SW8091003_HISTORICAL FILE_20110308

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW_8 �q�pp3
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
Cl7 HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE
2U1103U8
YYYYMMDD

Date:
rroject Location: 1�))A L> 1 Add info required (yef/—o)) Date received:
Rule(s) Subject (check all that apply): Symbols for completing farm '✓'= Yes/OK ' x'= No/Deficient 'n/a' o
❑ 1995 Coastal ❑ 2008 Coastal ❑ Phase II ❑ Universal
Paperwork:
❑ Check for $505 (must be no older than 6 months)
❑ Application form with correct/original signatures (original plus 1 copy). If Corporation or LLC also:
o Print the info from the NCSOS
o Either, 1.) The applicant is listed on the NCSOS with his/her correct title or, 2.) A notarized letter of
authorization has been provided:
❑ Supplements (1 original per BMP). BMP type(s): Do
❑ O&M with correct/original signatures (1 original per BMP, except level spreaders/filter strips and swales)
❑ Deed restrictions (if outparcel or subdividing) (original plus 1 copy)
o Deed restriction template (signed and notarized) or
o Proposed Declaration of Covenants and Restrictions (signed. and notarized)
❑ Soils report identifying the SHWT
❑ Supporting calculations, signed & sealed (if necessary)
(J Receiving stream classification: , If SA or ORW also:
o SA: USGS topo map with the site, the receiving waters and the Y mile radius shown to scale.
o ORW: 575 ft of MHWL for Area of Environmental Concern and max BUA per1rule.
❑ Modificati0 ilt: Designer's Cert., .) JIfartially built: Partial Cert., 3.) If not built: No Cert. needed.
Development T� a (check a I that apply
❑ Residen�(ial or ❑ m erclal ❑ Deed rest ricti 'ns match?
❑ Subdivi on for ElTi��gl Lot DaDe d ur°s fictions match?
❑ High Density or LoP, Density g p.g�pec�restnctions match?
❑ Offsite project ❑ developments M dii ati6n ❑ Exempt
❑ NCG02 (bulkhe-81 ❑ NCG03 (clear/grade) ❑ N G04 (linear)
Density: ► pW ❑ BUA calculations%inude'common areas, clue ho}�se de�walks, etc.
❑ BUA %: Matches high/low densi. gquirement for rule and receiving stream class.
❑ No obvious math errors \�\1
❑ If High Density: Design storm correct for rule and receiving stream class.
Plans, signed and sealed (2 sets):
❑ Two sets received ❑ Layout (with proposed BUA dimensions)
❑ Grading ❑ Drainage area map (all HD systems & curb outlet swales)
❑ Vicinity map ❑ Project Boundaries ❑ Legend
❑ Wetlands:
o Delineated on plans o "No wetlands onsite" on plans
❑ Details:
o Roads o Cul-de-sacs o Curbing o Sidewalk
o BMPs/ Level spreaders/ Filter strips/ Curb outlet swales o Buildings (Apts or Condos)
Offsite Projects:
❑ Designer's Certification has been submitted for the Offsite BMP receiving the runoff from the project.
❑ Deed restrictions have been recorded and a copy submitted for the Offsite BMP permit.
❑ Lot size has not changed from what was approved under the Master Plan.
❑ Correct lot number is referenced on the supplement form.
❑ Offsite system is in compliance with its permit, if known.
Infiltration Projects:
❑ Soils report: SHWT, soil type, and expected infiltration rate are provided.
❑ DWQ has conducted a site visit? Date:
Wet Ponds: Permanent Pool Meets One of the Following:
❑ Is located no lower than 6" below the estimated SHWT.
❑ Incoming groundwater is quantified and evaluated, AND Storage volume verified, AND Outlet evaluated for free
drainage to the receiving waters under SHWT conditions.
Decision (check one):
❑ Complete: Return file to admin (Jo Casmer) to log in. (Stamped in received date = BIMS date)
❑ Slightly incomplete: E-mail consultant, request information to be returned within one business day (24 hours after
request. Info requests on Friday, allow a return on the following business day). If info not returned, issue an
application return letter and give everything to admin. (Add info received date = BIMS date)
13 Substantially incomplete: Issue an application return letter and give everything to admin.

THOMAS & HUTTON ENGINEERING CO.
Via Hand Delivery
219 STATION ROAD
SUITE 101
WILMINGTON, NORTH CAROLINA 28405-3713
TELEPHONE (91 a) 332-3360
FAX [phone]
January 27, 2011
Ms, Kelly Johnson
North Carolina Department of Environment and Natural Resources
Division of Water Quality
127 Cardinal Drive Extension
Wilmington, NC 28405
Dear Ms. Johnson:
RECD JAN 9 7 2011
RE: Plan Revision # 2
Stormwater Project No. SW8 091003
Smith Creek Park
New Hanover County
J-20523.0004.303
The above referenced project has been revised to update the building square
footage, add a dumpster pad, add sidewalk connections to adjacent properties and add a
sanitary sewer lift station site. The plan revision increases the Phase 1 Built Upon Area (BUA) by
2,110 square feet and subsequently reduces the Future BUA by the same amount. Therefore,
there is no increase in the overall permitted BUA. The Phase 1 land disturbance and drainage
patterns generally remain the same. Construction has not begun on the previously permitted
plans. On behalf of the New Hanover County Parks Department, we are pleased to provide the
following items for your review:
• One (1) original and One (1) copy of the Storm Water Plan Revision Application; and
• Two (2) copies of the applicable revised Site Development Plans (sheets C3, C15, C16 &
C 17).
Please review the above information and, if acceptable, we respectfully request NCDENR
approval of the permit modification. Please feel free to contact me at [phone] should
you have any questions or comments. Thank you for your time and assistance with this project.
Sincerely,
THO�MASS & HHUTTON ENGINEERING CO.
Brian Riley
Project Manager
BDR/kap =
Enclosures: As listed above l JAN 2 7 2011
I
cc: Sara Burroughs (Haden Stanziale, P.A)
N:A20523, 0004VDocsVCorrespondcnccANC D EN R-Johnson-L"I'-S W -rcvis i onN3.docx
SAVANNAH, GEORGIA • CHARLESTON, SOUTH CAROLINA • MYRTLE BEACH, SOUTH CAROLINA • BRUNSWICK, GEORGIA

As'J � r
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins
Governor Director
June 25, 2010
Mr. William Neal Lewis, CPRP, Director
New Hanover County Parks Department
230 Government Center Drive, Suite 120
Wilmington, NC 28403
Subject: Approved Plan Revision
New Hanover County Parks — Smith Creek
Stormwater Project No. SW8 091003
New Hanover County
Dear Mr. Lewis:
Dee Freeman
Secretary
On June 15, 2010, the Wilmington Regional Office received a plan revision for Stormwater
Management Permit Number SW8 091003. The revisions include the addition of a boat ramp and
turn -around area totaling 4,909 square feet of additional built -upon -area. It has been determined that
a formal permit modification is not required for the proposed changes. We are forwarding you an
approved copy of the revised plans for, your files. Please replace the old approved plan sheets with
the new ones.
Please be aware that all terms and conditions of the permit issued on April 9, 2010, remain in full
force and effect. Please also understand that the approval of this revision to the approved plans
for the subject State Stormwater Permit is done on a case -by -case basis. Any other changes to
this project must be submitted to and approved through the Division of Water Quality prior to
construction. The issuance of this plan revision does not preclude the permittee from complying
with all other applicable statutes, rules, regulations or ordinances which may have jurisdiction over
the proposed activity, and obtaining a permit or approval prior to construction.
If you. have any questions concerning this matter, please do not hesitate to call me at [phone].
Sincerely,
CIVVLL. C3 a„_
Chris Baker
Environmental Engineer II
GDS\csb: S:\WQS\STORMWATER\PERMIT\091003PR.jun10
cc: Mr. Brian Riley —Thomas & Hutton Engineering Co.
New Hanover County Inspections
New Hanover County Engineering
Wilmington Regional Office
Central Files
Wilmington Regional Office One
127 Cardinal Drive Extension, Wilmington, North Carolina 28405 NorthCarotina
Phone: [phone] FAX: [phone] Customer service: 1-877623.6748 n���tu"
Internet:w .ncwaterquality.org N!Lar

Name:
Project Location: I Add info requiredfies/bo). Date received: (O/tC/i n I
Rule(s) Subject (check all that apply): I Symbols for completing form: '✓ =Yes/OK ' x'= No/Deficient 'n/a' of
❑ 1995 Coastal ❑ 2008 Coastal ❑ Phase II ❑ Universal
Paperwork:
❑ Check for $505 (must be no older than 6 months)
❑ Application form with correct/original signatures (original plus 1 copy). If Corporation or LLC also:
o Print the info from the NCSOS
o Either, 1.) The applicant is listed on the NCSOS with his/her correct title or, 2.) A notarized letter of
authorization has been provided:
❑ Supplements (1 original per BMP). BMP type(s):
❑ O&M with correcUoriginal signatures (1 original per BMP, except level spreaders/filter strips and swales)
❑ Deed restrictions (if outparcel or subdividing) (original plus 1 copy)
o Deed restriction template (signed and notarized) or
o Proposed Declaration of Covenants and Restrictions (signed and notarized)
❑ Soils report identifying the SHWT
❑ Supporting calculations, signed & sealed (if necessary)
❑ Receiving stream classification: If SA or ORW also:
o SA: S topo map with the ite, the receiving waters and the 1% mile ra s shown to scale.
o O of MHWL for Area f Environmental Concern and m BUA p r rule.
❑ Modific ions: 1.) If uilt: Designer's Cert., .) If partially built: Partial Cert., wlt: No Cert. needed.
DevelopmeneTvve (chec ,all that avolv)1 n�
❑ Re rdential or ❑ or�P%rcial
❑ S division or It
Lot
❑ H gh Densitd( or �❑ L w Density
❑ OTkjjtE projec Re velopment
❑ NCG 2 (bulkhe ) ElG03 (clear/grade)
Density:
❑ BUA calculations in de common areas, clubhouse,
❑ BUA %: atches high/low density re
❑
No obvious math errors
❑
If High Density: Design storm
Plans,
signed and sealed (2 sets):/
❑
Two sets received C
❑
Grading
❑
Vicinity map
❑
Wetlands:
o Delineated on plans
�D strictions match?
eVstrictions match?
❑ed restrictions match?
❑ tc tion ❑ Exempt
❑ �G04/(linear)
de a: ks, etc.
it ° ent for rule an 'ice ving stream class.
,ing stream claso
❑ Layoo"� t (with roposed BUA dimensions)
❑ an ge ea map (all ystems & curb outlet swales)
❑ P e oundaries ❑ Legend
o "N etla s or E�n plans
❑ Details:
o Roads o Cul-de-sacs urbing o Sidewalk
o BMPs/ Level spreaders/ Filter strips/ rb outl ales o Buildings (Apts or Condos)
Offsite Projects:
❑ Designer's Certification has been submitted for O site BMP receiving the runoff from the project.
❑ Deed restrictions have been recorded and a copy submitted for the Offsite BMP permit.
❑ Lot size has not changed from what was approved under the Master Plan.
❑ Correct lot number is referenced on the supplement form.
❑ Offsite system is in compliance with its permit, if known.
Infiltration Projects:
❑ Soils report: SHWT, soil type, and expected infiltration rate are provided.
❑ DWQ has conducted a site visit? Date:
Wet Ponds: Permanent Pool Meets One of the Following:
❑ Is located no lower than 6" below the estimated SHWT.
❑ Incoming groundwater is quantified and evaluated, AND Storage volume verified, AND Outlet evaluated for free
drainage to the receiving waters under SHWT conditions.
Decision (check one):
❑ Complete: Return file to admin (Jo Casmer) to log in. (Stamped in received date = BIMS date)
❑ Slightly incomplete: E-mail consultant, request information to be returned within one business day (24 hours after
request. Info requests on Friday, allow a return on the following business day). If info not returned, issue an
application return letter and give everything to admin. (Add info received date = BIMS date)
❑ Substantially incomplete: Issue an application return letter and give everything to admin.

t(C.I,.0 Jull 1 0 cutu
MM
THOMAS & HUTTON
Engineering I Surveying I Planning I GIS I Consulting
To; Ms. Kelly Johnson
127 Cardinal Drive
Wilmington, North Carolina 28401
Letter of Transmittal
Date: June 15, 2010
Job 20523.0004.303
Re: Smith Creek Park
WE ARE SENDING YOU THE FOLLOWING ITEMS (® attached) (❑ under separate cover via
❑ Shop Drawings ❑ Prints ® Plans ❑ Samples ❑ Specifications
❑ Copy of Letter ❑ Change Order ❑ Other:
Copies
Date
Description
1
06/10/10
Site Development Plans
THESE ARE TRANSMITTED AS CHECKED BELOW
❑ For Approval ❑ Approved as Submitted ❑ Resubmit Copies for Approval
® For Your Use ❑ Approved as Noted ❑ Submit Copies for Distribution
❑ As Requested ❑ Returned for Corrections ❑ Return Corrected Prints
❑ For Review and Comment
Remarks
Copy to 20523.0004.303
RECEIVED
Ly
JUN 1 5 2010
:_,___
Signed off -
Brian Riley
219 Station Road, Suite 101 1 Wilmington, INC 284051 910.332.33601 Fax [phone]

Via Hand Delivery
THOMAS & HUTTON ENGINEERING CO.
219 STATION ROAD
SUITE 101
WILMINGTON, NORTH CAROLINA 28405-3713
TELEPHONE (91 O) 332-3360
FAX (91 O) 332-3361
June 14, 2010
Ms. Kelly Johnson
North Carolina Department of Environment and Natural Resources
Division of Water Quality
127 Cardinal Drive Extension
Wilmington, NC 28405
Dear Ms, Johnson:
RECD vuN 14 2010
RE: Plan Revision
Stormwater Project 1\16,—.SW8 0 11003�
Smith Creek Park
New Hanover County
J-20523.0004.303
The above referenced project has been revised to include an emergency boat ramp tc
the lake. The overall land disturbance and drainage patterns remained the some. A detailed
account of the revisions can be found in the project narrative included with the updated design
considerations listed below. On behalf of New Hanover County Parks Department, we are
pleased to provide the following items for your review:
• One (1) copy of revised Stormwater and Erosion Control Design Considerations including
Project Narrative and Vicinity Map; and
• Two (2) sets of revised Site Development Plans.
Please review the above information and, if acceptable, we respectfully request
NCDENR approval of the plan revision. Please feel free to contact me at [phone] should
you have any questions or comments. Thank you for your time and assistance with this project.
Sincerely,
THOMAS & HUTTON ENGINEERING CO.
Brian Riley
Project Manager
BDR/kap
Enclosures: As listed above 2010
cc: Sara Burroughs (Haden Stanziale, P.A.) JUN 14
N:A20523.0004\DoesVCorrespondcncON CDEN R-JAnson- I: f-SW-rcvisi on.doce
SAVANNAH, GEORGIA • CHARLESTON, SOUTH CAROLINA • MYRTLE BEACH, SOUTH CAROLINA • BRUNSWICK, GEORGIA

to
SEAL.
028179
NEW HANOVER COUNTY PARKS
SMITH CREEK
MEW HANOVER COUN"CY, NOR'I'I-1 CAROLINA
STORMWATER & EROSION CONTROL.
DESIGN CONSIDERATIONS
AND SPECIFICATIONS
PREPARED FOR
NEw HANOVER COUNTY
Aucus-r 1, 2009
REVISED 6/3/10
20523.0004.406
THOMAS & HUTTON ENGINEERING CO.
WILMINGTON, NORTH CAROLINA
SAVANNAH, GEORGIA
CHARLESTON, SOUTH CAROLINA
MYRTLE BEACH, SOUTH CAROLINA
BRUNSWICK, GEORGIA

SEAL
02E179
NEW HANOVER COUNTY PARKS
SMITH CREEK
NEW HANOVER COUNTY, NOR"TI-I CAROLINA
STORNIWATER & EROSION CONTROL
DESIGN CONSIDERATIONS
AND SPECIFICA'CIONS
PREPARED FOR
NEW HANOVER COUNTY
AUGUST 1, 2009
REVISED 6/3/10
20523.0004.406
THOMAS & HUTTON ENGINEERING CO.
WILMINGTON, NORTH CAROLINA
SAVANNAH, GEORGIA
CHARLESTON, SOUTH CAROLINA
MYRTLE BEACH, SOUTH CAROLINA
BRUNSWICK, GEORGIA

TABLE OF CONTENTS
LOCATIONMAP................................................................................................. 8 1/2" x 1 1" map
SECTION 1 — Project Narrative
SECTION 2 — Pond Routing
Purpose
Proposed Drainage System
Stormwater Quantity Methodology
Hydrology
Conclusions
Summary of Results
2.1 Time of Concentration and Curve Number Calculations
2.2 Pre -Development ICPR Model Inputs and Results
2.3 Post Development ICPR Model Inputs and Results
2.4 Combined Unit Hydrograph Calculations
2.5 Pre and Post Development Drainage Area Exhibits (24" x 36")
Overall Site Plan Exhibit (24" x 36")
Drainage Pipe & Swale Exhibit (24" x 36")
SECTION 3 — State Stormwater, Sediment and Erosion Control Calculations
3.1 Grassed Swale Design Calculations (See Section 4 for Energy Dissipater
Calculations)
SECTION 4 — NFIC Stormwater, Sediment and Erosion Control Calculations
4.1 Grassed Swale Design Calculations
4.2 Pipe Capacity and Energy Dissipater Calculations
SECTION 5 — Stormwater and Erosion Control Specifications
Specification 02110 - Site Clearing
Specification 02204 - Earthwork
Specification 02210 —Soil Erosion Control
Specification 02231 — Aggregate Base Course
Specification 02275 — Rip -Rap
Specification 02512NC — Asphaltic Concrete Binder/Surface Courses
Specification 02902 — Grassing
Revisions:
6/3/10 — Revised to include addition of emergency boat ramp
N:�20523.0004Wsgn\smrmwaten20523-4 Stomwater Repon 8-1-09,doc

REVISION 6/3/10:
The proposed project described below was revised to include an emergency boat & turn around
area. The proposed ramp will be pervious concrete as required by the Army Corps of Engineers,
but is being considered as impervious coverage for storm water considerations. The proposed
drainage system and conveyances generally remained the same. The area of disturbance
remained unchanged at 9.30 acres as originally permitted for the Phase 1 improvements. The
boat ramp increased the Phase 1 built upon area (BUA) by 4,909 square feet and reduced the
allowable future BUA by the same amount to keep the overall BUA at 24% of the permit area.
The revision also included the addition of grate inlet #4 and 15" culvert under the access road at
approximately station 10+30. This inlet and culvert was added to convey the runoff from the
swale 2 under the road such that it would be redirected away from the adjacent subdivision along
the eastern boundary. Calculations for the culvert and energy dissipater are included in the
revised report.
ORIGINAL PROJECT NARRATIVE
New Hanover County Park Smith Creek is a 92.14 acre proposed low -density community park
located directly off of Harris Road (SR 2117) approximately 0.65 miles northeast of the
intersection of Harris Road and Gordon Road (SR 1327). From aerial photo and field survey, the
existing site conditions may be classified as good and fairly wooded, fair and good open space
lands, and an existing lake. The site contains 404 wetlands, isolated wetlands, and surface water
as determined by the Army Corps of Engineers. A draft copy of the wetland plat and application
has been provided with this submittal. The existing topography is both flat and hilly with slopes
ranging from 0-25%. The pre -development runoff drains via overland flow to the various
ditches throughout the property and into the existing lake that lies in the center of the property
before ultimately discharging to Smith Creek. Smith Creek is located just to the west of the
property boundary and is classified as C; Sw waters and the stream index number is 18-74-63.
The soils on this site are classified as hydrologic soil groups "A", "A/D", " B", "B/D", and "D".
The proposed low -density community park project will ultimately not exceed 24% impervious
area of the site. Phase 1 will consist of roads, parking, picnic shelter/restroom building, water &
sewer infrastructure, multi -use paths and sidewalks, playground, and a floating dock and
gangway to serve the residents of New Hanover County. Future BUA has been included within
the development model and is shown in the Overall Site Plan sheet C3 in the construction plans.
The applicable permit revisions and/or modifications will be applied for at the time of future
development.
The stormwatcr system for Phase 1 will be designed to low density standards and will treat the
stormwater via overland, sheet flow, and vegetative conveyance swalcs before discharging to the
existing pond. The pipe end at the end of Swale #3 that is adjacent to the existing pond is
designed to discharge into a zero percent slope swale that runs parallel to existing contours at a
minimum length of 100' in an effort to reduce velocities and diffuse the flow. An energy
dissipater has also been designed for the 25-year storm even(._nd will be installed to further
JUN 14 2010

decrease discharge velocity from the pipe. The parking lot will drain via sheet now to existing
vegetated areas while the entrance drive will drain via sheet flow to vegetative roadside
conveyance swales. The curb around the parking lot is depressed and thus will not act as a
collection/curb outlet system. The existing pond was previously a sand mining pit but is now
used as a stormwater pond and has an existing control structure device located at the west end of
the site. In order to meet the pre and post development runoff rate requirements of New Hanover
County Stormwater Ordinance, a modification to the existing control structure is necessary and is
modeled in ICPR (Section 2.3 of this report). A detail of the modification to the control structure
is illustrated in the site development plans. The proposed stormwater conveyances will consist
of, but not limited to, overland flow, vegetated conveyance swales, and drainage pipe for road
and path crossings.
Erosion control devices will consist of, but not limited to, temporary silt fencing, stone check
dams, erosion control grassing, and energy dissipaters at outlets and areas of concentrated flows.
The anticipated construction sequence is as follows:
1. Install silt fence and tree protection
2. Clearing
3. Install remaining erosion control measures
4. Install drainage conveyances
5. Site rough grading
6. Install water and sewer service
7. Structural Features: Floating Dock and Gangway
8. Entrance and final grading
9. Final grassing and stabilization. Restore all drainage conveyances to design
specifications upon project completion.

