20080757 Ver 1_401 Application_20080408

WITHERS R"EN EL
ENGINEERS I PLANNERS I SURVEYORS
April 29, 2oo8
?F I,, .
US Army Corps of Engineers NC-Division of Water Quality FAY .. o ;-)
I L..
Attn: Mr. Monte Mathews Attn: Ms. Cyndi Karoly F,?ECE
3331 Heritage Trade Drive, Suite 105 2321 Crabtree Boulevard.
Raleigh, North Carolina 27587 Raleigh, North Carolina 27604
Re: Montvale - Phase II - Low Impact Development Project
Request for 404/401 Certification D ?'1 l5
W&R Project Number - 0204409.00
APR 2 9 2008
Dear Mr. Mathews and Ms. Karoly, DENR WATERQUAUTY
NCH
On behalf of Branston LLC, we are requesting authorization from the USAC??NDSTQRNNVA'fERBRA
NWP's 29 & 12 for the construction of a roadway crossing and sanitary sewer needed
to support a residential development. The development is the first Low Impact
Development (LID) in the Town of Cary and is being used as a pilot project by the
Town of Cary staff. The goal of this project is to mimic the pre-development
hydrologic regime through the use of bio-retention basins and grassed bio-swales.
The subject property is approximately 14.85 acres in size and is located on the east
side of Earnest Jones Rd (SR 1737), approximately 25ooft north of the intersection of
East Farrell Road (SR 1677) and Green Level Church Rd (SR 16o9) at Latitude
35.8o631o9°N and Longitude 78.9265739°W in Green Level, Wake County, North
Carolina. The site contains unnamed tributaries of Indian Creek. The site is located in
the Cape Fear River Basin. The Water Quality Classification is WSW; NSW, the
Stream Index is: 16-41-1-18-(1), and the Hydrologic Unit code is: 03030002.
Project History
Wetlands were delineated by Soil and Environmental Consultants on January 13 and
17, 2005. On March 2nd, 2007 a site meeting was conducted with Mr. Matt Flynn of
the Town of Cary to evaluate streams potentially subject to the Town of Cary Riparian
Buffer Rules. Mr. Flynn agreed with our determinations. A copy of the buffer letter is
included with the attachments.
On July 6`h, 2007 a request for 404 authorization from the USACE for impacts
associated with Phase I of the subdivision was submitted. The previous request was
for 126 linear feet of perennial stream channel and 0.0283 acres of wetland for road
construction. The impacts were authorized due to the fact that the permit "timed-
out". Because the impacts were less than 150 linear feet and less than o.1 acres,
401-Certification was not required.
iii MacKenan Drive i Cary, NC 27511 1 tel: [phone] fax: [phone]oo8 i www.withersravenel.com
7040 Wrightsville Avenue i Suite io1 i Wilmington, NC 28403 1 tel: [phone] fax: [phone]
Brunswick Surveying 1 1027 Sabbath Home Rd, SW i Supply, NC 28462 1 tel: [phone] fax: [phone]oi9
Proposed Impacts
The proposed impacts for Phase II consists of 159 linear feet of perennial/important
stream channel for the installation of a road crossing and 20 linear feet of temporary
channel impact for the installation of a sanitary sewer line. Impacts are summarized
in the PCN form.
Avoidance and Minimization
Prior to site plan development, the applicant requested that a detailed wetland
delineation be conducted so that impacts to wetlands and `waters' could be
minimized. The current site plan was developed, and approved by the Town of Cary,
to minimize impacts to wetlands and streams based on the original wetland
delineation. The original delineation identified wetlands and a potential
stream/buffer that bisected the entire site, and it was assumed that a stream impact
would be necessary to develop the entire parcel. Upon further review, it was
determined that the stream channel did not extend throughout the site, However, the
design plans had already been approved by the Town of Cary and the road
alignments were set. In order to minimize impacts, the stream crossing was made at
a perpendicular angle and the fill slopes were steepened at the crossing.
Additionally, the original plans called out another culvert for a greenway trail, but the
plans have been revised to avoid this impact by crossing with a bridge.
Stormwater Management Plan
The proposed impervious for this project is expected to be approximately 25%.
Attached is a copy of the stormwater management plan, approval letter from the
Town of Cary, and approved construction drawings. During construction the
applicant will utilize BMP devices to prevent sediment from entering jurisdictional
stream channels or wetlands.
Mitigation
The applicant proposes payment to NC-EEP for the 285 linear feet of perennial
stream impact. The NC-EEP acceptance letter is included in the attachments.
Please feel free to call if you have questions or require additional information.
Sincerely,
WITHERS & RAVENEL, Inc.
Todd Preuninger
Director of Wetland and Biological Services
Attachments -
i) PCN Form
2) Site plans
3) Buffer Letter
4) NC-EEP Acceptance Letter
5) Agent Authorization
6) USGS Quad Map
7) Wake/Chatham Counties Soil Survey Map
8) Stormwater Approval Letter & Plans
08-075?
Office Use Only: Form Version March 05
USACE Action ID No. DWQ No.
(If any particular item is not applicable to this project, please enter "Not Applicable" or "N/A".)
1. Processing
Check all of the approval(s) requested for this project:
® Section 404 Permit ? Riparian or Watershed Buffer Rules
? Section 10 Permit ? Isolated Wetland Permit from DWQ
® 401 Water Quality Certification ? Express 401 Water Quality Certification
2. Nationwide, Regional or General Permit Number(s) Requested: NWP 29 & 12
3. If this notification is solely a courtesy copy because written approval for the 401 Certification
is not required, check here: ?
4. If payment into the North Carolina Ecosystem Enhancement Program (NCEEP) is proposed
for mitigation of impacts, attach the acceptance letter from NCEEP, complete section VIII,
and check here:
5. If your project is located in any of North Carolina's twenty coastal counties (listed on page
4), and the project is within a North Carolina Division of Coastal Management Area of
Environmental Concern (see the top of page 2 for further details), check here: ?
