20081394 Ver 1_Stormwater Info_20081014

v?IVtCIQM£dCREED
TO: NCDWQ 401 Oversight Unit
2321 Crabtree Blvd., Suite 250
Raleigh, NC 27604
I ATTENUON: Annette Lucas
LETTER OF TRANSMITTAL
DATE: October 13, 2008
PROJECT NO: 1517_0178 TASK NO:
RE: SECU-Madison
08- 3q'k
TRANSMITTAL NO: PAGE 1 OF 1
WE ARE SENDING: ? Originals ® Prints ? Shop Drawings ? Samples
? Specifications ® Calculations ® Other
Quantity Drawing No. Rev Description Status
2 Original & 1 Copy of SMP Application Form
2 Original Supplement forms for BMP's
2 Original O&M Agreements for BMP's
1 Copy of Stormwater Narrative & Calculations
1 Copy of the Soils Report

REMARKS: Please find the enclosed Stormwater Management Plan Submittal for the proposed State
Employees' Credit Union in Madison. Two sets of Construction Plans will be forwarded to
you by Cory Larsen in the Stormwater Permitting Unit. Let me know of you do not receive
the drawings. Please feel free to call me with any questions or comments.
Thanks,
1730 Varsity Dr., Suite 500, Raleigh, NC 27606 919/233-8091 Fax [phone]
Cc:
iJ McKIM & CREED, PA
O C i 1 4 2008
DENR - t.NArER QUALF[Y
WETLANDS AND STCRMIMATER MA,NC 1
Signed
DWQ USE ONLY
Date Received Fee Paid Permit Number
0S - 139{
State of North Carolina
Department of Environment and Natural Resources
Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION
This form may be photocopied for use as an original
1. GENERAL INFORMATION
7-3
1? ?C W
1. Applicants name (specify the name of the corporation, individual, etc. who owns the project): 1 4 20n$
State Employees' Credit Union 1)Er4g _+NATER. (1UALITY
VJETLAyDS 010 STORM?!ATER 3RbA "A
2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance):
Robert S. Hall Sr., Senior Executive Vice President
3. Mailing Address for person listed in item 2 above:
P.O. Box 26055
City:Raleigh State:NC Zip:27611
Phone: (919 ) 839-5000 Fax: ( )
Email:
4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on
plans, specifications, letters, operation and maintenance agreements, etc.):
State Employees Credit Union Madison Office
5. Location of Project (street address):
654 Chief Martin Street
City:Madison County:Rockingham Zip:27025
6. Directions to project (from nearest major intersection):
From Intersection of US 311 and US 220 Business, head north on US 220 Business. Follow US 220 Business
through town and take a left on Chief Martin St. The site is on the right past an existing shopping center.
7. Latitude:36° 23' 38" N Longitude:79° 58' 18" W of project
8. Contact person who can answer questions about the project:
Namejason C. Allen, PE Telephone Number: (919 ) 233-8091
Email: [e-mail]
II. PERMIT INFORMATION:
1. Specify whether project is (check one): ®New ?Renewal ?Modification
Form SWU-101 Version 03.27.08 Pagel of4
RECEIVED
N.C. Dept. of ENR
OCT 0 32008
)RM
Winston-Salem
Regional office
2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the
existing permit number and its issue date (if known)
3. Specify the type of project (check one):
[]Low Density []High Density []Redevelop ®General Permit []Universal SMP []Other
4. Additional Project Requirements (check applicable blanks; information on required state permits can be
obtained by contacting the Customer Service Center at 1-877-623-6748):
?CAMA Major ®Sedimentation/Erosion Control ®404/401 Permit ?NPDES Stormwater
III. PROJECT INFORMATION
1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative
(one to two pages) describing stormwater management for the project.
Stormwater will be collected and distributed into two grassed bioretention areas. The bioretention areas have
been designed to control the first 1" of runoff and bypass larger storms Bypass pipes will tie into the proposed
site storm drainage system
2. Stormwater runoff from this project drains to the Roanoke River basin.
3. Total Property Area: 6.99 acres 4. Total Wetlands Area: acres
5. 100' Wide Strip of Wetland Area: acres (not applicable if no wetlands exist on site)
6. Total Project Area**:2.96 acres 7. Project Built Upon Area:17.6 %
8. How many drainage areas does the project have?2
9
'Basin' Information Drainage Area 1 Drainage Area 2
Receiving Stream Name Big Beaver Island Creek Big Beaver Island Creek
Stream Class & Index No. C (22-29) C (22-29)
Total Drainage Area (so 57,064 40,946
On-site Drainage Area (so 57,064 40,946
Off-site Drainage Area (so 0 0
Existing Impervious* Area (so 0 0
Proposed Impervious*Area (so 31,799 21,780
Impervious* Area (total) 55.7 53.2
Impervious* Surface Area Drainage Area 1 Drainage Area 2
On-site Buildings (so 3,762 4,888
On-site Streets (so 0 0
On-site Parking (so 26,175 15,082
On-site Sidewalks (so 1,879 1,810
Other on-site (so 0 0
Off-site (so 0 0
Total (so: 31,799 21,780
Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas,
sidewalks, gravel areas, etc.
**Total project area shall be calculated based on the current policy regarding inclusion of wetlands in the built upon
area percentage calculation. This is the area used to calculate percent project built upon area (B LIA).
Complete the following information for each drainage area. If there are more than two drainage areas in the
project, attach an additional sheet with the information for each area provided in the same format as below.
For high density projects, com lete the table with one drainage area for each engineered stormwater device.
Form SWU-101 Version 03.27.08 Page 2 of 4
10. How was the off-site impervious area listed above derived?N/A. All offsite drainage was bypassed around
the site via piping or swales.
IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
One of the following deed restrictions and protective covenants are required to be recorded for all subdivisions,
outparcels and future development prior to the sale of any lot. If lot sizes vary significantly, a table listing each
lot number, size and the allowable built-upon area for each lot must be provided as an attachment. Forms can
be downloaded from http://h2o.enr.state.nc.us/su/bmp forms.htm - deed restrictions.
Form DRPC-1 High Density Commercial Subdivisions
Form DRPC-2 High Density Developments with Outparcels
Form DRPC-3 High Density Residential Subdivisions
Form DRPC-4 Low Density Commercial Subdivisions
Form DRPC-5 Low Density Residential Subdivisions
Form DRPC-6 Low Density Residential Subdivisions with Curb Outlets
By your signature below, you certify that the recorded deed restrictions and protective covenants for this
project shall include all the applicable items required in the above form, that the covenants will be binding
on all parties and persons claiming under them, that they will run with the land, that the required covenants
cannot be changed or deleted without concurrence from the State, and that they will be recorded prior to the
sale of any lot.
V. SUPPLEMENT FORMS
The applicable state stormwater management permit supplement form(s) listed below must be submitted for
each BMP specified for this project. Contact the Stormwater and General Permits Unit at [phone] for the
status and availability of these forms. Forms can be downloaded from
http://h2o.enr.state.nc.us/suj2ml2 forms.htm.
Form SW401-Low Density
Form SW401-Curb Outlet System
Form SW401-Off-Site System
Form SW401-Wet Detention Basin
Form SW401-Infiltration Basin
Form SW401-Infiltration Trench
Form SW401-Bioretention Cell
Form SW401-Level Spreader
Form SW401-Wetland
Form SW401-Grassed Swale
Form SW401-Sand Filter
Form SW401-Permeable Pavement
Form SWU-101 Version 03.27.08
Low Density Supplement
Curb Outlet System Supplement
Off-Site System Supplement
Wet Detention Basin Supplement
Infiltration Basin Supplement
Underground Infiltration Trench Supplement
Bioretention Cell Supplement
Level Spreader/Filter Strip/Restored Riparian Buffer Supplement
Constructed Wetland Supplement
Grassed Swale Supplement
Sand Filter Supplement
Permeable Pavement Supplement
Page 3 of 4
VI. SUBMITTAL REQUIREMENTS
Only complete application packages will be accepted and reviewed by the Division of Water Quality
(DWQ). A complete package includes all of the items listed below. The complete application package
should be submitted to the appropriate DWQ Office. (Appropriate office may be found by locating project on
the interactive online map at http://h2o.enr.state.nc.us/su/msi mans.htm)
1. Please indicate that you have provided the following required information by initialing in the space
provided next to each item.
Initials
• Original and one copy of the Stormwater Management Permit Application Form TCA
• Original and one copy of the Deed Restrictions & Protective Covenants Form (if &.1A
required as per Part IV above)
• Original of the applicable Supplement Form(s) and O&M agreement(s) for each BMP TL _
• Permit application processing fee of $505 (Express: $4,000 for HD, $2,000 for LD)
payable to NCDENR C
• Calculations & detailed narrative description of stormwater treatment/ management J
• Copy of any applicable soils report r 76A
• Two copies of plans and specifications (sealed, signed & dated), including: GA
- Development/ Project name
- Engineer and firm
-Legend
- North arrow
- Scale
- Revision number & date
- Mean high water line
- Dimensioned property/ project boundary
- Location map with named streets or NCSR numbers
- Original contours, proposed contours, spot elevations, finished floor elevations
- Details of roads, drainage features, collection systems, and stormwater control measures
- Wetlands delineated, or a note on plans that none exist
- Existing drainage (including off-site), drainage easements, pipe sizes, runoff calculations
- Drainage areas delineated
- Vegetated buffers (where required)
VII. AGENT AUTHORIZATION
If you wish to designate authority to another individual or firm so that they may provide information on your
behalf, please complete this section. (ex. designing engineer or firm)
Designated agent (individual or firm):McKim & Creed
Mailing Address:1730 Varsity Dr., Suite 500
City:Raleigh State:NC Zip:27606
Phone: (919 ) 233-8091 Fax: (919 ) 233-8031
Emaii:[e-mail]
VIII. APPLICANT'S CERTIFICATION
I, (print or type name of person listed in General Information, item 2) Robert S. Hall, Sr.
certify that the information included on this permit application form is, to the best of my knowledge, correct and
that the project will be constructed in conformance with the approved plans, that the required deed restrictions
and protective covenants will be reco ded, and that the proposed project complies with the requirements of 15A
NCAC 2H.1000.
Z Q
Signature: Date: j
Form SWU-101 Version 03.27.08 Page 4 of 4
r . 1%
Permit Number:
(to be provided by DWQ)
Drainage Area Number:
Bioretention Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BMP elements noted in the inspection will be
corrected, repaired or replaced immediately. These deficiencies can affect the integrity
of structures, safety of the public, and the removal efficiency of the BMP.
Important operation and maintenance procedures:
- Immediately after the bioretention cell is established, the plants will be watered
twice weekly if needed until the plants become established (commonly six
weeks).
- Snow, mulch or any other material will NEVER be piled on the surface of the
bioretention cell.
- Heavy equipment will NEVER be driven over the bioretention cell.
- Special care will be taken to prevent sediment from entering the bioretention cell.
- Once a year, a soil test of the soil media will be conducted.
After the bioretention cell is established, I will inspect it once a month and within 24
hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal
County). Records of operation and maintenance will be kept in a known set location
and will be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element: Potential problems: How I will remediate the problem:
The entire BMP Trash/debris is resent. Remove the trash/debris.
The perimeter of the Areas of bare soil and/or Regrade the soil if necessary to
bioretention cell erosive gullies have formed. remove the gully, and then plant a
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
The inlet device: pipe, The pipe is clogged (if Unclog the pipe. Dispose of the
stone verge or swale applicable). sediment off-site.
The pipe is cracked or Replace the pipe.
otherwise damaged (if
applicable).
Erosion is occurring in the Regrade the swale if necessary to
swale (if applicable). smooth it over and provide erosion
control devices such as reinforced
turf matting or riprap to avoid
future problems with erosion.
Stone verge is clogged or Remove sediment and clogged
covered in sediment (if stone and replace with clean stone.
applicable).
Form SW401-Bioretention O&M-Rev.3
Page 1 of 4