PURPOSE
The purpose of the Pond Routing Calculations is to define the limits of the drainage basin or
basins that comprise this project. These routing calculations are intended to demonstrate
compliance with the local regulations with respect to runoff Quantity Control as listed below.
Additional, the theoretical I00-year peak stage in the pond will be evaluated to ensure it is below
the minimum finished floor elevation.
o NCDENR Storm water Requirements (Reference Section 3.1 for Calculations and
Results):
➢ Impervious surface will not exceed 24% of the total site acreage.
➢ For a low density project, maintain a minimum 100' length in the vegetative
conveyance swales.
➢ Design proposed swales for the 10-year storm and ensure peak flow is non -erosive.
o New Hanover County Requirements:
➢ Post Development peak run-off rate for the 2, 10 and 25-year storms must be equal or
less than pre -development run-off rate.
➢ Design proposed swales for the 25-year stone event.
PROPOSED DRAINAGE SYSTEM
The components of the proposed drainage system are an existing lake and vegetative conveyance
swales. Runoff from the built upon area will be directed to the existing lake via sheet flow,
proposed vegetative swales, and/or existing ditches.
STORMWATER QUANTITY METHODOLOGY
The existing and proposed conditions will be analyzed using the Advanced Interconnected
Channel and Pond Routing (ICPR) computer program developed by Streamline Technologies.
The program is used to model rainfall and storm water runoff and to perform hydraulic routing
through the storm drainage system. The ICPR program is a FEMA approved model that has the
ability to analyze complex interconnected drainage systems dynamically over extended time
periods.
The hydrologic input data consists of information for each drainage basin, or subwatershed,
within the project. Input variables include runoff curve number, rainfall distribution pattern,
hydrograph peaking factor, area of each drainage basin, and time of concentration (see below
section "Flydrology" for specifics on the values of these variables that were used in this model).
The ICPR program generates runoff hydrographs for each subwatershed based on the user -
specified variables. Hydrographs are generated by ICPR using the SCS Unit Hydrograph
Method.
N:\20523.0004\dsgn\stormwater\205234 Stormwater Report 8-1-09_doc 3

The model hydraulic input data consists of a system of nodes and links. Nodes represent
locations where flows enter or exit the system, pipe or channel characteristics change, or where
stage/storage/time relationships are provided. Links represent traditional types of hydraulic
conveyance such as pipes, channels, drop structures, weirs, etc. The sizes, inverts, lengths, and
Manning n values for all pipes connecting the lagoons are input into the model. In addition to pipe
information, all lagoon and detention area stage -storage information and the respective outfall
structure information is input into the model. The node and link conditions are analyzed within
the model for a given storm, and flow conditions are determined.
The basic equation used by ICPR to route flows through the system is:
Os= (Qin - Qoul) At
Where: Change in storage for time step = As
Flow into a node at time "t" = Q 11
Flow out of a node at time "t" = Qnr,t
Length of time step; user defined range from 1.0 sec to 0.1 sec. = At
Hydrographs for each drainage area are merged within the ICPR program, and the hydrologic
results are then combined with the hydraulic information to model the hydraulic interactions of
the entire drainage system. The results include lagoon and detention area discharge rates and
stage/storage information during the design storm.
For the design of the storm drainage system, a warning stage elevation is set for each lagoon,
detention area, and/or structure to assure no storm water ponding. In addition, the ultimate
discharge rate from the system cannot exceed the pre -developed runoff rate. Knowing these two
factors, the drainage system is designed by trial and error.
HYDROLOGY
• SCS Unit Hydrograph Method is used. SCS 484 Fiydrograph Peaking Factor is used for
developed basins as specified in the New Hanover County Stormwater Design Manual.
• Amount of rainfall for each storm frequency is determined based on National Oceanic and
Atmospheric Administration (NOAA) Atlas 14 (Volume 2, 2004). The following design
storms are used in the model simulations:
- 2-year, 24-hour Design Storm = 4.67 inches
- 10-year, 24-hour Design Storm = 7.25 inches
- 25-year, 24-hour Design Storm = 9.11 inches
- 100-year, 24-hour Design Storm = 12.65 inches
• SCS Type III Statistical Rainfall Distribution is used. This distribution pattern is detennincd
by the Soil Conservation Service comparing regional rain -gage data.
N:\20523.0004tdsgn\stonnwater\20523-4 Stonnwater Report 8-1-09.doc 4

CONCLUSIONS
The proposed drainage system meets the criteria set forth by New Hanover County and North
Carolina Department of Natural Resources.
SUMMARY OF RESULTS
This project has been designed to meet the minimum requirements of the New Hanover County
Storm Water Design Manual and the State of North Carolina Department of Natural Resources.
The existing and proposed hydrology conditions were analyzed using the Advanced
Interconnected Channel and Pond Routing (ICPR) version 3 computer program developed by
Streamline Technologies. The post -development runoff rates did not exceed the pre -development
rates for the 2, 10 and 25-year storms. The I00-year storm event was analyzed to ensure no
structures are flooded. Reference Section 3.1 of this report for compliance with NCDENR
Water Quality requirements.
Storm
Pre -Development
Post -Development
Frequenev
Runoff Rates
Discharge Rates
2-Year
7.84 cfs
4.65 cfs
10-Year
22.50 cfs
10.85 cfs
25-Year
35.87 cfs
15.49 cfs
100-Year
53.22 cfs
24.81 cfs
WATER QUALITY
The project is a low density community park that utilizes overland, sheet flow in additona to
vegetative conveyance swales with a minimum length of one -hundred (100) If per North
Carolina Department of Natural Resources regulations for water quality purposes. Reference
Section 3.1 of this report.
N:\20523.0004\dsgn\stor .ater\20523-4 Stomiwater Report 8-1-09.doc 5

J 20523-4.404
ALG/.IDR
STORMWATER
STORM WATER DESIGN CONSIDERATIONS
Smith Creek
PREPARED BY: Thomas and Hutton Engineering Company
DATE: August 1, 2009
REVISED: 6/3/10
PRE -DEVELOPMENT DRAINAGE CALCULATIONS
B-LAKE
Calcul:lte'Fime of Concentration
Use Tavel Nine Concept:
Overland Flow: I =(0.007(n'I)10.8)/((P.A0.5).(SAO.4)) TR-55 Fit 3-3
where: I = Travel time for Overland Flow (min)
n = Manning's coefficicnl - from 7R-55 Table 3-1
1 = length of flow (ft)
P., = 2-yr rainfall depth (in)
S = Hydraulic slope (f1/n)
11 = 0.24 glass
I = 100 It
Pi = 4.5 in
S = 0.015 ti/n
t= 13.5 ratio
Shallow Concentrated Flow: 1=1/60v
where: t='rravei tinge for Shallow Concentated Flow (min)
I = Length of flow (f )
S = Average watercourse slope (fl/fl)
v = Velocity (n/s)- From TR-55
1= 765.00 ft
S= 0.010 Unpaved
v= 1.61 Ii/s
1= 7.90 olio
Shallow Concentrated Flow: 1=1/60v
where: I = Tnlve] time for Shallow Concentrated Flow (taint
1 = Icnglh of flow (n)
S = Average watercourse slope If1/f0
v= Velocity aft/s)- From I-R-55
1= 255.00 ti
S= 0,040 Unpaved
v= 3.23 fils
1= 1.32 min
'fherefore,Tc= 22.7 min
Determine Composite CN Value from TR-55'rable 2-2
Description
HSG
CN
A (act
CN x A
Impervious
-
98
0.43
42.14
Lake
-
100
35.77
3576.74
Open Space (Fair)
A
49
4.58
224.42
Open Space (Fair)
H
69
It 36
783.84
Woods (Fail)
B
60
12.24
734.11
Woods lFai r)
A
36
10.63
382.54
75.00
5743.79
Composite CN Value = 77
N:\20523A(IU4\dsgn\ctormwalcr\20523-41c&en-xis 'Thomas & Hutton Engineering Co. Page I at 3

J-20523-4A04
ALG/.IDR
PRE -DEVELOPMENT DRAINAGE CALCULATIONS
BASIN Pre-2
Calculatc Time of Concentration
Use Travel Time Concept:
Overland Flow: I = 10.0070r'0^0.8)/((P; 0.5)^(S^0.4)I'rR-55 Eq 3.3
where: t = Travel lime for Overland Flow (nin)
n = Manning's coefficient - from TR-55'rable 3-1
1 = 1-englh of Flow (fl)
P = 2-yr rainfall depth (in)
S = Hydraulic slope (fl/f0
Ranec/natural
n = 0.24 grass
1 = 100 It
P2 = 4.5 in
S = 0.015 li/h
t= 13.5 min
Shallow Concentrated Flow: (=1/60v
where: t=Travel tittle for Shallow Concentrated Flow (min)
I = length of Flow Ht)
S = Average watercourse slope (fl/ft)
v = Velocity (It/s)- Front TR-55
1= 320.00 fl
S= 0.010 Unpaved
v= L61 his
l= 3.31 min
Therefore,Tc= 16.8 min
Determine Composite CN Value from'I'R-55 Tahle 2.2
_Description HSG
CN
A (ac)
CN x A
Impervious -
98
0.22
21.81
Open Space (Fair) B
69
0.64
44.43
0.87
66.23
Composite CN Value =
76
N:A20523.0004VdsgnAalorntwulcrA20523-4lc&en.xls 'rhom:as & Hutton Engineering Co. page 2 of 3

1-30527-4.404
ALG/.IDR
PRE-DEVELOPNIE.NT DRAINAGE CALCULATIONS
BASIN Pre-3
CaIculate Time of Concentration
Use Travel Time Concept:
Overland Flow: I =(0.0070r'0^0.8)/((11_10.5)'(S^0.4)) TR-55 Eq 3-3
where: I = Tr: vet lime for Overland flow man)
it = Manning:s coefficient - from TR-55 Table 3-1
1 = lxngth ofllow (ft)
P2 = 2-yr rainfall depth (in)
S = Hydraulic Slolx (f1/fl)
R:mge/nutw:d
n =
0.40
1 =
100
P2=
45
S =
0.005
1=
31.5
woods (light underbrush)
IT
in
f /ft
min
Shallow Cnncenlrnled Flow: 1=1/60v
where: 1=Travel time for Shallow Concentrated Flow (ntro)
I=Length of flow (t 1
S = Average watercourse slope (Il/ft)
v = Velocity (ft/s)- From'I'R-55
1= 1200.00 It
S= 0.007 Unpaved
V= 1.35 HIS
t= 14.82 min
Therefore. Tc = 46.3 min
Determine Composite CN Value from TR•55 Table 2-2
Description HSG
CN A (ac) CN x A
Wetlands (woods fair) D
79 0.15 11.79
Woods (Fair) B
6f) 5.29 317.18
5.44 328.97
Composite CN Value = 61
N:\20523 nUO4\dsgn\sloitnwaler\20523-4 tc&en..rls 'I'houuts & Hutton Engineering Co. Page 3 ol'3

.I-20523-4 404
ALG/JDR
STORMWATER
STORM WATER DESIGN CONSIDERATIONS
Smith Creek
PREPARED BY: Thomas and Hutton Engineering Company
DATE: August 1, 2009
REVISED: 6/3/10
POS'I'-UI?VELOPNIEN'I' DRAINAGE CALCULATIONS
B-LAKE
Calculate'fime of Cuncenlrulion
Use Travel Time Concel
Overland Flow: t =(0.0070N0^O.R)/((I',^0.5)'1S^0.411 TR-55 Ey 3-3
where i = Travel time for Overland Flow (min)
n = Manning's Coefficient - from TR-55 Table 3-1
1= Length of flow (0)
P, = 2-yr Raint ll Dcpi h (in)
S= Hydraulic slope (Nit)
n = 0.24 grass
1 = 100 ft
P, = 4.5 in
S= 0.010 IUft
1= 15.9 min
Shallow Coaccnimlcd Flow: 1=1/60v
where: 1 =Travel line for SIm11ow Conecntmled Flew (olio)
I =Length of flow (li)
S = Average watercourse slope (R/f)
v= Velocity (f0.$)- From TR-55
1= 454.(X) It
S= 0.007 Unpaved
v= 1.35 R/S
1= 5.61 min
Shallow Coacenn:acd Flow: 1=I/(i0v
where: t =Travel time for Shallow Concentrated Flow Onin)
I = Length of flow (11)
S = Avenge watercourse. slope (fL/f0
v = Velocity (0/s)- Front TR-55
1= 315.00 0
S= 0.035 Unpaved
x= 3.02 k1s
1= 1.74 min
Pipe Flow: 1=1/60v
where: 1 =Travel lime for Pipe Flew (min)
1 = I-ength of few (n)
v = Velocity (ft/s)- Front TR-55
1= 256.00 ft
v= 2.00 fUs
1= 2.13 min
Therefore,l'c. = 25.4 nlin
Determine Composite CN Value from'rR-55 Table 2-2
Description HSG CN
A (ac)
CN n A
'!Include, Future Parking Impervious - 98
2.58
252.84
Lake - 100
35.79
3578.74
Open Space (Far) A 49
3.97
194.73
Open Space (Fair) 13 69
12.02
829.66
Woods(Fa0 A 36
10.62
382.41
Woodu(Faia) 13 60
11.09
665.14
76p7
5903,52
Composite CN Value = 78
NA20523.0004\dsgn\.mnnwater\20523-4 tc&cn.xls Thomas & lluvun Engineering Co.
Page I of 3

J-20923-4.404
AI-G/JDR
POS7--DEtlHLOPMENT DRAINAGE CALCULATIONS
Il-DDI
Calculate Time of Concentration
Usc'rmsel'rune Concel
O.edand Flow: I=/O.W70o^p^0.3 N(I P;^0.5145^O..l))TR-55 Ell 3-1
where: I =Tmeel linen for Owrland Flu. unin)
it = Manning's coefficient - horn rR-55 Tahle 3-1
I = Length of flow If; 1
P, = 2y1 modall depth tin)
S = Hydraulic slope (fi/Il)
Ranee/natural
n = 0.24 Grass
I = IGo ti
P. = 4.5 io
S = 0.010 JIM
t= 15.9 min
Shallow Conccmmted Flow: t=1/60v
whet,: I = Travel bone for Sludlow Conmd,nI,d Flow Ino ill
I = I-ength of flow (it)
S = Average wntemouraa elope (fl/It)
v = Velocity (htAF rn).n TR-55
1= 4250) It
S= 0.008 Unpaired
v= 1.42 It/,
1= 5.00 loin
Therefare, Te= 20.9 min
Determine Composite CN Vnine from TR-55'rahle 2-2
Description HSG
CN
A (ac)
CN x A
Impervious -
98
0.35
34.41
Open Space (Fail) e
69
0.75
51.89
1.10
86.30
Cnmpusite CN Value=
7H
N:\2(1523,(N)04\dsgn\stonnwmer\20523-4 m&en.xls 'photons & Hutton Engineering Co. page 2 of 3

J-20521.4.404
ALr/JDR
POST-DEVELOPNI ENT DRAINAGE. CALCULATIONS
R-DD2
Calculate Time or Coneenlmtion
Use Tercel Time Co.. eq
Overland Flow: I=(0.007(i("I)A0.8V(tP A0.5)•(S^0.4)) TR-55 Ey 3-3
where. t =Tm,el time fbr Oreriand Flow train)
it = Manniagt Coelliciem - from TR-55 Table 1-1
1 = Ixogih of flow (I'[)
P_- = 2-yr Rni of all Depth I in)
S = Hydraulic dupe (ftAl)
n= 0.40 woods (light uodcrhrush)
I= IM ft
P, = 4.5 o
S= 0.005 flirt
t= 31.5 min
Shallow Concentrated Flow: (=1/60v
where (= Trwel time for Shallow Conanmued Flow (iniN
I = Ixngth of flow rr)
S = Average watercourse slope (li/It)
v=Velocnl (ft/s)-Flom TR-55
I= 1200.00 b
S= 0.007 Unpaved
v= 1.35 his
l= 14.82 min
Therefore•Te = 46.3 min
Determine Composite CN Value from TR-55 Table 2-2
Description HSC
CN
A (ac)
CN x A
*Includes Future Parking Impervious -
98
0,45
43.68
Wetlands (wo...Khair) D
79
0.15
11.79
Woad,(Fnir) H
60
3.54
212.59
4.14
268.07
Composite CN Value =
65
N:\20523.0004\dsgnkmrmwater\20523-4 (c&cn.Je Thonms k Hutton Engineering Co. Page 3 of 3

New Hanover County Parks:
Smith Creek
New Hanover County, North Carolina
Section 2.2
Pre -Development ICPR Model Inputs and Results
Prepared By
Thomas & Hutton Engineering Co.
219 Station Rd. / Wilmington / NC / 28405
50 Park of Commerce Way / Savannah / GA / 31405
935 Houston Northcutt Blvd. / Mt. Pleasant / SC / 29464
1350 Farrow Pkwy / Myrtle Beach / SC / 29577
116 West Palm Plaza Drive / Brunswick / GA / 31523
J-20523.0004
N:\20523.0004\dsgn\stnmiwatcr\20523-4 Stonnwater Repon 8-1-09.doc

Smith Creek
Pre -Development
8/1/09
..................
Nodes
A Stage/Area
V Stage/Volume
T Time/Stage
M Manhole
Basins
O Overland Flow
U SCS Unit co
S SBUH CN
Y SCS Unit GA
Z SBUH GA
Links
P Pipe
W weir
C Channel
D Drop SCruCture
B Sr idge
R Rating Curve
H Breach
E Percolation
F Filter
X Enfil Trench
A: Lake
D: LAKE - eNDYl I / T: BNDYl
U: B-LAKE __-_-_____ __
T: BNDY2
U:Basin Pre-2
T: BNDY3
U:Basin Pre-3
Interconnected Channel and Pond Routing Model (ICPR) ©2002 Streamline Technoloeies. Inc.

Smith Creek
Pre -Development
6/3/10
...................INPUT REPORT ..................
==_= Basins
Name: B-LAKE
Group: BASE
Unit Hydrograph: Uh484
Rainfall File: Scsiii
Rainfall Amount(in): 0.000
Area(ac): 75.000
Curve Number: 77.00
DCIA(8): 0.00
Node: Lake Status: Onsite
Type: SCS Unit Hydrograph CN
Peaking Factor: 484.0
Storm Duration(hrs): 24.00
'Pine of Conc(min): 22.70
Time Shift(hrs): 0.00
Max Allowable p(cfs): 999999,000
________________
Name: Basin Pre-2
______
Node: BNDY2
_ _____
Status: Onsite
Group: BASE
Type: SCS Unit Hydrograph
CN
Unit Hydrograph:
Uh484
Peaking Factor:
484.0
Rainfall File:
Scsiii
Storm Duration(hrs):
24.00
Rainfall Amount(in):
0.000
Time of Cone(mie):
16.80
Area(ac):
0.870
Time Shift(hrs):
0.00
Curve Number:
76.00
Max Allowable D(cfs):
999999.000
DCIA(%):
0.00
___________
Name: Basin Pre-3
____ ___
Node: BNDY3
______________________
Status. Onsite
Group: BASE
Type: SCS Unit Hydrograph
CN
Unit Hydrograph:
Uh484
Peaking Factor:
484.0
Rainfall File:
Scsiii
Storm Duration(hrs):
24,00
Rainfall Amount(in):
0.000
Time of Conc(min):
46,30
Area(ac):
5.440
Time Shift(hrs):
0.00
Curve Number:
61.00
Max Allowable p(cfs):
999999.000
DCIA(%):
0.00
Nodes
Name: BNDY1
Group: BASE
Type: Time/Stage
Time(hrs)
_______________ --
0.00
24.00
-----------------
Name BNDY2
Group: BASE
Type: Time/Stage
Base
Flow(cfs):
0.000
Init
Stage(R):
14.000
Warn
Stage(ft):
20.000
stage (ft-)
14, 000
14.000
---------------------------
Base Flow(cfs): 0,000
Time(hrs) Stage(f L)
---------------
0.00 43.800
24.00 43.800
--------------------------------------------------
Name: BNDY3 Base Flow(cfs): 0.000
Group: BASE
Type: Time/Stage
Timelhrs) Stage(ft)
-----------
0 00 ------
37.000
24.00 37.000
--------------------------------------------------
______________________
Init Stage(fL): 43.800
Warn Stage(ft): 45.000
---------------------------
Init Sta9 e(f L): 37.000
Warn Stage(tt). 42..000
Interconnected Channel and Pond Routing Model (]CPR) V2002 S(rean line Technologies, Inc. Page I nI'4

Smith Creek
Pre -Development
613/10
...................INPUT REPORT ........ ,.. ,......
Name: Lake
Group: BASE
Type: Stage/Area
Base Flow(cfs): 0.0D0
Stage(ft) Arealac)
_______________ ---------------
20.600 35.8000
21.000 36.4000
22.000 37.4000
Drop Structures ______________________—____________
Name: LAKE - BNDY1 From Node: Lake
Group: BASE To Node: BNDYI
UPSTREAM DOWNSTREAM
Geometry: Circular Circular
Spao(in): 24.00 24.00
Rise(in): 24.00 24.00
Invert(ft): 14.090 14.340
Manning's N: 0,013000 0,013000
Top Clip(in): 0.000 0.000
Bot Clip(in): 0.000 0.000
Upstream FHWA Inlet Edge Description:
Circular Concrete: Groove end projecting
Downstream FHWA Inlet Edge Description:
Circular Concrete: Groove end projecting
"' Weir 1 of 1 for Drop Structure LAKE - BNDY1
Init Stage(ft): 20.600
Warn Stage(ft): 22,000
Length(ft): 303.00
Count: 1
Friction Equation: Average Conveyance
Solution Algorithm: Automatic
Flow: Both
Entrance Loss Coef: 0,000
Exit Loss Coef: 0.000
Outlet Ctrl Spec: Use do or tw
Inlet Ctrl Spec: Use do
Solution Ines: 10
TABLE
Count:
1
BOttom Clip(in);
0.000
Type:
Horizontal
Top Clip(in):
0.000
Flow:
Both
Weir Disc Coe E:
3.200
Geometry:
Rectangular
Orifice Disc Coe E:
0.600
Span(in):
49.00
luvert(ftl:
20.600
Rise(inl:
48.00
Control Elev(ftl:
20.600
Hydrology Simulations
____________________________a.....____---------
_______=_______
Name: pre002-YR
Filename: N:\20523.0004\dsgn\stormwater\ICPR Model\pre002-YR.R32
Override Defaults: Yes
Storm Ouration(hrs): 24.00
Rainfall File: Scsiii
Rainfall Amounc(in): 4.67
Time(hrs) Print Inc(min)
--------------- --_____
10.000 15.00
15.000 10.00
24.000 15.00
---- -
Name: pre IO-YR
Filename: N:\20523.0004\dsgn\stormwater\ICPR Model\pre010-YR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsiii
Rainfall Amount(in): 7.25
Time(hrs) Print Inc(min)
10 000 15.00
15.000 10.00
24.000 15. 00
----- --- - - - - - -
Name: p1e025-YR
Filename: N:\20523.0004\dsgn\stormwater\ICPR Model\pre025-YR.R32
Interconnected Channel and Pond Routing Model (ICPR) i•2002 Streamline Technologies, Inc. Page 2 of 4

Smith Creek
Pee-Developmant
613/10
...................INPUT REPORT .....
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsiii
Rainfall Amount(in): 9.11
Time(hrs) Print Inc(min)
10.000 15.00
15.000 10.00
24.000 15.00
_____________________________________________________________________
Name: prel00-YR
Filename: N:\20523.0004\dsgn\stormwater\ICPR Model\prelOO-YR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsiii
Rainfall Amount(in): 12.65
Time(hrs) Print Inc(min)
10.000 15.00
15.000 10.00
24.000 15.00
Routing Simulations =_____________________------ ________
Name: pre002-YR Hydrology Si.: pre002-YR
Filename: N:\20523.0004\DSGN\STORMWATER\ICPR MODEL\preo02-YR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00
Time Step Optimizer: 10.000
Start Time(hrs): 0,000
Min Cale Time(sec): 0.5000
Boundary Stages:
Time (lira) Print Inc(min)
10.000 15,000
15.000 10.000
30.D0o 15.000
Group Run
--------------- -----
BASE Yes
Delta Z Factor: 0,00500
End Time(hrs): 30.00
Max Cal. Time(Eecl: 60.0000
Boundary Flows:
____________________________________________________________________________________________________
Name: preOlO-YR Hydrology Sim: preOlO-YR
Filename: N:\20523.0004\DSGN\STORNWATER\ICPR MODEL\pre010-YR.132
Execute: Yes Restart No Patch: No
Alternative: NO
Max Delta Z(ft): 1.00 Delta 'Z Factor: 0.00500
Time Step Optimizer: 10.000
Start Time(hrs): 0.000 End Time(hrs): 30.00
Min Calc Time(sec): 0.5000 Max Ca1C Time(sec): 60,0000
Boundary Stages: Boundary Flows:
Time(hrs) Print Inc(minl
_______________ ______
10.000 15.000
15.000 10.000
30. coo 15.000
Group Run
_______________ -----
BASE Yes
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologic., Inc. -- -------�—PaVc 3 nt'4