II. Applicant Information E c?c?foW?
Owner/Applicant Information
APR 2 9 2008
Name: Branston LLC. Attention: Glen Futrell DM. WATERQUIWTY
BRANCH
Mailing Address: 150 Towerview Court WEnA"ANDSTOWMI
Carv, NC 27513
Telephone Number: 919-535-0125 Fax Number: 919-535-0126
E-mail Address:[e-mail]
2. Agent/Consultant Information (A signed and dated copy of the Agent Authorization letter
must be attached if the Agent has signatory authority for the owner/applicant.)
Name: Todd Preuninger
Company Affiliation: Withers & Ravenel
Mailing Address: 111 MacKenan Drive
Carv, NC 27511
Telephone Number: 919-469-3340 Fax Number: 919-535-4545
E-mail Address: T reuninger&WithersRavenel.com
III. Project Information
Attach a vicinity map clearly showing the location of the property with respect to local
landmarks such as towns, rivers, and roads. Also provide a detailed site plan showing property
Page I of 8
boundaries and development plans in relation to surrounding properties. Both the vicinity map
and site plan must include a scale and north arrow. The specific footprints of all buildings,
impervious surfaces, or other facilities must be included. If possible, the maps and plans should
include the appropriate USGS Topographic Quad Map and NRCS Soil Survey with the property
boundaries outlined. Plan drawings, or other maps may be included at the applicant's discretion,
so long as the property is clearly defined. For administrative and distribution purposes, the
USACE requires information to be submitted on sheets no larger than I 1 by 17-inch format;
however, DWQ may accept paperwork of any size. DWQ prefers full-size construction
drawings rather than a sequential sheet version of the full-size plans. If full-size plans are
reduced to a small scale such that the final version is illegible, the applicant will be informed that
the project has been placed on hold until decipherable maps are provided.
1. Name of project: Montvale Subdivision Phase II
2. T.I.P. Project Number or State Project Number (NCDOT Only): N
3. Property Identification Number (Tax PIN): 0724-19-3099, 0724-29-1036, 0724-25-1657,
0724-18-0589 0724-18-2026 0724-17-8257 0724-16-7987 0724-17-8527 0724-16-9863
0724-27-0073
4. Location
County: Chatham/Wake Counties Nearest Town: Cary
Subdivision name (include phase/lot number): Montvale
Directions to site (include road numbers/names, landmarks, etc.): The site is located on the
east side of Earnest Jones Rd (SR 1737), approximately 2500ft north of the intersection of
East Farrell Road (SR 1677) and Green Level Church Rd (SR 1609).
5. Site coordinates (For linear projects, such as a road or utility line, attach a sheet that
separately lists the coordinates for each crossing of a distinct waterbody.)
Decimal Degrees (6 digits minimum): 35.8063109 ON 78.9265739 °W
6. Property size (acres): 14.85 acres
7. Name of nearest receiving body of water: Indian Creek
8. River Basin: Cape Fear River Basin
(Note - this must be one of North Carolina's seventeen designated major river basins. The
River Basin map is available at http://h2o.enr.state.nc.us/admin/maps/.)
9. Describe the existing conditions on the site and general land use in the vicinity of the project
at the time of this application: The site is currently 100% wooded. The surrounding land
use consist of agriculture to the west and residential develop to the north south and east
10. Describe the overall project in detail, including the type of equipment to be used: This
project includes the development of approximately 14.85 acres into an LID subdivision
which will consist of approximately 72 building lots. Large grading equipment will be
Page 2 of 8
utilized to install the infrastructure (i.e. roads, sewer, lot grading erg_enway trail)
necessary for the development of this site.
11. Explain the purpose of the proposed work: The purpose of this work is to meet the demand
of residential housing in the area. In addition, it is serving as pilot project for the Town of
Cary's low impact development studies. Several aspects of this project will be studied to
determine the effectiveness of the low impact design. Mainly, bio-retention BMP's, which
have been specifically designed for this project.
IV. Prior Project History
If jurisdictional determinations and/or permits have been requested and/or obtained for this
project (including all prior phases of the same subdivision) in the past, please explain. Include
the USACE Action ID Number, DWQ Project Number, application date, and date permits and
certifications were issued or withdrawn. Provide photocopies of previously issued permits,
certifications or other useful information. Describe previously approved wetland, stream and
buffer impacts, along with associated mitigation (where applicable). If this is a NCDOT project,
list and describe permits issued for prior segments of the same T.I.P. project, along with
construction schedules. Wetlands were delineated by Soil and Environmental Consultants on
January 13 and 17, 2005. On March 2°d, 2007 a site meeting was conducted with Mr. Matt Fl Wynn
of the Town of Cary to evaluate streams potentially subject to the Town of Cary Riparian Buffer
Rules. Mr. Flynn agreed with our determinations. A copy of the buffer letter is included with
the attachments.
On July 6th, 2007 a request for 404 authorization from the USACE for impacts associated with
Phase I of the subdivision was submitted. The previous request was for 126 linear feet of
perennial stream channel and 0.0283 acres of wetland for road construction. The impacts were
authorized due to the fact that the permit went statutory. Because the impacts were less than 150
linear feet and less than 0.1 acres, 401-Certification was not required.
V. Future Project Plans
Are any future permit requests anticipated for this project? If so, describe the anticipated work,
and provide justification for the exclusion of this work from the current application.
No future phases are anticipated at this time.
VI. Proposed Impacts to Waters of the United States/Waters of the State
It is the applicant's (or agent's) responsibility to determine, delineate and map all impacts to
wetlands, open water, and stream channels associated with the project. Each impact must be
listed separately in the tables below (e.g., culvert installation should be listed separately from
riprap dissipater pads). Be sure to indicate if an impact is temporary. All proposed impacts,
permanent and temporary, must be listed, and must be labeled and clearly identifiable on an
accompanying site plan. All wetlands and waters, and all streams (intermittent and perennial)
should be shown on a delineation map, whether or not impacts are proposed to these systems.