BMP element: Potential problems: How I will remediate the problem:
The pretreatment area Flow is bypassing Regrade if necessary to route all
pretreatment area and/or flow to the pretreatment area.
gullies have formed. Restabilize the area after grading.
Sediment has accumulated to Search for the source of the
a depth greater than three sediment and remedy the problem if
inches. possible. Remove the sediment and
restabilize the pretreatment area.
Erosion has occurred. Provide additional erosion
protection such as reinforced turf
matting or riprap if needed to
prevent future erosion problems.
Weeds are present. Remove the weeds, preferably by
hand.
The bioretention cell: Best professional practices Prune according to best professional
vegetation show that pruning is needed practices.
to maintain optimal plant
health.
Plants are dead, diseased or Determine the source of the
dying. problem: soils, hydrology, disease,
etc. Remedy the problem and
replace plants. Provide a one-time
fertilizer application to establish the
ground cover if a soil test indicates
it is necessary.
Tree stakes/wires are present Remove tree stake/ wires (which
six months after planting. can kill the tree if not removed).
The bioretention cell: Mulch is breaking down or Spot mulch if there are only random
soils and mulch has floated away. void areas. Replace whole mulch
layer if necessary. Remove the
remaining much and replace with
triple shredded hard wood mulch at
a maximum depth of three inches.
Soils and/or mulch are Determine the extent of the clogging
clogged with sediment. - remove and replace either just the
top layers or the entire media as
needed. Dispose of the spoil in an
appropriate off-site location. Use
triple shredded hard wood mulch at
a maximum depth of three inches.
Search for the source of the
sediment and remedy the problem if
possible.
An annual soil test shows that Dolomitic lime shall be applied as
pH has dropped or heavy recommended per the soil test and
metals have accumulated in toxic soils shall be removed,
the soil media. disposed of properly and replaced
with new planting media.
Form SW401-Bioretention O&M-Rev.3 Page 2 of 4
t .
BMP element: Potential problems: How I will remediate the problem:
The underdrain system Clogging has occurred. Wash out the underdrain system.
(if applicable)
The drop inlet Clogging has occurred. Clean out the drop inlet. Dispose of
the sediment off-site.
The drop inlet is damaged Repair or replace the drop inlet.
The receiving water Erosion or other signs of Contact the NC Division of Water
damage have occurred at the Quality 401 Oversight Unit at 919-
outlet. 733-1786.
Form SW401-Bioretention O&M-Rev.3 Page 3 of 4
e
Permit Number:
(to be provided by DWQ)
I acknowledge and agree by my signature below that I am responsible for the
performance of the 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.
Project name: SECU - Madison
BMP drainage area number:
Print name: Robert S. Hall, Sr.
Title: Senior Executive Vice President
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, ?uA??A We- C?, i/ -e f- , a Notary Public for the State of
r-? C.- , County of W O? K 2, , do hereby certify that
4. S ?A 0'- 1 1 personally appeared before me this 05
day o6e- to\D c olG? , and acknowledge the due execution of the
forgoing bioretention maintenance requirements. Witness my hand and official seal,
JMN w4
v)eauelr
IJ B
SEAL
My commission expires ?JU J ? i l
Form SW401-Bioretention I&M-Rev. 2
av l a
Page 4 of 4
Address: _ 1000 Wade Ave., Raleigh, NC 27605
Permit Number:
(to be provided by DWQ)
Drainage Area Number:
Bioretention Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BMP elements noted in the inspection will be
corrected, repaired or replaced immediately. These deficiencies can affect the integrity
of structures, safety of the public, and the removal efficiency of the BMP.
Important operation and maintenance procedures:
- Immediately after the bioretention cell is established, the plants will be watered
twice weekly if needed until the plants become established (commonly six
weeks).
- Snow, mulch or any other material will NEVER be piled on the surface of the
bioretention cell.
- Heavy equipment will NEVER be driven over the bioretention cell.
- Special care will be taken to prevent sediment from entering the bioretention cell.
- Once a year, a soil test of the soil media will be conducted.
After the bioretention cell is established, I will inspect it once a month and within 24
hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal
County). Records of operation and maintenance will be kept in a known set location
and will be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element: Potential problems: How I will remediate the problem:
The entire BMP Trash/debris is resent. Remove the trash/debris.
The perimeter of the Areas of bare soil and/or Regrade the soil if necessary to
bioretention cell erosive gullies have formed. remove the gully, and then plant a
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
The inlet device: pipe, The pipe is clogged (if Unclog the pipe. Dispose of the
stone verge or swale applicable). sediment off-site.
The pipe is cracked or Replace the pipe.
otherwise damaged (if
applicable).
Erosion is occurring in the Regrade the swale if necessary to
swale (if applicable). smooth it over and provide erosion
control devices such as reinforced
turf matting or riprap to avoid
future problems with erosion.
Stone verge is clogged or Remove sediment and clogged
covered in sediment (if stone and replace with clean stone.
__applicable).
Form SW401-Bioretention O&M-Rev.3 Page I of 4
BMP element: Potential problems: How I will remediate the problem:
The pretreatment area Flow is bypassing Regrade if necessary to route all
pretreatment area and/or flow to the pretreatment area.
gullies have formed. Restabilize the area after grading.
Sediment has accumulated to Search for the source of the
a depth greater than three sediment and remedy the problem if
inches. possible. Remove the sediment and
restabilize the pretreatment area.
Erosion has occurred. Provide additional erosion
protection such as reinforced turf
matting or riprap if needed to
prevent future erosion problems.
Weeds are present. Remove the weeds, preferably by
hand.
The bioretention cell: Best professional practices Prune according to best professional
vegetation show that pruning is needed practices.
to maintain optimal plant
health.
Plants are dead, diseased or Determine the source of the
dying. problem: soils, hydrology, disease,
etc. Remedy the problem and
replace plants. Provide a one-time
fertilizer application to establish the
ground cover if a soil test indicates
it is necessary.
Tree stakes/wires are present Remove tree stake/wires (which
six months after planting. can kill the tree if not removed).
The bioretention cell: Mulch is breaking down or Spot mulch if there are only random
soils and mulch has floated away. void areas. Replace whole mulch
layer if necessary. Remove the
remaining much and replace with
triple shredded hard wood mulch at
a maximum depth of three inches.
Soils and/or mulch are Determine the extent of the clogging
clogged with sediment. - remove and replace either just the
top layers or the entire media as
needed. Dispose of the spoil in an
appropriate off-site location. Use
triple shredded hard wood mulch at
a maximum depth of three inches.
Search for the source of the
sediment and remedy the problem if
possible.
An annual soil test shows that Dolomitic lime shall be applied as
pH has dropped or heavy recommended per the soil test and
metals have accumulated in toxic soils shall be removed,
the soil media. disposed of properly and replaced
with new planting media.
Form SW401-Bioretention O&M-Rev.3 Page 2 of 4
BMP element: Potential problems: How I will remediate the problem:
The underdrain system Clogging has occurred. Wash out the underdrain system.
(if applicable)
The drop inlet Clogging has occurred. Clean out the drop inlet. Dispose of
the sediment off-site.
The drop inlet is damaged Repair or replace the drop inlet.
The receiving water Erosion or other signs of Contact the NC Division of Water
damage have occurred at the Quality 401 Oversight Unit at 919-
outlet. 733-1786.
Form SW401-Bioretention O&M-Rev.3 Page 3 of 4
Permit Number:
(to be provided by DWQ)
I acknowledge and agree by my signature below that I am responsible for the
performance of the 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.
Project name: SECU - Madison
BMP drainage area number: 2
Print name: Robert S. Hall, Sr.
Title: Senior Executive Vice President
Address: 1000 Wade Ave., Raleigh, NC 27605
Phone:
Signati
Date:
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, 1-k. \A A V1 Y\ Ct i1 e t- , a Notary Public for the State of
C_ , County of W aA? Q , do hereby certify that
7 . S . } (;L ` personally appeared before me this a 5
day of Sep{-r-vv ?o,? , ;Dtpp , and acknowledge the due execution of the
forgoing bioretention maintenance requirements. Witness my hand and official seal,
,. 4 N
OTA
v
C06
SEAL

My commission expires MO-\J.. 1% 1 a o k a
W 0-a \1 e-f
Form SW401-Bioretention I&M-Rev. 2 Page 4 of 4
Permit Number:
(to be provided by DWQ)
OF W A rF9
0 QG
=NR
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
BIORETENTION CELL SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part 111) must be printed, filled out and submitted along with all of the required information.
SECT INFORMATION
name SECU - Madison
name Jason C. Allen, PE
lumber [phone]
October 1, 2008
e area number 1
;IGN INFORMATION
aracteristics
e area
-)us area
impervious
rainfall depth
ow Calculations
-hr runoff depth
-hr intensity
elopment 1-yr, 24-hr peak flow
velopment 1-yr, 24-hr peak flow
t 1-yr, 24-hr peak control
Volume: Non-SR Waters
volume
: Volume: SR Waters
elopment 1-yr, 24-hr runoff
velopment 1-yr, 24-hr runoff
n volume required
provided
tiensions
depth of water
depth of water
area of the top of the bioretention cell
radius
eport Summary
wn time, ponded volume
rvn time, to 24 inches below surface
wn time, total:
oil:
ermeability
media soil:
ermeability
omposition
Sand (by weight)
Fines (by weight)
Organic (by weight)
57,064.00 ft2
31,799.00 ft 2
55.7% %
1.00 inch
in
in/hr
ft 3/sec
ft 3/sec
ft 3/sec
2,623.00 ft3
ft3
ft3
0.00 ft3
ft3
10.00 inches OK
0.83 ft
3174.00 ft2 OK
80.00 ft OK
45.00 ft OK
10.00 ft OK
5.00 hr OK
5.00 hr OK
10.00 hr
0.52 in/hr OK ?"'^ V S Ga? rv? i h
'?? ?ESiSn
0.52 in/hr OK
86% OK
10% OK
4% OK
Total: 100%
Form SW401-Bioretention-Rev.3 Parts I and II. Design Summary, Page 1 of 2
't
J
a
yea
Uoyd
'ejuOD
3afad
Ald 'I
r
Permit Number:
(to be provided by DWQ)
3 Index (P-Index)
Cations
pool elevation
,evation (top of the mulch)
,the cell
epth
uepth of mulch
SHWT elevation
Are underdrains being installed?
How many clean out pipes are being installed?
What factor of safety is used for sizing the underdrains? (See
BMP Manual Section 12.3.6)
Additional distance between the bottom of the planting media and
the bottom of the cell to account for underdrains
Bottom of the cell required
Distance from bottom to SHWT
Type of bioretention cell (answer "Y" to only one of the two
following questions):
Is this a grassed cell?
Is this a cell with trees/shrubs?
Planting Plan
Number of tree species
Number of shrub species
Number of herbaceous groundcover species
Additional Information
Does volume in excess of the design volume bypass the
bioretention cell?
Does volume in excess of the design volume flow evenly distributed
through a vegetated filter?
What is the length of the vegetated filter?
Does the design use a level spreader to evenly distribute flow?
Is the BMP located at least 30 feet from surface waters (50 feet if
SA waters)?
Is the BMP localed at least 100 feet from water supply wells?
Are the vegetated side slopes equal to or less than 3:1?
Is the BMP located in a recorded drainage easement with a
recorded access easement to a public Right of Way (ROW)?
Inlet velocity (from treatment system)
Is the area surrounding the cell likely to undergo development in
the future?
Are the slopes draining to the bioretention cell greater than 20%?
Is the drainage area permanently stabilized?
Pretreatment Used
(Indicate Type Used with an "X" in the shaded cell)
Gravel and grass
(8'inches gravel followed by 3-5 ft of grass)
Grassed swale
Forebay
20 (unitless) OK
622.83 fmsl
622.00 fmsl Insufficient temporary pool elevation.
619.75 fmsl
2.25 ft
3.00 inches OK
fmsl <' ho 5ro.>nd Wo..-1 C-e
ire
Y (Y or N)
4 OK
10.00 OK
1ft
618.75 fmsl
618.75 ft OK
Y (Y or N) OK
(Y or N)
Y (Y or N) OK
N (Y or N) Excess volume must pass through filter.
ft plpe sfs
N (Y or N) Show how flow is evenly distributed.
Y (Y or N) OK
Y (Y or N) OK
Y (Y or N) OK
Y (Y or N) OK
5.82 fUsec Insufficient inlet velocity unless energy dissipating devices are
being used.
N (Y or N) OK
N (Y or N) OK
Y (Y or N) OK
'R 'r rc%i- gvevForm SW401-Bioretention-Rev.3 Parts I and II. Design Summary, Page 2 of 2

Permit No:
(to be assigned by DWQ)
III. REQUIRED ITEMS CHECKLIST
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Page/ Plan
Initials Sheet No.
C1203 1. Plans (1" - 50' or larger) of the entire site showing:
Design at ultimate build-out,
Off-site drainage (if applicable),
Delineated drainage basins (include Rational C coefficient per basin),
Cell dimensions,
Pretreatment system,
High flow bypass system,
Maintenance access,
Proposed drainage easement and public right of way (ROW),
Clean out pipe locations,
Overflow device, and
Boundaries of drainage easement.
?- C5104 2. Plan details (1" = 30' or larger) for the bioretention cell showing:
Cell dimensions
Pretreatment system,
High flow bypass system,
Maintenance access,
Recorded drainage easement and public right of way (ROW),
Design at ultimate build-out,
Off-site drainage (if applicable),
Clean out pipe locations,
Overflow device, and
Boundaries of drainage easement.
T6
4 "
'
C5104
1 3. Section view of the bioretention cell (1
= 20
or larger) showing:
Side slopes, 3:1 or lower
Underdrain system (if applicable), and
Bioretention cell layers [ground level and slope, pre-treatment, ponding depth, mulch depth, fill media
depth, washed sand, filter fabric (or choking stone if applicable), #57 stone, underdrains (if applicable),
SHWT level(s), and overflow structure]
I'CA
Enclosed 4. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. The
results of the soils report must be verified in the field by DWQ, by completing & submitting the soils
investigation request form. County soil maps are not an acceptable source of soils information. All
elevations shall be in feet mean sea level (fmsl). Results of soils tests of both the planting soil and the in
situ soil must include:
Soil permeability,
Soil composition (% sand, % fines, % organic), and