Smith Creek
Pre -Development
6/3/10
...................INPUT REPORT ..................
Name. pre025-YR Hydrology Sim: pre025-YR
Filename: N:\20523.000i\DSGN\STOR ATER\ICPR MODEL\pre025-YR.13C
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(Et): 1.00
Time Step Optimizer: 10.000
Start Timethrs): 0.000
Min Cale Time(sec): 0.5000
Boundary Stages:
Delta Z Factor: 0.00500
End Time(hrs): 30.00
Max Cale Timelsec): 60.0000
Boundary Flows:
Time(hrs) Print Inc(min)
------------------------------
10.000 15.000
15.000 10.000
30.000 15.000
Group Run
--------------- -----
BASE Yes
----------------------------------- ____-----------_---------__----------'_---_----
Name: prel00-YR Hydrology Sim: prelOO-YR
Filename: N:\20523.0004\DSGN\STOR ATER\ICPR MODEL\prel00-YR.I32
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(tt): 1.00
Time Step Optimizer: 10.000
Start Timethrs): 0.000
Min Cale Time(sec): 0.5000
Boundary Stages:
Time(hr.) Print Inc(min)
------------------------------
10.000 15.000
15.000 10.000
30.000 15.000
Group Run
--------------- -----
BASE Yes
Delta Z Factor: 0.00500
End Tine(hrs): 30.00
Max Cale Time(sec): 60.0000
Boundary Flows:
Interconnected Channel and Pend Routing Model (ICPR) 92002 Sheanilinc Technologies. Inc. Pups 4 nl 4

Smith Creek
Pre -Development
6/3/10
...................NODE M.IN/MhX REPORT ......., .. .,......
Max Time Max Warning Max Delta Max Surf Max Time Max Max Time Max
Name Group Simulation Stage Stage Stage Stage Area Inflow Inflow Outflow Outflow
hrs ft ft ft ft2 hrs cfs hrs cfs
BNDY1
BASE
pre002-YR
0.00
14.000
20.000
0.0000
0
16.85
7.351
0.00
0.000
BNDY1
BASE
pre010-YR
0.00
14.000
20.000
0.0000
0
15.01
18.508
0.00
0.000
BNDY1
BASE
pre025-YR
0.00
14.000
20.000
0.0000
0
14.59
28.259
0.00
0.000
BNDY1
BASE
pre100-YR
0.00
14.000
20.000
0.0000
0
15.52
30.874
0.00
0.000
BND'i2
BASE
pre002-YR
0.00
43.800
45.000
0.0000
0
12.33
1.548
0.00
0.000
514DY2
BASE
pre010-YR
0.00
43.800
45.000
0.0000
0
12.33
2.964
0.00
0.000
BNDY2
BASE
pre025-YR
0.00
43.800
45.000
0.0000
0
12.33
4.009
0.00
0-000
BNDY2
BASE
pre100-YR
0.00
43.800
45.000
0.0000
0
12.1"
6.014
0.00
0.000
BNDY3
BASE
pre002-YR
0.00
37.000
42.000
0.0000
0
12.67
3.043
0.00
0.000
BNDY3
BASE
pre010-YR
0.00
371
000
42.000
0.0000
0
12.50
8.224
O.Do
0.000
BNDY3
BASE
pre025-YR
0.00
39.000
42.000
0.0000
0
12.50
12.607
0.00
0.000
BNDY3
BASE
pre100-YR
0.00
39.000
42.000
0.0000
0
12.50
21.552
0-00
0.000
Lake
BASE
pre002-YR
16.85
20.874
22.000
0.0049
15/7364
12.33
121.359
16.85
7.351
Lake
BASE
preOIO-YR
15.01
21.107
22.000
0.0049
1590265
12.33
251.682
15.01
18.508
Lake
BASE
pre025-YR
14.59
21.282
22.000
0.0050
1597888
12.33
341.923
14.59
26.259
Lake
BASE
pre100-YR
15.52
21.907
22.000
0.0050
1616394
12.33
512.019
15. 52
30.874
lu;ernnm�etcd Chauucl and P,,nd Rouen, Modd I ICPR) C'00' Suearilu:e Tcehnolog,, Inc Pugc 1 u i

smith Creek
Pre -Development
6/3/10
' ...... .... —LINK
MIN/MAX
REPORT "••••^•^•^-^•
Max Time
Max
Max
Max Time
Max
Max Time
Max
Name
Group
Simulation
Fl.
Flow
Delta Q
US Stage
US Stage
DS Stage
DS Stage
hrs
cfs
efs
hrs
ft
hrs
ft
LAKE - BNDY1
BASE
pre002-YR
16.85
7.351
0.134
16.85
20.874
0.00
14.000
LAKE - BNDY1
BASE
pre010-YR
15.01
18.508
0.195
15.01
21.107
0.00
14.000
LAKE - BNDY1
BASE
pre025-YR
14.59
28.259
0.240
14.59
21.282
0.00
14.000
LAKE - BNDY1
BASE
pre100-YR
15.52
30.874
0.298
15.52
21.707
0.00
14.000
I il.ILUI1nBeleJ Q Limr ! mid Paou Ro,: ng Aiudel (ICPR) C2002 Sucanihne Tedlnolo_fa, hie. Ps . I of I

New Hanover County Parks:
Smith Creek
New Hanover County, North Carolina
Section 2.3
Post Development ICPR Model Inputs and Results
Prepared By
Thomas & Hutton Engineering Co.
219 Station Rd. / Wilmington / NC / 28405
50 Park of Commerce Way / Savannah / GA / 31405
935 Houston Northcutt Blvd. / Mt. Pleasant / SC / 29464
1350 Farrow Pkwy / Myrtle Beach / SC / 29577
116 West Palm Plaza Drive / Brunswick / GA / 31523
J-20523.0004
N:\20523.0004\dsgn\stonnwater\20523-4 Stonnwatcr Repon 8-1-09.doc

Smith meek
Post Development
a/1/O9
..................
Nodes
A Stage/Area
V Stage/Volume
T Time/Stage
M Manhole
Basins
O Overland Flow
U SCS Unit CN
S SBUH CN
Y SCS Unit GA
Z SBUH GA
Links
P Pipe
w weir
C Channel
D Drop Struc[ure
B Bridge
P. Rating Curve
H Breach
E Percolation
F Filter
Y. Ertil Trench
D. LAKE - BNDYl T:BNDY1
T: BNDY2
U B-DD1
kT: BNDY3
U:B-DD2
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies. Inc.

Smith Creek
Post Development
6/3/10
...................INPUT REPORT ........ ,.........
Basins_________________________________
________________________e_—=_______
Name: B-DD1
Node: BNDY2
Status: Ousite
Group: BASE
Type: SCS Unit Hydrograph
CN
Unit Hydrograph:
U1,484
Peaking Factor:
484.0
Rainfall File:
Scsiii
Storm Duration(hrs):
24.00
Rainfall Amount(in):
0.000
Time of Conc(min):
20.90
Area(ac):
1.100
Time Shift(hrs):
0.00
Curve Number:
78.00
Max Allowable Q(cfs):
999999.000
DCIA(B):
0.00
____________________________________________________________________________________________________
Name: B-DD2
Node: BNDY3
Status: Onsite
Group: BASE
Type: SCS Unit Hydrograph
ON
Unit Hydrograph:
Uh484
Peaking Factor:
484.0
Rainfall File:
Scsiii
Storm Duration(hrs):
24.00
Rainfall Amount(iu):
0.000
Time of Conc(miu):
46.30
Area(ac):
4.140
Time Shift(hrs):
0.00
Curve Number:
65.00
Max Allowable Q(cfs):
999999.000
DC TA(B):
0.00
___
Name: B-LAKE
_ ____
Node: Lake
___ __________
Status: Onsite
Group: BASE
Type: SCS Unit Hydrograph
ON
Unit Hydrograph:
Uh484
Peaking Factor:
4B4.0
Rainfall File:
Scsiii
Storm Duration(hrs):
24.00
Rainfall Amcuut(in):
0.000
Time of Conc(min):
25.40
Area(ac):
76,090
Time Shiftlhrs):
0.00
Curve Number:
78.00
Max Allowable Q(cfs):
999999.000
DCIA(8):
0.00
Nodes________________________________
Name: BNDY1 Base Flow(cfs): 0.000 Init Stage(ft): 14.000
Group: BASE Warn Stage(ft): 16.000
Type: Time/Stage
Time(hrs) Stage(ft)
0.00 14.000
24.00 14.000
--------------------------
Name: BNDY2
Group: BASE
Type: Time/Stage
Time(hrs) Stagelft)
0.00 43.800
24.00 43.600
--------------------------
Name; BNDY3
Group: BASE
Type: Tiine/Stage
Time(hrs) Stage(ft)
0.00 37.000
24.00 37,000
_______________________________________9_____________
Base Flow(cfs): 0,000 [nit Sta sift): 43.800
Warn Stage(ft): 45.000
----------------------------------------------------------
Base Flow(cfs): 0.000 Tnit Stage(f U): 39.000
Warn Stage(ft): 40.000
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline 'Technologies, Inc.
Pngc I ,1 4

Smith Creek
Post Development
6/3/10
...................INPUT REPORT ............ ......
Name: Lake
Group: BASE
Type: Stage/Area
Stage(ft) Areafacl
20 600 35.8000
21.000 36.4000
22.000 30.4000
Drop Structures
Name: LAKE - BNDY1
Group: BASE
UPSTREAM
Geometry: Circular
Span(in): 24.00
Rise(in): 24.00
Invert(ft): 14.090
Manning N: 0, 013000
Top Clip(iu): 0.000
But Clip(in): 0,000
Base F1OW(cfs) 0,000
From Node: Lake
To Node: BNDY1
DOWNSTREAM
Circular
24.00
24.00
14.340
0.013000
O.D00
0,000
Upstream FHWA Inlet Edge Description:
Circular Concrete: Groove end projecting
Downstream FHWA Inlet Edge Description:
Circular Concrete: Groove end projecting
..' Weir 1 of 2 for Drop Structure LAKE - BNDY1 —
rnit Stage(ft). 20,600
Warn Stage(ft), 22,000
Length(ft): 303.00
Count: I
Friction Equation: Average Conveyance
Solution Algorithm: Automatic
Flow: Both
Entrance Loss Coef 0,000
Exit LOSS Coal: 0,000
Outlet Ctrl Spec: Use do Or tw
Inlet Girl Spec: Use do
Solution Inc.: 30
TABLE
Count: 1
Type: Horizontal
Flow: Both
Geometry: Rectangular
Span(in): 48.00
Riselin): 48.00
Bottom Clip(in): 0.000
Top Clip(in): 0.000
Weir Disc Coef: 3,200
Orifice Disc Coef: 0.600
Invert(ft): 21.350
Control Elev(ft): 21.350
— Weir 2 of 2 for Drop Structure LAKE - BNDY1 —
TABLE
Count: 2
Type: Vertical: Mavis
Flow: Both
Geometry: Rectangular
Span(in): 12.00
Rise(in): 3.00
----------------
Hydrology Simulations
Bottom Clip(in): 0.000
Top Clip(in): 0.000
Weir Disc Cost: 3.200
Orifice Disc Coef: 0.600
Invertlft): 20.600
Control Elev(ft): 20.600
Name: post002-YR
Filename: N:\20523.0004\DSGN\STORMWATER\ICPR MODEL\poat002-YR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsiii
Rainfall Amount(in): 4.69
Time(hrs) Print Inclmin)
--------------- -------------..-
10.000 15.00
15,000 10.00
24.000 15.00
____ __-_ _ -_ ___-------
Name: postOIO-YR
Filename: N:\20523.0004\DSGN\STORMWATER\ICPR MODEL\postOlD-YR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsiii
Rainfall Amount(in): 9.25
Intemonnecled Channel and Pond Rowing Model (ICPR)--�2002 Strevnline Technologies, Inc. -- Page 2 of 4

Smith Creek
Post Development
6/3/10
...................INPUT REPORT ..................
Timc(hrs)
__
Print Inc(min)
10.000
15.00
______
15.000
10.00
24.000
15.00
__ ___ ______-__
Name: posL025-YR
Filename: N:\20523.0004\DSGN\STORM'JATER\ICPR MODEL\post025-YR.R32
Override Defaults: Yes
Storm Duration(hrs): 24.00
Rainfall File: Scsiii
Rainfall Amountlin): 9.11
,rime(hrs) Print Inc(min)
_______________ ______
10.000 15.00
15.000 10.00
24.000 15.00
- --
Name: postl00-YR
Filename: N:\20523.0004\DSGN\STOR ATER\ICPR MODEL\pcst100-YR.R32
Override Defaults: Yes
Storm Duratioo(hrs): 24.00
Rainfall File: Scsiii
Rainfall Amount(in): 12.65
Time(hrs) Print Inc(min)
___________
10.000 15.00
15.000 10.00
24.000 15.00
___________________________________________________________
Routing Simulations
Name: postO02-YR Hydrology Sim: post002-YR
Filename: N:\20523.OD04\DSGN\STOR ATER\ICPR MODEL\postO02-YR, 132
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00
Time Step Optimizer: 10.000
Start Time(hrs): 0,000
Min Cale Timelsec): 0.5000
Boundary Stages:
Delta Z Factor: 0.00500
End Time(hrs): 30.00
Max Cale Time(sec): 60.0000
Boundary Flows:
Time(hrs) Print Inc(min)
_______________ _______________
10.000 15.000
15.000 10.000
30.000 15.000
Group Run
BASE Yes
____________ _____________ ___
Name: post010-YR Hydrology .Sim: p0st010-YR
Filename: N:\20523.0004\DSGN\STOR ATER\ICPR MODEL\pos[OIO-YR.I32
Execute: Yes Restart: No Patch: No
Alternative: NO
Max Delta Z(ft): 1.00 Delta Z Factor: 0.00500
Time Step Optimizer: 10.000
Start Time(hrs): 0.000 End Time(hrs): 30.00
Min Cale Time(sec): 0.5000 Max Cale Time(soc): 60,0000
Boundary Stages: Boundary Flows:
Time(hrs) Print Inc(min)
Interconnected Channel and Pond Routing Model (ICPR) 02002 Streamline Technologies, Inc.
Page 3 nl1

Smith Creek
Post Development
6/3/10
...................INPUT REPORT ..................
10.000 15.000
15.000 10.000
30,000 15.000
Group Run
BASE Yes
____________________________________Y_-___-- ______ ________
Name: post025-YR Hydrology Sim: poat00.5-YR
Filename: N:\20523.0004\DSGN\S'rOR ATER\ICPR MODEL\pos L025-YR.L32
Execute: Yes Restart: No Patch: No
Alternative: NO
Max Delta Z(ft): 1.00 Delta Z Factor. 0,00500
Time Step Optimizer: 10.000
Start Time(hrs): O.D00 End Timelhrsl: 30.00
Min Calc Time(sec): 0.5000 Max Cale Time(sec): 60.0000
Boundary Stages: Boundary Flows:
Time(hrs) Print Inc(min)
10.000 15.000
15.000 10.000
30.000 15.000
Croup Run
BASE Yes
Name: postl00-YR Hydrology Sim: post100-YR
Filename: N:\20523.0004\DSGN\STOR ATER\ICPR MODEL\postl00-YR.132
Execute: Yes Restart: No Patch: No
Alternative: No
Max Delta Z(ft): 1.00
Time Step Optimizer: 10.000
Start Timelhrsl: 0.000
Min Cale Time(sec): 0.5000
Boundary Stages:
Time(hrs) Print Inc(min)
________-__-
10.000 15.000
15.000 10.000
30.000 15.000
Group Run
BASE Yes
Delta Z Factor: 0.00500
End Timelhrsl: 30.00
Max Cale Time(seC): 60.0000
Boundary Flows:
hHe connected Channel and Pond Routing Model (IC PR) 02002 StrrunIine Technnlogics, lnc. Pre, 4 nl'-1

Smith Creek
Post Development
6/3/10
•••- ...........-NODE MIN/MAX REPORT ......'•••^.
^ ^
Max Time
Max
Warning Max
Delta
Max Surf
Max Time
Max
Max Tine
Max
Name Group Simulation
Stage
Stage
Stage
Stage
Area
Inflow
Inflow
Outflow
Outflow
firs
It
ft
ft
ft2
hrs
CIS
hrs
Cfs
BNDY1
BASE
postO02-YR
0.00
14.000
16.000
0.0000
0
24.01
1.250
0.00
0.000
BNDY1
BASE
postOlD-YR
0.00
14.000
16.000
0.0000
0
24.00
2.046
0-00
0.000
BNDY1
BASE
post025-YR
0.00
14.000
16.000
0.0000
0
22.15
7.234
0.00
0.000
SNDY1
BASE
postl00-YR
0.00
14.000
16.000
0.0000
0
16.95
23.141
0.00
0.000
BNDY2
BASE
post002-YR
0.00
43.800
45.000
0.0000
0
12.33
2.029
0.00
0.000
BNDY2
BASE
post010-YR
0.00
43.800
45-000
0.0000
0
12.33
3.831
0.00
0.000
BNDY2
BASE
post025-YR
0.00
43.800
45.000
0.0000
0
12.33
5.161
0.00
0.000
BNDY2
BASE
postl00-YR
0.00
43.800
45.000
0.0000
0
12.33
7.676
0.00
0.000
BNDY3
BASE
post002-YR
0-00
37.000
40.
000
0.0000
0
12.66
2.956
0.00
0.000
BNDY3
BASE
Pos:OlO-YR
0.00
37.000
40.000
0.0000
0
12.50
Z296
0.00
0.000
BNDY3
BASE
poer025-YR
0.00
37.000
40-000
0.0000
0
12.50
10.804
0.00
0.000
BNDY3
BASE
post100-YR
0-00
37.000
40.000
0.0000
0
12.
50
17.813
0.00
0.000
Lake
BASE
post002-YR
24.01
20.995
22-000
0.0049
1565263
12.33
132.369
24.01
1.250
Lake
BASE
postO10-YR
24.00
21.367
22.000
0.0049
1601589
12.34
252.910
24-00
2.046
Lake
BASE
post025-YR
22.15
21.563
22.000
0.0050
1610106
12.33
342.371
22.15
7.234
Lake
BASE
pest100-YR
16.95
21.894
22.000
0.0050
1624524
12.33
511.
993
16.95
23.141
Iumianuicaed CChmmd Lnd Pond Routing Nodrl IICPRI G2003 Sttauuilinc I cchnalogiu. Lw. Page 1 of I

Smith Creek.
Post Development
G/3/10
"•"'•'•^••"•'•'LINK
MIN/MAX
REPORT •^•••'•^^^^••
Max Time
Max
Max
Max Time
Max
Max Time
Max
Name
Group
Simulation
Flow
Flow
Delta p
US Stage
US Stage
DS Stage
DS Stage
hrs
Ofs
cfs
hrs
'_t
hrs
ft
LASE - BNDYI
BASE
post002-YR
24.01
1.250
0.016
24.01
20.995
0.00
14.
000
LAKE - BNDYI
BASE
post0t0-YR
24.00
2-046
0.022
24.00
21.367
0.00
14.000
LAKE - BNDYI
BASE
post025-YR
22.15
7.234
0.024
22.15
21.563
0.00
14.000
LP.KE - BNDYI
BASE
postl00-YR
16.95
23.141
0.121
16.95
21.894
0.00
14.000
------------
In:rmumiraed Cli.n;nei mid P, nd Ruueing Mod.l (ICPR) L_'OU' 4mainlinc Tcehnolugics, Inc. Page I ul 1

New Hanover County Parks:
Smith Creek
New Hanover County, North Carolina
Section 2.4
Combined Unit Hydrograph Calculations
Prepared By
Thomas & Hutton Engineering Co.
219 Station Rd. / Wilmington / NC / 28405
50 Park of Commerce Way / Savannah / GA / 31405
935 Houston Northcutt Blvd. / Mt. Pleasant / SC / 29464
1350 Farrow Pkwy / Myrtle Beach / SC / 29577
116 West Palm Plaza Drive / Brunswick / GA / 31523
J-20523.0004
N:\205230004`,dsgn\stoimwatcrQ0523-4 Stonnwwer Report 8-1-09.doc

J-20523.0004
ALGADR
Stormwater
Combined Unit Hydrograph Calculations
Smith Creek
Pre -Development
Post Development
Prepared By: Thomas &HUtton Engineering Company
Date: August I, 2009
Revised: 6/3/ 10
PRE and POST DEVELOPMENT INFLOW RESULTS
2-Yr Storm
7.84 cfs
4.65 cfs
10-Yr Storm
22.50 cfs
10.85 cfs
25-Yr Storm
35.87 cfs
15.49 cfs
100-Yr Storm
53.22 cfs
24.81 cfs
N:A20523.0004\dsgnAstonuwaterAICPR Mode1\2I1523-4 Comhined Hydro ResulIs Table 8-1-09.xIsx

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New Hanover County Parks Smith Crook
Pre Development Punolf Rates
Thomas and Hutton Engmearmg Co.
�QI� � �_�.Z.3l67ijlT=

12
10
E
Gi
C!
N
w
COMPOSITE POST DEV. MAX FLOW = 4.65 cfs
COMPOSITE PRE DEV. MAX FLOW = 7.84 cfs
—BNDYi
—BNDY2
—BNDY 3
„
-COMPOSITE
i
I
0
5 10 15
TIME (Hrs.)
20
25
30

30
25
to
5
0
0 5 10 15 20 25 30
TIME (Hrs.)

40
35
30
44 �5
CU
O
W 20
F
15
10
5
0
COMPOSITE POST DEV. MAX FLOW = 15.49 cfs
COMPOSITE PRE DEV. MAX FLOW = 35.87 cfs
n
it
\�
i!
—BNDY1
—BNDY2
—BNDY3
---COMPOSITE
i
It
c
ii
.0
5 10 15 20
TIME (Hrs.)
25
Ki

50
10
0A,
0
COMPOSITE POST DEV. MAX FLOW= 24.81 cfs
COMPOSITE PRE DEV. MAX FLOW= 53.22 cfs
3
5 10 15
TIME (Hrs.)
20
— BNDY1
— BNDY2
—BNDY3
COMPOSITE
25 30

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COMBINED UNIT HYDROGRAPH
COMPOSITE POST DEV. MAX FLOW = 4.65cfs,
COMPOSITE PRE DEV-MAX FLOW = �.84 cfs
C
—BNDY i
—BNDY2
—BNDY 3
—COMPOSITE
,i
0 5 10 15 20 25 30
TIME (Hrs.)

12
10
COMPOSITE POST DEV. MAX FLOW =10.85 cfs
COMPOSITE PRE DEV. MAX FLOW = 22.50 cfs,
i
BNDY1
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—BNDY 3
—COMPOSITE
4
2
O
0 5 10 15 20 25 30
TIME (Hrs.)