Wetland and stream evaluation and delineation forms should be included as appropriate.
Page 3 of 8
Photographs may be included at the applicant's discretion. If this proposed impact is strictly for
wetland or stream mitigation, list and describe the impact in Section VIII below. If additional
space is needed for listing or description, please attach a separate sheet.
1. Provide a written description of the proposed impacts: The proposed permanent impacts for
phase II consist of 159 linear feet of perennial/important stream channel for the installation of
a road crossing. Temporary impacts include 20 linear feet of perennial/important stream
channel for the installation of a sanitary sewer line.
2. Individually list wetland impacts. Types of impacts include, but are not limited to
mechanized clearing, grading, fill, excavation, flooding, ditching/drainage, etc. For dams,
separately list impacts due to both stnicture and flonding
Wetland Impact Type of Wetland Located within Distance to Area of
Site Number Type of Impact (e.g., forested, marsh, 100-year Nearest Impact
(indicate on map) herbaceous, bog, etc.) Floodplain Stream (acres)
(yes/no) (linear feet)
NA NA NA NA NA NA
Total Wetland Impact (acres) NA
3. List the total acreage (estimated) of all existing wetlands on the property: < 1 acre
4. Individually list all intermittent and perennial stream impacts. Be sure to identify temporary
impacts. Stream impacts include, but are not limited to placement of fill or culverts, dam
construction, flooding, relocation, stabilization activities (e.g., cement walls, rip-rap, crib
walls, gabions, etc.), excavation, ditching/straightening, etc. If stream relocation is proposed,
plans and profiles showing the linear footprint for both the original and relocated streams
must be included. To calculate acreage- multinlv length X width then divide by Al 560
Stream Impact Perennial or Average Impact Area of
Number Stream Name Type of Impact Intermittent? Stream Width Length Impact
(indicate on ma) Before Impact (linear feet) (acres)
Impact I UT to Indian Creek Permanent/Culvert Perennial 3 159 0.007
Impact 2 Indian Creek Temporary Perennial 5 20 0.0006
Total Stream Impact (by length and acreage) 179 0.0076
5. Individually list all open water impacts (including lakes, ponds, estuaries, sounds, Atlantic
Ocean and any other water of the U.S.). Open water impacts include, but are not limited to
fill. excavation. dredging. flooding- drainage- bulkhead,- etc
Open Water Impact Name of Waterbody Type of Waterbody Area of
Site Number (if applicable) Type of Impact (lake, pond, estuary, sound, bay, Impact
(indicate on ma) ocean, etc.) (acres)
NA NA NA NA NA
Total Open Water Impact (acres) NA
6. List the cumulative impact to all Waters of the U.S. resulting from the nroiect-
Stream Impact (acres): 0.0076
Wetland Impact (acres): NA
Open Water Impact (acres): NA
Page 4 of 8
Total Impact to Waters of the U.S. (acres) 0.0076
Total Stream Impact (linear feet): 179
7. Isolated Waters
Do any isolated waters exist on the property? ? Yes ® No
Describe all impacts to isolated waters, and include the type of water (wetland or stream) and
the size of the proposed impact (acres or linear feet). Please note that this section only
applies to waters that have specifically been determined to be isolated by the USACE.
8. Pond Creation
If construction of a pond is proposed, associated wetland and stream impacts should be
included above in the wetland and stream impact sections. Also, the proposed pond should
be described here and illustrated on any maps included with this application.
Pond to be created in (check all that apply): ? uplands ? stream ? wetlands
Describe the method of construction (e.g., dam/embankment, excavation, installation of
draw-down valve or spillway, etc.): NA
Proposed use or purpose of pond (e.g., livestock watering, irrigation, aesthetic, trout pond,
local stormwater requirement, etc.): NA
Current land use in the vicinity of the pond: NA
Size of watershed draining to pond: NA Expected pond surface area: NA
VII. Impact Justification (Avoidance and Minimization)
Specifically describe measures taken to avoid the proposed impacts. It may be useful to provide
information related to site constraints such as topography, building ordinances, accessibility, and
financial viability of the project. The applicant may attach drawings of alternative, lower-impact
site layouts, and explain why these design options were not feasible. Also discuss how impacts
were minimized once the desired site plan was developed. If applicable, discuss construction
techniques to be followed during construction to reduce impacts. Prior to site plan development,
the applicant requested that a detailed wetland delineation be conducted so that impacts to
wetlands and `waters' could be minimized. The current site plan was developed and approved
by the Town of Cary, to minimize impacts to wetlands and streams based on the original wetland
delineation. The original delineation identified wetlands and a potential stream channel running
through the site in a north/south orientation and it was assumed that a stream impact would be
necessary to develop the entire site. Upon further review, it was determined that the stream
channel did not extend throughout the site, However, the design plans had already been approved
by the Town of Cary and the road alignments were set. In order to minimize impacts the stream
crossing was made at a perpendicular angle and the fill slopes were steepened at the crossing.
Additionally, the original plans called out another culvert for a greenway trail but the plans have
been revised to avoid this impact by crossing with a bridge.
VIII. Mitigation
DWQ - In accordance with 15A NCAC 2H .0500, mitigation may be required by the NC
Division of Water Quality for projects involving greater than or equal to one acre of impacts to
Page 5 of 8
freshwater wetlands or greater than or equal to 150 linear feet of total impacts to perennial
streams.
