided.
Lam.! Vegetation above the permanent pool elevation is specified.
Lah1 ~ An emergency drain is provided to drain the basin.
GMc/ The temporary pool draws down in 2 to 5 days.
G/tl/ Sediment storage is provided in the permanent pool.
GJlfl/ A sediment disposal area is provided.
GIkJ Access is provided for maintenance.
G,NY./ A site specific, signed and notarized operation and maintenance agreement is provided.
LNt/ The drainage area (including any offsite area) is delineated on a site plan.
L/1d Access is provided for maintenance.
G/fir~ Plan details for the wetland are provided .
Lrwi/ Plan details for the inlet and outlet are provided.
G,lks' A site specific operation and maintenance agreement, signed and notarized by the responsible party is provided (see
http://h2o.ehnr.state.nc.us/ncwetland s/oand m.doc).
* Pocket Wetlands have different design parameters and are only assumed to remove 35% TSS -See pp. 19 and 20 of the NC DENR
stormwater BMP Manual, April 1999. 10% open water, 50% high marsh, 40% low marsh.
~ wiL~ N>r,~ -ra 6F ~1=R~iIu E;D w tTH PAM P.

WETLAND DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT
- Woodcreek - Tract F Phase (BMP #2)
The wetland detention basin system is defined as the wetland detention basin, pretreatment including forebays
and the vegetated filter if one is provided.
Maintenance activities shall be performed as follows:
After every significant runoff producing rainfall event and at least monthly:
a. Inspect the wetland detention basin system for sediment accumulation, erosion, trash accumulation,
vegetated cover, and general condition.
b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within
2 to 5 days as designed.
2. Repair eroded areas immediately, re-seed as necessary to maintain good vegetative cover, mow
vegetative cover to maintain a maximum height of six inches, and remove trash as needed.
3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to
maintain proper functioning.
4. Remove accumulated sediment from the wetland detention basin system semi-annually or when depth is
reduced to 75% of the original design depth (see diagram below). Removed sediment shall be disposed
of in an appropriate manner and shall be handled in a manner that will not adversely impact water quality
(i.e. stockpiling near a wetland detention basin or stream, etc.).
The measuring device used to determine the sediment elevation shall be such that it will give an accurate
depth reading and not readily penetrate into accumulated sediments.
If the elevation of the marsh areas exceeds the permanent pool elevation, the sediment should be
removed to design levels. This shall be performed by removing the upper 6 inches of soil and stockpiling
it. Then the marsh area shall be excavated six inches below design elevations. Afterwards the stockpiled
soil should be spread over the marsh surface. The soil should not be stockpiled for more than two weeks.
When the permanent pool depth reads Z. Z S feet in the forebay and micro-pool, the sediment shall be
removed.
BASIN DIAGRAM
(fill in the blanks)
Permanent Pool Elevation 333
Sediment I~moval EI.33e•
Bottom E~vation 330 ~ ~5%
75%
Sediment Removal Elevation N~A~ 75%
------------------------------- ------
N
FOREBAY/ Micro-pool
MAIN POND
5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These
plants shall be encouraged to grow along the vegetated shelf and forebay berm.
Page 1 of 2

5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These
plants shall be encouraged to grow along the vegetated shelf and forebay berm.
6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment
through the emergency drain shall be minimized to the maximum extent practical.
7. All components of the wet detention basin system shall be maintained in good working order.
8. Level spreaders or other structures that provide diffuse flow shall be maintained every six months. All
accumulated sediment and debris shall be removed from the structure, and a level elevation shall be
maintained across the entire flow spreading structure. Any down gradient erosion must be repaired and/or
replanted as necessary.
I acknowledge and agree by my signature below that I am responsible for the performance of the seven
maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any
changes to the system or responsible party.
Print name: Ginger Warner.
Title: Project Manager
Address: 140 Tower View Court
Phor
Sign
Date. ~-co-~-
Note: The legally responsible party should not be a homeowners association unless more than 50% of the
lots have been sold and a resident of the subdivision has been named the president.
I, KC.~~i e_ ~>°~ i.4. , a Notary Public for the State of North Carolina, County of
Wake, do hereby certify that Ginger Warner personally appeared before me this 28th day of September, 2007
and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness
my hand and official seal,
\\\~,uiuniiuh-,,i
,.~~~~IE MEN
~.~ ........ , /q ''%
~pTgRy. ~~~,
p • `
~~~~''%F ~0 UN~~;,,~ ,.
SEAL
My commission expires~Dr~ 1 ~v ~ 2 pl D
Page 2 of 2

WITHERS ~~°~~' RAVEN EL
WOODCREEK - Tract F Phase
Stormwater Management Report
Holly Springs, North Carolina
Prepared For:
Colen E. Davidson
Impact Design-Build, Inc.
14o Towerview Court
Cary, NC 27513-3595
Prepared By:
WITHERS & RAVENEL, INC
111 MacKenan Drive
Cary, North Carolina 27511
OCR ~ I Zi1i;l
DENR - WATER QUv~.ITY
t+rlEn,~,~asnao stc;~~x~;aT~ mRnncn
September, Zoo?
W&R Project No. 02040232.55 ~""""°""""'~~,,,
.,ti
~~PoFE s o~~:
. N •'9
:~~ SEAL 9`'~ 07
~ 28421
F9 .Ql~.•• •~-
rH WAOS
~-
C. Heath Wadsworth, P.E.

WOODCREEK - Tract F Phase
Stormwater Management Report
Holly Springs, North Carolina
INTRODUCTION
The purpose of this study is to document the stormwater management plan for the Tract F Phase of
the proposed development in accordance with the 4oi Water Quality Certification and Authorization
Certificate's Additional Conditions (DWQ Project # o6-i2iq; designated as "Tract F" in Additional
Condition #7). The plan includes the design of three constructed wetlands in the Tract F Phase in
order to treat stormwater runoff. The site is located in the Neuse River Basin and all of the site
drainage is received by Middle Creek.
The proposed constructed wetlands are located adjacent to the Middle Creek floodplain and within
the vicinity of several existing wetlands. The constructed wetlands will be excavated into the
existing ground so that approximately z to i.5 feet of the normal pool depth is beneath the existing
ground surface. Due to the characteristics of the existing Augusta (Au) soils which have a
seasonably high watertable that is i.5 feet from the ground surface (Soil Survey of Wake County,
North Carolina - November i97o) and the presence of adjacent existing wetlands, it is anticipated
that the water table will contribute to the sustainability of the constructed wetlands' normal pool.