,T
A P-index.
?_ C5104
C 5. A detailed planting plan (1" = 20' or larger) prepared by a qualified individual showing:
A variety of suitable species,
Sizes, spacing and locations of plantings,
Total quantity of each type of plant specified,
A planting detail,
The source nursery for the plants, and
Fertilizer and watering requirements to establish vegetation.
TLA- C1203 6. A construction sequence that shows how the bioretention cell will be protected from sediment until the
entire drainage area is stabilized.
/?
T& A Enclosed 7. The supporting calculations (including underdrain calculations, if applicable).
:Y4A Enclosed 8. A copy of the signed and notarized operation and maintenance (0&M) agreement.
'=-F L N/A 9. A copy of the deed restrictions (if required).
Form SW401-Bioretention-Rev.3 Part III, Page 1 of 1
Permit Number:
(to be provided by DWQ)
,A
NCDENR
O? ? W A T ?R H?G
t ??+rv?Ci
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STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
BIORETENTION CELL SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part 1/1) must be printed, filled out and submitted along with all of the required information.
I. PROJECT INFORMATION
Project name SECU - Madison
Contact name Jason C. Allen, PE
Phone number [phone]
Date October 1, 2008
Drainage area number 2
II. DESIGN INFORMATION
Site Characteristics
Drainage area 40,946.00 ft2
Impervious area 21,780.00 ft2
Percent impervious 53.2% %
Design rainfall depth 1.00 inch
Peak Flow Calculations
1-yr, 24-hr runoff depth in
1-yr, 24-hr intensity in/hr
Pre-development 1-yr, 24-hr peak flow ft3/sec
Post-development 1-yr, 24-hr peak flow ft 3/sec
Pre/Post 1-yr, 24-hr peak control ft3/sec
Storage Volume: Non-SR Waters
Design volume 1,804.00 ft3
Storage Volume: SR Waters
Pre-development 1-yr, 24-hr runoff ft 3
Post-development 1-yr, 24-hr runoff ft3
Minimum volume required 0.00 ft3
Volume provided ft 3
Cell Dimensions
Ponding depth of water 10.00 inches OK
Pgnding depth of water 0.83 ft
Surface area of the top of the bioretention cell 2298.00 ft2 OK
Length: 65.00 ft OK
Width: 45.00 ft OK
-or- Radius 10.00 ft OK
Soils Report Summary
Drawdown time, ponded volume 5.00 hr OK
Drawdown time, to 24 inches below surface 5.00 hr OK
Drawdown time, total: 10.00 hr
In-situ soil:
Soil permeability
0.52 in/hr
OK t " A55,irne-al rhtn • T-e
Planting media soil: -
`0? cl
Soil permeability 0.52 in/hr OK L
Soil composition
% Sand (by weight) 86% OK
% Fines (by weight) 10% OK
% Organic (by weight) 4% OK
Total: 100%
Form SW401-Bioretention-Rev.3 Parts I and II. Design Summary, Page 1 of 2
Permit Number:
(to be provided by DWQ)
Kosphon 5 Index (P-Index) 20 (unitless) OK
Basin Elevations
Temporary pool elevation 621.83 fmsl
Planting elevation (top of the mulch) 621.00 fmsl Insufficient temporary pool elevation.
Bottom of the cell 618.75 fmsl
Planting depth 2.25 ft
Depth of mulch 3.00 inches OK
SHWT elevation fmsl 4Z, no 5 ro v'd'3 G?.4-er
er+co ?.+-?-?rec? i r., b o r i v, 5
Are underdrains being installed? Y (Y or N) 5
How many clean out pipes are being installed? 4 OK
What factor of safety is used for sizing the underdrains? (See 10.00 OK
BMP Manual Section 12.3.6)
Additional distance between the bottom of the planting media and 1 ft
the bottom of the cell to account for underdrains
Bottom of the cell required 617.75 fmsl
Distance from bottom to SHWT 617.75 ft OK
Type of bioretention cell (answer "Y" to only one of the two
following questions):
Is this a grassed cell? Y (Y or N) OK
Is this a cell with trees/shrubs? (Y or N)
Planting Plan
Number of tree species
Number of shrub species
Number of herbaceous groundcover species
Additional Information
Does volume in excess of the design volume bypass the Y (Y or N) OK
bioretention cell?
Does volume in excess of the design volume flow evenly distributed N (Y or N) Excess volume must pass through filter.
through a vegetated filter?
What is the len
th of the ve
etated filter?
ft LL
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CD ?'>F?.?IS T?? i .?'?'D
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S-ho r ^?, 5 sdC?.
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oe
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eve
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er
o even
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ow (Y or N) Show how flow is eve6lly distributed.
Is the BMP located at least 30 feet from surface waters (50 feet if Y Y or N)
( ) OK
SA waters)?
Is the BMP located at least 100 feet from water supply wells? Y (Y or N) OK
Are the vegetated side slopes equal to or less than 3:1? Y (Y or N) OK
Is the BMP located in a recorded drainage easement with a Y (Y or N) OK
recorded access easement to a public Right of Way (ROW)?
Inlet velocity (from treatment system) 5.74 ft/sec Insufficient inlet velocity unless energy dissipating devices are
being used.
Is the area surrounding the cell likely to undergo development in N (Y or N) OK
the future?
Are the slopes draining to the bioretention cell greater than 20%? N (Y or N) OK
Is the drainage area permanently stabilized? Y (Y or N) OK
Pretreatment Used
(Indicate Type Used with an "X" in the shaded cell)
Gravel and grass

(8'inches gravel followed by 3-5 It of grass) c?
Grassed Swale
Forebay
Form SW401-Bioretention-Rev.3 Parts I and II. Design Summary, Page 2 of 2
Permit No:
(to be assigned by DWQ)
` III, REQUIRED ITEMS CHECKLIST
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Pagel Plan
Initials Sheet No.
16A C1203 1. Plans (1" - 50' or larger) of the entire site showing:
Design at ultimate build-out,
Off-site drainage (if applicable),
Delineated drainage basins (include Rational C coefficient per basin),
Cell dimensions,
Pretreatment system,
High flow bypass system,
Maintenance access,
Proposed drainage easement and public right of way (ROW),
Clean out pipe locations,
Overflow device, and
Boundaries of drainage easement.
TGg C5104 2. Plan details (1" = 30' or larger) for the bioretention cell showing:
Cell dimensions
Pretreatment system,
High flow bypass system,
Maintenance access,
Recorded drainage easement and public right of way (ROW),
Design at ultimate build-out,
Off-site drainage (if applicable),
Clean out pipe locations,
Overflow device, and
Boundaries of drainage easement.
?i_
J ? C "
'
5104 3. Section view of the bioretention cell 0
= 20
or larger) showing:
Side slopes, 3:1 or lower
Underdrain system (if applicable), and
Bioretention cell layers [ground level and slope, pre-treatment, ponding depth, mulch depth, fill media
depth, washed sand, filter fabric (or choking stone if applicable), #57 stone, underdrains (if applicable),
SHWT level(s), and overflow structure]
TCEnclosed 4. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. The
results of the soils report must be verified in the field by DWQ, by completing & submitting the soils
investigation request form. County soil maps are not an acceptable source of soils information. All
elevations shall be in feet mean sea level (fmsl). Results of soils tests of both the planting soil and the in
situ soil must include:
Soil permeability,
Soil composition (% sand, % fines, % organic), and
?-?
A C5104
( P-index.
A
"
'
_
- 5.
detailed planting plan (1
= 20
or larger) prepared by a qualified individual showing:
A variety of suitable species,
Sizes, spacing and locations of plantings,
Total quantity of each type of plant specified,
A planting detail,
The source nursery for the plants, and
Fertilizer and watering requirements to establish vegetation.
?^
J Lpt
C1203 6. A construction sequence that shows how the bioretention cell will be protected from sediment until the
entire drainage area is stabilized.
TLA Enclosed 7. The supporting calculations (including underdrain calculations, if applicable).
51-A Enclosed 8. A copy of the signed and notarized operation and maintenance (0&M) agreement.
N/A 9. A copy of the deed restrictions (if required).
Form SW401-Bioretention-Rev. 3 Part 111, Page 1 of 1
?.??tt+it}?:
September 12, 2007
Julie McLaurin
O'BRIEN ATKINS & ASSOCIATES
P.O Box 12037
Research Triangle Park, NC 27709
Re: Report of Subsurface Investigation
Proposed SECU Bank - Chief Martin Street
Madison, North Carolina
GeoTechnologies Project No. 1-07-1112-EA
Dear Ms. McLaurin:
3200 Wellington Court, Suite 108
Rdoigh, North Carolina 27615
919.954-1514
Fax 919••954-14213
GeoTechnologies, Inc. has completed the authorized investigation to evaluate subsurface soil
conditions for a SECU bank proposed for construction off Chief Martin Street in Madison, North
Carolina. Subsurface conditions at the site were investigated by completing 13 soil test borings at the
approximate locations shown on the attached Figure I. The boring locations were established in the field
by measuring distances from existing site landmarks, and therefore the indicated locations should be
considered approximate. The soil test borings were extended to depths ranging from approximately 10 to
25 feet below site grade utilizing standard penetration test procedures at selected intervals to evaluate the
consistency and density of the subsurface soils. This report presents the findings of our investigation and
our recommendations concerning site grading and foundation support considerations for the proposed
new bank facility.
SITE AND PROJECT INFORMATION
It is our understanding that a new SECU bank will be constructed on the north side of Chief
Martin Street, west of the Rockingham Square shopping center in Madison, North Carolina. At the time
of our investigation, a majority of the site was wooded. An overhead power easement was observed on
the south side of the property along Chief Martin Street, and a sanitary sewer easement was observed near
the western border of the property. Additionally, the discharge point for a 36 inch CMP from the
Rockingham Square shopping center was observed near what is currently planned to be about the middle
of the east side wall for the new bank building. The pipe presently carries storm water from the shopping
center to the referenced discharge spot where the water then flows west in an open channel through about
the middle of the proposed building. The pipe is not exposed (below grade) until about the last 10 feet
before discharging, and therefore, the channel in the building is the only place that is deep and where
water was observed. The channel width ranges from a few feet up to 15 to 20 feet, and bottom depths
relative to the side banks appear to be on the order of about 8 to 12 feet. The water in the channel is
deepest below the discharge point of the pipe.
Based on observations of site topography, we anticipate that some cuts and fills will be necessary
during site grading to achieve grade; however, proposed finished grades were not provided.
GeoTechnologies was not provided with any information regarding structural loading details; however,
we anticipate the structure will be supported on relatively light columns and load bearing walls. Column
Ge,otechnicol and Consfruction Molorials h;Wing Se;ivices
O'Brien Atkins & Associates
SBCU - Chief Martin Street
September 12, 2007
Page: 2
loads are not expected to exceed 100 kips with wall loads in the range of 3 to 4 klf or less. In addition to
the proposed bank building, drive-thru teller lanes and parking and driveway areas will be constructed.
SUBSURFACE CONDITIONS
Generalized subsurface profiles prepared from the test boring data are attached to this report as
Figures 2A and 2B to graphically illustrate subsurface conditions encountered at this site. More detailed
descriptions of the conditions encountered at the individual boring locations are then presented on the
attached test boring records.
Below a surface layer of topsoil which did not exceed more than about 8 inches in thickness, the
near surface profile on this site was found to generally consist of 3 to 12.5 feet of fill or possible fall soils
whose penetration resistances were in the range of 3 to 25 blows per foot (bpf). The fall generally
consisted of low to moderate plasticity silts and clays with occasional minor organics along with some
zones of more concentrated organics (B-1 and B-12). Below the fall, the borings typically encountered
silty and clayey residual soils, except in boring B-1 where some alluvial silts were underlain by more
granular soils. Penetration resistances within these soils were in the range of 5 to 52 bpf.
Partially weathered rock (PWR) was encountered in borings B-3 and B-10 at depths of 20 and 10
feet. PWR is defined as material which could be penetrated with the soil drilling augers but which
exhibited penetration resistances in excess of 100 bpf. All of the borings were terminated at the plan
boring depths which ranged from about 10 to 25 feet.
Groundwater was not encountered in any of the borings at the time of boring completion.
However, it should be noted that the near surface soils at the site are conducive to the temporary
development of perched groundwater conditions during periods of wet weather, and that groundwater
levels will fluctuate during different periods of the year. Additionally, water was observed running in the
drainage channel in the center of the proposed building at the time of our site visit.
RECOMMENDATIONS
The following recommendations are made based upon a review of the attached test boring data,
our understanding of the proposed construction, and past experience with similar projects and subsurface
conditions. Should site grading or structural plans change significantly from those now under
consideration, we would appreciate being provided with that information so that these recommendations
may be confirmed, extended, or modified as necessary. Additionally, should subsurface conditions
adverse to those indicated by this report be encountered during construction, those differences should be
reported to us for review and comment.
Suitability of Site. The results of our test borings indicate that this site has previously been graded
with the placement of up to 12.5 feet of fill in some areas. Figure 3 shows the depth of old fill or possible
fall encountered in our borings. Although most of the fill was firm and free of significant organics, some
lower penetration resistances were recorded in borings B-1 and B-6, and some zones of heavy organics
were encountered in borings B-1 and B-12. Based on these conditions, and our past experience with
similar profiles, it is our opinion that the in-place fall is not consistently adequate for support of the
footings or the vault pad, However, the fill appears suitable for support of a lightly loaded slab-on-grade
and for pavements.
e o-e
O'Brien Atkins & Associates
SPCU - Chief Martin Street
September 12, 2007
Page: 3
In addition to the in-place fill, a deep drainage channel with water is located near the center of the
proposed building. The channel is associated with a 36 inch CMP from the Rockingham Square shopping
center to the east. The channel width ranges from a few feet up to 15 to 20 feet, and bottom depths
relative to the side banks appear to be on the order of about 8 to 12 feet. Probing of the channel bottom
typically indicated the presence of soft soils to depths in the range of 3 to 4 feet.
Based on the described conditions, it should be expected that repairs associated with the existing
subsurface conditions at this site will be more extensive than normal, most notably within the limits of the
proposed building footprint.
Site Grading Considerations. The support method used for the footings (including the canopy)
and vault pad will have an impact on the type of subsurface repair recommended within the limits of the
building pad. The first option would be to undercut all of the existing fill soils as well as the soft soils
along the base of the drainage channel from within the limits of the building pad. However, this would
involve removing up to 12.5 feet (or more) of soil in some areas. Additionally, even after flow into the
drainage channel is diverted, we anticipate that the contractor would have to be prepared to handle water
with sumps/pumps. Several feet of clean stone would also be needed along the lowest elevations to help
handle the water and to facilitate compaction of newly placed fill soils.
If this option is considered, we estimate that about 4,500 cubic yards of soil would need to be
removed for the building, with most (but not all) of that soil being suitable for reuse as fill in other areas
following moisture conditioning. If the future expansion to the east is repaired at the same time
(recommended), we estimate that another 1,000 cubic yards of soil would need to be removed,
Additionally, we estimate that about 160 cubic yards of clean (#57 or 467) stone would have to be placed
in the lowest elevations before soil fill could be used, with an additional 50 cubic yards of stone needed to
cover the future expansion. The volume of stone needed will in part be a function of the contractors
ability to control water levels. It is noted that the indicated volumes are only rough estimates, and we
suggest that a fair unit price be established in the contract for dealing with the undercut. Due to the
potential for variability, we do not recommend that the repair be bid as an "unclassified" item.
Alternatively, a stone replaced footing could be used in conjunction with limited repairs for the
slab-on-grade. This repair involves performing neatline over excavation to firm approved soils, and then
placing #57 or #67 stone to grade. If we can be provided with grading and foundation plans,
GeoTechnolgies will be happy to estimate the quantity of undercut needed for the stone replaced footings.
The stone should be compacted in 3 to 4 foot lifts with the backhoe bucket, except at the top where a
wacker packer should be used. If this repair is utilized (and grade is not raised), we expect that over
excavation repairs will generally be in the range of 3 to 12,5 feet; however, this will have to be confirmed
in the field by a geotechnical engineer at the time of excavation. Once approved soils are encountered, we
recommend that the excavations quickly be backfilled. Due to the potential for encountering groundwater
and for sidewail caving, the excavations must proceed in short segments. To facilitate the repair, we
suggest that separate equipment be used for excavation and for backfill. This is a common repair
technique, but it does require some operator skill and experience where over excavation depths become
significant, With this approach, the vault pad could either be fully undercut, or a structural (reinforced)
slab could be used. This would need to be designed by the structural engineer.
If a stone replaced footing is used, consideration should be given to how footings for the future
expansion will be installed, because the stone will cave without confinement. Possible alternatives include