18
16
14
12
i'!
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COMPOSITE PRE DEV. MAX FLOW = 35.87 cfs
ji
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COMPOSITE
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New Hanover County Parks:
Smith Creek
New Hanover County, North Carolina
Section 3.1
Grassed Swale Design Calculations
Prepared By
Thomas & Hutton Engineering Co.
219 Station Rd. / Wilmington / NC / 28405
50 Park of Commerce Way / Savannah / GA / 31405
935 Houston Northcutt Blvd. / Mt. Pleasant / SC / 29464
1350 Farrow Pkwy / Myrtle Beach / SC / 29577
116 West Palm Plaza Drive / Brunswick / GA / 31523
J-20523.0004
N.\20523.00041dsgn\stonnwated20523-4 Stonnwater Report 8-1-09.doe

PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
JOB No.: 20523.0004
DATE: 8/ 1 /2009 (REv 6/3/ 1 O)
CALCULATED BY: ALG
CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS - GRASSED SWALE DESIGN
Swale #1
Determine 10-Year Flow for Channel
Use Rational Method for 10-fear Rnw:
Flow': Q=CIA
Where: Q = Design Flow reR)
C = RunoO Coeffcicnt
I = 10-Year Rain ali Intensity
A = Area (acre)
IS t'ILhl, 3-0" pg. 1-2 in NCISP.NIt S1,ain, iter II,NII' Maruull
t See Scctral 1,5I1n 1'11e m Swale Ura i nape Arta Ishthi1)
Area Description
'I able 2
Runoff
Cenicient. C
Area
(ac)
pavement
0.95
0.20
Grass, Fat, Sandy
0.15
0.39
Composite Runoff Coefficient. C= 0.42
Calculate Time of Concentration
Use "fr:rsrl I'inse Concept:
Uverinnd plow: 1=(0.lq](r'I)"QR)/I(l'_^0.5)-,S^4411'I'R-55 Fy 3-3
where: t ='I ravel'rirte for Overland plow ( min)
it = Manning s Coefficient - from "IA.55'fable 3-1
1 = length of plow tftl
P; = 2-yr Rainfoll Depth lint
S = Hydraulic Slope lft/ff
a= 0011 Asphalt
I= 41 It
P. = 4.67 in
S= 0.020 ft/R
t = 0.5 min
Channel Flow: t = 1/60v
where: t =Travel Tine for Pipe Flow (min)
I = length of Flow (ft)
v = Velocity tf(A)- Prop, I R-55
1= 485.00 If
v= ].fNl ft/s
1= .1.04 min
"rherefore.'fc = 4.5 min
Use 5fX) in
N:\20523.0004\dsgn\stormwater\DENR Calcs\20523.0DN DENR Grassed Swale-Suppfement.xlsx Page 1 of 5

PROJECT NAME: SMITH CREEK PARK
° A0 PROJECT LOCATION: NEW HANOVER COUNTY
f � z
' JOB NO.: 20523.0004 CALCULATED BY: ALG
DATE: 8/ 1 /2009 (REV 6/3/ 10) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS - GRASSED SWALE DESIGN
Swale #1
Peak Plow Calculation - Post-Develoumeirl
Peak Flow mte. Om = C-l-A
C = 042
I ... = 9.70 in/hr(5minsl(Fnnu Atlnela-NOAA)
A = 0.59 ucns
Qtv= 2.41 efs
Channel Characteristics and Permissable Velocity
Slope. S(7)= 0.5
Soil Characteristics = easily Erodible
Grass Lining 'I'ype = Grass Lego". Mixture
Soil Characteristics (enter -x" below)
Sand/Sill (easily erodible) %
Clay Mix (erosion resistant)
Gov, I'ype (enter "x" helowl
Bermuda
'Fall Fescue
Bahiagmss
Kentucky Bluegrass
Grass-Icg one Mismre K
Permissible Velocity (fps) 35 Fmm Table 14-2
I:stimale Channel Dimensions
VViormed Channel Area. A (h') = 069
Guesses for Actual Channel Aren:
Sidc,)"N, M:1 = 3
Channel Depth, d = 1.2
Bottom Width. B (ft) 0
Anna) Area (hc) = 4.32 OK
Hydraulic Radius. R (0)= 0.57
Mannini s n value:
Renrdance Claffable 60-4)= D
RenrMnce Class to Use with Graph on Page 60-5 NEW Manual = li
Parini nsahla Veloeily,01A)= .15
Hydmulir Rmlik, M)= R57
V- k I For Usa on Gntph on Page 8.06.7)= 199
Manning's it value front Graph on Page 5.05.7 DBNR .Manual = 003
N:\20523.0004\dsgn\stormwater\DENR Caics\20523.0004 DENR Grassed Swale-Supplement.slsx Page 2 of 5

PROJECT NAME: SMITH CREEK PARK
A PROJECT LOCATION: NEW HANOVER COUNTY
AJOB No.: 20523.0004 CALCULATED BY: ALG
DATE: 8/ 1 /2009 (REV 6/3/ 10) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS - GRASSED SWALE DESIGN
Swale #1
Swale Type - Max Velocity from 10-Year Storm
Alas Vel, iap can M AemnnineJ from Manning\ 13yuanon:
Hov:e\cr. area and hydraulic radius are nrn knox'n
Kr,nn l' I'r..rY Ai.r L.rp'.. I,. rlx.. bemr'I lrni
tt IlrAunL� wlu wdh.Lu.LnN: ..rrx.nJ
I..I rli. In rr ..IIIe a. l`illl 1`
. - I.nnr,rr�xlilurlr.l,.l..,.r rlx1 ur..-.1.-'r�,:. M1.mr.'1 (Ir r..11/Ir r.lnl
nlJrr..l�.{.r nnl`�'+r'irinl...rnrad'
I ♦ y
\1 11
� o a
nn n-prr... tllxl-�1
xnlr ..IVren...�..1r.r.lirrl rrr lL....... n...•.,r,
Area can he expressed as:
A=By+My2
Hydraulic Radius. R can be expressed as:
R - :1
P
whcre I'ix:
P=R-2y(I
I,.. n...l ...... . ,n.r..: rn...xirt.l r- A... ni.
x - Rlrron. wulrh........nnrx.....
\I - ::.I...I.�......i. xl l.,,n..-,I..I:II ...ti..11 r.l.r.-...x..l la,:,,n,.xl
N:\20523.0004\dsgn\stormwater\DENR Calcs\20523.0004 DENR Grassed Swale-Supplement.xlsx Page 3 of 5

PROJECT NAME: SMITH CREEK PARK
7 %) PROJECT LOCATION: NEW HANOVER COUNTY
? O JOB NO.: 20523.0004 CALCULATED BY: ALG
DATE: 8/ 1 /2009 (REV 6/3/ 1 0) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS • GRASSED SWALE DESIGN
Swale #1
All ,unable, are kit mvn in Mmmings Equation esecla) tfouad in AR Tenn)
Rearranging Manning', liqunion
AR'""1=Q'a/(I 49'S"")=I13"y+M"y-)"I(B"y+M'yc)/(B+2"y(1+M2)'')1 "7
Mes Qt„(et ,)= 2.41
Longitudinal Slope= 0.005
Mnnnin,sn= 0,03
AR "'= 00
AR orO I M'I A
00J5
Velocity = Q/A
I0-Year Velocity (fps)= 66 OK
Pcrmixrihle Vclociry (Ij1s)= 35
Additional Information - Death of Freeboard
Depth of Freeboard = Ditch Depth - Water Depth for 10-Year Storm
Ditch Depth tfq= 1.20
Water Depth Db= 0.695
Depth Freeboard (f) = 0,51 OK
F,vali ate Need forTemporary Liner
reny)orary Liner was evaluated to meet NCDENR requirements for the 2-year. Pi hour design storm evert.
Peak Flowrme. Q.=C'P'A
C= 042
1, = 7,43 in/hr (5 mi.,) (From Ado, lJ - NOAA)
A= 0.59 ucres
Qa= 1.85 cfs
AR"=Q'n/(1.49'S"s)=tB'y+M"y )"I(Il"y+M'y-)/18+2'ytl+Mal')1 ""1
Max Q, (cfs)= 1.85
Longita&u,d Slopc = 0.(X)5
Morning', n = 0.02 i Scc'fuhle 8.0%. pg 8.05.1)
ARC"'= 0.35
AR1M11 17 y M:I A
�OAf) 0.540 3.00 087
Vclacuy = Q/A
2-Year Velocity ffp,)= 2,11 'Iraq pmar)'Lincr Rl?EDISD. evaluate liner or.0urial
Permissible Velocity (fps)= 2.0 Mao, Etnh Condition)
N:\20523.0004\dsgn\stormwater\DENR Calcs\20523.0004 DENR Grassed Swale-Supplement.alsv Page 4 of 5

PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
JOB No.: 20523.0004
DATE: S/ 1 /2009 (REV 6/3/ 10)
CALCULATED BY: ALG
CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS - GRASSED SWALE DESIGN
Swale #1
Determine Temporary Liner Material
Calculate chanrel design wish Slmw MNel a+Temporary Liaer.'I'd = 1.45 (See'Urble 8,05g. pg. &05.13 in NCDENR Manual).
Prn,ccure for dcnigning mmporary liners is sanr am that of riprap channels page 60-5).
Shear Sncss.'I0b / Ii') = V'd"s
where: V0b/11)= density of w user=
614
d(h)=depth of)low=
0.540
s(0/ft)= slope =
0.005
'therefore. 't (Ib / tU =
0.17
Ten)porary Liner SCIeCtIOr) (front figure 60-6)=
Straw with Net (Use Exeelsior Malting)
Permissible Unit Shear Stress. (Ib / f(") =
1.45 OK
N:\20523.0004\dsgn\stormwater\DENR Calcs\20523.0004 DENR Grassed Swale-Supplemenexlsx Page 5 of 5

PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
v
�CEF�N
JOB NO.: 20523.0004 CALCULATED BY: ALG
DATE: B/ 1 /2009 (REV 6/3/ 10) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS • GRASSED SWALE DESIGN
Swale #2
Doerunine 10-Year Flow for Channel
U, Rational .\Tnh)d for 10.1'ear How:
Flow: Q=CIA
W here: Q = Drsign Plmc refs I
C= Runoff Coefficient
tSee1':0o, 3. 2. pg 3 2... NCURAId Storuns mcr Mill Al.mua11
I = 10-Year Rainfall lntensily
A=Area0,c,6
iS,,Section.15lo,l'I1n•.Aassala 1), unw, c Area I AnInil
Area Description
'fable 3-2
Runoff
Coclliclerf c
Area
fnc)
Pavement
0.95
0.10
Grass. Flat. Sandy
0.15
0.21
Comlwsi(e Runoff' Coeflicient. C= 041
Calculale'rime of Concenbodinn
Unc'I'ravel 'I'i ntc Concept'.
Overland Flow: t=00007tn*11^0.8)/((P,"O5?(S^04)I'1'R-55Fig1-3
where: t='rruvel'I'inn, for Overland Flow (min)
a = planning's Coefficient - from TR-55'I'able 3-1
1 = length of Flow (it)
V. = 2-yr Rainfall Depth (in)
S = Hydraulic Slope (h/f)
n = 0.240 Grass
1 = 22 fit
P.= 467 in
S= 0.008 Wit
1= 52 am
Channel Flow: t=1/60v
when: t ='Travel Time for Pipe Flow Onin)
I = length of Flow (fit
v = Velocity (ft/s)- From 'I'R-55
1= 270.00 ft
= 2.00 fa,
I = 225 inin
'ITcteforc. Tc = 7.5 inia
Use 5.00 min
N:\20523.0004\dsgn\stormwater\DENR Caics\20523.0004 DENR Grassed Swale 5uppleanentxlsr Page 1 of 5

o13, a h� A PROJECT NAME: SMITH CREEK PARK
z, PROJECT LOCATION: NEW HANOVER COUNTY
�. JOB No.: 20523.0004 CALCULATED BY: ALG
�6'fFp I NG. DATE: B/ 1 /2009 (REV 6/3/ 10) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS - GRASSED SWALE DESIGN
Swale #2
Peak FloeCalculation - Port-Develooment
Peak Floeode. Q,= C" I N
C= 0.41
Im= 0.70 in/hr fs mind iPnnn Arms l4-Nt)AAI
A = 0.31 acres
Qn,= 1.23 cfs
Channel Characteristics and Pennissable Velocity
Slope. S (ZO = 0.75
Soil Charucmrivics= Easily l irodible
Grass Laing ng Fylx = Grass lcFume Mixture
Soil Chatucrerislie> (enter "c" below)
Sand/Sill (easily erodible) X
Clay Mis (cm.ion resismnl)
Got, 1'ype(enter "i W-ow)
Bermuda
'full Fescue
Bahiagrass
Kentucky Hlucg a,
Grus-Iegun a Mismrc %
Permi"ible Velocity(fps)=
3.5 Ron, Table 14-2
F,4imate Channel Dimensions
Estimated Chmmel Area. A (bi) =
035
Guc,es for Actual Channel Area:
Sideslope. M:I =
3
Channel Depth. d=
1,2
Bottom width. B (f0 =
0
Aetna]Area (b')=
4.32 OK
Hydraulic Radius. R (a)= 0.57
h'lunnlnL s n value,
Relurdnnre Clans (]',able 60-) = D
Retardance Clans to Use with Graph on Page 60-5 NHC Manual = E
Permi,able Velocity (11A) = 3.5
Hydraulic Radius (b)= 0.57
V * R (For Use on Graph on Page 8.06.71 = 1.99
Manning', n slue Irons (kaph on Pages Y 05.7 DENR Mnnunl = 003
N:\20523.0004\ds8n\stormwater\DENR Calcs\20523.0004 DENR Grassed Swale-SupplemenLxlsx Page 2 of 5

PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
Joe No.: 20523.0004 CALCULATED BY: ALG
DATE: B/ 1 /2009 (REV 6/3/ 1 0) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS, GRASSED SWALE DESIGN
Swale #2
Swale Type -Max Velocity from 10-Year Sturm
Ala\ Velocitycan to determined from Manning: 8yualion:
Hotsecer. mM;md hydraulic radius are not known
I.h.>Lm..... c e„wrrr.r, r.rr L..1-.d,.
1r
a-n.,.. C r..n di•. e,rp:r..r... n. ..t r.
v.,..,.r..p ....pr,., ...n. i,r,r............,....r
Nn. n...o,ltn..,,el. ..Irc:n n..w
I�.1ll., In .. I..I I•..in..r.v, I'i llt l:1,
I.T.,Ir..JrmrLLgv..11F.llu�'m.er nl .'F..r..¢l Vr ral:Ia mm.
I rSary .J
Duper .Ja nlr .n.dl. hrt.M•
•11nY,•••.•nrnl M'.Ir..nrcl.i.lu .4 qw n.......... .. w6irfi nu.....
urJrv.r.O..n.v... yn� 4J mp.a. nrnnrul.
Area can be expressed as:
A=By+My2
Hydraulic Radius, R can he expressed as:
R - ,1
P
where P is:
r=R+2y(1+n11)r1,
..rF. Ilrrv.. y.r.r r.rv.a1:..:v:rl...r.r:u1.4�Ivr..rF••I.II..r: Yrlf rr..u.ir:4`I,,I... nlr.r I.r
-.. ...1 ..r III. •. 1�I I:I
P - nu ..1dtl:..l r1..'aFand In
I•
R - IlcJuuL. r��Lminr
N:\20523.0004\dsgn\stormwater\DENR Caics\20523.DDG4 DENR Grassed Swale-Supplemenlxlsv Page 3 of 5

ape s H�r� PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
JOB No.: 20523.0004 CALCULATED BY: ALG
tir:En1\,,G' DATE: 8/1/2009(REV 6/3/ 10) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS • GRASSED SWALE DESIGN
Swale #2
All cariablas are Anoscn in Mull ine's Equation wept v (found in AR "7 wall
R,,,arging Manning, Equation
ARnn'=Q'n/(1.49'Sa'x)=(B•y+NI'y')•liB'y+AI*y'1/Ili+2'y(l+Nl `I)j'a7
Nlaa Qlu (cf,)= 1.23
Langiuldinul Slope= 0,0075
Manning', a = 003
AR-'= 029
AR ""' 11
M:I A
l 0.1,0 0.501 3.00 0,75
Velocity =Q/A
I0-Year Velocity (lp'l = Lai OK
Permissible Velocity lips) = 3.5
Additional Information • Deluth of Freeboard
Depth of Prel,Ksad= Duch Depth - Water Depth for Ill -Year Smnn
Ditch Depth (a) = 1 20
Water Depth(f)= 0.501
Depth Freeboard (0) = o70 OK
Evaluate Need for Temporary Liner
temporary Liner was evaln:ned to meet NCDENR requirements for the 2-year. 24 hour design storm event.
Pcak Flowrate. Q;=C'1'A
C = 0.41
1.= 7.43 iWhr (5 Iran,) l From Allis 14-NOAAI
A= 0.31 acres
Qr= 0.94 efs
AR"=Q'n/I J9'S4')=(It'y+M'y)'I(B'y+Nl'y')/(if +2'y(1+M°)711
Max Q7 fiefs)= 0,94
Ianlgn udinal Slope0,0075
Mannhl n= 0,02 (Se, l ahlcg.05h.pg.SJlib)
AR `n°= 0.15
AR `"7 11 v M:I ,A
VXLI.ra Whil 0390 31N) 0,46
Velocity = Q/A
2-Year Vel,x,ay(Ij),1= 2.06 ' truquu'unLine. NF1 )FD.,,nh.ak li ner lnalerial
Penni"able Velocity t ljty= 2.0 (Rare Earth Condrinn)
N:\20523.0004\dsgn\stormwater\DENR Ca1a\20523.0004 DENR Grassed Swale -Supplement xlsx Page 4 of 5

�p,5 8.ryvJ
s
F° °z
i o
.~FentN
v
PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
JOB NO.: 20523.0004 CALCULATED BY: ALG
DATE: 8/ 1 /2009 (REV 6/3/ 1 O) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS - GRASSED SWALE DESIGN
Swale #2
Determine Temporary Liner Material
Calndate ehannel design with Straw w/Nc, as Teml orary 1-iner. Id = 1:15 (See 'fabin 8 05g. pg. 5.05.13 in WDI-NR Manual).
Procedure for designing tenynnary liners is none as 111.1 of riprap elmnnela (Pape 60-5).
Shear Stress.'f (Ib / fl')= V'd"n
where: Vdb/Po=density ofwaler=
624
d1f0=depthof llow=
0.390
e(11/f0=slope=
0.0075
Theretore.'I(lb / it) =
0.18
I'cnlpoony Liner Selection from Figure 60-61=
Stnwwdh Net (Ilse F.ceelsior .Milting)
Permissible Unit Shen, Suess. (Ih / ffl =
1.45 OK
N:\20523.0004\dsgn\stormwater\DENR Calcs\20523.0004 DENR Grassed Swale-Supplementvlsi, Gage 5 of 5

BPS, n H4j,..
Fib v '.
01
YEERt WG.
PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
JOB NO.: 20523.0004 CALCULATED BY: ALG
DATE: B/ 1 /2009 (REV 6/3/ 10) CHECKED BY: JOR
SUPPLEMENTAL DENR CALCULATIONS - GRASSED SWALE
Swale N3
Determine 10-1'ear Flom for Channel
Uac Rational blodunl for 10-Year Flow:
Flow: Q=CIA
Where: Q = Design Flow (efs)
C= Ru mtf Rktticienl (See'I ahle 3-2, 1)g.3-2 in NO)IihR Storm,a cr Ithll' SLmua11
I = I0-Year Rainfall Imensity
A=Area (acre) 'See Se, two t,i wr Pilw• R .Src:d� Uriinage Area Inhibit
Area Description
'Fable 3-2
RuW1T
Coeffieiem.0
Area
(ac)
Pavement
0.95
0.61
Grass, Flat. Sandy
0.15
4.34
Compasile Runoff CceffiJent. C = 0,25
Culeulate'Eimc of Concentration
use'1'ravet Time Concept
Overhaul Flow: I = (0.1107(n*I)^o.S)fl(I ;^0.5MS-0.4))1R-55 [(I .1-3
where. I = Travel'I'inm far Overland Ilow onin)
n = %lannin); s Coefficient - from 'FR-55'Fable 3-1
1= Length of Flow In)
P_ = 2-yr Rainfall Depth (in)
S = Hydmolic Slope 0V111
n= 0240 Grass
= 100 ft
P,= 4.67 in
S = 0.010 ft/ft
t= 15,6 min
Channel Flow: t=1/60v
where: 1='I ravel 'I'one for Pipe Flow (min)
I = Length of Flow (fl)
v = Velocity (fUs). From TR-55
I == 82� .00 ft
v = 2.00 IVs
t = o85 min
Therefore. 'I c= 224 min
Use 15.4f) min
N \20523D004\dsgn\stormwater\DENR Calcs\20523.0004 DENR Grassed Swale-Supplmnentrlsx Page 1 of 5

PROJECT NAME: SMITH CREEK PARK
ter° z, PROJECT LOCATION: NEW HANOVER COUNTY
,o ( Joe No.: 20523.0004 CALCULATED BY: ALG
iyEEn t N° DATE: S/ 1 /2009 (REV 6/3/ 1 0) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS - GRASSED SWALE DESIGN
Swale #3
Peak Flow Calculation - Post-Deyeloument
Peak Flmmate. Q, ,=C"I"A
C= 0a-5
I,, = b.54 iNhrllS trains( (Enna Anus la-NOA.M
A= 4.95 acres
Q„�= 8.05 el"
Channel Characteristics and Permissahle Velocity
Slope, S I%) = 0.5
Soil Characteristics= Easily Erodible
Grass Lining'I'ylK = Grass Ixgurne Mixture
Soil Characteristics (enter V' below)
Sand/Silt (easily crodihle) X
Clay Mix (eut,don rc'mant)
Grnss'Fype (enter '' below)
Not ... do
Tall Fescue
Bahiagrass
Kentucky Bluegmss
Grass-legune Mixture X
Permissible Velocily(fps)= 3.5 Front I -able 14.2
Estimate Channel Dimensions
latimaed Channel Aren. A (f6 = 2,30
Guesses for Actual Channel Area:
Sideslole. M:I = 3
Channel Depth, d = 2
BoOom Width. ll (i)= 0
Actual Area (fr) = 12,00 OK
Hydraulic Radius. R TO = 0.95
Manninc's a value:
Retardant, Class (Table 60-4)= D
Retardunce Class to Use with Graph on Page e0-5 NHC Manual = F
Pernim,ahle Wocily (M)= 3.5
Hydraulic Radio, (it)= 0.95
V " R I For Use on Graph on Page 8,06.7) = 3.32
Mnnning;v n value front Graph on Page 5.05.7 IXNR Manual = 0,027
N:\20523.0004\dsgn\stormwater\DENR Cabe\20523.0004 DENR Grassed Swale-Supplement,xlsx Page 2 of 5

FO T'
. Z
in
14 ,.
fee R 1 NG
PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
JOB No.: 20523.0004 CALCULATED BY: ALG
DATE: 6/ 1 /2009 (REV 6/3/ 10) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS -GRASSED SWALE DESIGN
Swale #3
Sale Type - Ntax Velocity from 10-Year Storm
htas VeInet I, can In do, 111l pled tIII n III: III 'mI,'s Equ:ai'ITT
.
Hosaerer, area and hydraulic radius are not known
1.. \Ivnrur'� eV"^rir+r..rr 1•-'rrral.r.
t_ 1
Ws. rr.' (.r
I.r4 rli..' I..........rlrr..rvrrrrr. l
rr..r1.1..-M1.....r.i.i..i...uli..il.+.i
LIn..........Ru,nIY.I. .AJre ll.e.
,
I,.rxrcJ,e..a.e.r..eru�I�i,.r.n.•m, .n.,r.rr,t pr l.dlnrr.rm.
I1Vuu 1
ftn g..� y.I Fr; F.0 .H .iJe.A.p rprr nua .vl'.i.fi.. r.pi:�llr'. :bq-A
Area can be expressed as:
A=By+My:
Hydraulic Radius, R can he expressed as:
R a A
P
whom P is
PIll Pt24(I-WIP.,
r.. a. Inl...yrrnr.r. d..r..: m,1-11L- n.r. Il..l.nn.,aJK.r...,rr..c e,l.. ,,e, n.
n m 1 n
VI � 'Ir.l,•.l'.1'r.r .. nr l...rrlr.rr.rlllr ...rr
I'
(' II.'.�lir1.l.. ♦i
y - I1..rrF.�l nr.xl lrrl rrl
N:\20523.0D04\dsgn\stormwater\DENR Calcs\20523.0004 DENR Grassed Swale-Supplementalss Page 3 of 5