The low-profile design of the constructed wetlands made it necessary to use weir spillways instead
of riser spillway configurations, and will require pumping of the wetlands if maintenance is
WOODCREEK - Tract F Phase i W&R Project ozo4oz3z~55
Stormwater Management Report September z9, zoo7
Fgure i. Site outlined in red on 2005 Aerial Photography; the phase is shown in yellow

WOODCREEK - Tract F Phase
• Stormwater Management Report
Holly Springs, North Carolina

• necessary. The proposed design will allow the constructed wetlands to function in a mannerthat is
similarto the surrounding existing wetlands, and in conjunction with the existing natural wetland
filt
ti
ra
on water quality system.
The proposed constructed wetlands are designed to draw down the first inch of runoff over a 2 to 5
day period and sized according to the Division of Water Quality surface area requirements in order to
• achieve 85%Total Suspended Solids and 4o%total nitrogen reduction. The future phases of this
development that require Stormwater management will employ the use of constructed wetlands
,
bioretention areas, and/or wet detention basins followed by a forested filter strip in order to meet
• Water Quality Certification #3402 in order to manage Stormwater (from 4oi Water Quality
Certification the Tract D, Tract F, Tract J, and the Recreation Tract phases require a stormwater
l
management p
an). These BMPs will be designed and submitted at a later date.

• METHODOLOGY
• The stormwater study was conducted using the natural drainage features as depicted by the Wake
County aerial topographic information (2-ft contours), field survey data and proposed development
ithi
h
d
i
w
n t
e
ra
nage areas.
The scope of work included the following analyses:

Hydrology
^ Simulation of the io-year and ioo-year rainfall events for the Holly Springs area
• ^ Formulation of the io-year, and Zoo-year flood hydrographs for the proposed developed
drainage area

Hydraulic
^ Routing the Zo-year and ioo-year flood hydrographs for post development runoff through
• the proposed stormwater BMPs
The results of the hydrologic calculations are used in the hydraulic analyses. The hydraulic design
• requires the development of stage-storage and stage-discharge functions for the wet detention
basins. The rainfall/runoff hydrographs, stage-storage and stage-discharge functions have been
il
comp
ed to create a routing computer simulation model using Haestad Methods PondPack vio.o
• software. This PondPack model was then used to assess the impact of the peak discharges for the
design rainfall events. The PondPack modeling results are provided as appendices to this report.

• HYDROLOGY
The SCS Method was used to develop runoff hydrographs for the io-year and ioo-year storm events.
• NOAA Atlas 14 rainfall data for Raleigh-Durham International Airport was used to determine the 24-
hourduration rainfall for the io-year and ioo-year storm events. This method requires three basic
aram
t
p
e
ers: a curve number (CN), time of concentration (t~), and drainage area.

Curve numbers were based on soil type and land use. Soil types were delineated from the Soi(
S
f
k
urvey o
Wa
e County, North Carolina (November i97o). Land use data was determined using aerial
• photography and the most recent site plans for the proposed site. The curve numbers used in this
study are listed in the appendix of this report.

•
• WOODCREEK - Tract F Phase z W&R Project ozo4oz3z•55
Stormwater Management Report September 29, zoo?

•

WOODCREEK - Tract F Phase
Stormwater Management Report
Holly Springs North Carolina
HYDRAULICS
Computer simulated reservoir routing ofthe io-year, and ioo-year design storms utilized stage-
storageand stage-discharge functions. Stage-storage functions were derived from the proposed
contours for the constructed wetlands. Anon-linear regression relation for surface area versus
elevation was derived for the BMP. This relation estimates the incremental volume ofthe basin to
the stage or elevation of the basins. Stage-discharge functions were developed to size the outlet
structures for the wetlands.
CONCLUSIONS
Based on the routing study, the weir outlets proposed for the constructed wetlands pass the ioo-
yearstorm with at least one foot of freeboard. The results for the run are included in the appendix of
this report. The drainage area map on Sheet i of the appendix includes the outlet design for this
phase's BMPs. Planting schedules and more detailed design information are included on the
Construction Drawings submitted with this report.
WOODCREEK - Tract F Phase 3 W&R Project ozogoz3z•55
Stormwater Management Report September z9, zoo7

1
•
•
•
•
•
•
•
•
/ /,
i
4 Legend
Proposed Site Plan
'' ~-- Proposed Site Plan
Layer
t•.,,,,. WETLANDS
effective terra
FLOODZONE
AE
AEFW
SHADED X

F•1
~,
..
,.
BMP F-1:
(51% IMPERVIOUS)
2.0-IN DRAWDOWN ORFICE
N AT EL 335;
5 FT WEIR AT EL 336.5
WOODCREEK - TRACT F PHASE
-Constructed Wetlands Drainage Areas -
1 inch equals 150 feet
,;
i; _ , ''.'