O'Brien Atkins & Associates
SECU - Chief Martin Street
September 12, 2007
Page: 4
using full-depth concrete at the future tie-ins, carrying over excavation repairs somewhat outside the
initial walls, using spanning grade beams, or planning on using helical piers adjacnet to the building.
With a stone replaced footing, repairs for the slab could then likely be limited to only near surface
repairs (assuming summertime grading), except where the drainage channel is present. In this area, we
expect that the repair discussed previously would still be needed. Therefore, we estimate the need for
about 300 cubic yards of undercut, with about 210 cubic yards of clean stone needed to floor-in the
channel bottom. Both of these numbers include repairing the fixture expansion areas, and would be about
25% less without the expansion. We also suggest including about 150 cubic yards of undercut repair for
near surface repairs outside of the channel in the building pad, again assuming a summertime grading
operation where shallow repairs can be completed with moisture conditioning and recompaction rather
than undercut.
One alternative to using stone replaced footings would be to use helical piers. Most specialty
contractors who install the piers will provide a cost estimate if provided with a foundation plan and
loading information. We suggest comparing the cost of stone replacement with installing helical piers as
both would be adequate for this site.
Because the near surface soils in the borings are firm, we do not expect that significant undercut
type repairs will be needed in pavement areas. We recommend that all parking and driveway areas at
grade or designated to receive fill be proofrolled with a loaded dump truck in the presence of a
geotechnical engineer once site grading begins. Areas found to be unstable during the proofroll should be
repaired as directed by the on-site engineer. We suggest including about 250 cubic yards or undercut for
random pavement repairs; however, conducting site grading during the typically cooler and wetter winter
months may result in the need for more significant repairs.
The on site soils, excluding organics and unsuitable undercut soils, should be suitable for reuse as
structural fill provided compaction moisture is maintained near optimum during placement. If off site
borrow is required, a low plasticity clay, silt, or sand with Unified Soil Classifications of CL, ML, SM,
and SC may be imported for use as structural fill. All new fill should be compacted to not less than 95%
of the standard Proctor maximum dry density except in the final foot where this requirement should be
increased to 98% of the standard Proctor maximum.
If any areas of the building pad will receive more than 8 feet of fill, a minimum waiting period of
30 days should be observed between the time of completion of backfilling and the beginning of building
construction to allow fill induced settlements to subside. An alternative to this would be to establish
settlement points in the fill section to monitor the fill induced settlement for a period of time until the
settlement has subsided, or reduced to an acceptable level.
Difficult Excavation Considerations. Two of our test borings encountered PWR at 10 feet or
greater. Therefore, our borings suggest that difficult excavation type materials could be encountered in
isolated areas, notably in deeper cuts or excavations.
Foundation Support Considerations. With stone replaced footings, or with removal and
replacement of the existing fill, the proposed building may be supported on shallow spread footing
foundations designed for a bearing pressure of 3,000 psf subject to the restriction that column and wall
footings have least dimensions of not less than 24 and 16 inches, respectively. These foundations may
bear at nominal depth below finished exterior grade except that a minimum embedment depth of not less
::m.,r
O'Brien Atkins & Associates
SECU - Chief Mai-tin Street
September 12, 2007
Page: 5
than I8 inches is recommended for frost protection. All footings should be inspected by a geotechnical
engineer.
In order to assist the project structural engineer with an estimate of settlement potential, we have
prepared the attached Figures 4A and 4B to graphically illustrate the magnitude of settlement anticipated
for a range of column and wall loadings assuming subgrade repair. Typically, differential settlements are
equal to approximately one-half of the total settlement for a project of this nature. These values assume
that the bearing materials will be repaired as discussed previously.
Pavement Design Considerations. Neither field nor laboratory CBR tests have been performed on
representative samples from this site; however, we anticipate that properly prepared subgrades will
exhibit a design subgrade CBR value on the order of 4% or greater. A typical pavement structure for these
conditions would consist of 2 inches of asphalt over 8 inches of stone in areas subject only to light car
traffic such as the car parking stalls and a section consisting of 3 inches of asphalt over 8 inches of stone
in areas subject to channelized car traffic and occasional truck traffic. It is recommended that a minimum
5 inch thick concrete pad be constructed in front of the dumpster pad in order to better distribute the
heavy front wheel loadings from that vehicle during dumping operations. We further suggest placing a
minimum of 4 inches of CABC base course stone under the concrete slab to provide more uniform
support.
The most important parameters affecting pavement life on a site of this nature are the condition of
the subgrade at the time of base course stone placement and post construction drainage. It is
recommended that pavement subgrades be reworked and compacted to not less than 98% of the standard
Proctor maximum dry density immediately prior to base course stone placement. Additionally, site grades
should be detailed to promote drainage away from the pavement areas.
Miscellaneous Considerations. If low concrete retaining walls are constructed as a part of the
new construction, we suggest that they be designed for an equivalent triangular lateral earth pressure
based on the assumption that the soils behave as an equivalent fluid weighing 50 pounds per cubic foot
assuming level backfill behind the wall. For this value to be applicable, the material placed within 3 feet
of the retaining walls should be compacted with hand held rather than with heavy mechanized equipment.
If segmental unit retaining walls such as Keystone or Rockwood will be used, we suggest importing a
select granular fill for use in the reinforced zone and placing a drainage composite against cut slopes if the
walls will be used in front of cut slopes.
Seismic Design. This site is a seismic site class "D" under the building code based on the test
boring data.
GeoTechno logics, Inc. appreciates the opportunity to have provided you with our services on this
project. Please contact us if you should have questions regarding this report or if we may be of any
further assistance. '1111irti,,
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Sincerely,
ebT :cpnologies, Inc.
Ernest L. Stitzinger, P.E.
NC Registration No. 25534
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TEST BORING RECORD
DEPTH
(FT.)
0.0
0.3
6.5
12.5
17.0
20.5
DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (BLOWS/FT.) SIX INCHES
n in 20 an 60 inn
Topsoil ML
Fill - Stiff Red Fine Sandy SILT
4-5-8
5-6-6
Fill - Soft Black-Brown Slightly Organic Clayey
SILT OL
2-2-1
Alluvium - Firm Gray Clayey SILT ML
1-2-3
Possible Alluvium - Medium Dense Tan Slightly
Pine SAND SM
10
10
16
Boring terminated at 20.5' -
-

Groundwater not encountered at time of boring.
JOB NUMBER 1-07-1112-EA
BORING NUMBER B- I
DATE 9-10-07
PAGE 1 OF I
Maw!, t CeoTechnologies, Inc.
rn
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TEST BORING RECORD
DEPTH DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (FT.) (BLOWS/FT.) SIX INCHES
0.0
0.3
3.0
12.5
15.5
0 1 0 2 0 4 0 6 0 1 0 0
Topsoil ML
Possible Fill - Stiff Orange Fine Sandy Clayey

SILT
6-7-8
Very Stiff to Hard Red Brown Clayey SILT ML
9-12-12
i
8-12-24
Hard Tan Fine Sandy SILT ML
13-25-27
Boring tenninated at 15.5'

Groundwater not encountered at time of boring.
JOB NUMBER 1-07-1112-EA
BORING NUMBER B- 2
DATE 9-10-07
PAGE 1 OF 1
IM ME, eoTe(hnologies, Inc.

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TEST BORING RECORD
DEPTH
(FT.)
0.0
0,4
7.C
12.5
20.0
22.0
25.5
DESCRIPTION
ELEVATION PENETRATION BLOWS PER
(FT.) (BLOWS/FT.) SIX INCHES
10 20 40 60 100
Fill -Topsoil ML
Fill - Stiff to Very Stiff Red Orange SILT
5-7-9
6-6-7
Possible Fill - Firm Brown Fine Sandy Clayey SILT MI.
2-3-4
Stiff to Hard Brown Slightly Micaceous SILT ML
3-4-7
Partially Weathered Rock - Silty d
.D 6-24-50/5"
Hard Purple Fine Sandy SILT ML

Boring terminated at 25.5' 40-18-30

Groundwater not encountered at time of boring.
JOB NUMBER
BORING NUMBER
DATE
PAGE 1 OF 1
1-07-1112-EA
B- 3
9-10-07
3
0
fV
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TEST BORING RECORD
DEPTH
(FT.)
0.0
0.4
3.0
6.0
12.0
15.5
DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (BLOWS/FT.) SIX INCHES
0 10 20 46 60 100
Fill - Topsoil ML
Fill - Very Stiff Red Brown Fine Sandy SILT
a-s-lo
Possible Pill -Stiff Brown Fine Sandy Clayey SILT ML
5-6-7
Very Stiff Brown Pine Sandy SILT ML
5-7-9
Very Moist Cirm Brown Slightly Micaceous Fine
Sandy SILT ML
4
3
3
Boring terminated at 15.5' -
-

Groundwater not encountered at time of boring.
JOB NUMBER 1-07-1112-BA
BORING NUMBER B- 4
DATE 9-10-07
PAGE I OF 1

a
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TEST BORING RECORD
DEPTH
(FT.)
0.0
0.4
3.0
7.5
12.0
15.5
DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (BLOWS/FT.) SIX INCHES
0 10 20 40 60 100
Fill - Topsoil ML
Fill - Very Stiff Red Fine Sandy SILT
9-$-9
Fill - Stiff Brown Silty CLAY w/Some Organics CL
CH
5-5-5
Fill - Firm Brown Silty CLAY CL
2-3-2
Very Stiff Red Slightly Micaceous Fine Sandy
SILT MI..
3-7-9
Boring ternabiated at 15.5'

Groundwater not encountered at time of boring.
JOB NUMBER 1-07-1112-EA
BORING NUMBER B- 5
DATE 9-10-07
PAGE 1 OF 1