USACE - In accordance with the Final Notice of Issuance and Modification of Nationwide
Permits, published in the Federal Register on January 15, 2002, mitigation will be required when
necessary to ensure that adverse effects to the aquatic environment are minimal. Factors
including size and type of proposed impact and function and relative value of the impacted
aquatic resource will be considered in determining acceptability of appropriate and practicable
mitigation as proposed. Examples of mitigation that may be appropriate and practicable include,
but are not limited to: reducing the size of the project; establishing and maintaining wetland
and/or upland vegetated buffers to protect open waters such as streams; and replacing losses of
aquatic resource functions and values by creating, restoring, enhancing, or preserving similar
functions and values, preferable in the same watershed.
If mitigation is required for this project, a copy of the mitigation plan must be attached in order
for USACE or DWQ to consider the application complete for processing. Any application
lacking a required mitigation plan or NCEEP concurrence shall be placed on hold as incomplete.
An applicant may also choose to review the current guidelines for stream restoration in DWQ's
Draft Technical Guide for Stream Work in North Carolina, available at
http://h2o.enr.state.nc.us/ncwetlands/strmgide.html.
1. Provide a brief description of the proposed mitigation plan. The description should provide
as much information as possible, including, but not limited to: site location (attach directions
and/or map, if offsite), affected stream and river basin, type and amount (acreage/linear feet)
of mitigation proposed (restoration, enhancement, creation, or preservation), a plan view,
preservation mechanism (e.g., deed restrictions, conservation easement, etc.), and a
description of the current site conditions and proposed method of construction. Please attach
a separate sheet if more space is needed.
The applicant proposes payment to NC-EEP for the 285 linear feet of perennial stream
impact associated with Phases I & II. A copy of the NC-EEP acceptance letter is attached.
2. Mitigation may also be made by payment into the North Carolina Ecosystem Enhancement
Program (NCEEP). Please note it is the applicant's responsibility to contact the NCEEP at
[phone] to determine availability, and written approval from the NCEEP indicating
that they are will to accept payment for the mitigation must be attached to this form. For
additional information regarding the application process for the NCEEP, check the NCEEP
website at http://h2o.enr.state.nc.us/wry/index.htm. If use of the NCEEP is proposed, please
check the appropriate box on page five and provide the following information:
Amount of stream mitigation requested (linear feet): 285
Amount of buffer mitigation requested (square feet): NA
Amount of Riparian wetland mitigation requested (acres): NA
Amount of Non-riparian wetland mitigation requested (acres): NA
Amount of Coastal wetland mitigation requested (acres): NA
Page 6 of 8
IX. Environmental Documentation (required by DWQ)
1. Does the project involve an expenditure of public (federal/state/local) funds or the use of
public (federal/state) land? Yes ? No
2. If yes, does the project require preparation of an environmental document pursuant to the
requirements of the National or North Carolina Environmental Policy Act (NEPA/SEPA)?
Note: If you are not sure whether a NEPA/SEPA document is required, call the SEPA
coordinator at [phone] to review current thresholds for environmental documentation.
Yes ? No ?
3. If yes, has the document review been finalized by the State Clearinghouse? If so, please
attach a copy of the NEPA or SEPA final approval letter. Yes ? No ?
X. Proposed Impacts on Riparian and Watershed Buffers (required by DWQ)
It is the applicant's (or agent's) responsibility to determine, delineate and map all impacts to
required state and local buffers associated with the project. The applicant must also provide
justification for these impacts in Section VII above. All proposed impacts must be listed herein,
and must be clearly identifiable on the accompanying site plan. All buffers must be shown on a
map, whether or not impacts are proposed to the buffers. Correspondence from the DWQ
Regional Office may be included as appropriate. Photographs may also be included at the
applicant's discretion.
1. Will the project impact protected riparian buffers identified within 15A NCAC 2B .0233
(Neuse), 15A NCAC 213 .0259 (Tar-Pamlico), 15A NCAC 02B .0243 (Catawba) 15A NCAC
2B .0250 (Randleman Rules and Water Supply Buffer Requirements), or other (please
identify )? Yes ? No
2. If "yes", identify the square feet and acreage of impact to each zone of the riparian buffers.
If buffer mitigation is required calculate the required amount of mitigation by applying the
buffer multipliers.
Zone* I Impact ( Multiplier Required
1 NA i 3 (2 for Catawba) I NA
2 NA 1.5 NA
Total I NA I I NA
* Zone 1 extends out 30 feet perpendicular from the top of the near bank of channel; Zone 2 extends an
additional 20 feet from the edge of Zone 1.
3. If buffer mitigation is required, please discuss what type of mitigation is proposed (i.e.,
Donation of Property, Riparian Buffer Restoration / Enhancement, or Payment into the
Riparian Buffer Restoration Fund). Please attach all appropriate information as identified
within 15A NCAC 213.0242 or.0244, or.0260. NA
XI. Stormwater (required by DWQ)
Page 7 of 8
Describe impervious acreage (existing and proposed) versus total acreage on the site. Discuss
stormwater controls proposed in order to protect surface waters and wetlands downstream from
the property. If percent impervious surface exceeds 20%, please provide calculations
demonstrating total proposed impervious level. The proposed impervious for this project is
expected to be approximated 25% Attached is a copy of the stormwater management plan,
approval letter from the Town of Cary and approved construction drawings. During
construction the applicant will utilize BMP devices to prevent sediment from entering
jurisdictional stream channels or wetlands.
XII. Sewage Disposal (required by DWQ)
Clearly detail the ultimate treatment methods and disposition (non-discharge or discharge) of
wastewater generated from the proposed project, or available capacity of the subject facility.
SanitM Sewer
XIII. Violations (required by DWQ)
Is this site in violation of DWQ Wetland Rules (15A NCAC 2H .0500) or any Buffer Rules?