o~~~
%DA F-3J
_i
MINIMUM WATER QUALITY DESIGN
BMP # DA (AC) NORMAL POOL
SURFACE (AC) NORMAL POOL
SURFACE (SF) W.Q. STORAGE VOLUME (AC-F~
ABOVE NORMAL POOL
F-i 5.oi o.io5 4590 o.2i4
F z i2.i5 0.198 86zo D.391
F 3 4.44 0.097 4zzo 0.197
ACTUAL DESIGN
BMP# DA (AC) NORMAL POOL
SURFACE (AC) NORMAL POOL
SURFACE (SF~ W.Q. STORAGE VOLUME (AC-FQ
ABOVE NORMAL POOL
Fi 5.oi Da38 5995 o.z4o
F-z iz.i5 o.2i2 9232 o.4i7
F-3 4.44 o.i39 6059 o.zzi
/I

~ v
o O
~''~ ".,
%~, ``;
BMPF2:
(37% IMPERVIOUS) V~,
2.5-IN DRAWDOWN ORFICE ~ ~
AT EL 333;
10 FT WEIR AT EL 334,7 ~ o O ~ Q
_~ ' BMP F-3:
(54% IMPERVIOUS)
2•IN DRAWDOWN ORFICE
AT EL 332.5;
4' X 4' RC RISER
WEIR AT EL 333.9
WITHERS ~` RAVENEL
.. ,r,~~ ~ a ~~nr~~ . ~~,-~~,.~~
111 MacKenan Drive Cary, North Carolina
telephone.[phone] w+N+.wRhersravenel.com

oC~--2,~~v2
BMP SIZING
CALCULATION S

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
BMP 1
Project Name: Woodcreek - Tract F Phase
City/State: Holly Springs, NC
Project #: 2040232.55
.Date: 28-Sep-07
Table 1.1 Surface Area to Drainage Area Ratio for Permanent Pool Sizing for 85% Pollutant
Ramnval Fffi~' .., f/.e D:o.~..,....s
Impervious
Cover Permanent Pool Depth (feet)
3.0 4.0 5.0 6.0 7.0 8.0 9.0
10 0.59 0.49 0.43 0.35 0.31 0.29 0.26
20 0.97 0.79 0.70 0.59 0.51 0.46 0.44
30 1.34 1.08 0.97 0.83 0.70 0.64 0.62
40 1.73 1.43 1.25 1.05 0.90 0.82 0.77
50 2.06 1.73 1.50 1.30 1.09 1.00 0.92
60 2.40 2.03 1.71 1.51 1.29 1.18 1.10
70 2.88 2.40 2.07 1.79 1.54 1.35 1.26
80 3.36 2.78 2.38 2.10 1.86 1.60 1.42
90 3.74 3.10 2.66 2.34 2.11 1.83 1.67
~~~~«~ ~~~~..~.~.,~~~~ „~~~~~w^iri °ex iv~anagemem rracnces, pg. 5, npru 7999
STORMWATER BMP F-1 -CONSTRUCTED WETLAND (85% TSS Removal 8r 40% TN Removal)

Land Use Area
(ac) % IA Imp. Area
(ac)
O en S ace 2.44 0 0.0
Im ervious (1/4 ac) 0 0 0.0
Impervious (1/8 ac) 2.57 100 2.6
Totals 5.01 2.6
Total % Impervious Surface Area = 51.3 °/
Normal Pool Depth 3 4 5 6 7 8 9
SA/DA Ratio 2.10 1.77 1.53 1.33 1.11 1.02 0.94
Minimum Surface Area Required
Acres 0.105 0.089 0.077 0.067 0.056 0.051 0.047
Sq. Ft 4589.09 3860.42 3344.32 2907.85 2432.56 2233.32 2050.24
Surface Area of Permanent Pool:
Assumed depth = 3 feet
SA/DA ratio = 2.10 % From Table 1.1
Minimum pond surface area (SA) _ (DA * SA/DA ratio)/100
SA = 0.105 acres
4589 sq. ft.
Normal pool elevation = 335.00 feet
Surface area provided = 0.138 acres
5995 sq. ft.
1-Inch Runoff Volume Calculation
Using the runoff volume calculations in the "Simple Method" as described by Schueler (1987)
Rv = 0.05 + 0.009(1) where, Rv =Runoff coefficient, in./in.
I =Percent impervious
Rv = 0.51 in./in.
Total runoff volume from 1-inch precipitation:
Runoff volume, S = (Design rainfall) (Rv) (Drainage Area)
S = 0.214 acre-ft
9306 cu. ft.

Project Name: Woodcreek - Tract F Phase
City/State: Holly Springs, NC
Project #: 2040232.6
Date: 28-Sep-07
STORMWATER BMP F-1 -CONSTRUCTED WETLAND (85% TSS Removal 8~ 40% TN Removal)
Orifice Calculator

Variables Constants
WQ Volume: 0.213625 Acre-ft 9305.505 cf g = 32.2 ft/s2
Head: 0.50 ft 0.25 ft Cd = 0.6
Draw down time: 48.4 hrs 174240 s
Orifice Area = 0.022183 sq. ft 3.194408 sq. in
Orifice Diameter = 2.02 in

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
BMP 2
Project Name• Woodcreek - Tract F Phase
City/State: Holly Springs, NC
Project #: 2040232.55
Date: 28-Sep-07
Table 1.1 Surface Area to Drainage Area Ratio for Permanent Pool Sizing for 85% Pollutant
Removal Effi['iPnc'v in tha Pin`tmnnt
Impervious
Cover Permanent Pool Depth (feet)
3.0 4.0 5.0 6.0 7.0 8.0 9.0
10 0.59 0.49 0.43 0.35 0.31 0.29 0.26
20 0.97 0.79 0.70 0.59 0.51 0.46 0.44
30 1.34 1.08 0.97 0.83 0.70 0.64 0.62
40 1.73 1.43 1.25 1.05 0.90 0.82 0.77
50 2.06 1.73 1.50 1.30 1.09 1.00 0.92
60 2.40 2.03 • 1.71 1.51 1.29 1.18 1.10
70 2.88 2.40 2.07 1.79 1.54 1.35 1.26
80 3.36 2.78 2.38 2.10 1.86 1.60 1.42
90 3.74 3.10 2.66 2.34 2.11 1.83 1.67
~~~~__~ ~~~.~..~.~~~~..~ ~~~~~~~wa~r~ oex rvianagemenr rraaices, pg. 5, npru iyyy
STORMWATER BMP F-2 -CONSTRUCTED WETLAND (85% TSS Removal 8r 40% TN Removal)

Land Use Area
(ac) % IA Imp. Area
(ac)
O en S ace 6.31 0 0.0
Im ervious (1/4 ac) 2 35 0.7
Impervious (1/8 ac) 3.84 100 3.84
Totals 12.15 4.54
Total % Impervious Surface Area = 37.4
Normal Pool De 3 4 5 6 7 8 9
SA/DA Ratio 1.63 1.34 1.18 0.99 0.85 0.77 0.73
Minimum Surface Area Required
Acres 0.198 0.163 0.143 0.121 0.103 0.094 0.089
Sq. Ft 8612.47 7080.46 6225.38 5250.50 4484.50 4088.98 3866.17
Surface Area of Permanent Pool:
Assumed depth = 3 feet
SA/DA ratio = 1.63 % From Table 1.1
Minimum pond surface area (SA) _ (DA * SA/DA ratio)/100
SA = 0.198 acres
8612 sq. ft.
Normal pool elevation = 333.00 feet
Surface area provided = 0.212 acres
9232 sq. ft.
1-Inch Runoff Volume Calculation
Using the runoff volume calculations in the "Simple Method" as described by Schueler (1987)
Rv = 0.05 + 0.009(1) where, Rv =Runoff coefficient, in./in.
=Percent impervious
Rv = 0.39 in./in.