0
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TEST BORING RECORD
DEPTH DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (FT.) (BLOWS/FT.) SIX INCHES
0.0
0.3
8.0
12.0
15.5
0 1 0 2 0 4 0 6 0 1 0 0
Fill - Topsoil
Fill - Stiff to Very Stiff Iced Fine Sandy SILT
9-8-$
5-4-5
Fill - Soft Brown Silty CLAY w/Some Organics CL
T 3-1-2

Stiff Tarr Fine Sandy SILT
ML - ' I
5-6
3
Boring terminated at 15,5' -

Groundwater not encountered at time of boring.
JOB NUMBER 1-07-1112-EA
BORING NUMBER B- 6
DATE 9-10-07
PAGE 1 OF 1
I
• 1 11
0
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TEST BORING RECORD
DEPTH
(FT.)
0.0
0.3
3.0
10.5
DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (BLOWS/FT.) SIX INCHES
n in In en Kn inn
Fill -Topsoil
Fill - Stiff Tan Brown Clayey SILT 4-G-8
Possible Fill - Very Stiff Red Fine Sandy SILT ML
10-11-14

Boring terminated at 10.5' 6-6-8

vcvunuwdter not encounterea at time of boring.
JOB NUMBER
BORING NUMBER
DATE
PAGE 1 OF 1
1-07-1112-EA
B-7
9-10-07 V1111110, Gw _
S
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TEST BORING RECORD
DEPTH
(FT.)
U
0.3
3.0
8.0
10.5
DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (BLOWS/FT.) SIX INCHES
n 1 n 2n An An 1 AA
Fill -Topsoil CL
Fill - Very Stiff Brown Fine Sandy Silty CLAY 4-8-8
Very Stiff Brown Clayey SILT ML
6-9-15
Stiff Red Brown Clayey SILT ML

Boring terminated at 10.5' 6-7-8

Uroundwater not encountered at time of boring.
JOB NUMBER
BORING NUMBER
DATE
PAGE 1 OF 1
1-07-1112-1?A \
B-8
9-10-07 ? e f 1 1
0
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TEST BORING RECORD
DEPTH
(FT.)
0.0
0.3
3.0
6.5
10.5
DESCRIPTION ELEVATION PENETRATION
(FT.) (BLOWS/FT.)
(A in nn AA -
BLOWS PER
SIX INCHES
ynn
Fill -Topsoil ?
Fill - Very Stiff Tan SILT
5-7-9
Fill - Firm Purple Fine Sandy Clayey SILT ML
3-3-5
Possible Fill - Stiff Micaceous Fine Sandy SILT ML
Boring letminated at 10.5' 5-5-7

vruunuwuter not encounterea at time of boring.
JOB NUMBER 1-07-1112-EA
BORING NUMBER B- 9
DATE 9-10-07
PAGE 1 OF 1
• 1 11
0
0
0
a
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N
n
Q
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U
4
TEST BORING RECORD
DEPTH
(FT.)
0.0
0.3
3.0
8.0
9.5
10.0
DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (BLOWS/FT.) SIX INCHES
u 10 20 40 60 1 00
Possible Fill -Topsoil ?
Possible Fill - Very Stiff Red Brown SILT
5-8-10
Stiff Purple Clayey SILT ML
5-5-8
Bard Tan Fine Sandy SILT MI
Partially Weathered Rock - Silty "
Boring terminated at 10' 30-50/4

%jwu,ruwater not encounterea at Me of boring.
JOB NUMBER
BORING NUMBER
DATE
PAGE 1 OF 1
1-07-1112-EA \
B-10
9-10-07
• - 1 1g
0
3
ti
0
C7
C7
CL
fV
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TEST BORING RECORD
DEPTH
(FT.)
0.0
0.4
7.5
10.5
DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (BLOWS/FT.) SIX INCHES
U 1 0 2 0 40 60 100
Fil] - Topsoil ML
Fill - Stiff to Very Stiff Tan Fine Sandy SILT 5-8-9
4-5-6
Very Stiff Brown Silty CLAY CL
CI'l
Boring terminated at 10.5 12-8-12

uivunuwater not encounierea at time of boring.
JOB NUMBER 1-07-1112-EA
BORING NUMBER B-l I
DATE 9-10-07;: <.. a a gi e s, I n c.
PAGE 1 OF I
m
0
c?
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V
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N
O
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S ?1
TEST BORING RECORD
DEPTH
(FT.)
0.0
0.3
7.5
12.0
15.5
DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (BLOWS/FT.) SIX INCHES
0 1 0 20 40 60 100

Fill - Stiff Brown Clayey SILT
4-8-7
3-5-5
Possible Fill - Wood
3-3-4
Bard Tan SILT

Boring terminated at 15.5'
6-15-22
I

kirounawater not encountered at time ol'boring;.
JOB NUMBER 1-07-1112-EA
BORING NUMBER B-12
DATE 9-10-07
PAGE 1 OF i
?...... 4mc--oTe(hnologies, Inc
ti
a
0
c?
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r
0
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a

DEPTH
(FT.)
0.0
0.3
6.0
10.5
Groundwater not encountered at time of boring.
TEST BORING RECORD
DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (BLOWS/FT.) SIX INCHES
n IA 1n AA /n

Fill - Topsoil
ML 7V V V 1 VV
Fill - Finn to Very Stiff Red Fine Sandy SILT
6-9-11
3-3-4
Possible Fill - Stiff Red Silty CLAY CL
Boring terminated at 10.5' 4-5-8

JOB NUMBER 1-07-1112-BA
BORING NUMBER B-13
DATE 9-10-07
PAGE 1 OF 1

RECEIVED
N.C. Deot. of ENR
' 013 - 3 q 4 OCT 0 3 2008
Wlnston•Salem
Regional Office
CONTROL
STORMWATER AND EROSION
NARRATIVE AND CALCULATIONS RD
0 % 1 1 4 2008
DENR - `DATER CuAUlY
NC State Employees' Credit Union WETU1yDS 00 S??`Rt`?'.^!?^?TER
1 ' Madison
Rockingham County, North Carolina
Prepared for:
' State Employees' Credit Union
c/o O'Brien Atkins Architects
PO BOX 12037
' RTP, NC 27709
[phone]
'
Date:
4/9/2008
Revised: 9/19/2008

, yN CAR 0
?

Prepared by: r AL
033748
McKim & Creed, PA ??;GINe'?
1730 Varsity Drive C.?P??
Suite 500
Raleigh, NC 27606

? v?MCMM&crzEED
' TABLE OF CONTENTS
' NARRATIVE
FIGURES
' SITE AERIAL PHOTO
' USDA SOIL SURVEY MAP
PRE-DEVELOPMENT DRAINAGE AREA MAP
' POST-DEVELOPMENT DRAINAGE AREA MAP
WATER QUALITY
BIORETENTION AREA DESIGN SUMMARY SHEETS
' WATER QUANTITY
PRE- vs. POST-DEVELOPMENT WATER QUANTITY SUMMARY
' EROSION CONTROL CALCULATIONS
SEDIMENT TRAP CALCULATIONS
SWALE & DIVERSION DITCH DESIGN CALCULATIONS
' RIP RAP APRON SIZING
PRE-DEVELOPMENT STORMWATER CALCULATIONS
' POST-DEVELOPMENT STORMWATER CALCULATIONS
' STORM DRAINAGE CALCULATIONS
L
DESIGN NARRATIVE
' 1. GENERAL
The project site is located on Chief Martin Street approximately 1115 feet from the intersection
' of Highway Street and Chief Martin Street in Rockingham County, North Carolina. The total
area of the parcel is 6.99 acres. The total disturbed area for site construction is 2.96 acres.
The intent of this project is to construct a new State Employees Credit Union and all associated
' parking required to serve the facility. The bank will incorporate a four lane drive-up teller bay
area that will be serviced from the interior parking drives. The site will be served by public
water and public sewer systems.
' Stormwater and erosion control devices will be designed and constructed in accordance with
the NCDENR Division of Land Quality and Division of Water Quality requirements.
2. EXISTING SITE DESCRIPTION
' The existing topography of the site is slight to moderate slopes (4% - 6%) with a high point
generally in the northeast property corner around elevation 637. The site drains east to west to
an existing stream.
' The point of interest used for stormwater calculations is the existing creek immediately
downstream of the site. Pre-construction runoff at the point of interest is 4.51 cfs for the 1-yr,
t 24-hour storm. The water body downstream from the site is Big Beaver Island Creek, which is
considered class C water. Existing vegetation consists primarily of trees, and existing soils on
the site are, per USGS soils survey, SvB (Stoneville Loam, 2-8% slopes) and SwC (Stoneville-
urban land complex, 2-10% slopes). The soils are classified as hydrologic soil type B.
3. PROPOSED IMPROVEMENTS
' An existing 36" corrugated metal pipe currently enters the site from the east and outlets
stormwater from the adjacent site into the existing stream mentioned above. The corrugated
metal pipe will be shortened and rerouted around the site to bypass offsite runoff. The offsite
drainage area to this pipe was estimated using aerial photographs to have 10.02 acres of
impervious surface and 2.90 acres of pervious surface. There is also a 12" CMP at the
southeast corner of the site that discharges stormwater from the same adjacent property. The
' offsite drainage area to this pipe was estimated to be 1.42 acres of impervious surface and 2.57
acres of pervious surface. This drainage will also bypass the proposed site.
' Onsite stormwater controls were designed for 85% TSS removal and control of the first 1 " of
runoff per NCDWQ requirements. Two grassed bioretention areas are proposed to meet these
requirements. Pre-development runoff for the 1-yr, 24-hour storm is 4.51 cfs while post-
development runoff is 3.68 cfs. Offsite areas where there was no change in runoff between
pre- and post-development were not included in these calculations.
Stormwater runoff will be conveyed to the proposed bioretention areas through a system of
' reinforced concrete pipes, catch basins, drop inlets, flared end sections and manholes. Rip-rap
aprons will serve to reduce exit velocities at proposed flared end sections.
J
4. EROSION AND SEDIMENTATION CONTOL
' Erosion control measures have been designed per NCDENR Division of Land Quality
requirements. Temporary diversion ditches, silt fence, inlet protection and sediment traps have
all been implemented to reduce sediment laden runoff from the site. A temporary construction
' entrance will be constructed on Chief Martin Rd.

D

11

FIGURES

3
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WATER QUALITY
1
1
I
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
NORTH BIORETENTION AREA
Project Information:
Project Name: SECU - Madison
McKim & Creed Project #: 01517-0178
Designed by: JCA Date: 9/23/2008
Revised by: Date:
Revised by: Date:
Checked by: Date:

Site Information:
Sub Area Location: Post-1
Drainage Area (DA) = 1.31 Acres
Impervious Area (IA) = 0.73 Acres
Percent Impervious (1) = 55.7 %
Required Storage Volume:
Design Storm = 1.0 inch
Determine Rv Value = 0.05 +.009 (1) = 0.55
Storage Volume Required = 2,623 cf
Surface Area:
Ponding Depth = 10 in.
Surface Area = 3,147 sf
Elevations:
Top Elevation = 624.00 ft
Temporary Pool Elevation = 622.83 ft (Riser Elev.)
Bottom Elevation = 622.00 ft
Areas/Volumes:
Area @ Top of Temporary Pool = 3,756 sf (Elev = 622.83)
Bottom Surface Area = 3,174 sf (Elev = 622.00)
Volume of Temporary Storage = 2,923 cf Bottom Elev. (622') to Riser Elev. (622.83'))
Bioretention Area Side Slopes = 3 : 1
Volume of Storage for 1" Storm = 2,923 Yes ( 2923 > 2623 ) cf
1
1
1
1
1
1
1
1
1
1
1
1
1
NORTH BIORETENTION AREA
Find Time Drawdown of Water Through Bio-Retention Soil Laver
A. Rate of Drawdown Qd = (2.3e-5) * k * SA * H / L H / L Approximatley = 1
Qd= 0.1448 cf
B. Find Time to Drawdown Water from Inundation to Saturation at Surface:
Volume to Drawdown: Vi-s = SA *Depth
Vi-s = 2,623
Time to Remove Volume of Water at Flowrate Qd:
Ti-s = Vi-s / Qd = 18,116 sec.
5 hr.
C. Find Time to Drawdown Water from Saturation at Surface to 2 feet Below Surface:
Porosity (n) = 0.45
Volume to Drawdown: Vi-s = 2 feet * SA * n
Vs-2 = 2,832
Time to Remove Volume of Water at Flowrate Qd:
Ts-2 = Vs-2 / Qd = 19,565 sec.
= 5 hrs
D. Total Time to Draw Water Through Soil:
T= 10 hrs