PROJECT NAME: SMITH CREEK PARK
z\ PROJECT LOCATION: NEW HANOVER COUNTY
Joe No.: 20523.0004 CALCULATED BY: ALG
N6, DATE: S/ 1 /2009 (REV 6/3/ 1 0) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS - GRASSED SWALE DESIGN
Swale #3
All sariubles are known in Nimaing,s Equation escept y (round in AR "" lennI
Rearranging Nbiamgl Equation
ARdo=Q*n/(I19"S"s)=(11"y+N1°pe)'^JWB• Wv2)/(It +2')il+M°)'s IJ".r
Mln Qln(c fs)= 805
Longitudinal Slope = 0.005
Manning'sn= 0.027
.1RB M:I A
W"thi 000 IA46 3,00 328
Vclodly = Q/A
10-Ye:v Velocity 0ju)= 2,45 OK
Permissible Velocity (fps) = 3.5
Additional Information - Death of Freeboard
Depth of FreeMtard = Ditch Depth - Water Depth for 10-Year Smnn
Ditch Depth (ft) = 2.00
Water Depth (A)= 1.046
Depth Fmehonnl (f0= 0.95 OK
Evaluate Need for Temporary Liner
Temporary Liner was evaluated to meet NCDBNR require meets for the 2-year. 24 hoar design storm event.
Peak Flowmtc. Q,=C'1-A
C= 025
1,= 498 iNhr(15 mins)(Rum Alla, 14-NOAA)
A = 495 acres
Qt = 6.13 crs
AR""r=Q*n / (1.49*S"') =(B-v+WY2). p8^y+ W/) / (B+2-yl I+102Y`)7'"'r
MnsQ_(c6)= 6.13
LangiaWimd Slope = 0,005
Mnnningkn= O.o2 (Sec1' thlce.1151, pg, S 05,(o
AR"= 1.16
Nl A 1356 0.00 0 845 3,00 2,14
Velocity = Q/A
2-Year Velocity (fps) = 2.86 'Temporary liner NFEDED, c,duate lim, mates iul
Pnmissibie Velocity (fps) = 2.0 (hare I7urth Condition)
N:\20523.0004\dsgn\stormwater\DENR Cal a\20523.0004 DENR Grassed Swale-5upplemerasis. Page 4 of 5

�p5, ra N(aT
G-
�eEnsNG.
PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
JOB No.: 20523.0004 CALCULATED BY: ALG
DATE: 6/ 1 /2009 (REV 6/3/ 10) CHECKED BY: JDR
SUPPLEMENTAL DENR CALCULATIONS - GRASSED SWALE DESIGN
Swale #3
Determine TemuorarV Liner Material
Calculate channel design with Straw a'/Net ar Temporary Liner, Id = 1.45 (See'I;ahle 3 05g, pg. 8.05.13 in NCDENR Nlantml)
Procedure liar designing temporary liners is same nS that of riprnp.:hannels (Page 00-5 ),
Shear Soeas.'I alb / 1r21= V'd's
whem: VIIb/it) =density of water=
62:1
d(ID=depth of flow =
0.545
s(ft/f0=ao'=
OHMS
Ilmmtore, I flb/It) =
0.20
fcmporary Liner Selection (from Figure o0-b) =
Svow with Net (Else P:xceMior Molting)
Permissible Unit Shear Stress. (Ib / ft) =
145 OK
N:\20523, 0004\dsgo\slormwater\DENR Cal¢\20523.0004 DENR Grassed Swale-SupplemenLvlsx Page 5 of 5

New Hanover County Parks:
Smith Creek
New Hanover County, North Carolina
Section 4.1
Grassed Swale Design Calculations
Prepared By
Thomas & Hutton Engineering Co.
219 Station Rd. / Wilmington / NC / 28405
50 Park of Commerce Way / Savannah / GA / 31405
935 Houston Northcutt Blvd. / Mt. Pleasant / SC / 29464
1350 Farrow Pkwy / Myrtle Beach / SC / 29577
116 West Palm Plaza Drive / Brunswick / GA / 31523
J-20523.0004
N:\20523.0004Ndsgnktonnwater\20523-4 Stomiwater Repon 8-1-09.doc

F hs s HufQ PROJECT NAME: SMITH CREEK PARK
i PROJECT LOCATION: NEW HANOVER COUNTY
o° JOB NO.: 20523.0004 CALCULATED BY: ALG
�eerar N° DATE: B/ 1/2009(REv 6/3/ 10) CHECKED BY: JDR
NEW HANOVER COUNTY CALCULATIONS • GRASSED SWALE DESIGN
Swale NI
Uhler ill,_'S-1'rt I I1xl-1'en Flon for Clintund
Vm Itxlion,l McIhW for 25.)'c:rr I Imv:
I'h,, p=CI•\
Where:U= Dc,,igll hlcw cciq
l'=Ranull Culliei.m Is,,Iahl.ill J.,, hl. l in V(t' Nnrnm:nfr Pl,nul,ll
I ='_5. Ynrf R."W III Imcnnily
Araa 1)..cripli...
'NM,A1-I
linnatf
Cu•I llcicnl.0
Anit
reel
In"
0,95
1 0.20
(;Iuls.lhm Saudv
0.15 1
o.39
Cun,"ilc HnneffCrxti ficienl, C= 042
Culeulme'I'ime of Canttmlrotion
❑.v Tra.ct l'inn r.tOlmcPc
UmdunJ Hhw:=JIfMDln'p"(I,g1IQI :"11.5PIS^f1All'rli-551: 1-t
where. 1=Tn9H'lins far lherland I'Inw (min)
n = Manning � Gxti li.icm - fmm'rlt-55 T,hle 1.1
1= Lcnglh of linty Ji 1
1'.= ^_-p R,Iniall I),& (in)
S = flydfauht: Slolw (1i/1),
a.Hn A,ItA,
I= 40 It
1•.= 4.67
.S= 0020 (i/fI
t= 0,5 ntm
Chanel 11".
1=1/6111
where:
I = Tnnai Tnat, lin Ill, liuw Ilnin l
I =1 cnglh 'I 11". (ill
t = Vch,cily(l iA) 1'1 ml TIt-55
1= 485 ) It
.= 2.00 liA
I= IIIJ min
Thcrclorc. Tc = 4.5
nill
I:.linIho=
10.96
Ilni(in /hit =
12.911
1)"on I'hnn
C=
0.42
C=
042
_.=
1,91,
1,,,=
1298
A=
Il$9
A=
0.59
lj, =
2.72 e11
(JI,x.=
3.20 i,R
E'limnle Clmnnel Siac
P.climnwd Ch,ntid Arc,. A titt:)= 0l91
Guc..en I;n Aanal Channel AI'ca:
,tiidglule. M:I = l
Chunncl l Ypth. d= 1.2
Halm.. Width. It(It1= tl
AUIn,l Arco lli"1= 412 ()K
I lyJmuli, ILdlu..If (11)= (1.57
N:\20523.0004\dsgn\stormwater\NHC Calcs\20523.0004 25-yr NHC Swale Calc.nlsx Page 1 of 2

PROJECT NAME: SMITH CREEK PARK
F o
z
PROJECT LOCATION: NEW HANOVER COUNTY
�.
o°
JOB NO.: 20523.0004 CALCULATED BY: ALG
A`R•1'rx•"O,
DATE: 8/1/2009(REV 6/3/ 10) CHECKED BY: JDR
NEW HANOVER COUNTY CALCULATIONS - GRASSED SWALE DESIGN
tiN Ole li I
DPI"'nillt' \1: 1 nne,, r'Ih e
Itmurd;lnac ❑lun, CI'uhla 60-11= D
Hccnd:lncc llla.. ,, U, , (1, Ol:q.h n 1 Peg. Ml-S NHC Manual = li
I'enniavhle Vcllvin'(Iu,)= 1 Fenn"rahle M)-I
II,*,ndic R.Idi., ill)= 0.57
V -R,For Ua'rrn ❑Ivph nn lLgc 61-5= 1.71
M:mning:,nv:iluc l ium(h;lph rrn l'.I@c 60-5= 003
D,wi-ruine Drl lh of Fln.. in S...k
.\@n Vcllairvcan N, &wnnincd Ir..n .Manning, I*,,i6on'
Hae'accr.:rtcn :mJ hvd.,flh, cW'w, arc nm Annwn
ru. +I.. ... ... .. ..... 1• .r.r.a ..,
LC
1, e.... r......... r...m r., n....1..r..r.,1.,..r
vI.
�, ..I+ •�I ti... .,rl•iitmu. ..r..r n.. ..el, ..n.nF n,...
N 111'. +ulr. 1r 1e1,. r.l n,'.1 r. r.InrN.• ... Iw•rul +r r+. .\
'. In r. .Iria.1.I..I••..r ., r.rrr...r.1r1...M1nr. r..l lrr r.11i r. rrrrrr.
..�....l rrr...rv.r.r�n.FrcT nr 1.'1"^IF'�:11\I•�1
i........... .
N.l .n rhimnr.r++l.
Alt, l:an lN: t'%P,,,d:l\;
I lyilrndic Radian. It cnn he c,tv,,d ay.
R� A
Y
where I' is.
P=B+24 f1 +811P"
LrrM ltrr...yv..rnr.+l+u.. rF...nrubL..lu.. J.. l..11,rx yr pi+l..nbru.
l ipure I.
r. ul.r. Ill..x 1�11.1
11 fin+ x1Ntb �d rNa Anv.i lln
51 - r.lr..lr.l•.. r+ ..Ill lv. rrr+ri+l' Il...n.....:........
I.Ie .I.M...l u......rvl
r u:a.d l•r.•r. r..:m
4 Il:.lnn.l. rnllr:. lfll
All r'driahlc arc nnuwn ln:vunnmg, rynam'n uccPlyuuunu In nN unnl
RcalnnFing M:mning'. liyumioil
Alt �°n=(Yn 111 J9+ti 1=llt+y�Mry"1'hli`y�,M"yV01a?'»HM'I'l..r
V:•,cfsp 17' Ili,„ ICGI= 3,20
Langiuulinu131u1w= ,1.1105 I. mgilndin:d Slaw= o(Xl5
Vamlin, n= 0.111 M'annin,% IIAI
AK 0,74 AK 0,91
AR1,1r it I M:I A
25-Yi,", 0.971 OA10 07^_, 101) sN
IINI-Year r 1 IIIN) 0770 l.,Nl 1.7s
('alculaeJ Ucpihnl I low,li)= 0.73
A„nrgc W all, Ucplh,li l= I.2 1&. Soek lna'1. Jc.iyl cllpn. il,
N:\20523.OW4\dsgn\sto,mwater\NHC Calcs\20523.0004 25-yr NHC Swale Calcxlev Page 2 of 2

PROJECT NAME: SMITH CREEK PARK
■ '°.
ILg11I i PROJECT LOCATION: NEW HANOVER COUNTY
c . u JOB NO.: 20523.0004 CALCULATED BY: ALG
A�Fwr"G DATE: 8/1/2009(REV 6/3/10) CHECKED BY: JDR
NEW HANOVER COUNTY CALCULATIONS • GRASSED SWALE DESIGN
Swm1e #2
Urlermine 25-1 ear and II)II-fear Floc I r Chanincl
U.r It:ninmJ \ICILad for 2y-1'c.nbina^
to,: Q = C I A
When: Q= )"ipn 1'I,11 R'IA
C = liwwl l G'Iffi' c n
I = _S YCar I lm;llI In nn.ily
Ama lkx riplinn
TnhIC J0-I
Kunol l'
GnflieicnLC
,\ma
lad
Im 'r,mn, 10.95
1 0.to
Gmnn. blur. Sandy 1
0.15
1 0,21
ISee'I':d•I<:0-I. pg. J0-1 m Sllt' Auu m��nnel \Idnu:dl
Comry.nila ltunull'Cnd'Iicicn6 C= 0.41
('nleulnty Tinre of Concentration
Use Trncl'ri ne Ciniccin:
uvcrlanJ 11o"' I=I0,011J(n'1)"O, 8VUI10.5)'(SIO 4)'1'K-55Rg3d
whet<: 1=TrllvCl'r'IInC hn O,,, kmd I low (nal)
= hlanning',v Cndlicicnl - liven 1'I1-55 Tahlc 3-1
1= LCnglh u1' linw (mq
I'_ = 2-N H.Iint:dl I Lp1h lint
S=Hyilmulic Slope ItIft1
n = 0.24II 6."
1= _2 It
I'.= Jb] in
S= 0009 IUII
1= 5.2 lain
t'hunnd 14nw: I = IHn'
wham:='rruvd'I'inn, in I•,,m Ili—Onin)
I = Length ul IOnw f h l
v= Vy1'0y(I)d). v.... 1It-55
1= 270.(M) 11
r = 2,00 lid
1= 2.25 Inn
ThcmtLn. Tc= "IS
min
Uu' 50)
lain
1-tin/hr1= 10.96
luo tin/hrl=
12.99
k.ien 19aw
C= 0,41
(;=
ISII
ly= 1096
Inn=
12.88
A= 031 cr
A=
h11 r av
Qu= 1.19 d'
Qluu=
1.63 et.
Pktimate Channd.siz
F%innWd Ch'innel Ama. A it )= 04h
( inenm5 In, Aco,al Channel Anu:
S n&,h,,, N:I = 3
Ch,nnd UCpth. J= 1.2
Iln@nn Width. I3(11)= 1
ALI,U Ana lffl= Jig OK
I I,lr.ndhc l<aJiun. 1111),= 657
N:\20523.0004\dsgn\stormwater\NHC Cal a\20523.0004 25-yr NHC Swale Cale.xlsx Page 1 of 2

ps a ^ ,s, PROJECT NAME: SMITH CREEK PARK
F u
i, PROJECT LOCATION: NEW HANOVER COUNTY
(0 JOB No.: 20523.0004 CALCULATED BY: ALG
rokewl�G' DATE: 8/1/2009(REV 6/3/ 10) CHECKED BY: JDR
NEW HANOVER COUNTY CALCULATIONS - GRASSED SWALE DESIGN
Savale #2
Drtrnnine 3lnnninn'n n \nlu
Ret'lid.111ce(1..11N(I'ehlc On-J)=
U
Itcl:udancc Clmaa tkl,ilh (n:!ph un I'.Igc INI-5 SHl' ?I:nnn1=
li
I'crani..,lhlc Vchain'Iftl.)=
3 1...m Tahklt)-I
• II)Jcndic l<:ulim llil=
LLSI
V' It l 1, Ll.eon Grapbr.n Vagc 605=
IJI
.Manning:nv:duc l i and (Icylh nn l`,gc Ml-i-
0.03
Determine Dentl.9f Flnnin Salk
Max Velrailyc:m h dclarmincd tram M:mning'n liynatiun:
Huwa\cc :uea and 1,,d, a li, r:.d,u., x, nol kno\cn
\t lrrr.� l' 1`.n4J:.r h.rrG•'r••nm.lunr rr!I. r.i
.r . It ..nrp l...
alrr .rF'L.Iln, mr
..r... nrr r,. r,errrn rlrrr.
a.�y.. �a..�•r..rw
I< II)tlraulr. rwluw vr.lrnµ.r.
n..r..lw.rvl nrr,, .\
I-!,!.",nv,
I•.1111. In x I..I l.r.rm..ni. 1'r lr)IIt.
rl.r. r.l
Ia�rr.;aaJrn.l.l..l".'r•Ir. rrxvr!.n rlr.
rl1ltr l,n/!r rrrrrr.
1\rn�.r:urr ..r .• M,!!I �. ,�I,!nl .l.nrrrw.l'
'\Iv y.nerr mlix'.Ir.rnr'N .r.Ir�Wrl.r�n.nrrrarn.'rrl� nl.uF nr rvr•r[.JI\-"1 1,\1-r1
uxlr�.-.rlM�r.. i..�ry.m!•r.l �•Ini. rr•nrru,l,
A,a can M cnprcacd'm:
A=lay+My2
uydll! dle I lm. It can M cxPrc.xd:n:
rs-
x here I' la.
1'=14 2y 11 All)"-'
Iry nr. r! ..r)u.l.ern J•rn.:llr. rarr.WL.. . .....lurvnul•.Ilr.rv:nl: rnr�,rurrr)rilrr. r.v.r 4.
A .- ul..r tn.rr. l•y l!I
Ir I: rrl 1i!rl!rrl ray ...-0Illr
'.I - rr L•�rl•i.. r. r, lrr lrrrrl,.rl:I;�trrnrrr,ll /l.rr.rvrrr..l rv.rr.rnrr.f
1. IIr J:,xlr: rnaru. l!rl
v '.IaA ri rl.v llr
All rari:l!r:a an' nnrl\r II III nra,ln ngn nyllulian e\ael!1 yIlnllna m r\rc 11l'n1l
Itcurr: ,,,n, Mauningaiyuulinn
Alt"' Q-n I I 1.49-S") (11-v + MY) I (Il'y r My)/III. 2')1I N12)'II
lJ;acl'yk 1.39 O (I,,)- 1 iI
Lnngiuldinul Shaw= IIINI75 Iamgiludin:d Slam= 0.01A5
Manning, 003 Manning'nn= 0A3
N<"'O_ 0.32 AltIbis
Alt rm It v MA _.A
2S-Y<.II' "�+03: II IIII 11.520 3W 0.81
111141'car 11,110 11,555 3l)0 11,1A
Colculalcd l Kplh of l'1ow (11)= 0.52
A%cogc S,dc Ucp0l till= 1.2 I)k. Slink nnc1s.1, i, rxpnril)
N \20523.0004\dsgn\stormwater\NHC Cala\20523.0004 25-yr NHC Swale Calcalsx Page 2 of 2

Ps n Div PROJECT NAME: SMITH CREEK PARK
F` i 0 to
PROJECT LOCATION: NEW HANOVER COUNTY
■ �J JOB NO.: 20523.0004 CALCULATED BY: ALG
�cl.l`'v DATE: 8/1/2009(REv6/3/10) CHECKED BY: JDR
NEW HANOVER COUNTY CALCULATIONS • GRASSED SWALE DESIGN
Swale N3
Derennine 25-5'enr and IIN61'eur Flo.. ror Chunnd
Uw Manion:, .\Inh.N far _5-1'car I low:
I low: U=CIA
Where: Q=UcnipnI low ml.)
C=Io 11 CurlliJ e7u
1 = 25-yan R:Ju11111 Inl"1131
Ar.a IRw'riPlinn
Tahk JIl-I
ILmol'l
GwYliue,oX
A".,
W1
Im crvimm
0.95
0.61
(lro,. I'I:n, S:mJ
0.15
4,34
iSac'I'ahc li l.l. Pp..h1 :1 m NI LL' Sl.n mlrun' Al:wuep
Compo.i"Rt1nn11'Gw111c IcnI.C= 025
Cukulme Tin. of Cancemrnrion
Uw I nmd Tin. CnnccP1:
U¢v IanJ 19ow: I = (n.p0aln•U^II,g)/((I _^I1.5)•(SAII,J)) Tlt"55 1, 3-3
'I.ean. I ='four, TI1nc lb, (mcrhwJ I low pain)
o = Marvin,%C.II icicnl - limn'fl("55'I'Al, 3-1
1 = Lc,Ih all low (I,)
I'_= 2-yr ltuinhdl l krlll lint
S = HyJnmlic Slo, (h/l))
= I(240 rmxe
= 00
io
S= 0010 It/I,
1 = 15.6 min
Channel Plow: I=1/61v
where: I = rmttl'rioe Il.r hiv I low mrin)
I = I unplh nl Plow I1,)
v = Velcvily (11h)- hoot "rk-55
I= 822.IK1 It
= 2A) IUn
= 6.85 min
Thodo,a.'I'o= 22A ,i
Uxc I5.W nna
1_.(in/hr)= 7.39 11,alin/h0= 9.(,2
Urwiun I low
C= 025
I = 7,38
A= 4,95 , ( O= 9.08 ofx y
F'slimme Chnnnd Size
11.1inllncd (Ihaunul Am.l. A I1'1°) = 3,03
(lucnec. hm Aoj Ch.lnnol At,.,.
.SocdoPc, M:1 = 3
Ch:umcl l k,,h. J =
Ilu0nln Widlh. ❑ 111) II
Acuul Aw;. (1ill= 1200 1)K
I lyiluulic Radio, It(1)) 095
C = 11.25
= 8.62
N:\20523.00D4\dsgn\stormwater\NHC Cal¢\20523.0D04 25-yr NHC Swale Calo.xlsv Page 3 of 2

1,,s . ^io , PROJECT NAME: SMITH CREEK PARK
s r9 0
z PROJECT LOCATION: NEW HANOVER COUNTY
0.
JOB No.: 20523.0004 CALCULATED BY: ALG
~�-e:v\ljei DATE: 8/1/2009(REV 6/3/ 10) CHECKED BY: JDR
NEW HANOVER COUNTY CALCULATIONS - GRASSED SWALE DESIGN
Swale #3
Dc,tcrinine flu itW t %AJC1
telardallee la a.. ITaFle l041= U
KuclNJna 0hu'.l11",—I1 owh en 1-.,160-5 S111, pl:nm:I= li
livini oahlc vo,"Ilvllll'I= 3 Irv.n Tahlc 60-1
111dnn1lic lt'JJ IuF IfU= 0,95
V- It lfbr Um.,. Oc.ph an l'Jgr 60-5= _.Ns
Manninp:duo lion, (l,,hnn Page 60-5= 0,027
Nkw-ninr 1) It of Flnx''n S.at,
M:u Whicily can tw down, it liom Nanning I'yumiulr
I11m'o,, Jtra and h)ilr uh, IJJiUl are nol k.1.1n
l u., •.v.r.r unr: Gl, r.e l..r r..rr l.-r.rr..r ...
L..n..
I..
...... ..r rl.... 1-.I lrl. r., ur.... rr.r....rn
1..4. r.l..,
It Il..l r..n.r r�lr.w lrrlf l..IrnJ M J.vl.nnr{vr. n,.rvvin.n.l .r....\
- I...nr:ir..,l.n..l .l..l• ..r rl...r..e.r .1 r1...Ir..rir .1llr r,.11.•1r ..r.rl.
J.,.......... n.....nll.
....hi....nr..r.
Anu can h\.' expo'\. rl a..:
A = By +:yy=
Nydrauk la.di.... K can he .......ed
R . .I
w'hcrc I' I..
P=11+:y N. J111r'..
L.r n,......... ...... I,. ..... ...n.
\ .. ..I ....u.1. ll.rx I.I It
H I.ttrnttnl'1•.tl 1411t—m 1:1.
I . . I ....II l., n.lirr ...l...11 FI.. n..0
r�vnr..n.••
J...... r.,r..1
A II,Jr.r..l.i r..J iu. llli
I .rrIF ,II111
All .'ariuhlc. urc nnnwn III vlimnnlp• cy,,mu:nlon c.\ccpl y I nvnu In nn 1¢nnr
II %Iwnlin.=�'. Iryualiun
nit"=Q'n III J9•S°11=11f`crM'y'I "UI'y+M^Ylllll�2'ytLM°)'l:eu
Q11(01)= 1)011
IJIcl'n1=
ItUI
Lnnphudinal $lt pW= 0111
h,tip ,dlna151ope=
0.01
.Nanning: n= 11.10q7
.M,inning: n=
O(I'_]
AR10_ 165
nK "e1-
192
AK.., If
M:I A
`$-War
�_-1AS 0IXI 1146?
3IXI 2,79
I fHb Year
I f1,IXl 1,020
300 3.12
L'aladioud l lcpol III 1hnr 1111= 091,
Aur'agr Swale Ucplh llll= '_II
Ok S,,ak nu'vh Jv.ign
capu.' it,
N:\20523.0004\dsen\starrnwater\NHC Calcs\20523,0004 25-yr NHC Swale Calcnls. page 2 of 2

New Hanover County Parks:
Smith Creek
New Hanover County, North Carolina
Section 4.2 r o,
0
Pipe Capacity and Energy Dissipater Calculations
Prepared By
Thomas & Hutton Engineering Co.
219 Station Rd. / Wilmington / NC / 28405
50 Park of Commerce Way / Savannah / GA / 31405
935 Houston Northcutt Blvd. / Mt. Pleasant / SC / 29464
1350 Farrow Pkwy / Myrtle Beach / SC / 29577
116 West Palm Plaza Drive / Brunswick / GA / 31523
J-20523.0004
N:\20523.0004\dsga\stonnwalcr\20523-4 Stonnwalcr Repot 8-1-09.doc

PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
Joe No.: 20523.0004
DATE: 8/ 1 /2009 (REV 6/3/ 1 O)
CALCULATED BY: BDR
CHECKED BY: JDR
NEW HANOVER COUNTY CALCULATIONS • PIPE CAPACITY & ENERGY DISSIPATER
Pipe End #1
Us,er Inpnl Data
Culeulared \'xlue
Rrl'enmee Ilion
Ikecn Lion
C
Area lac)
Gros. sandy. as `.
0.15
0,79
hn%'r\'Inn,
0.95
0,17
Calenlate Design Flow
Use Rational Method: Conipnsile Runoff C el icient. C = 0.19
Flow: Q=CIA
Where: Q = Design Plow (cfs )
C= ILuml'ICoeffcienl (So,lahIC10-I.pg. 10-3 in NIIC Smrn'maa" M anu:dl
I = 25-Year Rainfall Intensity
Dei cn PWw
C= 0 6
1 = I0 06 mche, (F =5 ntin) (Prune Allay 14. NOAA)
A = 0.96 acre
Q = 1.68 cfs
Check Capacily & Design Velocily of Culvcrl
Use M: nnings P:qu:nion to Gdculalc• Maxlnuun Allowable Flom,
Q,,,=(I19/n)-A-R467"S^.5
Wl,re. Qn= Maximum Ramona, Icfsl
n = Mannings Roughness Cocifewrit
A = Cross Sectional Area W)
R = Hydr idic Radius (1t)
S = Slops (ft/ft)
Calculate Cross Sectional Area of Pipe
Financier= 15 in
A(st)= Pi-d^2/4
A= 1.23 sf
CWculale Hydraulic Radius
Rib) = Areo / Wow,] Perimeter
R(ft)= IPI"d^2/4y(PI"d)
Rift)= 0_+I it
Select Variables
It 0.011
S= 00W h/ft
Velocily. V,s= 1.17 It/sec
Q,(cfs)= 4.08 ds
Q (cf") 1.611 is Q in less than Qm, Iherfore 15" pipe is OK
Velocity = 1.37 fpa < 2.0 fps ('emussible Velocity of Bare Soil)
'I'Irerefore. an energy disnipator IS NOT required.
Calculate Energy Dissipater Puramders
Dcsiga Plow. Q=CIA 1,68 cfs
Pit, Dianeter(d): IS in
Maximum VClocity. V = 1.37 fps
%ono of Apron: I :,Sec Pigum iIF II, pg. ill-]5 in ,VI IC Santmc:acf pl:um,tll
length of Apron 14upipe Jia.l:5 f." !Se¢Figure 50-15.1,, 5026 iu N I IC' St.... :ncr Nl:mnah
Widtb (4"pipe dia.): 5 li" LScc I'igua St)-15. fig. 50 26 in NHC' Sto ntw.a<r 61:muu0
Mini noun Stone Si/e: t in. isco I igun• i0-15. pg, 5p.26 to KI IC Stornns:ncr Tlannadt
Dcpth of Rip -Rap: 12 in. ISee ligurc 50-15. pg. 50-_6 in KIR: Slnnu,aal, Mwnuad)
+"Ylinimunt lenglh:md width of apron shall be S'
N?20523.0004\dsgn\,stormwater\NHC Calcs\20523.0004 Supporting -Pipe Calcs.xlsx Page 1 of 4

PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
JOB No.: 20523.0004
DATE: S/ 1 /2009 (REV 6/3/ 1 O)
CALCULATED BY: BDR
CHECKED BY: JDR
NEW HANOVER COUNTY CALCULATIONS • PIPE CAPACITY Et ENERGY DISSIPATER
Pipe End #2
p.rt to wt lhdn
C:drulah•d Vuhe•
Rrfe yr l,, W
(inclusive of entire Swale #3 drainage area)
I "Cri umn
1 C
Area lac)
Gross, sundv. ns -.1
15
4.34
Inttervlou,
10.95
0,61
Cakutwe. Resign Plow
Use National Method: Cnnlx ite RunoffC Hicient. C = 0,25
Plow: Q=CIA
Where: Q = De,igu flow (cfs)
C= Runoff C,&f.cicnt (See'I bl,401,le,.10-1 in NIIC Stem mvurcr•Alanunll
1 = 25-Year Rainfall Intensity
Doran [low
C= 016
1= 7.39 inches l'r= 15 min)(Frtn Allan 14-NOAA)
A= 49) acre
Q= 5,84 efs
Check Capacity & Design Velocity of Culvert
Use Mannings Equation to Calculate Maxintwn Allowable Flow
V== ( I J9/n)' A - R^.67' S^.5
W here: Q, = Maximum Flowr.te (cfs I
n = Manning, Roughness Coefficient
A=Cross Sectional Area W)
R = Hydraulic Radius In)
S = Slope (ft/fq
Calculate Cross Sectional Area of Pipe
Di:nitener= 18 in
Aof) = PI"d^2/4
A= 1.77 sf
Calculate Hydraulic Radius
Ittftt= Are. / We ted Perivteter
Rtft)= (PI'd"2/40PI"d)
lithe= 0.38 It
Select Varin Hes
It = 0.011
S = 0.005 tuft
Velocity. Vs= 3,31 lihec
Q,,,(elo= 7.42 cfs
Q lclk)= 5.84 c1, Q is less (hon Qm, therf.re IN" pipe is OK
Velocity= 3.31 fps > 2.0 Ijrs lPerntissible Velocityof Banc Soil)
'I'Ixt-efore. an energy dissipator IS required.
Calculate Energy Dissipater Paramelers
Design Flow. Q=CIA 5,84 c1,
P11V Diantulcr(d): Is in
Maximum Velocity. V = 1.31 fps
/,one of Apron: I tSee 1'i;;mc 50-I 1, pg, 50-25 in NIIC Slnrnnr,ncr M:nundl
Irngth of Apron 4'1ope din.) : 6 ft"' iSee l iware 50-15, pg. 50-26 in NIIC SIonnsumr,Atan unit
Witlid,W ipedin.0 6 nl. (S, Figs, 51Ll5. pr 50-21, nNIIC .Sto,"I .xlnauah
Mimi nnmt Slone Slre: 3 in, (Sea Fi"ute 50-15, 1% 50-20 in NIIC \Iu,uevnlcn Mmul.16
Dquh of Rip -Rap: 12 in. tSea 19guro 50.15- pg. 50'-1, in NIIC Slarmwatcr \1:muall
"Il inimuni length and width orapron shall he 5'
N:\20523.0004\dsgn\stormwater\NHC Caics\20523.0004 Supporting -Pipe Calcs.xls. Page 2 of 4

PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
JOB No.: 20523.0004
DATE: B/ 1 /2009 (REv 6/3/ 10)
CALCULATED BY: BDR
CHECKED BY: JDR
New HANOVER COUNTY CALCULATIONS - PIPE CAPACITY & ENERGY DISSIPATER
Pipe End #3 (includes pipe N4 area)
INcr Input hula
Calculated \'clue
Reference Pate
Ikserinion
C
Anon Inc)
Lawns. sand.a,g.
0A5
0.81
nitcreioue
0,95
0.11
Calculae Design pinw
Use Rational Melhod: Composite Runoff Coefficient. C = 0.37
Flow: Q=CIA
When: Q = Design Plow (cfsl
C= Runoff Coefficient ISce'I?IhlcO 1. pg.,103 "NHC 5lonmaadr9lunu:d)
I = 25-Year Ruinlidl Intensity
Desii-n flow
C= 0.16
1= 7,38 inches if 15ndn)fPrum Atlas 14-NOAA)
A = 1.12 acre
Q= 1.32 cfs
Check Capacity & flesign Vrlocity of Culvert
Use Manningp Equation to Calculate Maximum Allowable Flow
Q. = (I 49/n) - A - RA.67 ^ SA.S
Where: Q== Maximum Ploxernte (cfs)
n = Mannings Roughness Coefficient
A = Cross Sectional Arco (A)
R = Hydraulic Radius (I1)
S = Slope (i/h )
Calculate Cross Sectional Area of Pipe
Diunue, = 15 in
AIsD= PI. IA2/4
A= 1,21 sf
Calculate Hydraulic Radius
R(k) = Area / Wcned Perinne er
R00= (PI*dA2/4)/IPI"d)
RHO= 0.31 It
Select Variables
n = 0.013
Velocity. V_y = Intl ft/sec
Q=(cfs1= 3.53 cfs
Q (cls) = 1.32 cfs Q is less than Qm, therfnre 15" pipe ix OK
Velocity = 1.08 fax < 20 fps (Permissible Velocity of hunt Soil)
'I'heratorc. mI energy dissipntor IS NO'1' required.
Calculate Energy Dixeipater Paruneters
Design Flow, Q=CIA 1.32 cis
Pipe Diumeter(d): 15 in
Maximum VcUsity. V = 1.118 fax
%one of Apron: I IScc I'i"are 50-11, pg, 50.25 1n ,NHC Smrnnaw r.M nuu11
Lmgthof Apron(4*pipe dia.l', 5 n.. (Sccl4µwc5(1-Ii po 5026 'm NIIC A)
Width (F"pipa ia.): 5 rt'• ISce ligwn?I-15, p;:. 51) 26 io NI IC Sunlmvmer AI:vulall
Mininnnn Stone Size: 1 in. ISce figure 50-15. pg. 9n-'o in SHC.Smnm.u6r Manual
IApth of Rip -Rap: 12 in. ISce I'ipnrr 50 15. pe. 50.'o in NHC Sun on"'a" Man iah
•*\linimum length and s,idth of apron xhall be 5'
N:\20523.0004\dsgn\stormwatelaNHC Calcs\20523.0004 Supporting -Pipe Calcs.elsx Page 3 of 4

PROJECT NAME: SMITH CREEK PARK
PROJECT LOCATION: NEW HANOVER COUNTY
JOB No.: 20523.0004
DATE: 8/ 1 /2009 (REV 6/3/ 1 O)
CALCULATED BY: BDR
CHECKED BY: JDR
NEW HANOVER COUNTY CALCULATIONS - PIPE CAPACITY & ENERGY DISSIPATER
Pipe End #4 (inclusive of entire swale #2 drainage area)
Uner In nit Dana
Ca I".late d Value
RO'. one Data
Desch ,inn
C
Area tact
I-mv sand . av".
0,15
O.21
Imxrvious
0.95
0,1
Calculate Design Flow
Use Ratianal Method: Canytasite Ranoff Coefficient. C = 0AI
Row: Q=CIA
Where: Q= Design Flow (cis)
C= RanoffCoefficient �See'1'A],W-I. pg. 40J in N'1(C Sionuam Nlanaal)
I = 25-Year Rainfall haeusit,
Design 10ow
C= (). 16
1 = 10'96 inches 0 = 5 tun) (Ram Atlas 14- NOAA)
A = 0.31 acre
Q = 0.54 cfs
Check Capacity & Design Velocity of Culvert
Use Mannings Equation to Calculate Maximum Allownble Row
Q„ = 0.49/nl' A - RA.67' SA.S
Where: Q= Maximum Howruc tail '
a = Manning, ILn.ghnass Coefficient
A = Cross Sectional Area 64)
R = Hydraulic Radim (f)
S = Slope (ft/f )
Calculate Croxn Secllnnzl Area of Pipe
D'art'ter= 15 in
A(st)= PI"dA2/4
A= 1.23 sf
Calculate Hydraulic Radius
R(ft)= Area / Welled Perimeter
R(ft)= 41'I'd-2/41/0PI'd)
R(0)= 031 ft
Sden Variables
n= 0.013
S= 0.0025 Add
Velocity. Vy= 0,14 Nsec
Q,(cfs)= 3.22 cfs
Q (cls)= 0.54 cfs Q is less than Qua, therl'ore 15" pipe is IK
Velocity= 0.44 fps a 20 fps(PemtissiNe Velocity of Rare .Soil)
'fhurc(orc. nn energy disnip:uor ISNOF required.
Calculate Energy Dissipater Paramcters
Design Flow. Q=CIA 0,54 cfs
Pipe Diamelcr(dl: 15 io
Maximum Velocity. V = 0.44 fps
Zane of Apron: I 1Sen I tg1,c 50-14- pg. 50-25 is NI IC Slom as;ncr Nlamu:Jl
Icngth of Apran(4'pipc diaU: 5 0'" S,):i„wc5(1-15, pf;, 5nto is MY Smrmsvona Nlauunll
WiNh (4^pipw dial' 5 It— 1Sr, I ignm s0-I5. p 50 20 is NHC Sworn ar, NI;... dI
,Minimum Smne Size: 3 in. 1Sce I'Igare 50-15. pg. 50-26 in NIIC Swrnto:ner Manual)
Depth of Rip -Rap: 12 in. IScc Tiger, 50-I5. pg. 50 2(> at NI IC Siorm,:ner Manaal)
**%lininwm length and width of apron shall be, 5'
N?20523.0004\dsgn\stormwater\NHC Caics120523 0004 Supporting -Pipe Calcs,xtsx Page 4 of 4

TABLE OF CONTENTS
TECHNICAL PROVISIONS
PAGE NUMBERS
02110
Site Clearing
022
Earthwork
02110-1
thru
02110-3
02210
Soil Erosion Control
02204-1
thru
02204-6
02231
Aggregate Base Course
02210-1
thru
02210-3
02275
Rip -Rap
02231-1
thru
02231-5
02512NC
Asphaltic Concrete Binder/Surface Courses
02275-1
thru
02275-3
02902
Grassing
02275-1 1
thru
02275-3 7
02902-1
thru
02902-6
N:\20523.0004\Docs\Specs\Stormwater Specifications\0001-table of contents.doc

INDEX TO
SECTION 02110 - SITE CLEARING
Paragraph
PART 1-GENERAL
1.1 Section Includes
1.2 Related Sections
1.3 Measurement and Payment
1.4 Regulatory Requirements
PART 2 - PRODUCTS
2.1 Materials
PART 3 - EXECUTION
Title
Page
02110-1
02110-1
02110-1
02110-1
02110-1
3.1
Preparation
02110-1
3.2
Protection
02110-2
3.3
Clearing
02110-2
3.4
Removal
02110-2
3.5
Disposal
02110-2
3.6
Grubbing
02110-3

SECTION 02110
SITE CLEARING
PART 1 -GENERAL
1.1 SECTION INCLUDES
A. Removal of surface debris.
B. Removal of paving, curbs.
C. Removal of trees, shrubs, and other plant life.
D. Topsoil excavation.
1.2 RELATED SECTIONS
A. Section 02204 - Earthwork.
1.3 MEASUREMENT AND PAYMENT
A. See Section 1025 — Measurement and Payment
1.4 REGULATORY REQUIREMENTS
A. Conform to applicable code for disposal of debris.
B. Coordinate clearing Work with utility companies.
PART2-PRODUCTS
2.1 MATERIALS
None in this section.
PART 3 - EXECUTION
3.1 PREPARATION
A. Verify that existing plant life designated to remain is tagged or identified.
B. Identify a waste area for placing removed materials.
3.2 PROTECTION
A. All trees on the site inside the clearing limits will be removed during construction
except those marked specifically on the site by the Owner's representative to be
N:\20523.0004\Docs\Specs\Stormwater Specifications\02110.doc Page 1 of 3

saved. No trees, either those marked for removal on the site or any other tree,
may be removed from the site prior to the preconstruction conference. All trees
not to be removed will be protected from injury to their roots and to their top to a
distance three (3') beyond the drip -line and no grading, trenching, pruning, or
storage of materials may go in this area except as provided by a stakeout by the
Owner's representative.
B. Protect bench marks, survey control points, and existing structures from damage
or displacement.
C. Protect all utilities that remain.
D. Clearing operations shall be conducted so as to prevent damage by falling trees
to trees left standing, to existing structures and installations, and to those under
construction, and so as to provide for the safety of employees and others.
3.3 CLEARING
A. Clear areas required for access to site and execution of Work. Clearing shall
consist of the felling and cutting of trees into sections, and the satisfactory
disposal of the trees and other vegetation designated for removal, including
downed timber, snags, brush, and rubbish occurring within the area to be
cleared. Trees, stumps, roots, brush, and other vegetation in areas to be
cleared shall be removed completely from the site, except such trees and
vegetation as may be indicated or directed to be left standing. Trees and
vegetation to be left standing shall be protected from damage. Clearing shall
also include the removal and disposal of structures that obtrude, encroach upon,
or otherwise obstruct the work.
3.4 REMOVAL
A. Where indicated or directed, trees and stumps shall be removed from areas
outside those areas designated for clearing and grubbing. The work shall
include the felling of such trees and the removal of their stumps and roots.
Trees shall be disposed of as hereinafter specified.
B. Remove debris, rock, and other extracted plant life from site.
C. Partially remove paving, curbs. Neatly saw cut edges at right angle to surface.
3.5 DISPOSAL
A. Disposal of trees, branches, snags, brush, stumps, etc., resulting from the
clearing and grubbing shall be the responsibility of the Contractor and shall be
disposed of by burning, removal from the site of this work, or a combination of
both. All costs in connection with disposing of the material will be at the
Contractor's expense. Material disposed of by burning shall be burned in a
manner that will avoid all hazards, such as damage to existing structures,
construction in progress, trees and vegetation. The Contractor shall be
responsible for compliance with all local and State laws and regulations relative
N:\20523.0004\Docs\Specs\Stormwater Specifications102110.doc Page 2 of 3

to the building of fires. Disposal by burning shall be kept under constant
attendance until the fires have burned out or extinguished. All liability of any
nature resulting from the disposal of the cleared and grubbed material shall
become the responsibility of the Contractor. The disposal of all materials cleared
and grubbed will be in accordance with the rules and regulations of the State of
North Carolina. The Contractor shall obtain a permit to burn on site from the local
fire department, before beginning the work, as applicable.
3.6 GRUBBING
A. Grubbing shall consist of the removal and disposal of stumps, roots larger than one
(1) inch in diameter, and matted roots from the designated grubbing areas. This
material, together with logs and other organic or metallic debris not suitable for
building of pavement subgrade or building pads, shall be excavated and removed to
a depth of not less than 18-inches below the original surface level of the ground in
embankment areas and not less than 2-feet below the finished earth surface in
excavated areas. Depressions made by grubbing shall be filled with suitable
material and compacted to make the surface conform with the original adjacent
surface of the ground.
END OF SECTION
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INDEX TO
SECTION 02204 - EARTHWORK
Paragraph
PART 1 - GENERAL
1.1
Section Includes
1.2
Related Sections
1.3
Measurement and Payment
1.4
References
1.5
Submittals
1.6
Quality Assurance
1.7
Testing
PART 2-PRODUCTS
2.1 Materials
2.2 Source Quality Control
PART 3 - EXECUTION
Title
Page
02204-1
02204-1
02204-1
02204-1
02204-2
02204-2
02204-2
02204-3
02204-3
3.1
Topsoil
3.2
Excavation
02204-3
3.3
Ground Surface Preparation for Fill
02204-3
3.4
Fill
02204-4
3.5
Tolerances
02204-4
3.6
Finished Grading
02204-4
3.7
Disposal of Waste Material
02204-5
3.8
Protection
02204-5
3.9
Drainage
02204-5
3.10
Field Quality Control
02204-5
3.11
Proof Rolling
02204-
02204-6