Total runoff volume from 1-inch precipitation:
Runoff volume, S = (Design rainfall) (Rv) (Drainage Area)
S = 0.391 acre-ft
17037 cu. ft.

Project Name: Woodcreek - Tract F Phase
City/State: Holly Springs, NC
Project #: 2040232.6
Date: 28-Sep-07
STORMWATER BMP F-2 -CONSTRUCTED WETLAND (85% TSS Removal 8 40% TN Removal)
Orifice Calculator

Variables Constants
WQ Volume: 0.391125 Acre-ft 17037.41 cf g = 32.2 ft/sz
Head: 0.75 ft 0.375 ft Cd= 0.6
Draw down time: 47 hrs 169200 s
Orifice Area = 0.03415 sq. ft 4.917629 sq. in
Orifice Diameter = 2.50 in

BMP 3
Project Name: Woodcreek - Tract F Phase
C~/State: Holly Springs, NC
Project #: 2040232.55
Date: 28-Sep-07
Table 1.1 Surface Area to Drainage Area Ratio for Permanent Pool Sizing for 85% Pollutant
RPmnvat Ff{irianrv in tha Pinrlmnnf
Impervious
Cover Permanent Pool De
3.0 4.0 5.0 6.0 pth (feet)
7.0 8.0 9.0
10 0.59 0.49 0.43 0.35 0.31 0.29 0.26
20 0.97 0.79 0.70 0.59 0.51 0.46 0.44
30 1.34 1.08 0.97 0.83 0.70 0.64 0.62
40 1.73 1.43 1.25 1.05 0.90 0.82 0.77
50 2.06 1.73 1.50 1.30 1.09 1.00 0.92
60 2.40 2.03 1.71 1.51 1.29 1.18 1.10
70 2.88 2.40 2.07 1.79 1.54 1.35 1.26
80 3.36 2.78 2.38 2.10 1.86 1.60 1.42
90 3.74 3.10 2.66 2.34 2.11 1.83 1.67
aource:.vcutivivuwtl ~tormwater t5est Management Practices, pg. 5, April 1999
STORMWATER BMP F-3 -CONSTRUCTED WETLAND (85% TSS Removal & 40% TN Removal)

Land Use Area
(ac) % IA Imp. Area
(ac)
O en S ace 2.06 0 0.0
Im ervious (1/4 ac) 0 0 0.0
Impervious (1/8 ac) 2.38 100 2.4
Totals 4.44 2.4
Total % Impervious Surface Area = 53.6 %
Normal Pool Depth 3 4 5 6 7 8 9
SA/DA Ratio 2.18 1.84 1.59 1.39 1.16 1.06 0.97
Minimum Surface Area Required
Acres 0.097 0.082 0.071 0.062 0.051 0.047 0.043
Sq. Ft 4214.17 3555.02 3075.34 2688.52 2240.55 2059.52 1883.88
Surface Area of Permanent Pool:
Assumed depth = 3 feet
SA/DA ratio = 2.18 % From Table 1.1
Minimum pond surface area (SA) _ (DA * SA/DA ratio)/100
SA = 0.097 acres
4214 sq. k.
Normal pool elevation = 332.50 feet
Surface area provided = 0.139 acres
6059 sq. ft.
1-Inch Runoff Volume Calculation
Using the runoff volume calculations in the "Simple Method" as described by Schueler (1987)
Rv = 0.05 + 0.009(1) where, Rv =Runoff coefficient, in./in.
I =Percent impervious
Rv = 0.53 in./in.
Total runoff volume from 1-inch precipitation:
Runoff volume, S = (Design rainfall) (Rv) (Drainage Area)
S = 0.197 acre-ft
8581 cu. ft.

Project Name: Woodcreek - Tract F Phase
City/State: Holly Springs, NC
Project #: 2040232.6
Date: 28-Sep-07
STORMWATER BMP F-3 -CONSTRUCTED WETLAND (85% TSS Removal 8~ 40% TN Removal)
Orifice Calculator

Variables
WQ Volume:
Head:
Draw down time:
0.197 Acre-ft
0.50 ft
46.5 hrs
8581.32 cf
0.25 ft
167400 s
Constants
g=
Cd =
32.2 ft/s2
0.6
Orifice Area =
0.021293 sq. ft
3.066175 sq. in
Orifice Diameter = 1.98 in

RO UTI N G
CALCULATION S

Subarea 30
Subarea 10
0
a
a
Q
BMP F-1
,moo
w~
o,
~-
Out 10
Subarea 20
~4
d
0
BMP F-2
oI
N
O
Out 20
9
d~i~
~~
O
BMP F-3
0
~a
r
Out 30

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Table of Contents
Table of Contents
***+***********+*+**** MASTER SUMMARY **********+**+*+******
Watershed....... Master Network Summary ............. 1.01
****************** DESIGN STORMS SUMMARY *******************
RDU NOAA 14 Desi Design Storms ...................... 2.01
*********+*+********** TC CALCULATIONS **++**************+**
SUBAREA 10...... Tc Calcs ........................... 3.01
SUBAREA 20...... Tc Calcs ........................... 3.03
SUBAREA 30...... Tc Calcs ........................... 3.07
********************** CN CALCULATIONS *+*+*********+++*****
SUBAREA 10...... Runoff CN-Area ..................... 4.01
SUBAREA 20...... Runoff CN-Area ..................... 4.02
SUBAREA 30...... Runoff CN-Area ..................... 4.03
*************+********* POND VOLUMES ****+******************
i
BMP F-1......... Vol: Elev-Area ..................... 5.01
S/N: DOYXYWH3NLBE
PondPack (10.00.015.00)
4:55 PM
Withers & Ravenel
9/27/2007

Table of Contents
11
BMP F-2......... Vol: Elev-Area ..................... 5.02
BMP F-3......... Vol: Elev-Area ..................... 5.03
******************** OUTLET STRUCTURES *********************
Outlet F -1...... Outlet Input Data .................. 6.01
Outlet F -2...... Outlet Input Data .................. 6.03
Outlet F -3...... Outlet Input Data .................. 6.05
S/N: DOYXYWH3NLBE
PondPack (10.00.015.00)
4:55 PM
Withers & Ravenel
9/27/2007

Type.... Master Network Summary Page 1.01
Name.... Watershed
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
MASTER DESIGN STORM SUMMARY
Network Storm Collection: RDU NOAA 14 Desi
Total
Depth
Return Event in
2 3.4400
5 4.3000
10 4.9800
25 5.9000
50 6.6300
100 7.3700
1 3.0000
Rainfall
Type
Time-Depth Curve
Time-Depth Curve
Time-Depth Curve
Time-Depth Curve
Time-Depth Curve
Time-Depth Curve