Yes ? No
Is this an after-the-fact permit application? Yes ? No
XIV. Cumulative Impacts (required by DWQ)
Will this project (based on past and reasonably anticipated future impacts) result in additional
development, which could impact nearby downstream water quality? Yes ? No
If yes, please submit a qualitative or quantitative cumulative impact analysis in accordance with
the most recent North Carolina Division of Water Quality policy posted on our website at
http://h2o.enr.state.nc.us/ncwetlands. If no, please provide a short narrative description: Due to
the fact that this project is a low impact development and that stormwater BMP's are being
utilized; we do not believe downstream water quality will be impacted.
XV. Other Circumstances (Optional):
It is the applicant's responsibility to submit the application sufficiently in advance of desired
construction dates to allow processing time for these permits. However, an applicant may
choose to list constraints associated with construction or sequencing that may impose limits on
work schedules (e.g., draw-down schedules for lakes, dates associated with Endangered and
Threatened Species, accessibility problems, or other issues outside of the applicant's control).
NA
?Js
Applicant/Agent's Signature Date
(Agent's signature is valid only if an authorization letter from the applicant is provided.)
Page 8 of 8

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PERMANENT IMPACTS
IMPACT 1 :
STREAM : 159 LF (0.007 AC)
GRAPHIC SCALE
50 4 2? 50
1 inch = 50 ft.
MONTVALE PHASE 11 SHEET A WITS ZRE &- gt^vza4r-L
IMPACTS ¦NOINEERS 1 PLANNERS 1 SURVEYORS
_ 11 STREAM mrr?r 4r?.+.? rw-fw rmr?a wr.r?
AQUATIC LIFE PASSAGE
(EXISTING & PROPOSED ELEVATIONS)
LOCATION EXISTING PROPOSED INVERT.
GRADE ELEV.
UPSTREAM 295.20 294.20
IDOWNSTREAM 291.20 290.20
MVrVJGv
INVERT
UPSTREAM SECTION
A M or m rm I I v icm r
INVERT--V
DOWNSTREAM SECTION
NOT TO SCALE
NOT TO SCALE
WITHERS & RAVEN EL
ENGINEERS I PLANNERS I SURVEYORS
ill NacKenan Orive Cary. North Carolina 2T3ii
tel: [phone] fax: [phone] www.witheraravenel.com
2 - WAKE CO.,
FIGURE A: AQUATIC LIFE PASSAGE DETAIL
SINGLE 42" CULVERT - IMPACT #1
PLANNING DEPARTMENT
October 19, 2007
Branston, LLC
PO Box 3006
Cary, NC 27512
RE: Project: Montvale PH2 Subdivision, Preliminary Subdivision Plan Approval
Project #: 07-SB-008
Dear Sir or Madam:
I am pleased to advise on October 15, 2007, the Development Review Committee, approved
the above referenced site plan subject to the Special Conditions of Approval listed in this
letter. Please note the following items for construction:
Development authorized by this Permitlapproval may not take place until new water and
sewer connection permit is issued per Chapter 36 of the Cary Code of Ordinances. This
approval does not guarantee issuance of a water connection permit by the Town.
Special Conditions of Approval:
Be advised the following comments must be addressed in the master mylars (reproducible
set) submitted for staff signatures. If outstanding comments are not addressed, the
master mylars will be returned without approval:
Please submit street name application for at least 5 street names. The final master
plan set cannot be processed unless approved names appear in the final master plan
set.
2. Design for retaining wall on greenway must be approved and included as a part of this
plan. Please email pdf of designs sealed by structural engineer to PRCR for review &
3. Change 8' trail detail to standard detail (indicating compaction %); delete the greenway
sign, trail stop sign, trashcan and metal gate details. Change 10' asphalt trail detail to
standard ToC detail; ditch shown in detail should be outside of the level 2' shoulder.
4. Change BMP detail on Sheet 15... there should be no plantings within the ToC
Greenway Easements.
5. Adjust private drainage easement behind lot 38 to avoid crossing ToC Greenway
Easement. Also, as it is shown there will be g'way easement on the back of lot 38.
Tow N Of CARY
316 North Academy Street 9 Cary, NC 27513 • PO Box 8005 • Cary, NC 27512-8005
tel [phone] • fax [phone] • www.townofcary.org
6. Add bolded note to Site Plan sheet near ped tunnel: "Paved trail connections from
ToC Greenway to Yates Store Road will be designed with Yates Store Roadway plans.
Any necessary Town of Cary Greenway Easements will be dedicated at that time."
7. General Note #28 and G'way Construction Note # 23: add the spur between lots 36 &
37 to this note. Also coordinate with Wake County to complete connections to ATT.
8. Recommend relocating bollards at back of lots/property, but is not a requirement.
9. Add culvert under ToC greenway trail in eastern corner of Lot 47 or add swales to
avoid erosion of public trail from water coming down 8' trail. Email Of of this to PRCR
prior to submission of final plans.
10. Add note to the blowup on Sheet 9: "Additional drainage elements (catch basins,
trench drains) will be added during construction if needed to ensure that the tunnel
remains dry."
11. Please add an additional 25 MPH speed limit sign in the vicinity of lot 57 or 65.
12. Staffs intent on the median divided street was for it to be constructed all the way from
Yates Store Road to the first internal intersection. Please call Tammy Spivey to
discuss.
13. Sheet 16; RCP at approx sta 15+45 must be 24" above the sewer main or the sewer
main must be DIP.
14. Sheet 21, outfall B; the print for the inverts on the existing MH are not readable. Make
them readable.
15. Sheet 231 Update the standard detail utility sheets to those effective 8/23/07.
16. Related to prior comment no. 3, Sheet 7 and 8, note no. 5; It is the remaining "18that
needs to be changed to "24"".
17. Add a short note to the plan explaining that the Bio Swale is more of a water quantity
device and not a water quality device according to the design criteria.
18. The Homeowners Association declaration and covenants, and subsequent plats
submitted for the recordation of lots shall include a statement identifying the approved
individual lot clearing restriction imposed on certain lots within this development as
noted on the approved plan. Each lot submitted for a building permit shall include a
plot plan showing: the proposed dwelling location; the location and square footage of
lot area proposed to be cleared, and; the location and square footage of lot area
proposed to be preserved.