SECTION 02204
EARTHWORK
PART 1 - GENERAL
1.1 SECTION INCLUDES
A. Grading.
B. Excavation.
C. Backfilling.
D. Compaction.
E. Remove and Replace Topsoil..
F. Dressing of Shoulders and Banks.
G. Stone Drainage Filter
H. Water Control
I. Testing
1.2 RELATED SECTIONS
A. Section 01400 — Quality Control
B. Section 01410 — Testing Services
C. Section 02110 — Site Clearing
1.3 MEASUREMENT AND PAYMENT
A. See section 1025 — Measurements & Payments
1.4 REFERENCES
A. ASTM D 448-86 (Reapproved 1993) - Sizes of Aggregate for Road and Bridge
Construction.
B. ASTM D 1556-90 - Density and Unit Weight of Soil in Place by the Sand -Cone
Method.
C. ASTM D 1557-91 - Laboratory Compaction Characteristics of Soil Using Modified
Effort.
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D. ASTM D 2167-94 - Density and Unit Weight of Soil in Place by the Rubber
Balloon Method.
E. ASTM D 2487-93 - Classification of Soils for Engineering Purposes.
F. ASTM D 2922-91 - Density of Soil and Soil -Aggregate in Place by Nuclear
Methods (Shallow Depth).
G. ASTM D 3017-88 (Reapproved 1993) - Water Content of Soil and Rock in Place
by Nuclear Methods (Shallow Depth).
H. ASTM D 3740-94a - Minimum Requirements for Agencies Engaged in the Testing
and/or Inspection of Soil and Rock as Used in Engineering Design and
Construction.
I. ASTM E 329-93b - Agencies Engaged in the Testing and/or Inspection of
Materials Used in Construction.
1.5 SUBMITTALS
A. Section 01300 - Submittals: Procedures for submittals.
B. Materials Source: Submit names of materials source.
1.6 QUALITY ASSURANCE
A. Perform work in accordance with State of North Carolina Department of
Transportation.
1.7 TESTING
A. Laboratory tests for moisture density relationship for fill materials shall be in
accordance with ASTM D 1557, (Modified Proctor).
B. In place density tests in accordance with ASTM D 1556 or ASTM D 2922.
C. Testing laboratory shall operate in accordance to ASTM D 3740 and E 329 and
shall be accepted by the Engineer.
D. The testing laboratory and Project Engineer/Project Representative shall be given
a minimum of 48 hours notice prior to taking any of the tests.
E. Testing shall be the responsibility of the Contractor and shall be performed at the
Contractor's expense by a commercial testing laboratory that operates in
accordance with subparagraph C above.
F. Test results shall be furnished to the Engineer.
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PART 2-PRODUCTS
2.1 MATERIALS
A. Borrow shall consist of sand or sand -clay soils capable of being readily shaped
and compacted to the required densities, and shall be free of roots, trash and
other deleterious material.
B. All soils used for structural fills shall have a PI (plastic index) of less than 10, and
a LL (liquid limit) of less than 30. Fill soils shall be dried to appropriate moisture
contents prior to compaction.
C. Additionally, fill soils used for the top 2 feet of fill beneath roads and parking lots
shall have no more than 15% passing the # 200 sieve. Fill soils used for house
lots shall have no more than 25% passing the # 200 sieve.
D. Contractor shall furnish all borrow material
E. Contractor shall be responsible for and bear all expenses in developing borrow
sources including securing necessary permits, drying the material, haul roads,
clearing, grubbing, and excavating the pits, haul roads, placing, restoration of pits
and haul roads to a condition satisfactory to property owners and in compliance
with applicable state and local laws and regulations.
2.2 SOURCE QUALITY CONTROL
A. If tests indicate materials do not meet specified requirements, change material
and retest.
B. Provide materials of each type from same source throughout the Work.
PART 3 - EXECUTION
3.1 TOPSOIL
A. Contractor shall strip a minimum of 4 - 6 inches of topsoil and stockpile on site at
a location determined by the Owner at the Contractor's expense.
B. Topsoil shall be placed to a depth of 4" over all disturbed areas, except building
pads.
C. Any remaining topsoil will be hauled off site at the Contractors expense and
disposed in compliance with applicable state and local laws and regulations.
3.2. EXCAVATION
A. Shall be defined as unclassified excavation.
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B. Suitable excavation material shall be transported to and placed in fill areas within
the limits of the work.
C. Unsuitable material, encountered in areas to be paved and under building pads,
shall be excavated 2 feet below final grade and replaced with suitable material
from site or borrow excavations.
D. Unsuitable and surplus excavation material not required for fill shall be disposed
of on site in a location approved by the owner.
E. Proper drainage, including sediment and erosion control, shall be maintained at
all times. Methods shall be in accordance with the National Pollutant Discharge
Elimination System standards and other local, state and federal regulations.
F. Unsuitable materials as stated herein shall be highly plastic clay soils, of the CH
and MH designation, border line soils of the SC -CH description, and organic soils
of the OL and OH description based on the Unified Soils Classification System.
Further, any soils for the top two feet of pavement subgrade shall have no more
than 15% passing the # 200 sieve.
3.3 GROUND SURFACE PREPARATION FOR FILL
A. All vegetation such as roots, brush, heavy sods, heavy growth of grass, decayed
vegetable matter, rubbish, and other unsuitable material within the areas to be
filled shall be stripped and removed prior to beginning the fill operation.
B. Sloped ground surfaces steeper than 1 vertical to 4 horizontal, on which fill is to
be placed shall be plowed, stepped, or benched, or broken up as directed, in
such a manner that the fill material will bond with the existing surface.
C. Surfaces on which fill is to be placed and compacted shall be wetted or dried as
may be required to obtain the specified compaction.
3.4 FILL
A. Shall be reasonably free from roots, organic material, trash and stones having
dimensions greater than 4 inches.
B. Shall be placed in successive horizontal layers 8 inches to 12 inches in loose
depth for the full width of the cross-section and compacted as required.
3.5 TOLERANCES
A. Unpaved areas to within 0.1 feet of elevations shown on the drawings provided
such deviation does not create low spots that do not drain.
B. Paved Areas - Subgrade to within 0.05 feet of the drawing elevations less the
compacted thickness of the base and paving.
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3.6 FINISHED GRADING
A. All areas covered by the project including excavated and filled sections and
adjacent transition areas shall be smooth graded and free from irregular surface
changes.
B. Degree of finish shall be that ordinarily obtainable from either blade -grader or
scraper operations, supplemented with hand raking and finishing, except as
otherwise specified.
C. The finished surface of unpaved areas shall be not more that 0.10' above or
below the established grade or approved cross-section.
D. Ditches and lagoon banks shall be finished graded, dressed and seeded within
fourteen (14) calendar days of work to reduce erosion and permit adequate
drainage.
3.7 DISPOSAL OF WASTE MATERIAL
A. All vegetation roots, brush, sod, broken pavements, curb and gutter, rubbish, and
other unsuitable or surplus material stripped or removed from the limits of
construction shall be disposed of by the Contractor.
3.8 PROTECTION
A. Graded areas shall be protected from traffic, erosion, settlement, or any washing
away that may occur from any cause prior to acceptance.
B. The Contractor shall be responsible for protection of below grade utilities shown
on the drawings or indicated to him by the Owner at all times during earthwork
operations.
C. Repair or re-establishment of graded areas prior to final acceptance shall be at
the Contractors expense.
D. Site drainage shall be provided and maintained by Contractor during construction
until final acceptance of the project. Drainage may be by supplemental ditching,
or pumping if necessary, prior to completion of permanent site drainage.
3.9 DRAINAGE
A. The Contractor shall be responsible for providing surface drainage away from all
construction areas. This shall include maintenance of any ditches that exist or
may be constructed by others in the immediate vicinity of the work. Contractor
shall provide proper and effective measures to prevent siltation of wetlands,
streams, and ditches both on the Owner's property, and those properties
downstream.
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3.10
3.11
FIELD QUALITY CONTROL
A. Compaction testing shall be performed in accordance with ASTM D 1556 or
D 2922. Where tests indicate the backfill does not meet specified requirements,
the backfill shall be removed, replaced, and retested at the Contractor's expense.
B. Unpaved areas - at least 90% of maximum laboratory density at optimum
moisture content unless otherwise approved by the Engineer.
C. Paved Areas and Under Structures - top 6 inch layer of subgrade to at least 98%
of maximum laboratory density at optimum moisture content. Layers below top 6
inches shall be compacted to 95% of maximum laboratory density at optimum
moisture content.
D. Rolling and compaction equipment and methods shall be subject to approval by
the Engineer. Approval in no way relieves Contractor of the responsibility to
perform in correct and timely means.
E. Number of Tests - Under paved areas, no less than one density test per
horizontal layer per 5,000 square feet of subgrade shall be made. In unpaved
areas, no less than one density test per horizontal layer per 10,000 square feet of
fill area shall be made.
Under curb and gutter, no less than one density test per every 300 linear feet.
PROOF ROLLING
A. Shall be required on the subgrade of all curb and gutter and paved areas and on
the base of all paved areas where designated by the Engineer. Proof rolling shall
take place after all underground utilities are installed and backfilled. The
operation shall consist of rolling the subgrade or base with a fully loaded ten (10)
wheeled dump truck. A full load shall consist of ten (10) to twelve (12) cubic
yards of soil or rock. The dump truck shall be capable of traveling at a speed of
two (2) to five (5) miles per hour and be in sound mechanical shape with no
exhaust leaks or smoking from burning oil. The Engineer shall determine number
of passes and areas rolled.
END OF SECTION
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INDEX TO
SECTION 02210 - SOIL EROSION CONTROL
Paragraph Title
Page
PART 1-GENERAL
1.1
Related Documents
02210-1
1.2
Description of Work
02210-1
1.3
Purposes
02210-1
1.4
Quality Assurance
02210-2
1.5
Submittals
02210-2
1.6
Measurement and Payment
02210-2
PART2-PRODUCTS
2.1 Grassing Materials 02210-2
2.2 Silt Fence 02210-2
2.3 Chemicals for Dust Control 02210-3
PART 3 - EXECUTION
31
General
02210-3
3.2
Grassing
02210-3
3.3
Silt Fence
02210-3
3.4
Dust Control
02210-3

SECTION 02210
SOIL EROSION CONTROL
PART 1-GENERAL
1.1 RELATED DOCUMENTS
A. Drawings and general provisions of the Contract, including General and Special
Conditions apply to this section.
1.2 DESCRIPTION OF WORK
A. Extent of soil erosion control work includes all measures necessary to meet the
requirements of this section.
Erosion and sediment control measures such as silt fence and sediment basins
must be installed prior to grubbing and further land disturbance.
Soil erosion and sediment control measures shall include all temporary and
permanent means of protection and trapping soils of the construction site during
land disturbing activity. Activity covered in this contract is regulated by the North
Carolina Sedimentation Pollution Control Act of 1973, and NPDES General
Permit for Construction Activity.
1.3 PURPOSES
A. The purpose of this section is to achieve the following goals:
Minimize soil exposure by proper timing of grading and construction.
Retain existing vegetation whenever feasible.
Vegetate and mulch denuded areas as soon as possible.
Divert runoff away from denuded areas.
Minimize length and steepness of slopes when it is practical.
Reduce runoff velocities with sediment barriers or by increasing roughness with
stone.
Trap sediment on site.
Inspect and maintain erosion control measures.
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1.4 QUALITY ASSURANCE
A. Manufacturer's Qualifications: Firms regularly engaged in manufacture of soil
erosion control systems products of types, materials, and sizes required, whose
products have been in satisfactory use in similar service for not less than 5 years.
Codes and Standards: Comply with all applicable Local, State and Federal
Standards pertaining to soil erosion control.
1.5 SUBMITTALS
A. Product Data: Submit manufacturer's technical product data and installation
instruction for soil erosion control materials and products.
1.6 MEASUREMENT AND PAYMENT
A. See Section 1025 — Measurement and Payment.
PART 2-PRODUCTS
2.1 GRASSING MATERIALS
Disturbed areas must be grassed within 14 days of work ending unless work is to begin
again before 21 days.
A. Refer to Section 02902 - Grassing.
General: All grass seed shall be free from noxious weeds, grade A recent crop,
recleaned and treated with appropriate fungicide at time of mixture. Deliver to
site in original sealed containers with dealer's guarantee as to the year grown,
percentage of purity, percentage of germination and the date of the test by which
the percentages of purity and germination were determined. All seed sown shall
have a date of test within six months of the date of sowing.
Type of Seed: Either Annual Rye or Common Bermuda Grass seed will be used
depending on time of year in which seeding is to occur.
Mulch: Straw.
Fertilizer: Commercial balanced 4-12-12 fertilizer.
2.2 SILT FENCE
A. Silt fence shall be a woven fabric. The geotextile fabric shall be a woven sheet of
plastic yarn, of a long chain synthetic polymer composed of at least 85% by
weight propylene, ethylene, amide, ester, or vinylidene chloride, and shall contain
stabilizer and/or inhibitors added to the base plastic to make the filaments
resistant to deterioration due to ultra -violet and/or heat exposure. The fabric
should be finished so that the filaments will retain their relative position with
respect to each other. The fabric shall be free of defects, rips, holes, or flaws.
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The fabric shall meet the following requirements:
Woven Fabrics
Grab Stren th
90 lbs.
Mullen Burst Stren th
150 lbs.
IV Resistance
90%
Permitivity
15 al/min/sf
Product shall be equivalent to EXXON GTF-180 Fabric or AMOCO Woven
Construction Fabric No. 1380.
2.3 CHEMICALS FOR DUST CONTROL
A. Calcium Chloride, Anionic Asphalt Emulsion, latex Emulsion or Resin -in -Water
Emulsion may be used for dust control.
PART 3 - EXECUTION
3.1 GENERAL
A. All disturbed soil areas except those to support paving shall be graded and
protected from erosion by grassing. Storm water conveyance systems shall have
sediment barriers installed at all entrances, intersections, change in direction and
discharge points.
3.2 GRASSING
A. Refer to Section 02902 - Grassing.
3.3 SILT FENCE
A. Silt fence shall be placed at the approximate location shown on the plans and
installed in accordance with the manufacturers' recommendations.
3.4 DUST CONTROL
A. Dust raised from vehicular traffic will be controlled by wetting down the access
road with water or by the use of a deliquescent chemical, such as calcium
chloride, if the relative humidity is over 30%. Chemicals shall be applied in
accordance with the manufacturer's recommendations. There shall be no
separate payment to the Contractor for dust control measures. Any costs
connected thereto shall be a subsidiary responsibility of the Contractor.
END OF SECTION
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INDEX TO
SECTION 02231 - AGGREGATE BASE COURSE
Paragraph
PART 1-GENERAL
1.1
Section Includes
1.2
Related Sections
1.3
Measurement and Payment
1.4
References
1.5
Quality Assurance
1.6
Testing
PART 2 - PRODUCTS
2.1 Materials
PART 3 - EXECUTION
Title
Page
02231-1
02231-1
02231-1
02231-1
02231-2
02231-2
02231-2
3.1
Contractor's Examination
3.2
Preparation
02231-3
3.3
Aggregate Placement
02231-3
3.4
Prime Coat - OMITTED
02231-4
3.5
Tolerances
02231-4
3.6
Field Quality Control
02231-4
02231-5

SECTION 02231
AGGREGATE BASE COURSE
PART 1 - GENERAL
1.1 SECTION INCLUDES
A. Aggregate base course.
1.2 RELATED SECTIONS
A. Section 01025 - Measurement and Payment: Requirements applicable to unit
prices for the work of this section.
B. Section 01400 - Quality Control: Inspection of bearing surfaces.
C. Section 02204 - Earthwork
D. Section 02512 - Asphaltic Concrete Binder/Surface Courses: Binder and finish
asphalt courses.
1.3 MEASUREMENT AND PAYMENT
A. See Section 1025 — Measurement and Payment
1.4 REFERENCES
A. AASHTO T 96-91 - Resistance to Abrasion of Small Size Coarse Aggregate by
Use of Los Angeles Machine.
B. AASHTO T 180-90 - Moisture -Density Relations of Soils Using a 10-lb (4.54 kg)
Rammer and an 18-in. (457 mm) Drop.
C. ASTM D 1556-90 - Density and Unit Weight of Soil In Place by the Sand -Cone
Method.
D. ASTM D 1557-91 - Laboratory Compaction Characteristics of Soil Using Modified
Effort.
E. ASTM D 2167-94 Density and Unit Weight of Soil in Place by the Rubber
Balloon Method.
F. ASTM D 2922-91 - Density of Soil and Soil -Aggregate in Place by Nuclear
Methods (Shallow Depth).
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G. ASTM D 3017-88 (1993) - Water Content of Soil and Rock in Place by Nuclear
Methods (Shallow Depth).
H. ASMT D 3740-94 - Minimum Requirements for Agencies Engaged in the Testing
and/or Inspection of Soil and Rock Used in Engineering Design and
Construction.
I. ASTM E 329-93 - Agencies Engaged in the Testing and/or Inspection of
Materials Used in Construction.
1.5. QUALITY ASSURANCE
A. Perform work in accordance with
1.6 TESTING
A. Laboratory tests for moisture density relationship for fill materials shall be in
accordance with ASTM D 1557, (Modified Proctor).
B. In place density tests in accordance with ASTM D 1556 or ASTM D 2922.
C. Testing laboratory shall operate in accordance to ASTM D 3740 and E 329 and
shall be accepted by the Engineer.
D. The testing laboratory and Project Engineer/Project Representative shall be
given a minimum of 48 hours notice prior to taking any of the tests.
E. Testing shall be the responsibility of the Contractor and shall be performed at the
Contractor's expense by a commercial testing laboratory that operates in
accordance with subparagraph C above.
F. Test results shall be furnished to the Engineer.
PART 2-PRODUCTS
2.1 MATERIALS
A. Aggregate: The aggregate shall consist of processed and blended crushed
stone. Aggregates shall be free from lumps and balls of clay, organic matter,
objectionable coatings, and other foreign material and shall be durable and
sound. The coarse aggregate shall have a percentage of wear not to exceed 65
after 500 revolutions as determined by AASHTO T 96. Aggregate shall meet the
applicable requirements of Sections 306.03 and 306.04 in the North Carolina
Department of Transportation Standard Specifications. The material shall meet
the following gradation and other requirements:
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Percent b Wei ht Passin
100
95 - 100
MSieve
70 - 100
50 - 80
30 - 55
# 30
12 - 31
#200
6 - 15
Liquid Limit
0 to 25
Plasticit Index
0 to 6
B. Prime Coat: "Omitted".
PART 3 - EXECUTION
2.2 CONTRACTOR'S EXAMINATION
A. Verify subgrade has been inspected, is dry, and gradients and elevations are
correct
B. ON SITE OBSERVATIONS OF WORK: The Owner's Representative or
Engineer will have the right to require that any portion of the work be done in his
presence and if the work is covered up after such instruction, it shall be exposed
by the Contractor for observation at no additional cost to the Owner. However, if
the Contractor notifies the Owner that such work is scheduled, and the Owner
fails to appear within 48 hours, the Contractor may proceed without him. All
work done and materials furnished shall be subject to review by the Owner,
Engineer or Project Representative. Improper work shall be reconstructed, and
all materials, which do not conform to the requirements of the specifications,
shall be removed from the work upon notice being received from the Engineer
for the rejection of such materials. The Engineer shall have the right to mark
rejected materials so as to distinguish them as such.
The Contractor shall give the Owner, Project Engineer or Project Representative
a minimum of 48 hours notice for all required observations or tests.
3.2 PREPARATION
A. The subgrade shall be leveled to the lines and grades of the plans and cleaned
of all foreign substances prior to constructing the base course.
Do not place base on soft, muddy or frozen surfaces.
Correct irregularities in subgrade gradient and elevation by scarifying, reshaping,
and recompacting.
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B. At the time of construction of the base course, the subgrade shall contain no
frozen material.
C. The surface of the subgrade shall be checked by the Engineer or his
representative for adequate compaction and surface tolerances. Ruts or soft
yielding spots that may appear in areas of the subgrade course having
inadequate compaction, and areas not smooth or which vary in elevation more
than 3/8-inch above or below the required grade established on the plans shall
be corrected to the satisfaction of the Engineer or his designated representative.
Base material shall not be placed until subgrade has been properly prepared and
test results have so indicated.
3.3 AGGREGATE PLACEMENT
A. Aggregate shall be placed with an acceptable spreader in accordance with North
Carolina Department of Transportation Standard Specifications for Highway
Construction Section 306 and in accordance with all terms included in these
specifications. (The spreader shall contain a hopper, and adjustable screed and
be so designed that there will be a uniform, steady flow of material from the
hopper. The spreader shall be capable of laying material without segregation
across the full width of the lane to a uniform thickness and to a uniform loose
density.) Spreaders are not required on curb and gutter road sections.
A. Level and contour surfaces to elevations and gradients indicated.
B. Add small quantities of fine aggregate to coarse aggregate as appropriate to
assist compaction.
C. Add water to assist compaction. If excess water is apparent, remove aggregate
and aerate to reduce moisture content.
D. Use mechanical tamping equipment in areas inaccessible to compaction
equipment.
E. While at optimum moisture (± 1-1/2%), compact the base course with rollers
capable of obtaining the required density. Vibratory, flatwheel, and other rollers
accepted by the Engineer may be used to obtain the required compaction.
Rolling shall continue until the base is compacted to 98% of the maximum
laboratory dry density as determined by ASTM D 1557 or AASHTO T 180.
F. Inplace density of the compacted base will be determined in accordance with
ASTM D 1556 or ASTM D 2922.
3.4 PRIME COAT - OMITTED
3.5. TOLERANCES
A. Flatness: Maximum variation of ''14 inch measured with an acceptable 10-foot
straight edge.
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B. Scheduled Compacted Thickness: Within 3/8 inch.
C. Variation from Design Elevation: Within 3/8 inch.
D. Depth measurements for compacted thickness shall be made by test holes
through the base course. Where the base course is deficient, correct such areas
by scarifying, adding base material and recompacting as directed by the
Engineer. Measurements shall be made at staggered intervals not to exceed
250 feet for two-lane streets and roads.
3.6 FIELD QUALITY CONTROL
A. Section 01400 - Quality Assurance: Field inspection.
B. Density and moisture testing will be performed in accordance with ASTM D
1557.
C. If tests indicate Work does not meet specified requirements, remove Work,
replace and retest.
D. Frequency of Tests:
1. Base Density - One (1) test per 5,000 square feet.
END OF SECTION
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INDEX TO
SECTION 02275 - RIP -RAP
Paragraph
PART 1 - GENERAL
1.1 Section Includes
1•2 Related Sections
1.3 Allowable Tolerances
1.4 Measurement and Payment
1.5 References
PART 2-PRODUCTS
2.1 Materials
2.2 Product Review
PART 3 - EXECUTION
3.1. Preparation
3.2. Placement
Title
Page
02275-1
02275-1
02275-1
02275-1
02275-1
02275-1
02275-2
02275-2
02275-2

SECTION 02275
RIP -RAP
PART 1- GENERAL
1.1 SECTION INCLUDES
A. Material placed as bank protection and erosion control.
1.2 RELATED SECTIONS
A. Section 02210 - Soil Erosion Control
B. Section 02720 - Storm Drainage
1.3 ALLOWABLE TOLERANCES
A. The depth of rip -rap blanket as shown on the drawings and in these
specifications is a minimum depth.
1.4 MEASUREMENT AND PAYMENT
A. See Section 1025 — Measurement and Payment
1.5 REFERENCES
A. ASTM C 150-95 - Portland Cement.
PART 2- PRODUCTS
2.1 MATERIALS
A. Stone Rip -Rap: Shall be hard quarry or field stone, and shall be of such quality
that the pieces will not disintegrate on exposure to water, sunlight or weather.
Stone shall be solid and non -friable and range in weight from a minimum of 25
pounds to a maximum of 150 pounds. At least 50 percent of the stone pieces
shall weigh more than 60 pounds. The stone pieces shall have a minimum
dimension of 12 inches. Documents indicating stone analysis, source and other
pertinent data (i.e. - filter fabric) shall be submitted for review by the Engineer
prior to delivery.
B. Sand -Cement Bag Rip -Rap:
1. Bags: Shall be of cotton, burlap, or fiber -reinforced paper capable of
containing the sand -cement mixture without leakage during handling and
placing. Bags previously used for any purpose shall not be used.
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Capacity shall be not less than 0.75 cubic foot nor more than two (2)
cubic feet.
2. Cement: Portland cement shall be Type I meeting requirements of ASTM
C 150-94. Cement which has been damaged, or which is partially set,
lumpy, or caked shall not be used.
3. Fine Aggregate: Shall be composed of hard, durable particles, free from
injurious amounts of organic impurities and shall contain, in the material
passing the No. 10 sieve, not more than 7 percent clay, and not more
than 20 percent passing the No. 200 sieve.
C. Filter Fabric: Shall be a non -woven heat -bonded fiber of polypropylene and
nylon filaments equivalent to Mirafi 140N. The fabric shall be finished so the
filaments will retain their relative position with respect to each other. The fabric
shall contain stabilizers and/or inhibitors added to the base plastic to make the
filaments resistant to deterioration due to ultraviolet and/or heat exposure. The
product shall be free of flaws, rips, holes or defects.
2.2 PRODUCT REVIEW
A. The Contractor shall provide the Engineer with a complete description of all
products before ordering. The Engineer will review all products before they are
ordered.
PART 3- EXECUTION
3.1 PREPARATION
A. The surface to receive Rip -Rap shall be prepared to a relatively smooth condition
free of obstruction, depressions, debris, rises, and soft or low density pockets of
material. The contours and elevations on the drawings are to the surface of the
rip -rap material.
3.2 PLACEMENT
A. Fabric: The filter fabric shall be placed with the long dimension running up the
slope. The strips shall be placed to provide a minimum width of one (1) foot of
overlap for each joint. The fabric shall be anchored in place with securing pins of
the type recommended by the fabric manufacturer. Pins shall be placed on or
within 3 inches of the centerline of the over -lap. Place the fabric so that the
upstream strip will overlap the downstream strip. The fabric shall be placed
loosely so as to give and avoid stretching and tearing during placement of the
stones.
B. Stone: Minimum depth or thickness of stone blanket shall be 12 inches with no
under tolerance. The stones shall be dropped no more than three (3) feet during
construction. Placing shall begin in a toe trench constructed at the bottom of the
slope with the filter fabric wrapped in stone at least five (5) feet up the slope.
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The entire mass of stone shall be placed so as to conform with the lines, grades,
and thickness shown on the plans. The rip -rap shall be placed to its full course
thickness at one operation and in such a manner as to avoid displacing the
underlying material. Placing of rip -rap in layers, or by dumping into chutes, or by
similar methods likely to cause segregation, will not be permitted.
The larger stones shall be well distributed and the entire mass of stone shall
conform to the gradation specified. All material used in the rip -rap protection
shall be so placed and distributed that there will be no large accumulations of
either the larger or smaller sizes of stone.
It is the intent of these specifications to produce a fairly compact rip -rap
protection in which all sizes of material are placed in their proper proportions.
Hand placing or rearranging of individual stones by mechanical equipment may
be required to the extent necessary to secure the results specified.
C. Sand -Cement Bag Rip -Rap: Bags shall be uniformly filled. The bagged rip -rap
shall be placed by hand with tied ends facing the same direction, with close,
broken joints. After placing, the bags shall be rammed or packed against one
another to produce the required thickness and form a consolidated mass. The
top of each bag shall not vary more than 3 inches above or below the required
plane. When directed by the Engineer or required by the plans, header courses
shall be placed.
END OF SECTION
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INDEX TO
SECTION 02512NC - ASPHALTIC CONCRETE BINDER/SURFACE COURSES
Paragraph Title
Page
PART 1-GENERAL
1.1
Section Includes
02512NC-1
1.2
Related Sections
02512NC-1
1.3
Measurement and Payment
02512NC-1
1.4
References
02512NC-1
1.5
Quality Assurance
02512NC-2
1.6
Environmental Requirements
02512NC-2
1.7
Testing
02512NC-2
PART2-PRODUCTS
2.1
Tack Coat
02512NC-3
2.2
Asphaltic Cement and Additives
02512NC-3
2.3
Aggregates
02512NC-3
2.4
Source Quality Control and Tests
02512NC-4
PART 3 - EXECUTION
3.1
Examination
02512NC-4
3.2
Preparation
02512NC-5
3.3
Placement
02512NC-5
3.4
Tolerances
02512NC-6
3.5
Field Quality Control
02512NC-6