Synthetic Curve
RNF ID
RDU NOAA 2yr
RDU NOAA Syr
RDU NOAA l0yr
RDU NOAA 25yr
RDU NOAA 50yr
RDU NOAA 100yr
TypeII 24hr
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID Type Event ac-ft Trun hrs cfs ft ac-ft
BMP F-1 IN POND 2 .663 12.1000 14.37
BMP F-1 IN POND 5 .957 12.1000 19.15
BMP F-1 IN POND 10 1.201 12.1000 22.93
BMP F-1 IN POND 25 1.591 12.1000 27.11
BMP F-1 IN POND 50 1.818 12.1000 29.67
BMP F-1 IN POND 100 2.103 12.1000 32.46
BMP F-1 IN POND 1 .522 11.9500 9.43
BMP F-1 OUT POND 2 .657 12.3500 3.21 336.85 .299
BMP F-1 OUT POND 5 .951 12.2500 8.76 337.20 .367
BMP F-1 OUT POND 10 1.194 12.2000 13.06 337.43 .412
BMP F-1 OUT POND 25 1.535 12.2000 17.64 337.64 .457
BMP F-1 OUT POND 50 1.812 12.1500 20.25 337.76 .481
BMP F-1 OUT POND 100 2.097 12.1500 22.53 337.85 .502
BMP F-1 OUT POND 1 .515 12.5500 .92 336.64 .261
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Master Network Summary Page 1.02
Name.... Watershed
File.... K:\04\04-230\04232.55-WOOdCreek Tract F\H-H\stormwater\ppack\TRF.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond Storage
Node ID Type Event ac-ft Trun hrs cfs ft ac-ft
BMP F-2 IN POND 2 1.275 12.1500 23.53
BMP F-2 IN POND 5 1.918 12.1500 33.13
BMP F-2 IN POND 10 2.463 12.1500 90.51
BMP F-2 IN POND 25 3.237 12.1000 49.47
BMP F-2 IN POND 50 3.872 12.1000 55.56
BMP F-2 IN POND 100 4.532 12.1500 61.18
BMP F-2 IN POND 1 .973 12.0000 16.29
BMP F-2 OUT POND 2 1.266 12.3500 6.99 335.07 .516
BMP F-2 OUT POND 5 1.910 12.2500 19.84 335.46 .631
BMP F-2 OUT POND 10 2.454 12.2000 29.24 335.69 .702
BMP F-2 OUT POND 25 3.228 12.2000 90.41 335.93 .780
BMP F-2 OUT POND 50 3.864 12.2000 46.65 336.06 .821
BMP F-2 OUT POND 100 4.529 12.2000 52.21 336.17 .857
BMP F-2 OUT POND 1 .965 12.6000 1.75 334.89 .450
BMP F-3 IN POND 2 .614 12.1000 13.32
BMP F-3 IN POND 5 .879 12.1000 17.57
BMP F-3 IN POND 10 1.098 12.1000 20.93
BMP F-3 IN POND 25 1.403 12.1000 24.61
BMP F-3 IN POND 50 1.651 12.1000 26.84
BMP F-3 IN POND 100 1.906 12.1000 29.30
BMP F-3 IN POND 1 .486 11.9500 8.79
BMP F-3 OUT POND 2 .608 12.2500 5.49 334.13 .256
BMP F-3 OUT POND 5 .873 12.2000 12.22 334.29 .286
BMP F-3 OUT POND 10 1.092 12.1500 17.95 334.90 .305
BMP F-3 OUT POND 25 1.397 12.1500 18.82 334.51 .326
BMP F-3 OUT POND 50 1.645 12.1500 19.03 334.61 .345
BMP F-3 OUT POND 100 1.899 12.2000 19.26 334.72 .367
BMP F-3 OUT POND 1 .479 12.3000 1.27 333.98 .231
S/N: DOYXYWH3NLBE
PondPack (10.00.015.00)
4:55 PM
Withers & Ravenel
9/27/2007

__

• Type.. .. Master Netw ork Summary Page 1.03
Name.. .. Watershed
• File.. .. K:\04\04-23 0\09232.55-WoodCreek Tract F\H-H\s tormwater\ppack\TRF.ppw
•

MASTER NETWORK SUMMARY
SCS Unit Hydrogra ph Method
*
( Node=Outfa ll; +Node =Diversion;)
• (Trun= HYG Tru ncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)

• Max

Node ID
T Return H
E YG Vol Qpeak Qpeak Max WSEL Pond Storage
ype vent ac-ft Trun hrs cfs ft ac-ft

• --------
*OUT 10 --- ------ ----
JCT ------ ---
2 -------
.657 -- -----
12.3500 --- ----
3.21 --------
• *OUT 10
* JCT 5 .951 12.2500 8.76
OUT 10 JCT 10 1.194 12.2000 13.06
• *oUT 10 JCT 25 1.535 12.2000 17.64
*OUT 10 JCT 50 1.812 12.1500 20.25
*OUT 10 JCT 100 2.097 12.1500 22.53
*OUT 10 JCT 1 .515 12.5500 .92
•
*oUT 20 JCT 2 1.266 12.3500 6.99
• *OUT 20 JCT 5 1.910 12.2500 19.84
• *OUT 20
* JCT 10 2.454 12.2000 29.24
OUT 20 JCT 25 3.228 12.2000 40.41
• *oUT 20
* JCT 50 3.864 12.2000 96.65
OUT 20 JCT 100 4.524 12.2000 52.21
• *OUT 20 JCT 1 .965 12.6000 1.75
• *oUT 30 JCT 2 .608 12.2500 5.49
*OUT 30 JCT 5 .873 12.2000 12.22
• *oUT 30 JCT 10 1.092 12.1500 17.95
*OUT 30 JCT 25 1.397 12.1500 18.82
• *OUT 30 JCT 50 1.645 12.1500 19.03
*OUT 30
*OUT 30 JCT 100 1.899 12.2000 19.26
JCT 1 .479 12.3000 1.27
•
SUBAREA 10 AREA 2 .663 12.1000 14.37
• SUBAREA 10 AREA 5 .957 12.1000 19.15
SUBAREA 10 AREA 10 1.201 12.1000 22.93
• SUBAREA 10 AREA 25 1.541 12.1000 27.11
SUBAREA 10 AREA 50 1.818 12.1000 29.67
SUBAREA 10 AREA 100 2.103 12.1000 32.46
SUBAREA 10 AREA 1 .522 11.9500 9.43
•
•
•
•
•
•
•

•

• S/N: D OYXYWH3NLBE Withers & Ravenel
PondPac k (10.00.015.0 0) 4:55 PM 9/27/2007
•
•
•

Type.... Master Network Summary Page 1.09
Name.... Watershed
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)
Return HYG Vol Qpeak Qpeak
Node ID Type Event ac-ft Trun hrs cfs
SUBAREA 20 AREA 2 1.275 12.1500 23.53
SUBAREA 20 AREA 5 1.918 12.1500 33.13
SUBAREA 20 AREA 10 2.463 12.1500 90.51
SUBAREA 20 AREA 25 3.237 12.1000 99.97
SUBAREA 20 AREA 50 3.872 12.1000 55.56
SUBAREA 20 AREA 100 4.532 12.1500 61.18
SUBAREA 20 AREA 1 .973 12.0000 16.29
SUBAREA 30 AREA 2 .619 12.1000 13.32
SUBAREA 30 AREA 5 .879 12.1000 17.57
SUBAREA 30 AREA 10 1.098 12.1000 20.93
SUBAREA 30 AREA 25 1.903 12.1000 29.61
SUBAREA 30 AREA 50 1.651 12.1000 26.84
SUBAREA 30 AREA 100 1.906 12.1000 29.30
SUBAREA 30 AREA 1 .486 11.9500 8.79
S/N: DOYXYWH3NLBE