I

NORTH BIORETENTION AREA
Underdrain Pipe Sizing
Note: Underdrain pipes are to be used when existing soil is clay.
NxD=16*( 10*Qd*n/s^0.5)^(3/8)
N (Numbr of Underdrain Pipes )
D (Pipe Diameter) = 6 in
s (Internal Slope of Pipe) = 0.50%
n (Mannings Roughness Coefficient) = 0.011
N x D = 9.15
N = 1.52
= 2 Pipes
Pipe Type and Diameter Manning Roughness Coeff.
4" Single Wall Corrugated Plastic 0.014 - 0.015
4" Smooth Wall Plastic 0.010 - 0.011
6" Single Wall Corrugated Plastic 0.014 - 0.015
6" Smooth Wall Plastic 0.010 - 0.011
8" Single Wall Corrugated Plastic 0.015 - 0.016
Gravel Envelope: Underdrain pipe should have 2 inches gravel cover.
The minimum depth for the gravel envelope should be 6 inches.
Depth = 8 in
1
1
1
1
1
1
1
i
1
1
1
1
1
1
1
1
1
1
1
SOUTH BIORETENTION AREA
Project Information:
Project Name:
McKim & Creed Project #:
Designed by:
Revised by:
Revised by:
Checked by:
Site Information:
Sub Area Location:
Drainage Area (DA) _
Impervious Area (IA) _
Percent Impervious (1) _
Required Storage Volume:
Design Storm =
Determine Rv Value =
Storage Volume Required =
SEW - Madison
01517-0178
JCA Date: 9/23/2008
Date:
Date:
Date:
Post-2
0.94 Acres
0.50 Acres
53.2 %
1.0 inch
0.05 +.009 (1) = 0.53
1,804 cf
Surface Area:
Ponding Depth = 10 in.
Surface Area = 2,165 sf
Elevations:
Top Elevation = 623.00 ft
Temporary Pool Elevation = 621.83 ft (Riser Elev.)
Bottom Elevation = 621.00 ft
Areas/Volumes:
Area @ Top of Temporary Pool = 2,763 sf (Elev = 621.83)
Bottom Surface Area = 2,298 sf (Elev = 621.00)
Volume of Temporary Storage = 2,137 cf Bottom Elev. (621') to Riser Elev. (621.83'))
Bioretention Area Side Slopes = 3 : 1
Volume of Storage for 1" Storm = 2,137 Yes ( 2137 > 1804 ) cf

1
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SOUTH BIORETENTION AREA
Find Time Drawdown of Water Through Bio-Retention Soil Laver
A. Rate of Drawdown Qd = (2.3e-5) * k * SA * H / L H / L Approximatley = 1
Qd= 0.0996 cf
B. Find Time to Drawdown Water from Inundation to Saturation at Surface:
Volume to Drawdown: Vi-s = SA *Depth
Vi-s = 1,804
Time to Remove Volume of Water at Flowrate Qd:
Ti-s = Vi-s / Qd = 18,116 sec.
5 hr.
C. Find Time to Drawdown Water from Saturation at Surface to 2 feet Below Surface:
Porosity (n) = 0.45
Volume to Drawdown: Vi-s = 2 feet * SA * n
Vs-2 = 1,948
Time to Remove Volume of Water at Flowrate Qd:
Ts-2 = Vs-2 / Qd = 19,565 sec.
= 5 hrs
D. Total Time to Draw Water Through Soil:
T= 10 hrs
SOUTH BIORETENTION AREA
Underdrain Pipe Sizing
Note: Underdrain pipes are to be used when existing soil is clay.
NxD=16*( 10*Qd*n/s^0.5)^(3/8)
N (Numbr of Underdrain Pipes )
D (Pipe Diameter) = 6 in
s (Internal Slope of Pipe) = 0.50%
n (Mannings Roughness Coefficient) = 0.011
N x D = 7.95
N = 1.33
2 Pipes
Pipe Type and Diameter Manning Roughness Coeff.
4" Single Wall Corrugated Plastic 0.014 - 0.015
4" Smooth Wall Plastic 0.010 - 0.011
6" Single Wall Corrugated Plastic 0.014 - 0.015
6" Smooth Wall Plastic 0.010 - 0.011
8" Single Wall Corrugated Plastic 0.015 - 0.016
Gravel Envelope: Underdrain pipe should have 2 inches gravel cover.
The minimum depth for the gravel envelope should be 6 inches.
Depth = 8 in

7

WATER QUANTITY
1

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EROSION CONTROL
' CALCULATIONS

11

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SEDIMENT TRAP #1
Project Information
Project Name: SECU - Madison
McKim & Creed Project #: 01517-0178
Designed by: JCA Date: 9116/2008
Revised by: Date:
Checked by: GML Date: 9/18/2008

Drainage Area Total, AT= 1.56 Ac
Disturbed, AD= 1.11 Ac
10-year Runoff (Q10) C = 0.60
Tc = 5.00 min
110 = 7.22 in/hr
Q10 = 6.76 cfs
Surface Area Required SA = 435 sf X Q10
SA = 2,940 sf (At Spillway Elevation)
Non-Rectangular Areas Surface = 3,520 sf (At Spillway Elevation)
Bottom = 1,388 sf
Volume Required VR = 3600 cf/Ac x AD
VR = 3,996 cf (At Spillway Elevation)
Side Slopes = 3 :1
Depth = 3.5 ft
Elevations Description Elevation
Top of Berm 624.00 (Allow 1ft freeboard above spillway flow height)
Emergency Spillway 622.50
Cleanout Mark 620.75 (Half of storage height)
Bottom 619.00
Provided SAP= 3,520 sf > 2,940
VP = 8,589 cf > 3,996
Emergency Spillway - Q10 110 = 7.22 in/hr
Q10 = 6.76 cfs
h = 1.5 ft
CW = 3.0
Minimum Lw= 6 ft (Minumum set by NCDENR)
Actual Lw= 10 ft (Based on Q10 Flows)
Depth at Spillway = 0.37

SEDIMENT TRAP #2
i

Project Information
Project Name: SECU - Madison
McKim & Creed Project #: 01517-0178
Designed by: JCA Date: 9/16/2008
Revised by: Date:
Checked by: GML Date: 9/18/2008

Drainage Area Total, AT= 1.55 Ac
Disturbed, AD= 1.29 Ac
10-year Runoff (Q10) C = 0.50
Tc = 5.00 min
110 = 7.22 in/hr
Q10 = 5.60 cfs
Surface Area Required SA = 435 sf X Q10
SA = 2,434 sf (At Spillway Elevation)
Non-Rectangular Areas Surface = 2,573 sf (At Spillway Elevation)
Bottom = 945 sf
Volume Required VR = 3600 cf/Ac x AD
VR = 4,644 cf (At Spillway Elevation)
Side Slopes = 3 :1
Depth = 3.5 ft
Elevations Description Elevation
Top of Berm 623.00 (Allow 1ft freeboard above spillway flow height)
Emergency Spillway 621.50
Cleanout Mark 619.75 (Half of storage height)
Bottom 618.00
Provided SAP= 2,573 sf > 2,434
VP = 6,157 cf > 4,644
Emergency Spillway - Q10 110 = 7.22 in/hr
Q10 = 5.60 cfs
h = 1.5 ft
Cw = 3.0
Minimum Lw= 6 ft (Minumum set by NCDENR)
Actual Lw= 10 ft (Based on Q10 Flows)
Depth at Spillway = 0.32
' SEDCAD 4.0
f -,Hri hf 1QQR P-I. I Ghuiah
1
Swale #1 Permanent Lining
Material: Grass mixture
Trapezoidal Channel
Left Ri ht
Bottom 9 Retardance Freeboard
Freeboard Freeboard Limitin
9
Width (ft) Sideslope Sideslope Slope (%) Classes
R
ti
R
ti Depth (ft) % of Depth Mult. x Velocity
(fps)
a
o
a
o (VxD)
3.50 3.0:1 3.0:1 3.9 D, B 0.50 5.0
Stability Stability Capacity Capacity
Class D w/o Class D w/ Class B w/o Class B w/
Freeboard Freeboard Freeboard Freeboard
Design Discharge: 1.67 cfs 1.67 cfs
Depth: 0.28 ft 0.78 ft j 0.61 ft 1.11 ft

Top Width:
5.21 ft
8.21 ft
--
r
-
7.15 ft
------------
10.15 ft
Velocity: 1.35 fps 0.52 fps
X-Section Area: 1.24 sq ft 3.24 sq ft
Hydraulic Radius: 0.234 0.441
Froude Number: 0.49 0.14
Roughness Coefficient: 0.0830 0.3296
SEDCAD Utility Run Printed 09-17-2008
1

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SEDCAD 4.0
1QOa ate. 1. 1
Diversion Ditch #1 Temporary Linina
Material: Straw w/ Net
Triangular Channel
Left Right Freeboard Freeboard Freeboard
Sideslope Sideslope Slope (%) Manning's n Mult. x
Ratio Ratio Depth (ft) % of
Depth (VxD)
3.0:1 3.0:1 3.9 0.0330 0.30
w/o Freeboard w/ Freeboard
Design Discharge: 1.67 cfs
Depth: 0.43 ft 0.73 ft
Top Width: 2.55 ft 4.35 ft
Velocity: 3.07 fps
X-Section Area: 0.54 sq ft
Hydraulic Radius:
Froude Number: 0.202
1.17
Check that T < Tmax for Straw w/ Net
For Straw w/ Net, Tmax =1.45
T=7xdxs
Where:
7 = 62.4
d = 0.43
s =0.039
62.4 x 0.43 x 0.039 = 1.05
T < Tmax
1.05 < 1.45
Straw w/ Net is acceptable
1
SEDCAD Utility Run
Printed 09-17-2008

1
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SEDCAD 4.0
r- ... ;m,* 1008 P-1. I Crh?eroh
1
Diversion Ditch #2 Temporary Lining
Material: Straw w/ Net
Triangular Channel
Left Right Freeboard Freeboard Freeboard
Sideslope Sideslope Slope (%) Manning's n Mult. x
Ratio Ratio Depth (ft) % of Depth (VxD)
. 3.0:1 3.0:1 5.0 0.0330 0.50
w/o Freeboard w/ Freeboard
Design Discharge: 1.15 cfs
Depth: 0.35 ft 0.85 ft
Top Width:
Velocity: 2.12 ft 5.12 ft
3.07 fps
X-Section Area: 0.37 sq ft
Hydraulic Radius: 0.168
Froude Number: 1.29
Check that T < Tmax for Straw w/ Net
For Straw w/ Net, Tmax =1.45
T= Yxdxs
Where:
'Y = 62.4
d = 0.35
s =0.050
62.4x0.35 x0.050=1.09
T < Tmax
1.09 < 1.45
.•. Straw w/ Net is acceptable
SEDCAD Utility Run
Printed 09-17-2008

SEDCAD 4.0
r-,Hnht 1 QQR P-1. I Rrh-.K
1
Diversion Ditch #3 Temporary Lining
Material: Straw w/ Mat
Triangular Channel
Left Right Freeboard Freeboard Freeboard
Sideslope Sideslope Slope (%) Manning's n Mult. x
Ratio Ratio Depth (ft) °/Q of Depth (VxD)
3.0:1 3.0:1 3.4 0.0330 0.50
w/o Freeboard w/ Freeboard
Design Discharge: 3.58 cfs
Depth: 0.58 ft 1.08 ft
Top Width: 3.49 ft 6.49 ft
Velocity: 3.53 fps
X-Section Area: 1.01 sq ft
Hydraulic Radius: 0.276
Froude Number: 1.15
Check that T < Tmax for Straw w/ Net
For Straw w/ Net, Tmax =1.45
T-7x dxs
Where:
7 = 62.4
d = 0.58
s =0.034
62.4 x 0.58 x 0.034 = 1.23
T < Tmax
1.23 < 1.45
.•. Straw w/ Net is acceptable
SEDCAD Utility Run
Printed 09-17-2008
SEDCAD 4.0
f'--;r h} 10QA 0-1. I Crhuroh
Diversion Ditch #4 Temporary Lim
Material: Straw w/ Net
Triangular Channel
Left Right Freeboard Freeboard Freeboard
Sideslope Sideslope Slope (%) Manning's n Mult. x
Ratio Ratio Depth (ft) % of Depth (VxD)
3.0:1 3.0:1 4.3 0.0330 0.50
w/o Freeboard w/ Freeboard
Design Discharge: 2.96 cfs
Depth: 0.52 ft 1.02 ft
Top Width: 3.11 ft 6.11 ft
Velocity: 3.66 fps
X-Section Area: 0.81 sq ft
Hydraulic Radius: 0.246
Froude Number: 1.27
Check that T < Tmax for Straw w/ Net
For Straw w/ Net, Tmax =1.45
T=yxdxs
Where:
7 = 62.4
d = 0.52
s =0.043
62.4 x 0.52 x 0.043 = 1.40
T < Tmax
1.40 < 1.45
.•. Straw w/ Net is acceptable
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SEDCAD Utility Run Printed 09-17-2008

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• • •

PROJECT NAME: SECU - Madison
PROJECT LOCATION: Madison, NC DATE: 9/16/08

PROJECT NO:
1517-0178 DESIGNED BY:
JCA
CHECKED BY
GML
Storm Outlet Structure
Structure= FES-5 Q10/Qfull = 1.58
Size= 48 in V/Vfull = 1.10
Q10= 74.19 cfs V = 7.3 fps
Qfull = 47.08 cfs
Vfull = 6.66 fps
From Fig. 8.06.b.1: Zone = 2
From Fig. 8.06.b.2: D5o = 8 in
DMAx = 12 in