SECTION 02512NC
ASPHALTIC CONCRETE BINDER/SURFACE COURSES
PART 1-GENERAL
1.1 SECTION INCLUDES
A. Surface Course
B. Binder Course
1.2 RELATED SECTIONS
A. Section 01025 - Measurement and Payment
B. Section 01400 - Quality Control
C. Section 02204 - Earthwork
D. Section 02231 - Aggregate Base Course
1.3 MEASUREMENT AND PAYMENT
A. See Section 1025 — Measurement and Payment
1.4 REFERENCES
A. ASTM D 946-82 (Reapproved 1993) - Penetration -Graded Asphalt -
Cement for Use in Pavement Construction.
B. ASTM E 329-93b - Agencies Engaged in the Testing and/or Inspection of
Materials Used in Construction
C. ASTM D 3740-94 - Minimum Requirements for Agencies Engaged in the
Testing and/or Inspection of Soil and Rock Used in Engineering Design
and Construction.
D. ASTM D 2726-93 - Bulk Specific Gravity and Density of Compacted
Bituminous Mixtures Using Saturated Surface -Dry Specimens.
E. ASTM D 2950-91 - Density of Bituminous Concrete in Place by Nuclear
Methods.
F. ASTM D-1188-89 - Bulk Specific Gravity and Density of Compacted
Bituminous Mixtures Using Paraffin -Coated Specimens.
G. ASTM-T 245-91 - Resistance to Plastic Flow of Bituminous Mixtures
Using Marshall Apparatus
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H. AASHTO-T 179-88 - Effect of Heat and Air on Asphalt Materials (Thin-
film Oven Test).
1.5 QUALITY ASSURANCE
A. Perform work in accordance with North Carolina Department of
Transportation Standard Specifications for Highway Construction -
Revised.
B. Mixing Plant: Conform to North Carolina Department of Transportation
Standard Specifications.
1.6 ENVIRONMENTAL REQUIREMENTS
A. Do not place asphalt mixture when ambient air temperature is less than
that indicated in the Table nor when the surface is wet or frozen.
Lift Thickness
Min. Air Tem erature, De rees F.
1" or Less
55
1.1" to 2"
45
2.1" to 3"
40
3.1" to 4.5"
35
B. Mixture shall be delivered to the spreader at a temperature between 250
degrees F and 325 degrees F.
1.7 TESTING
A. Testing laboratory shall operate in accordance to ASTM D 3740 and E
329 and shall be accepted by the Engineer.
B. The testing laboratory and Project Engineer/Project Representative shall
be given a minimum of 48 hours notice prior to taking any of the tests.
C. Testing shall be the responsibility of the Contractor and shall be
performed at the Contractor's expense by a commercial testing laboratory
that operates in accordance with subparagraph A above.
D. Test results shall be furnished to the Engineer including the QMS forms
as required by North Carolina Department of Transportation.
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PART2-PRODUCTS
2.1 TACK COAT
A. Material: Shall be AC-20 or AC-30, asphalt cement, conforming to the
North Carolina Department of Transportation Standard Specifications.
When the temperature in the shade exceeds 70 degrees F, an emulsion
such as CRS - 2h or CRS - 3 may be used at the Engineer's discretion.
2.2 ASPHALT CEMENT AND ADDITIVES
A. Asphalt Cement: Shall conform to the requirements of the North Carolina
Department of Transportation Standard Specifications. The material
shall be AC-20 or AC-30. The loss on heating from the Thin -Film Oven
Test shall not exceed 0.75 percent. Contractor shall provide supporting
documents to Engineer 7 days prior to commencing paving operations.
B. Anti -Stripping: Shall conform to requirements of the North Carolina
Department of Transportation Standard Specifications.
2.3 AGGREGATES
A. General: Mineral aggregate shall be composed of fine aggregate or a
combination of fine and coarse aggregate. Coarse aggregate shall be
that portion of the material retained on a No. 8 sieve.
Fine aggregate shall be considered that portion passing the No. 8 sieve.
Fine aggregate, coarse aggregate, and any additives in combination with
the specified percentage of asphalt cement shall meet the requirements
of tests specified, before approval may be given for their individual use.
B. Fine Aggregate: Shall conform to the requirements of the North Carolina
Department of Transportation Standard Specifications.
C. Coarse Aggregate: Shall conform to the requirements of the North
Carolina Department of Transportation Standard Specifications.
D. Surface Course: The surface course shall consist of fine and coarse
aggregate and mineral filler uniformly mixed with hot asphalt cement in
an approved mixing plant. The plant shall conform to North Carolina
Department of Transportation Standard Specifications. The gradations,
asphalt content and stabilities shall be the following:
TYPE 1
Square Sieve
% Passing
100
�2„
97 - 100
3/8"
80 - 100
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4
58 - 75
No. 8
42 - 60
No. 30
19 - 40
FNo.
No. 100
g _ 20
No. 200
3 _ g
s halt Cement
4.8 - 6.8No.
@ 50 Blows
(Design)
1,400
Air Voids, % (Design)
3.5 — 5.0
Marshall Stability @ 50 Blows
Field
1,250
Air Voids, % (Field)3-5
E. Intermediate or Binder Course: The mineral aggregates and asphalt
cement shall be combined in such proportions that the composition by
weight of the finished mixture shall be within the following range limits:
T e2
Sieve Designation
Percentage by Weight
Passin
1 inch
100
1/4 inch
90 - 100
inch
72 - 90
No. 4
42 - 60
No. 8
30 - 48
No. 30
12 - 29
No. 100
6 — 16
No. 200
2-8
Percent of Total Mixture
% Asphalt Cement
3.5 - 6.2
Marshall Stability, lbs. @ 50
Blows (Design)
1,200
2.4 SOURCE QUALITY CONTROL AND TESTS
A. Section 01400 - Quality Control, 01410 - Testing Laboratory Services.
Provide mix design for asphalt.
B. Submit proposed mix design for review prior to beginning of work.
C. Test samples in accordance with the requirements of these
specifications.
PART 3 - EXECUTION
3.1 EXAMINATION
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A. ON -SITE OBSERVATIONS: The Owner's Representative or Engineer
will have the right to require that any portion of the work be done in his
presence and if the work is covered up after such instruction, it shall be
exposed by the Contractor for observation at no additional cost to the
Owner. However, if the Contractor notifies the Owner that such work is
scheduled, and the Owner fails to appear within 48 hours, the Contractor
may proceed without him. All work done and materials furnished shall be
subject to review by the Owner, Engineer or Project Representative.
Improper work shall be reconstructed, and all materials, which do not
conform to the requirements of the specifications, shall be removed from
the work upon notice being received from the Engineer for the rejection of
such materials. The Engineer shall have the right to mark rejected
materials so as to distinguish them as such.
The Contractor shall give the Owner, . Project Engineer or Project
Representative a minimum of 48 hours notice for all required
observations or tests.
B. Contractor verify that base has been inspected, is dry, and gradients and
elevations are correct.
3.2 PREPARATION
A. Apply tack coat in accordance with the North Carolina Department of
Transportation Standard Specifications. Rate of application shall be 0.04
to 0.08 gallons per square yard of surface.
B. Work shall be planned so that no more tack coat than is necessary for
the day's operation is placed on the surface. All traffic not essential to
the work should be kept off the tack coat.
C. Apply tack coat to contact surfaces of curbs and gutters. Apply in
manner so exposed curb or gutter surfaces are not stained.
D. Coat surfaces of manhole frames and inlet frames with oil to prevent
bond with asphalt pavement. Do not tack coat these surfaces.
3.3 PLACEMENT
A. Construction shall be in accordance with the North Carolina Department
of Transportation Standard Specifications, latest edition.
B. Asphaltic concrete shall not be placed on a surface that is wet or frozen.
C. Compaction shall commence as soon as possible after the mixture has
been spread to the desired thickness. Compaction shall be continuous
and uniform over the entire surface. Do not displace or extrude
pavement from position. Hand compact in areas inaccessible to rolling
equipment. Perform rolling with consecutive passes to achieve even and
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smooth finish without roller marks. Compaction rolling shall be complete
before material temperature drops below 1850 F.
D. Areas of pavement with deficient thickness or density shall be removed
and replaced at no additional cost to the Owner.
3.4 TOLERANCES
A. General: All paving shall be subject to visual and straightedge inspection
during construction operations and thereafter prior to final acceptance. A
10-foot straightedge shall be maintained in the vicinity of the paving
operation at all times for the purpose of measuring surface irregularities
on all paving courses. The straightedge and labor for its use shall be
provided by the Contractor. The surface of all courses shall be inspected
with the straightedge as necessary to detect surface irregularities.
Irregularities such as rippling, tearing or pulling, which in the judgment of
the Engineer indicate a continuing problem in equipment, mixture or
operating technique, will not be permitted to recur. The paving operation
shall be stopped until appropriate steps are taken by the Contractor to
correct the problem.
B. Flatness: All irregularities in excess of 1/8 inch in 10 feet for surface
courses and 3/16 inch in 10 feet for intermediate courses shall be
corrected.
C. Variation from Design Elevation: Less than 1/4 inch under tolerance
D. Scheduled Compacted Thickness: Less than 1/4 inch.
E. Pavement Deficient in Thickness: When measurement of any core
indicates that the pavement is deficient in thickness, additional cores will
be drilled 10 feet either side of the deficient core along the centerline of
the lane until the cores indicate that the thickness conforms to the above
specified requirements. A core indicating thickness deficiencies is
considered a failed test. Pavement deficient in thickness shall be
removed and replaced with the appropriate thickness of materials. If the
Contractor believes that the cores and measurements taken are not
sufficient to indicate fairly the actual thickness of the pavement, additional
cores and measurements will be taken, provided the Contractor will bear
the extra cost of drilling the cores and filling the holes in the roadway as
directed.
3.5 FIELD QUALITY CONTROL
A. Quality acceptance of the in -place density of the binder and surface
courses shall be in accordance with the North Carolina Department of
Transportation Standard Specifications.
B. Density Testing: Performed in accordance with ASTM D-2726 and ASTM
D-2950. Core samples for each days operation shall be taken, tested
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and results reported to the Engineer the following day. The areas
sampled shall be properly restored by the Contractor at no additional cost
to the Owner. Compaction must be accomplished when the temperature
of the mix is above 185 degrees F and below 300 degrees F. When the
density of the compacted course is less than 96% or more than 98% of
the maximum laboratory density, the course will be rejected.
C. Temperature:
1. Asphaltic concrete shall not exceed 325 degrees F at any time.
2. Asphaltic concrete shall not be placed once the temperature of
the mix falls below 250 degrees F or the delivered temperature is
more than 15 degrees F below the batch plant's delivery ticket.
3. Temperature at time of loading shall be recorded on the truck
delivery ticket.
D. Frequency of Tests:
1. Asphaltic Concrete - One (1) test for each 250 tons placed.
a) Asphalt extraction and gradation test.
b) Marshall Stability Test
c) Core Sample
2. Field determination of density by nuclear method every 5,000
square feet during construction of the asphaltic concrete
binder/surface course.
END OF SECTION.
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INDEX TO
SECTION 02902 - GRASSING
Paragraph Title Page
PART 1 - GENERAL
1.1
Section Includes
1.2
Related Work
02902-1
1.3
Delivery, Storage & Handling
02902-1
1.4
Planting Dates
02902-1
1.5
Measurement and Payment
02902-1
02902-2
PART2-PRODUCTS
2.1
Seed
2.2
Fertilizer
02902-2
2.3
Seeding Schedule
02902-2
2.4
Lime
02902-3
2.5
Sod
02902-3
2.6
Wetland Plants
02902-3
2.7
Accessories
02902-3
2.8
Product Review
02902-3
02902-3
PART 3 - EXECUTION
3.1
Preparation
02902-4
3.2
Stand of Grass
3.3
Seeding Dates
02902-4
3.4
Applying Lime and Fertilizer
02902-4
3.5
Seeding
02902-4
3.6
Seed Protection (Straw Mulch)
02902-5
3.7
Seed Protection (Excelsior Mulch)
02902-5
3.8
Seed Protection (Wood Cellulose Fiber Mulch)
02902-5
02902-5
3.9
Sodding
3.10
Maintenance
02902-6
3.11
Acceptance
02902-6
02902-6

SECTION 02902
GRASSING
PART 1-GENERAL
1.1 SECTION INCLUDES
A. Seeding, planting grass and fertilizing graded areas behind the structures, pipeline
rights -of -way, roadway shoulders and other disturbed areas.
B. Seed protection.
C. Maintaining seeded areas until final acceptance.
1.2 RELATED WORK
A. Section 02204 - Earthwork: Grading.
1.3 DELIVERY, STORAGE AND HANDLING
A. Deliver grass seed in original containers showing analysis of seed mixture,
percentage of pure seed, year of production, net weight, date of packaging and
location of packaging. Damaged packages are not acceptable.
B. Deliver fertilizer in waterproof bags showing weight, chemical analysis, and name
of manufacturer. Damaged bags are not acceptable.
C. Deliver sod on pallets.
D. All material shall be acceptable to Engineer prior to use.
1.4 PLANTING DATES
A. This specification provides for the establishment of a permanent grass cover
between the dates of March 1 and September 30. If finished earth grades are not
completed in time to permit planting and establishment of the permanent grass
during the favorable season between the dates specified above unless otherwise
accepted, the Contractor will be required to plant a temporary cover to protect the
new graded areas from erosion and to keep windborne dust to a minimum. The
temporary cover shall be planted between October 1 and February 28 unless
otherwise permitted.
B. If project grassing occurs during the temporary grassing season, the Contractor is
still required to provide a stand of permanent grass cover as prescribed in Section
2.3 — Seeding Schedule, at the Contractor's expense.
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Page 1 of 6

1.5 MEASUREMENT AND PAYMENT
A. See Section 1025 — Measurement and Payment
PART2-PRODUCTS
2.1 SEED
A. Permanent Grass Seed Mixture: 33 percent centipede grass (commercial brand,
testing 98% purity and 85% germination) and 67 percent carpet grass (testing 98%
purity and 85% germination).
B. Temporary Grass Seed Mixture: Domestic Italian rye grass (testing 98% purity
and 90% germination).
C. All seed shall conform to all State Laws and to all requirements and regulations of
the State Department of Agriculture.
D. The several varieties of seed shall be individually packaged or bagged, and tagged
to show name of seed, net weight, origin, germination, lot number, and other
information required by the State Department of Agriculture.
E. The Engineer reserves the right to test, reject, or accept all seed before seeding.
2.2 FERTILIZER
A. 4-12-12, commercial fertilizer of approved type, conforming to state fertilizer laws.
2.3 SEEDING SCHEDULE
A. SEED RATE PLANTING DATES
Centipede 25 Ibs/acre March 1 - September 30
Carpet 30 Ibs/acre March 1 - September 30
Rye 75 Ibs/acre October 1 - February 28
B. In areas where existing grass is to be matched, Contractor shall sow seed at the
rate and dates recommended by seed distributor.
2.4 LIME
A. Agricultural grade, ground limestone.
2.5 SOD
A. Sod shall be densely rooted, good quality centipede grass, free from noxious
weeds. The sod shall be obtained from areas where the soil is reasonably fertile.
The sod shall be raked free of all debris and the grass mowed to two inches before
cutting. The sod shall contain practically all of the dense root system and not be
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less than one (1) inch thick. Sod shall be cut in uniform strips not less than twelve
(12) inches in width and not less than twenty-four (24) inches in length.
2.6 WETLAND PLANTS
A. Wetland plants shall be planted along the perimeter of the vegetative shelf for each
pond. Vegetative cover shall be any combination of the following wetland plants:
Andropogon virginicus (Broomsedge), Typha spp. (Cattail), Saururus cernuus
(Lizard's Tail).
2.7 ACCESSORIES
A. Straw Mulch: Oat or wheat straw, reasonably free from weeds, foreign matter
detrimental to plant life, and in dry condition.
B. Excelsior Mulch: Excelsior mulch shall consist of wood fibers cut from sound,
green timber. The average length of the fibers shall be 4 to 6 inches. The cut
shall be made in such a manner as to provide maximum strength of fiber, but at a
slight angle to the natural grain of the wood so as to cause splintering of the fibers
when weathering in order to provide adherence to each other and to the soil.
C. Wood cellulose fiber shall be made from wood chip particles manufactured
particularly for discharging uniformly on the ground surface when dispersed by a
hydraulic water sprayer. It shall remain in uniform suspension in water under
agitation and blend with grass seed and fertilizer to form a homogenous slurry.
The mulch fibers shall intertwine physically to form a strong moisture holding mat
on the ground surface and allow rainfall to percolate into the underlying soil. The
mulch shall be heat processed so as to contain no germination or growth -inhibiting
factors. It shall be dyed (non -toxic) an appropriate color to facilitate metering of
material.
2.8 PRODUCT REVIEW
A. The Contractor shall provide the Engineer with a complete description of all
products before ordering. The Engineer will review all products before they are
ordered.
PART 3 - EXECUTION
3.1 PREPARATION
A. The areas to be seeded shall be made smooth and uniform and shall conform to
the finished grade indicated on the plans.
B. Remove foreign materials, plants, roots, stones, and debris from surfaces to be
seeded.
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C. Grassing areas, if not loose, shall be loosened to a minimum depth of 3-inch
before fertilizer, seed or sod is applied.
3.2 STAND OF GRASS
A. Before acceptance of the seeding performed for the establishment of permanent
vegetation, the Contractor will be required to produce a satisfactory stand of
perennial grass whose root system shall be developed sufficiently to survive dry
periods and the winter weather and be capable of re-establishment in the spring.
B. Before acceptance of the seeding performed for the establishment of temporary
vegetation, the Contractor will be required to produce a stand of grass sufficient to
control erosion for a given area and length of time before the next phase of
construction or the establishment of permanent vegetation is to commence.
3.3 SEEDING DATES
A. Seeding shall be performed during the periods and at the rates specified in the
seeding schedules. Seeding work may, at the discretion of the Contractor, be
performed throughout the year using the schedule prescribed for the given period.
Seeding work shall not be conducted when the ground is frozen or excessively
wet. The Contractor will be required to produce a satisfactory stand of grass
regardless of the period of the year the work is performed.
3.4 APPLYING LIME AND FERTILIZER
A. Following advance preparation and placing selected material for shoulders and
slopes, lime, if called for based on soil tests and fertilizer, shall be spread uniformly
over the designated areas and shall be thoroughly mixed with the soil to a depth of
approximately 2-inches. Fertilizer shall be applied at the rate of 500 pounds per
acre for the initial application unless otherwise directed by the Engineer. Lime
shall be applied at the rate determined by the soil test. Unless otherwise provided,
lime will not be applied for temporary seeding. In all cases where practicable,
acceptable mechanical spreaders shall be used for spreading fertilizer. On steep
slopes subject to slides and inaccessible to power equipment, the slopes shall be
adequately scarified. Fertilizer may be applied on steep slopes by hydraulic
methods as a mixture of fertilizer and seed. When fertilizer is applied with
combination seed and fertilizer drills, no further incorporation will be necessary.
The fertilizer and seed shall be applied together when Wood Cellulose Fiber Mulch
is used. Any stones larger than 2-1/2 inches in any dimension, larger clods, roots,
or other debris brought to the surface shall be removed.
3.5 SEEDING
A. Seed shall be sown within 24 hours following the application of fertilizer and lime
and preparation of the seedbed as specified in Section 3.4. Seed shall be
uniformly sown at the rate specified by the use of acceptable mechanical seed
drills. Rotary hand seeders, power sprayers or other satisfactory equipment may
be used on steep slopes or on other areas that are inaccessible to seed drills.
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B. The seeds shall be covered and lightly compacted by means of cultipacker or light
roller if the drill does not perform this operation. On slopes inaccessible to
compaction equipment, the seed shall be covered by dragging spiked chains, by
light harrowing or by other satisfactory methods.
C. Apply water with fine spray immediately after each area has been sown.
D. Do not sow seed when ground is too dry, during windy periods or immediately
following a rain.
E. If permitted by the special provisions, wood cellulose fiber mulch or excelsior fiber
mulch may be used.
3.6 SEED PROTECTION (STRAW MULCH)
A. All seeded areas seeded with permanent grasses shall be uniformly mulched in a
continuous blanket immediately following seeding and compacting operations,
using at least 2 tons of straw per acre.
3.7 SEED PROTECTION (EXCELSIOR MULCH)
A. Seed shall be sown as specified in Section 3.5. Within 24 hours after the covering
of seed, excelsior mulch shall be uniformly applied at the rate of 2 tons per acre.
The mulch may be applied hydraulically or by other acceptable methods. Should
the mulch be placed in a dry condition, it shall be thoroughly wetted immediately
after placing. The Engineer may require light rolling of the mulch to form a tight
mat.
3.8 SEED PROTECTION (WOOD CELLULOSE FIBER MULCH)
A. After the lime has been applied and ground prepared as specified in Section 3.4,
wood cellulose fiber mulch shall be applied at the rate of 1,500 pounds per acre in
a mixture of seed and fertilizer. Hydraulic equipment shall be used for the
application of fertilizer, seed and slurry of the prepared wood pulp. This equipment
shall have a built-in agitation system with an operating capacity sufficient to agitate,
suspend, and homogeneously mix a slurry of the specified amount of fiber,
fertilizer, seed and water. The slurry distribution lines shall be large enough to
prevent stoppage. The discharge line shall be equipped with a set of hydraulic
spray nozzles which will provide an even distribution of the slurry on the various
areas to be seeded. The slurry tank shall have a minimum capacity of 1,000
gallons.
The seed, fertilizer, wood pulp mulch, and water shall all be combined into the
slurry tank for distribution of all ingredients in one operation by the hydraulic
seeding method specified herein. The materials shall be combined in a manner
recommended by the manufacturer. The slurry mixture shall be so regulated that
the amounts and rates of application shall result in a uniform application of all
materials at rates not less than the amount specified. Using the color of the wood
pulp as a guide, the equipment operator shall spray the prepared seedbed with a
uniform visible coat. The slurry shall be applied in a sweeping motion, in an arched
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stream so as to fall like rain, allowing the wood fibers to build upon each other until
an even coat is achieved.
3.9 SODDING
A. Sod shall be placed between March 1s` and December 1s`
B. Sod shall be placed within 48 hours of cutting.
C. Sod shall be moist when laid and placed on moist ground. The sod shall
be carefully placed by hand, beginning at the toe of slopes and working
upwards. The length of the strips shall be at right angles to the flow of
surface water. All joints shall be tightly butted and end joints shall be
staggered at least 12 inches. The sod shall be immediately pressed firmly
into the ground by tamping or rolling. Fill all joints between strips with fine
screened soil. Sod on slopes shall be pegged with sod pegs to prevent
movement. The sod shall be watered, mowed, weeded, repaired or
otherwise maintained, to insure the establishment of a uniform healthy
stand of grass until acceptance.
3.10 MAINTENANCE
A. Maintain seeded surfaces until final acceptance.
B. Maintenance shall consist of providing protection against traffic, watering to ensure
uniform seed germination and to keep surface of soil damp, mowing and repairing
any areas damaged as a result of construction operations or erosion.
3.11 ACCEPTANCE
A. Before acceptance of the seeding performed for the establishment of permanent
vegetation, the Contractor will be required to produce a satisfactory stand of
perennial grass whose root system shall be developed sufficiently to survive dry
periods and the winter weather and be capable of reestablishment in the spring.
END OF SECTION
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