PondPack (10.00.015.00) 4:55 PM
Max
Max WSEL Pond Storage
ft ac-ft
Withers & Ravenel
9/27/2007

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Type.... Design Storms
Name.... RDU NOAA 14 Desi
Page 2.01
File.... K:\04\04-230\04232.55-WOOdCreek Tract F\H-H\stormwater\ppack\TRF.ppw
Title... Project Date: 9/27/2007
Project Engineer: C. Heath Wadsworth
Project Title: Woodcreek - Tract F
Project Comments:
DESIGN STORMS SUMMARY
Design Storm File, ID = RDU NOAA 14 Desi
Storm Tag Name = 2
Data Type, File, ID
Storm Frequency
Total Rainfall Depth
Duration Multiplier
Resulting Duration
Resulting Start Time
Time-Depth Curve RDU NOAA 2yr
2 yr
3.4400 in
1
23.9904 hrs
.0000 hrs Step= .0833 hrs End= 23.9904 hrs
Storm Tag Name = 5
Data Type, File, ID = Time-Depth Curve RDU NOAA Syr
Storm Frequency = 5 yr
Total Rainfall Depth= 4.3000 in
Duration Multiplier = 1
Resulting Duration 23.9904 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9909 hrs
Storm Tag Name = 10
Data Type, File, ID = Time-Depth Curve RDU NOAA l0yr
Storm Frequency = 10 yr
Total Rainfall Depth= 4.9800 in
Duration Multiplier = 1
Resulting Duration = 23.9904 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9904 hrs
Storm Tag Name = 25
Data Type, File, ID = Time-Depth Curve RDU NOAA 25yr
Storm Frequency = 25 yr
Total Rainfall Depth= 5.9000 in
Duration Multiplier = 1
Resulting Duration = 23.9904 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9909 hrs
Storm Tag Name = 50
Data Type, File, ID = Time-Depth Curve RDU NOAA 50yr
Storm Frequency = 50 yr
Total Rainfall Depth= 6.6300 in
Duration Multiplier = 1
Resulting Duration = 23.9904 hrs
Resulting Start Time= .0000 hrs Step= .0833 hrs End= 23.9904 hrs
S/N: DOYXYWH3NLBE
PondPack (10.00.015.00)
Withers & Ravenel
4:55 PM
9/27/2007

Type.... Design Storms
Name.... RDU tdOAA 14 Desi
Page 2.02
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
Title... Project Date: 9/27/2007
Project Engineer: C. Heath Wadsworth
ProjE=_ct Title: Woodcreek - Tract F
Project Comments:
DESIGN STORMS SUMMARY
Design Storm File,ID = RDU NOAA 14 Desi
Storm Tag Name = 100
Data Type, File, ID
Storm Frequency
Total Rainfall Depth
Duration Multiplier
Resulting Duration
Resulting Start Time
Time-Depth Curve RDU NOAA 100yr
100 yr
7.3700 in
1
23.9990 hrs
.0000 hrs Step= .0833 hrs End= 23.9990 hrs
Storm Tag Name = 1
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 1 yr
Total Rainfall Depth= 3.0000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 9:55 PM 9/27/2007

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Type.... Tc Calcs
Name.... SUBAREA 10
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
...........................................................
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time: .0830 hrs
Total Tc: .0830 hrs
Calculated Tc < Min.Tc:
Use Minimum Tc...
Use Tc = .0833 hrs
-------------------------
-------------------------
Page 3.01
S/N: DOYXYWH3NLBE
PondPack (10.00.015.00)
4:55 PM
Withers & Ravenel
9/27/2007

Type.... Tc Calcs
Name.... SUBAREA 10
Page 3.02
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
Tc Equations used...
___= User Defined ------------------------------------------------------
Tc = Value entered by user
Where: Tc = Time of concentration
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

•
•
•
•
•
•
•
i
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Type.... Tc Calcs
Name.... SUBAREA 20
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
................................................................
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: TR-55 Sheet
Mannings n .1000
Hydraulic Length 96.00 ft
2yr, 24hr P 3.4400 in
Slope .041700 ft/ft
Avg.Velocity .32 ft/sec
Segment #1 Time: .0821 hrs
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 192.00 ft
Slope .091700 ft/ft
Unpaved
Avg.Velocity 4.89 ft/sec
Segment #2 Time: .0081 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Channel
Flow Area 2.0000 sq.ft
Wetted Perimeter 5.00 ft
Hydraulic Radius .40 ft
Slope .035000 ft/ft
Mannings n .0350
Hydraulic Length 314.00 ft
Avg.Velocity 9.32 ft/sec
Segment #3 Time: .0202 hrs
------------------------------------------------------------------------
Page 3.03
S/N: DOYXYWH3NLBE
PondPack (10.00.015.00)
4:55 PM
Withers & Ravenel
9/27/2007

Type.... Tc Calcs
Name.... SUBAREA 20
Page 3.04
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
Segment #9: Tc: TR-55 Channel
Flow Area 2.0000 sq.ft
Wetted Perimeter 3.00 ft
Hydraulic Radius .67 ft
Slope .037100 ft/ft
Mannings n .0130
Hydraulic Length 701.00 ft
Avg.Velocity 16.85 ft/sec
Segment #4 Time: .0116 hrs
Total Tc: .1219 hrs
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 9:55 PM 9/27/2007

Type.... Tc Calcs
Name.... SUBAREA 20
Page 3.05
File.... K:\04\09-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
Tc Equations used...