{; Riprap Class = B

Apron Thickness
Apron Length -
-
=
22
24.0
in
ft

Length Apron Width = 3 x Dia 12.0 ft
Storm Outlet Structure
Structure= FES-20 Q10/Qfull = 0.57
Size= 18 in V/Vfull = 1.024
Q10 = 8.00 cfs V = 8.2 fps
Qfull = 14.07 cfs
Vfull = 7.96 fps
From Fig. 8.06.b.1: Zone = 2
From Fig. 8.06.b.2: D50 = 8 in
DMAx = 12 in

y Riprap Class
Apron Thickness =
= B
22
in
'
; { t t
r Apron Length = 9.0 ft
Apron Width = 3 x Dia = 5.0 ft
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• • • •

PROJECT NAME: SECU - Madison
PROJECT LOCATION: Madison, NC DATE: 9/16/08

PROJECT NO:
1517-0178 DESIGNED BY:
JCA
CHECKED BY
GML
Storm Outlet Structure
Structure= FES-13 Q10/Qful1 = 0.53
Size= 15 in V/Vfull = 1.012
Q10 = 5.93 cfs V = 9.2 fps
Qfull = 11.17 cfs
Vfull = 9.10 fps
From Fig. 8.06.b.1: Zone = 2
From Fig. 8.06.b.2: D50 = 8 in
DmAx = 12 in
-I Riprap Class = B
Apron Thickness = 22 in

3 Apron Length = 7.5 ft

Length Apron Width = 3 x Dia = 4.0 ft
Storm Outlet Structure
Structure= FES-18 Q10/Qfull = 0.26
Size= 15 in V/Vfull = 0.831
Q10 = 3.68 cfs V = 9.8 fps
Qfull = 14.42 cfs
Vfull = 11.75 fps
From Fig. 8.06.b.1: Zone = 2
From Fig. 8.06.b.2: D50 = 8 in
DMAx = 12 in
-7 Riprap Class = B
sl Apron Thickness = 22 in
MR. Apron Length = 7.5 ft

Length Apron Width = 3 x Dia = 4.0 ft
PRE-DEVELOPMENT
STORMWATER
CALCULATIONS

1

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Pre-1
OLD
Off s ite-1
pre,,
n
POA #1

Type.... Master Network Summary Page 2.01
Name.... Watershed
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Prede
MASTER DESIGN STORM SUMMARY
Network Storm Collection: Raleigh, NC
Total
Depth Rainfall
Return Event in Type RNF ID
----
-------
Pre -----
1 ------
3.0000 ----------------
Synthetic Curve ------------
TypeII 24hr
Pre 2 3.6000 Synthetic Curve TypeII 24hr
Pre 10 5.3800 Synthetic Curve 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
------ cu.ft Trun
---------- -- hrs
--------- cfs
-------- ft
-------- cu.ft
------------
--------------
OFFSITE-1 --- ---
AREA 1 9647 11.9000 3.64
OFFSITE-1 AREA 2 11730 11.9000 4.39
OFFSITE-1 AREA 10 17921 11.9000 6.59
*POA #1 JCT 1 23062 11 . 9500 4.51 - ?' r s'?{ nn
*POA #1 JCT 2 30584 11.9500 5.83
*POA #1 JCT 10 54796 12.0000 10.17
PRE-1 AREA 1 13415 12.2000 2.78
PRE-1 AREA 2 18853 12.2000 4.03
PRE-1 AREA 10 36875 12.2000 8.11
SIN: 2BYXYWHCPK58 Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 10:27 AM 9/22/2008

11,

DESIGN STORMS SUMMARY

' Storm Tag Name =-
----- --- ---- Pre--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
' m
St
T
N
= Pre 2
orm
ag
a
e ------------- -------------------------------
----------------------
Data Type, File, ID = ----
Synthetic Storm TypeII 24hr
' Storm Frequency = 2 yr
Total Rainfall Depth= 3.6000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name =
----- --- ---- Pre-10----
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 10 yr
Total Rainfall Depth= 5.3800 in
' Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs

L

Type.... Design Storms
Name.... Raleigh, NC
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Prede
Title... Project Date: 7/9/2008
Project Engineer: Nick Lutzweiler
Project Title: SECU-Madison
Project Comments:
Design Storm File,ID = Raleigh, NC
Storm Tag Name = Pre100
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 100 yr
Total Rainfall Depth= 8.0000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Page 4.01
11

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SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:27 AM
Bentley Systems, Inc.
9/22/2008
1
1
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1

Type.... Tc Calcs
Name.... OFFSITE-1
Page 6.01
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Prede
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: TR-55 Sheet
Mannings n .0110
Hydraulic Length 100.00 ft
2yr, 24hr P 3.6000 in
Slope .040000 ft/ft
Avg.Velocity 1.93 ft/sec
Segment #1 Time: .0144 hrs
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 251.00 ft
Slope .051000 ft/ft
Unpaved
Avg.Velocity 3.64 ft/sec
Segment #2 Time: .0191 hrs
-----------------------------------------------------------------------
Segment #3: Tc: TR-55 Channel
Flow Area 2.5000
Wetted Perimeter 5.91
Hydraulic Radius .42
Slope .048000
Mannings n .0500
Hydraulic Length 272.00
sq.ft
ft
ft
ft/ft
ft
Avg.Velocity 3.68 ft/sec
---------------------------------------------------
Segment #3 Time 0205 hrs
Total Tc: .0541 hrs
Calculated Tc < Min.Tc:
Use Minimum Tc...
-Use-Tc-=------_0833-hrs-
S/N: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:28 AM
Bentley Systems, Inc.
9/22/2008
Type.... Tc Calcs
Name.... PRE-1
Page 6.04
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Prede
t
1
1
1

TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: TR-55 Sheet
Mannings n .8000
Hydraulic Length 100.00 ft
2yr, 24hr P 3.6000 in
Slope .027000 ft/ft
Avg.Velocity .05 ft/sec
Segment #1 Time: .5210 hrs
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 440.00 ft
Slope .063000 ft/ft
Unpaved
Avg.Velocity 4.05 ft/sec
Segment #2 Time: .0302 hrs
------------------------------------------------------------------------
Total Tc: .5512 hrs
-------------------------
-------------------------
S/N: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:28 AM
Bentley Systems, Inc.
9/22/2008

Type.... Runoff CN-Area
Name.... OFFSITE-1
Page 7.01
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Prede
RUNOFF CURVE NUMBER DATA
--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Impervious 98 .960 98.00
COMPOSITE AREA & WEIGHTED CN ---> .960 98.00 (98)
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:28 AM
Bentley Systems, Inc.
9/22/2008

Type.... Runoff CN-Area
Name.... PRE-1
Page 7.02
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Prede
RUNOFF CURVE NUMBER DATA
------------------------------------ ---- ---------- ------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- -
Open space (Lawns,parks etc.) - Goo ---
61 ---------
.220 ----- ----- ------
61.00
Impervious Areas - Paved; open ditc 89 .090 89.00
Newly graded area (pervious only - 86 2.270 86.00
Woods - good 55 .870 55.00
COMPOSITE AREA & WEIGHTED CN ---> 3.450 76.67 (77)
SIN: 2BYXYWHCPK58 Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 10:28 AM 9/22/2008
i

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POST-DEVELOPMENT
STORMWATER
CALCULATIONS
1
Offs ite-1
Untreated-2

Untreated-1

:; . O

a2
Untre
ated
'
A
North Pond Routing North
Post-1 North Bio POA #1
South pond
Post-2 South Bio
1
1
1
1
1
1

Type.... Master Network Summary Page 2.01
Name.... Watershed
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
MASTER DESIGN STORM SUMMARY
Network Storm Collection: Raleigh, NC
Total
Depth Rainfall
Return Event in Type RN F ID
-------
Dev -----
1 ------
3.0000 ---------
Synthetic -------
Curve -------
TypeII ---------
24hr
Dev 2 3.6000 Synthetic Curve TypeII 24hr
Dev 10 5.3800 Synthetic Curve TypeII 24hr
Dev100 8.0000 Synthetic Curve 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 cu.ft Trun hrs cfs ft cu.ft
----- -------
NORTH BIO -
----
IN ----
POND ------
1 ---
----- -- --
6556 ---------
11.9500 -
- -
2.72 - -
--- ------------
NORTH BIO IN POND 2 8870 11.9000 3.68
' NORTH BIO IN POND 10 16267 11.9000 6.77
NORTH BIO IN POND 100 27863 11.9000 11.43
NORTH BIO OUT POND 1 3683 12.1500 .51 622.88 3067
' NORTH BIO OUT POND 2 5997 12.0500 2.09 623.02 3602
NORTH BIO OUT POND 10 13394 12.0000 6.04 623.22 4411
NORTH BIO OUT POND 100 24990 11.9500 10.57 623.40 5141
' OFFSITE-1 AREA 1 9647 11.9000 3.64
OFFSITE-1 AREA 2 11730 11.9000 4.39
OFFSITE-1 AREA 10 17921 11.9000 6.59
OFFSITE-1 AREA 100 27043 11.9000 9.83
' SIN: 2BYXYWHCPK58 Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 10:29 AM 9/24/2008

1

Type.... Master Network Summary Page 2.01
Name.... Watershed
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
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
Node ID Type Event cu.ft Trun
------
-------------
*POA #1 ---- ----
JCT ------
1 ----
16948
*POA #1 JCT 2 23988
*POA #1 JCT 10 46982
*POA #1 JCT 100 84120
POST-1 AREA 1 6556
POST-1 AREA 2 8870
POST-1 AREA 10 16267
POST-1 AREA 100 27863
POST-2 AREA 1 4481
POST-2 AREA 2 6106
POST-2 AREA 10 11339
POST-2 AREA 100 19592
SOUTH BIO IN POND 1 4481
SOUTH BIO IN POND 2 6106
SOUTH BIO IN POND 10 11339
SOUTH BIO IN POND 100 19592
SOUTH BIO OUT POND 1 2383
SOUTH BIO OUT POND 2 4009
SOUTH BIO OUT POND 10 9241
SOUTH BIO OUT POND 100 17495
UNTREATED-1 AREA 1 1063
UNTREATED-1 AREA 2 1960
UNTREATED-1 AREA 10 5670
UNTREATED-1 AREA 100 12967
UNTREATED-2 AREA 1 172
UNTREATED-2 AREA 2 292
UNTREATED-2 AREA 10 756
UNTREATED-2 AREA 100 1625
Max
Qpeak Qpeak Max WSEL Pond Storage
hrs cfs ft cu.ft
---------

11.9000 -------- --------

3.67 <-
~ I`
------------
12.0500 5.97 y? Srr?
11.9500 16.93
11.9500 29.13
11.9500 2.72
11.9000 3.68
11.9000 6.77
11.9000 11.43
11.9500 1.86
11.9500 2.53
11.9000 4.72
11.9000 8.06
11.9500 1.86
11.9500 2.53
11.9000 4.72
11.9000 8.06
12.3000 .27 621.86 2173
12.0500 1.35 621.97 2480
11.9500 4.33 622.14 2971
11.9500 7.61 622.30 3449
12.3500 .10
12.3000 .26
12.2500 1.06
12.2500 2.71
12.0000 .06
12.0000 .11
11.9500 .31
11.9500 .67
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:29 AM
Bentley Systems, Inc.
9/24/2008

DESIGN STORMS SUMMARY
' Design Storm File,ID = Raleigh, NC
Storm Tag Name = Dev
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
u
L

1
Type.... Design Storms
Name.... Raleigh, NC
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
Title... Project Date: 7/9/2008
Project Engineer: Nick Lutzweiler
Project Title: SECU-Madison
Project Comments:
Storm Tag Name = Dev 2
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 2 yr
Total Rainfall Depth= 3.6000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Dev 10
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 10 yr
Total Rainfall Depth= 5.3800 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Storm Tag Name = Dev100
Data Type, File, ID = Synthetic Storm TypeII 24hr
Storm Frequency = 100 yr
Total Rainfall Depth= 8.0000 in
Duration Multiplier = 1
Resulting Duration = 24.0000 hrs
Resulting Start Time= .0000 hrs Step= .1000 hrs End= 24.0000 hrs
Page 4.01
1

SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:33 AM
Bentley Systems, Inc.
9/22/2008
Type.... Tc Calcs
Name.... OFFSITE-1
Page 6.01
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
........................................................................
........................................................................
Segment #1: Tc: TR-55 Sheet
Mannings n .0110
Hydraulic Length 100.00 ft
2yr, 24hr P 3.6000 in
Slope .040000 ft/ft
Avg.Velocity 1.93 ft/sec
Segment #1 Time: .0144 hrs
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 130.00 ft
Slope .035000 ft/ft
Paved
Avg.Velocity 3.80 ft/sec
Segment #2 Time: .0095 hrs
-----------------------------------------------------------------------
Segment #3: Tc: TR-55 Channel
Flow Area .6200 sq.ft
Wetted Perimeter 1.97 ft
Hydraulic Radius .31 ft
Slope .018000 ft/ft
Mannings n .0130
Hydraulic Length 28.00 ft
Avg.Velocity 7.11 ft/sec
Segment #3 Time: .0011 hrs
------------------------------------------------------------------------
S/N: 2BYXYWHCPK58 Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 10:33 AM 9/22/2008

i
1
1
1
1
1
1
1
1
1
1

Type.... Tc Calcs
Name.... OFFSITE-1
Page 6.01
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
Segment #4: Tc: TR-55 Channel
Flow Area 3.5300 sq.ft
Wetted Perimeter 4.71 ft
Hydraulic Radius .75 ft
Slope .020000 ft/ft
Mannings n .0130
Hydraulic Length 349.00 ft
Avg.Velocity 13.37 ft/sec
Segment #4 Time: .0072 hrs
-----------------------------------------------------------------------
Segment #5: Tc: TR-55 Channel
Flow Area 6.2800
Wetted Perimeter 6.28
Hydraulic Radius 1.00
Slope .005000
Mannings n .0130
Hydraulic Length 36.00
sq.ft
ft
ft
ft/ft
ft
Avg.Velocity 8.10 ft/sec
Segment #5 Time: .0012 hrs
-----------------------------------------------------------------------
Segment #6: Tc: TR-55 Channel
Flow Area 2.5000 sq.ft
Wetted Perimeter 5.91 ft
Hydraulic Radius .42 ft
Slope .042000 ft/ft
Mannings n .0500
Hydraulic Length 111.00 ft
Avg.Velocity 3.44 ft/sec
Segment 46 Time: .0090 hrs
------------------------------------------------------------------------
Total Tc: .0425 hrs
Calculated Tc < Min.Tc:
Use Minimum Tc...
Use Tc = .0833 hrs
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:33 AM
Bentley Systems, Inc.
9/22/2008
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Type.... Tc Calcs
Name.... POST-1
Page 6.05
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
Segment #1 Time 0833 hrs
-----------------------------------------------_---
-------------------------
-------------------------
-Total-Tc:-----.0833-hrs-
S/N: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:33 AM
Bentley Systems, Inc.
9/22/2008
1
1
1
1
1
1
ii

Type.... Tc Calcs
Name.... POST-2
Page 6.07
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: User Defined
------ ----------------------------------- -----_0833 - hrs
Segment #1 Time
-------------------------
-------------------------
-Total-Tc_-----.0833-hrs-
S/N: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:33 AM
Bentley Systems, Inc.
9/22/2008

1
1
f
1
1
1
1

Type.... Tc Calcs
Name.... UNTREATED-1
Page 6.09
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
........................................................................
........................................................................
TIME OF CONCENTRATION CALCULATOR
Segment #1: Tc: TR-55 Sheet
Mannings n .8000
Hydraulic Length 100.00 ft
2yr, 24hr P 3.6000 in
Slope .027000 ft/ft
Avg.Velocity .05 ft/sec
Segment #1 Time: .5210 hrs
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 142.00 ft
Slope .050000 ft/ft
Unpaved
Avg.Velocity 3.61 ft/sec
segment #2 Time: .0109 hrs
-----------------------------------------------------------------------
Segment #3: Tc: TR-55 Channel
Flow Area 3.7500
Wetted Perimeter 9.16
Hydraulic Radius .41
Slope .038000
Mannings n .0300
Hydraulic Length 236.00
sq.ft
ft
ft
ft/ft
ft
Avg.Velocity 5.34 ft/sec
Segment #3 Time: 0123 hrs
------------- ---------------------------
------------------------
S/N: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:34 AM
Bentley Systems, Inc.
9/22/2008

Type.... Tc Calcs
Name.... UNTREATED-1
Page 6.09
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
Segment #4: Tc: TR-55 Shallow
Hydraulic Length 142.00 ft
Slope .132000 ft/ft
Unpaved
Avg.Velocity 5.86 ft/sec
Segment #4 Time: .0067 hrs
-----------------------------------------------------------------------
Segment #5: Tc: TR-55 Channel
Flow Area 2.5000
Wetted Perimeter 5.91
Hydraulic Radius .42
Slope .036000
Mannings n .0500
Hydraulic Length 59.00
sq.ft
ft
ft
ft/ft
ft
Avg.Velocity 3.19 ft/sec
Segment #5 Time: - hrs
-Total-Tc_-----.5561-hrs_
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:34 AM
Bentley Systems, Inc.
9/22/2008
t

Type.... Tc Calcs
Name.... UNTREATED-2
Page 6.13
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
TIME OF CONCENTRATION CALCULATOR
Segment 41: Tc: User Defined

1
1

------ - ------------------------------------_-----_0833 - hrs
Segment 41 Time
-------------------------
-------------------------
-Total-Tc:-----.0833-hrs-
S/N: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:34 AM
Bentley Systems, Inc.
9/22/2008
Type.... Runoff CN-Area Page 7.01
Name.... OFFSITE-1
1
1
1

1

File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
RUNOFF CURVE NUMBER DATA
--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Impervious 98 .960 98.00
COMPOSITE AREA & WEIGHTED CN ---> .960 98.00 (98)
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:34 AM
Bentley Systems, Inc.
9/22/2008

' Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Impervious Areas - Paved parking to 98 .730 98.00
Open space (Lawns,parks etc.) - Goo 61 .580 61.00

Type.... Runoff CN-Area
Name.... POST-1
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
RUNOFF CURVE NUMBER DATA
COMPOSITE AREA & WEIGHTED CN ---> 1.310 81.62 (82)
Page 7.02

SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:34 AM
Bentley Systems, Inc.
9/22/2008
1
1
1
1
1
1
1
1

Type.... Runoff CN-Area
Name.... POST-2
Page 7.03
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
RUNOFF CURVE NUMBER DATA
--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open space (Lawns,parks etc.) - Goo 61 .440 61.00
Impervious Areas - Paved parking to 98 .500 98.00
COMPOSITE AREA & WEIGHTED CN ---> .940 80.68 (81)
...........................................................................
S/N: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:34 AM
Bentley Systems, Inc.
9/22/2008
s

t
1
1
1
1
1
1
L
I 1

Type.... Runoff CN-Area
Name.... UNTREATED-1
Page 7.04
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Woods - good 55 .760 55.00
Open space (Lawns,parks etc.) - Goo 61 .430 61.00
COMPOSITE AREA & WEIGHTED CN ---> 1.190 57.17 (57)
...........................................................................
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:35 AM
Bentley Systems, Inc.
9/22/2008
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Type.... Runoff CN-Area
Name.... UNTREATED-2
Page 7.05
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
RUNOFF CURVE NUMBER DATA
..........................................................................
..........................................................................
--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open space (Lawns,parks etc.) - Goo 61 .130 61.00
COMPOSITE AREA & WEIGHTED CN ---> .130 61.00 (61)
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:35 AM
Bentley Systems, Inc.
9/22/2008
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Type.... Vol: Elev-Area
Name.... NORTH BIO
Page 12.01
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
Elevation Planimeter Area Al+A2+sgr(Al*A2) Volume Volume Sum
(ft) (sq?in)
(sq?ft) (sq.ft) --- - (cu.ft)-- -- -(cu?ft)
----
----
622.00 -----
--
----- 3174 -----
0 0 0
623.00 ----- 3880 10563 3521 3521
624.00 ----- 4642 12766 4255 7776
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: EL1, EL2 = Lower and upper elevations of the increment
Areal,Area2 = Areas computed for EL1, EL2, respectively
Volume = Incremental volume between ELl and EL2
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:30 AM
Bentley Systems, Inc.
9/24/2008
1
1

1
1
1
Type.... Vol: Elev-Area
Name.... SOUTH BIO
Page 12.02
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
Elevation Planimeter Area Al+A2+sgr(Al*A2) Volume Volume Sum
(ft)
-
--- (sq.in) (sq.ft)
---------------------- (sq.ft)
----------------- (cu.ft)
--------- (cu.ft)
-------------
------
-
621.00 ----- 2298 0 0 0
622.00 ----- 2862 7725 2575 2575
623.00 ----- 3483 9502 3167 5742
POND VOLUME EQUATIONS
* Incremental volume computed by the Conic Method for Reservoir Volumes.
Volume = (1/3) * (EL2-EL1) * (Areal + Area2 + sq.rt.(Area1*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
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:31 AM
Bentley Systems, Inc.
9/24/2008
1

Type.... Outlet Input Data
Name.... North Outfall
Page 13.01
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 622.00 ft
Increment = .25 ft
Max. Elev.= 624.00 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
----------------- ---- ------- --------- ---------
Inlet Box R ---> C 622.830 624.000
Culvert-Circular C ---> TW 617.250 624.000
TW SETUP, DS Channel
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:31 AM
Bentley Systems, Inc.
9/24/2008
t
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Type.... Outlet Input Data
Name.... North Outfall
Page 13.01
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
OUTLET STRUCTURE INPUT DATA
Structure ID = R
Structure Type = Inlet Box
-
# of Openings = -
1
Invert Elev. = 622.83 ft
Orifice Area = 4.0000 sq.ft
Orifice Coeff. _ .600
Weir Length = 8.00 ft
Weir Coeff. = 3.000
K, Reverse = 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:31 AM
Bentley Systems, Inc.
9/24/2008
Type.... Outlet Input Data
Name.... North Outfall
Page 13.02
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
OUTLET STRUCTURE INPUT DATA
Structure ID = C
Structure Type = Culvert-Circular
------------------------------------
No. Barrels = 1
Barrel Diameter = 1.2500 ft
Upstream Invert = 617.25 ft
Dnstream Invert = 616.00 ft
Horiz. Length = 70.00 ft
Barrel Length = 70.01 ft
Barrel Slope = .01786 ft/ft
OUTLET CONTROL DATA...
Mannings n = .0130
Ke = .2000 (forward entrance loss)
Kb = .023225 (per ft of full flow)
Kr = .2000 (reverse entrance loss)
HW Convergence = .001 +/- ft
INLET CONTROL DATA...
Equation form = 1
Inlet Control K = .0045
Inlet Control M = 2.0000
Inlet Control c = .03170
Inlet Control Y = .6900
T1 ratio (HW/D) = 1.086
T2 ratio (HW/D) = 1.188
Slope Factor = -.500
Use unsubmerged inlet control Form 1 equ. below T1 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 = 618.61 ft ---> Flow = 4.80 cfs
At T2 Elev = 618.74 ft ---> Flow = 5.49 cfs
S/N: 2BYXYWHCPK58 Bentley Systems, Inc.
Bentley PondPack (10.00.023.00) 10:31 AM 9/24/2008
1
1
1
1
1
1
i
1
i
1
1
1
1
1
Type.... Outlet Input Data
Name.... South Outfall
Page 13.07
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 621.00 ft
Increment = .25 ft
Max. Elev.= 623.00 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
----------------- ---- ------- --------- ---------
Inlet Box R ---> C 621.830 623.000
Culvert-Circular C ---> TW 616.250 623.000
TW SETUP, DS Channel
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:32 AM
Bentley Systems, Inc.
9/24/2008
t
1
1
1
1
1
1
1
1
1
i
1
1

Type.... Outlet Input Data
Name.... South Outfall
Page 13.07
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
OUTLET STRUCTURE INPUT DATA
Structure ID = R
Structure Type
------------------ = Inlet Box
------------------
# of Openings = 1
Invert Elev. = 621.83 ft
Orifice Area = 4.0000 sq.ft
Orifice Coeff. _ .600
Weir Length = 8.00 ft
Weir Coeff. = 3.000
K, Reverse = 1.000
Mannings n = .0000
Kev,Charged Riser = .000
Weir Submergence = No
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:32 AM
Bentley Systems, Inc.
9/24/2008

11
1
1
1

Type.... Outlet Input Data
Name.... South Outfall
Page 13.08
File.... S:\1517\0178-Madison\20-Tech\24b-Civil,Site,Hydraulic\Stormwater Management\Postd
OUTLET STRUCTURE INPUT DATA
Structure ID = C
Structure Type = Culvert-Circular
------------------------------------
No. Barrels = 1
Barrel Diameter = 1.2500 ft
Upstream Invert = 616.25 ft
Dnstream Invert = 616.00 ft
Horiz. Length = 92.00 ft
Barrel Length = 92.00 ft
Barrel Slope = .00272 ft/ft
OUTLET CONTROL DATA...
Mannings n = .0130
Ke = .2000 (forward entrance loss)
Kb = .023225 (per ft of full flow)
Kr = .2000 (reverse entrance loss)
HW Convergence = .001 +/- ft
INLET CONTROL DATA...
Equation form = 1
Inlet Control K = .0045
Inlet Control M = 2.0000
Inlet Control c = .03170
Inlet Control Y = .6900
T1 ratio (HW/D) = 1.094
T2 ratio (HW/D) = 1.196
Slope Factor = -.500
Use unsubmerged inlet control Form 1 equ. below T1 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 = 617.62 ft ---> Flow = 4.80 cfs
At T2 Elev = 617.74 ft ---> Flow = 5.49 cfs
SIN: 2BYXYWHCPK58
Bentley PondPack (10.00.023.00) 10:32 AM
Bentley Systems, Inc.
9/24/2008

H

1

STORM DRAINAGE
CALCULATIONS
1

cl-
??
%h
Q?.
P-2
?,Jl
CI-17
<R
YI-15
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Title: State Employees' Credit Union Project Engineer: Don Bataille
s:\...\stormcad\secu-madison.stm StormCAD v5.6 [05.06.012.00]
' 09/22/08 10:39:58OVkntley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA [phone] Page 1 of 1

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