BEFORE ANY WORK CAN BEGIN ON THIS PROJECT, with exception of early grading
permits (Policy 66), you must obtain or submit the following required items to the Planning
Department:
Please submit a final master plan set (reproducible set) of the approved final plans. (Be sure
to include a copy of the letter of notification with your final master plan set
(reproducible set). The plans must include all information as shown on the original
drawings, as approved by the Development Review Committee, as well as any remaining
requirements or conditions of the approval addressed in this letter. Alterations to the plans,
beyond the scope of those indicated above, must be approved by the Town of Cary Staff
prior to incorporation into the final plans. Please submit the reproducible set to the Planner
who reviewed the plan. Each plan sheet within the final master plan set will be initialed by
staff as approved. The final master plan set will be returned to you.
All new and existing streets shown on this plan, whether public or private, must be labeled
with approved names. If you have not obtained road name approval, please contact Gina
Smith in Inspections and Permits at 460-4976.
SUBMITTAL OF CONSTRUCTION PLAN PACKAGE
After you receive the signed final master plan set you will receive a checklist outlining the
number of plans to be returned to complete the review process. All items indicated on the
checklist must be returned to the Town of Cary Planning Department prior to issuance
on any building permits.
• Town of Cary Water System Extension Permit Application
• Town of Cary Wastewater System Extension Permit Application
• Town of Cary environmental (grading) permit application
• Progress Energy Street Light Plan for Subdivisions Internal Lighting(Cary Engineering
Department, 469-4030)
• Notify the Town of Cary Engineering Department at 469-4039 that construction is about to
commence.
Please note that all plans delivered, or to be picked up, to Town Hall should go to the
Inspections & Permits Department located on the first floor of Town Hall.
Fees
PRIOR TO SUBMISSION OF THE CONSTRUCTION PACKAGE, the following fees must be
paid at the Inspections & Permits Department (refer to the attached STATEMENT OF
UTILITY INSPECTION FEES & WATER & SEWER TAP FEES):
Utility and street inspection fees
Water & sewer tap fees
Recreation payment-in-lieu (under separate cover)
Transportation Development Fees and Water & Sewer Development Fees are due prior to
the construction package submittal, and are determined by the Inspections and Permits
Department. For your reference the Water & Sewer Development Fees schedule is attached
to this letter. If you have any questions regarding Transportation Development Fees and
Water & Sewer Development Fees, please contact the Inspections and Permits Department
at [phone] or 460-4992.
If this project completes road improvements beyond a collector road design, the project
may be eligible for Transportation Development Fee reimbursement per policy statement
#99.
• Prior to the issuance of an environmental (grading) permit, a fee of $500.00 per denuded
acre must be paid.
Miscellaneous
The following must also be submitted or obtained:
• Town of Cary soil and erosion certificate of compliance (prior to issuance of building
permit)
PLEASE NOTE THE FOLLOWING SPECIAL ITEMS:
• Plan approval becomes null and void if no substantial progress is begun within two years
after the approval date. (See definition under Substantial Progress in Chapter 12 of the
Land Development Ordinance.)
• No Certificate of Occupancy may be issued until all on and off site improvements are
installed unless otherwise approved by the Planning Department.
• Signage is a separate approval process and has not been reviewed or approved as a part
of this development plan. Where applicable, you must obtain approval of a uniform sign
plan prior to the issuance of a building permit for site development plans, and prior to the
recording of lots for subdivision development plans.
Please be advised any person conducting business in the Town of Cary either by maintaining
a business location within the Town limits; personally or through agents, soliciting business
within the Town or picking up and /or delivering goods and services within the Town is
responsible for obtaining a Privilege License (Business License). For information please
call Kelli LaFrance-Girard at 919-460-4952.
Before erecting any signs on the property, you must obtain a sign permit. Please contact the
Zoning Compliance Supervisor at 469-4082 for information regarding temporary signs, or
Debra Grannan at 460-4980 regarding permanent signage.
No change can be made to the subdivision plan unless the Town of Cary Planning
Department is notified.
Pay any fees addressed in this letter and the attached Statement of Development Fees in the
Inspections & Permits Department not at the Finance Department. Please have the project
number available so the project can be identified correctly.
If you have any questions regarding the approved plan or if I can be of any assistance,
please contact me at [phone].
Very truly yours

Bob Benfield
Senior Planner
cc: David Johnson, Engineering Field Technician Supervisor
Doug McRainey, Parks, Recreation & Cultural Resources
Wayne Nicholas, Principal Planner
Wayne Mixon, Permit Administrator
Zoning Compliance Supervisor
Withers & Ravenel
Attn: Mike Schneider
111 MacKenan Drive
Cary, NC 27511
07-SB-008
STATEMENT OF UTILITY INSPECTION FEES & WATER & SEWER TAP FEES
Branston, LLC
PO Box 3006
Cary, NC
hase 2
Remit to:
Town of Cary
Inspections & Permits
PO Box 8005
Cary, NC 27512-8005
ITEM # DESCRIPTION UNIT TOTAL PRICE
PRICE
1 4,540.00 ft. of water line (Utility inspection $0.85 per $3,859.00
fee) linear foot
2 3,603.00 ft. of sewer line [gravity or force $0.85 per $3,062.55
main] linear foot
(Utility inspection fee)
3 4,946.00 ft. of street construction $1.60 per $15,827.20
(Street inspection fee) linear foot
per lane
4 Water & sewer tap fees (72 water, 72 $50.00 per $7,200.00
sewer) tap
TOTAL AMOUNT DUE: $29,948.75
INSPECTIONS & PERMITS DEPARTMENT
The commercial building permit process is a completely separate process from the site plan
approval process.