SCS TR-55 Sheet Flow ______________________________________________
Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))
Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %
___= SCS TR-55 Shallow Concentrated Flow ____________________________
Unpaved surface:
V = 16.1395 * (Sf**0.5)
Paved surface:
V = 20.3282 * (Sf**0.5)
Tc = (Lf / V) / (3600sec/hr)
Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft
S/N: DOYXYWH3NLBE
PondPack (10.00.015.00)
9:55 PM
Withers & Ravenel
9/27/2007

Type.... Tc Calcs
Name.... SUBAREA 20
Page 3.06
File.... K:\09\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
___= SCS Channel Flow __________________________________________________
R = Aq / Wp
V = (1.49 * (R**(2/3)) * (Sf**-0.5)) / n
Tc = (Lf / V) / (3600sec/hr)
Where: R = Hydraulic radius
Aq = Flow area, sq.ft.
Wp = Wetted perimeter, ft
V = Velocity, ft/sec
Sf = Slope, ft/ft
n = Mannings n
Tc = Time of concentration, hrs
Lf = Flow length, ft
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Tc Calcs
Name.... SUBAREA 30
Page 3.07
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #l: Tc: User Defined
Segment #1 Time: .0830 hrs
Total Tc: .0830 hrs
Calculated Tc < Min.Tc:
Use Minimum Tc...
Use Tc = .0833 hrs
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Tc Calcs
Name.... SUBAREA 30
Page 3.08
File.... K:\04\09-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
Tc Equations used...
___- User Defined
Tc = Value entered by user
Where: Tc = Time of concentration
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Runoff CN-Area
Name.... SUBAREA 10
Page 4.01
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C oUC CN
Open space (Lawns,parks etc.) - Goo 61 2.440 61.00
Impervious Areas - Paved parking lO 98 2.570 98.00
COMPOSITE AREA & WEIGHTED CN ---> 5.010 79.98 (80)
...........................................................................
...........................................................................
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Runoff CN-Area
Name.... SUBAREA 20
Page 4.02
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
Open space (Lawns,parks etc.) - Goo 61 7.610 61.00
Impervious Areas - Paved parking l0 98 4.590 98.00
COMPOSITE AREA & WEIGHTED CN ---> 12.150 74.83 (75)
...........................................................................
...........................................................................
S/N: DOYXYWH3NLBE
PondPack (10.00.015.00)
9:55 PM
Withers & Ravenel
9/27/2007

Type.... Runoff CN-Area
Name.... SUBAREA 30
Page 4.03
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C oUC CN
Open space (Lawns parks etc.) - Goo 61 2.060 61.00
Impervious Areas - Paved parking l0 98 2.380 98.00
COMPOSITE AREA & WEIGHTED CN ---> 4.440 80.83 (81)
...........................................................................
...........................................................................
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Vol: Elev-Area
Name.... BMP F-1
Page 5.01
File.... K:\04\04-230\09232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
Elevation Planimeter Area Al+A2+sgr(A1*A2) Volume Volume Sum
(ft) (sq.in) (sq.ft) (sq.ft) (ac-ft) (ac-ft)
335.00 ----- 5995 0 .000 .000
337.00 8348 21917 .328 .328
339.00 ----- 11052 29005 .494 .772
POND VOLUME EQUATIONS
* Incremental volume computed by the Conic Method for Reservoir Volumes.
Volume = (1/3) * (EL2-ELl) * (Areal + Areal + sq.rt.(Areal*Area2))
where: EL1, EL2 = Lower and upper elevations of the increment
Areal,Area2 = Areas computed for EL1, EL2, respectively
Volume = Incremental volume between EL1 and EL2
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Type.... Vol: Elev-Area
Name.... BMP F-2
File.... K:\04\04-230\09232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
Elevation Planimeter Area Al+A2+sgr(A1*A2) Volume Volume Sum
(ft) (sq.in) (sq.ft) (sq.ft) (ac-ft) (ac-ft)

333.00
----- 9232
0
.000 ---
.000
335.00 ----- 12446 32397 .496 .496
337.00 15999 92556 .651 1.147
POND VOLUME EQUATIONS
* Incremental volume computed by the Conic Method for Reservoir Volumes.
Volume = (1/3) * (EL2-EL1) * (Areal + Areal + sq.rt.(Areal*Area2))
where: ELl, EL2 = Lower and upper elevations of the increment
Areal,Area2 =Areas computed for ELl, EL2, respectively
Volume = Incremental volume between ELl and EL2
Page 5.02
S/N: DOYXYWH3NLBE
PondPack (10.00.015.00)
4:55 PM
Withers & Ravenel
9/27/2007

Type.... Vol: Elev-Area
Name.... BMP F-3
Page 5.03
File.... K:\09\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
Elevation Planimeter Area Al+A2+sgr(Al*A2) Volume Volume Sum
(ft) (sq.in) (sq.ft) (sq.ft) (ac-ft) (ac-ft)
332.50 ----- 6059 0 .000 .000
334.50 8119 21192 .324 .324
336.50 ----- 10433 27756 .425 .799
POND VOLUME EQUATIONS
* Incremental volume computed by the Conic Method for Reservoir Volumes.