The following items must be submitted to the Inspections and Permits Department to obtain
your building permit:
1. Completed application (available in the Inspections & Permits Department)
2. Four (4) complete sets of building plans including plumbing, mechanical and electrical.
3. One (1) set of approved site plans showing all site utilities including plumbing, mechanical
and electrical.
4. Water system calculations. (GPM)
5. Sewer flow calculations. (GPD)
6. Grease interceptors or oil separators must be approved by the Town's Utility Pre-
Treatment Coordinator. (919-462-3871)
7. Complete Appendix "B" from State Building Code.
8. Minimum plumbing facilities calculations shown on plan per table 407 of volume Il.
1.-
S
AIIcPROCHLAM
8, 2008
Glen Futrell
Branston LLC
150 Towerview Court
Cary, NC 27513 Expiration of Acceptance: October 8, 2008
Project: Montvale Subdivision
County: Chatham
The purpose of this letter is to notify you that the North Carolina Ecosystem Enhancement Program (NCEEP) is willing to
accept payment for impacts associated with the above referenced project. Please note that this decision does not assure that
the payment will be approved by the permit issuing agencies as mitigation for project impacts. It is the responsibility of the
applicant to contact these agencies to determine if payment to the NCEEP will be approved.
This acceptance is valid for six months from the date of this letter and is not transferable. If we have not received a copy of
the issued 404 Permit/401 Certification/CAMA permit within this time frame, this acceptance will expire. It is the
applicant's responsibility to send copies of the permits to NCEEP. Once NCEEP receives a copy of the permit(s) an invoice
will be issued based on the required mitigation in that permit and payment must be made prior to conducting the authorized
work. The amount of the In Lieu Fee to be paid to NCEEP by an applicant is calculated based upon the Fee Schedule and
policies listed at www.nceep.net.
Based on the information supplied by you the impacts that may require compensatory mitigation are summarized in the
following table.
Neuse
03030003 Stream (feet) Wetlands (acres) Buffer I
(Sq. Ft.) Buffer II
(Sq. Ft.)
Cold Cool Warm Riparian Non-Riparian Coastal Marsh
Impacts 0 0 290 0 0 0 0 0
Credits 0 0 580 0 0 0 0 0
Upon receipt of payment, EEP will take responsibility for providing the compensatory mitigation. If the regulatory agencies
require mitigation credits greater than indicated above, and the applicant wants NCEEP to be responsible for the additional
mitigation, the applicant will need to submit a mitigation request to NCEEP for approval prior to permit issuance. The
mitigation will be performed in accordance with the Memorandum of Understanding between the N. C. Department of
Environment and Natural Resources and the U. S. Army Corps of Engineers dated November 4, 1998.
If you have any questions or need additional information, please contact Valerie Mitchener at [phone].
Sincerely,
William . Gilmore, PE
Director
cc: Cyndi Karoly, NCDWQ Wetlands/401 Unit
Monte Matthews, USACE-Raleigh
Eric Kulz, NCDWQ-Raleigh
Todd Preuninger, agent
File

aAAk-W &-U

North Carolina Ecosystem Enhancement Program, 1652 Mail Service Center, Raleigh, NC 27699-1652 / 919-715-0476 / www.neeep.net
q4

ENGINEERING DEPARTMENT
March 16, 2007
Todd Preuninger
Withers and Ravenel
1 i 1 MacKenan Drive
Cary, NC 27511
O1q
'fd
L
Subject: Jordan Lake Watershed
Riparian Buffer Rules
Weldon Ridge LID Site
TCRB 07-002-
Dear Mr. Preuninger:
The site location map and other information that was provided, allowed a determination to be made as to whether or not the
referenced site would require compliance with The Town of Cary Riparian Buffer Rules. This project is referenced by the
Town of Cary as TCRB 07-002. Three stream features (A, B, C) are indicated on the Wake County Soil Survey, and one
feature (C) is indicated on the USGS Green Level Quadrangle. On March 5, 2007 Town of Cary staff completed a site visit
and determined that features A (Flag 100), B (Flag 101) and C are subject to protection under the Stormwater Management
Plan: Protecting Riparian Buffers, Town of Cary LDO - 7.3.2. This stream determination is valid until March 5, 2012. This
letter only addresses Town of Cary Buffer Rules at the referenced site.
Thank you for your attention to this matter and if this office can be of any assistance or if you have additional questions,
please do not hesitate to contact us.
Sincerel
Matthew Fly
Town of Cary Engineering Department
Cc: Stormwater Section/Tom Horstman
C: TCRB07002.doc
TOWN Of CARY
318 North Academy Street *Cary, NC 27513•PO Box 8005-Cary, NC 27512-8005
te1919-469-4030 0 fax [phone]• www.townofcary.org
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WITHERS RAVENEL
ENGINEERS 1 PLANNERS I SURVEY012S
Site Access/Agent Authorization Form
ow va?? S ??.? :?:s'.o?
Project Name:
Property Owner/Contract Purchaser: 172r -^Z. h LL-
Address: C .= 6, ke ter. F ? r ilk
1S0 0WC"U +E.W Vavj
Phone: S3Ss
Fax: O?. (e
Email: 6FU77-67-t- Ca JLGCo1zP, core,.
I hereby grant Withers and Ravenel, INC permission to conduct environmental
studies on the property described above. In addition, I authorize Withers and
Ravenel to act on my behalf as my agent when conducting site meetings and/or
correspondence (i.e. permit applications etc.) with the USACE and the NC - Division
of Water Quality, if necessary.