Volume = (1/3) * (EL2-ELl) * (Areal + Areal + sq.rt.(Areal*Area2))
where: EL1, EL2 = Lower and upper elevations of the increment
Areal,Area2 =Areas computed for EL1, EL2, respectively
Volume = Incremental volume between ELl and EL2
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Outlet Input Data
Name.... Outlet F-1
Page 6.01
File.... K:\09\09-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 335.00 ft
Increment .05 ft
Max. Elev.= 339.00 ft
OUTLET CONNECTIVITY
---> Forward Flow Only (Upstream to DnStream)
<--- Reverse Flow Only (DnStream to Upstream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall E1, ft E2, ft
Orifice-Circular 00 ---> TW 335.000 339.000
Weir-Rectangular WO ---> TW 336.500 339.000
TW SETUP, DS Channel
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Outlet Input Data
Name.... Outlet F-1
Page 6.02
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
OUTLET STRUCTURE INPUT DATA
Structure ID = 00
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 1
Invert Elev. = 335.00 ft
Diameter = .1700 ft
Orifice Coeff. _ .600
Structure ID
Structure Type
--------------
# of Openings
Crest Elev.
Weir Length
Weir Coeff.
WO
Weir-Rectangular
----------------
1
336.50 ft
5.00 ft
3.000000
Weir TW effects (Use adjustment equation)
Structure ID = TW
Structure Type = TW SETUP, DS Channel
FREE OUTFACE CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES ...
Maximum Iterations= 40
Min. TW tolerance = .O1 ft
Max. TW tolerance = .O1 ft
Min. HW tolerance = .Ol ft
Max. HW tolerance = .O1 ft
Min. Q tolerance = .00 cfs
Max. Q tolerance = .00 cfs
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Outlet Input Data
Name.... Outlet F-2
Page 6.03
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 333.00 ft
Increment = .05 ft
Max. Elev.= 337.00 ft
OUTLET CONNECTIVITY
---> Forward Flow Only (Upstream to DnStream)
<--- Reverse Flow Only (DnStream to Upstream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall E1, ft E2, ft
Orifice-Circular 00 ---> TW 333.000 337.000
Weir-Rectangular WO ---> TW 334.700 337.000
TW SETUP, DS Channel
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Outlet Input Data
Name.... Outlet F-2
Page 6.04
File.... K:\09\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
OUTLET STRUCTURE INPUT DATA
Structure ID = 00
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 1
Invert Elev. = 333.00 ft
Diameter = .2080 ft
Orifice Coeff. _ .600
Structure ID
Structure Type
--------------
# of Openings
Crest Elev.
Weir Length
Weir Coeff.
WO
Weir-Rectangular
1
334.70 ft
10.00 ft
3.000000
Weir TW effects (Use adjustment equation)
Structure ID = TW
Structure Type = TW SETUP, DS Channel
FREE OUTFACE CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES ...
Maximum Iterations= 40
Min. TW tolerance = .O1 ft
Max. TW tolerance = .Ol ft
Min. HW tolerance = .O1 ft
Max. HW tolerance = .Ol ft
Min. Q tolerance = .00 cfs
Max. Q tolerance = .00 cfs
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Outlet Input Data
Name.... Outlet F-3
Page 6.05
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 332.50 ft
Increment = .05 ft
Max. Elev.= 336.50 ft
OUTLET CONNECTIVITY
---> Forward Flow Only (Upstream to DnStream)
<--- Reverse Flow Only (DnStream to Upstream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall El, ft E2, ft
Inlet Box RO ---> CO 333.900 336.500
Orifice-Circular 00 ---> CO 332.500 336.500
Culvert-Circular CO ---> TW 329.000 336.500
TW SETUP, DS Channel
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Type.... Outlet Input Data
Name.... Outlet F-3
Page 6.06
File.... K:\04\04-230\04232.55-WoodCreek Tract F\H-H\stormwater\ppack\TRF.ppw
OUTLET STRUCTURE INPUT DATA
Structure ID = RO
Structure Type = Inlet Box
# of Openings = 1
Invert Elev. = 333.90 ft
Orifice Area = 16.0000 sq.ft
Orifice Coeff. _ .600
Weir Length = 16.00 ft
Weir Coeff. = 3.100
K, Reverse = 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
Structure ID = 00
Structure Type Orifice-Circular
# of Openings = 1
Invert Elev. = 332.50 ft
Diameter = .1700 ft
Orifice Coeff. _ .600
S/N: DOYXYWH3NLBE
PondPack (10.00.015.00)
4:55 PM
Withers & Ravenel
9/27/2007

Type.... Outlet Input Data
Name.... Outlet F-3
Page 6.07
OUTLET STRUCTURE INPUT DATA
Structure ID = CO
Structure Type = Culvert-Circular
No. Barrels = 1
Barrel Diameter = 1.5000 ft
Upstream Invert = 329.00 ft
Dnstream Invert = 328.50 ft
Horiz. Length = 44.00 ft
Barrel Length = 44.00 ft
Barrel Slope = .01136 ft/ft
OUTLET CONTROL DATA...
Mannings n = .0130
Ke = .5000
Kb = .018213
Kr = .5000
HW Convergence = .001
(forward entrance loss)
(per ft of full flow)
(reverse entrance loss)
+/- ft
INLET CONTROL DATA...
Equation form = 1
Inlet Control K = .0098
Inlet Control M = 2.0000
Inlet Control c = .03980
Inlet Control Y = .6700
T1 ratio (HW/D) = 1.155
T2 ratio (HW/D) = 1.301
Slope Factor = -.500
Use unsubmerged inlet control Form 1 equ. below Tl elev.
Use submerged inlet control Form 1 equ. above T2 elev.
In transition zone between unsubmerged and submerged inlet control,
interpolate between flows at T1 & T2...
At T1 Elev = 330.73 ft ---> Flow = 7.58 cfs
At T2 Elev = 330.95 ft ---> Flow = 8.66 cfs
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
FREE OUT FALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES ...
Maximum Iterations= 40
Min. TW tolerance = .O1 ft
Max. TW tolerance = .Ol ft
Min. HW tolerance = .O1 ft
Max. HW tolerance = .O1 ft
Min. Q tolerance = .00 cfs
Max. Q tolerance = .00 cfs
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007

Appendix A
Index of Starting Page Numbers for ID Names
A-1
----- B
BMP F-1... 5.01
BMP F-2... 5.02
BMP F-3... 5.03
0 -----
Outlet F-1... 6.01
Outlet F-2... 6.03
Outlet F-3... 6.05
----- R -----
RDU NOAA 14 Desi... 2.01
----- S -----
SUBAREA 10... 3.01, 4.01
SUBAREA 20... 3.03, 4.02
SUBAREA 30... 3.07, 4.03
W -----
Watershed... 1.01
S/N: DOYXYWH3NLBE Withers & Ravenel
PondPack (10.00.015.00) 4:55 PM 9/27/2007