Property Owner: 6LExrJ FUT ELL. Date: x'36-O?i
. (Print Name)
(Signature)
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WITHERS RAVENEL % •I r
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ENGINEERS I PLANNERS ? ]URVEYURS I ? p 1/? ?. ? t•h C \ ,•/
111 MacKenan Drive Cary, North Carolina
telephone' 919.469.3340 www.withersravenel.com
0 1,000 2,000 4,000
Feet
1 inch equals 2,000 feet
K904104-4001044091 isiWetiandstUSGS.mxd
FROM
Mgr.: TP
?''? Figure 2- Soil Survey
1 Date:
WOW WO Forest Oaks
Glen Futrell
Wake and ChathamCounties
NC
Sheets K2, 25, and 45
(TUE)OCT 10 2006 9:09/ST. 9:04/No.7500000072 P 10
Soil & Environmental Consultants, PA
11010 Raven Ridge Rd.° Raleigh, NC 27614
[phone] ° [phone]
Web Page: www.SandEC.com
DATA FORM
ROUTINE WETLAND DETERMINATION
(1987 COE Wetlands Determination Manual)
Project/Site: W&R Project # 02040409 _ Date:
Applicant/ Owner: Branston LLC County: Wake
State: NC
Investigator: TP
Do normal circumstances exist on the site? Yes No ?
Is the site significantly disturbed (Atypical situation)? Yes ? No Z

Is the area a potential problem area? Yes
?
No Community ID

(explain on reverse if needed) Mixed Pine HWD
Transect ID: -
PlotID:
VEGETATION
Dominant Plant Species Stratum Indicator Dominant Plant Species Stratum Indicator
1. Pinus taeda Tree FAC 9.
2. Liriodendron tulipifera Tree FAC 10.
3. Juniperus virginiana Tree FACU- 11.
4. Acer rubrum Tree FAC 12.
5. 13.
6. 14.

8. 16.
Percent of Dominant Species that are OBL, FACW, or FAC excluding FAC ). 75
Remarks:
Hydrophytic Vegetation Present
HYDROLOGY
? Recorded Data (Describe In Remarks): Wetland Hydrology Indicators
? Stream, Lake, or Tide Gauge
? Aerial Photographs Primary Indicators:
? Other ? Inundated
Saturated in Upper 12"
No Recorded Data Available ? Water Marks
? Drift Lines
Field Observations: ? Sediment Deposits
? Drainage Patterns in Wetlands
Depth of Surface Water. NA (in.)
Secondary Indicators:
Depth to Free Water in Pit: >12 (in.) ? Oxidized Roots Channels in Upper 12"
? Water-Stained Leaves
Depth to Saturated Soil: > 12 (in.) ? Local Soil Survey Data
[] FAC-Neutral Test
? Other (Explain in Remarks)
Remarks: Hydrology Indicators Absent
SOILS
Map Unit Name
(Series and Phase): White Store SL Drainage Class: Moderate
Taxonomy (Subgroup): Topic hapludults Confirm Mapped Type? YesQ No[]
Profile Description:
Depth Matrix Colors Mottle Colors Mottle Texture, Concretions,
(inches) Horizon (Munsell Moist) (Munsell Moist) Abundance/Contrast Structure, etc.
0-5 10 YR 6/4
5-12+ 10 YR 5/4

Hydric Soil Indicators:
Histosol ? Concretions
a Histic Epipedon ? High Organic Content in Surface Layer in Sandy Soils
n Sulfidic Odor F1 Organic Streaking in Sandy Soils
[1 Aquic Moisture Regime QListed On Local Hydric Soils List
Reducing Conditions Listed on National Hydric Soils List
Q Gleyed or Low-Chroma Colors II Other (Explain in Remarks)
Remarks:
Hydric Soils Absent
WETLAND DETERMINATION
Hydrophytic Vegetation Present? Yes M
Wetland Hydrology Present? Yes Q
Hydric Soils Present? Yes a
No Q Is the Sampling Point
No ED Within a Wetland? YesQ NoE
No El
Remarks:

APPROVED JURISDICTIONAL DETERMINATION FORM
U.S. Army Corps of Engineers
This form should be completed by following the instructions provided in Section IV of the JD Form Instructional Guidebook.
SECTION E BACKGROUND INFORMATION
A. REPORT COMPLETION DATE FOR APPROVED JURISDICTIONAL DETERMINATION (JD):
B. DISTRICT OFFICE, FILE NAME, AND NUMBER:
C. PROJECT LOCATION AND BACKGROUND INFORMATION:
State: NC County/parish/borough: Wake/Chatham City: Cary
Center coordinates of site (]at/long in degree decimal format): Lat. 35.8063109° , Long. 78.9265739°W.
Universal Transverse Mercator:
Name of nearest waterbody: Indian Creek
Name of nearest Traditional Navigable Water (TNW) into which the aquatic resource flows: Cape Fear River
Name of watershed or Hydrologic Unit Code (HUC): 03030002
Check if map/diagram of review area and/or potential jurisdictional areas is/are available upon request.
Check if other sites (e.g., offsite mitigation sites, disposal sites, etc... ) are associated with this action and are recorded on a
different JD form.
D. REVIEW PERFORMED FOR SITE EVALUATION (CHECK ALL THAT APPLY):
Office (Desk) Determination. Date:
Field Determination. Date(s):
SECTION II: SUMMARY OF FINDINGS
A. RHA SECTION 10 DETERMINATION OF JURISDICTION.
There ,appear to be no "navigable waters of the U.S." within Rivers and Harbors Act (RHA) jurisdiction (as defined by 33 CFR part 329) in
the review area. [Required]
Waters subject to the ebb and flow of the tide.
? Waters are presently used, or have been used in the past, or may be susceptible for use to transport interstate or foreign commerce.
Explain:
B. CWA SECTION 404 DETERMINATION OF JURISDICTION.
There Are "waters of the U.S." within Clean Water Act (CWA) jurisdiction (as defined by 33 CFR part 328) in the review area. [Required]
Waters of the U.S.
a. Indicate presence of waters of U.S. in review area (check all that apply): t
? TNWs, including territorial seas
? Wetlands adjacent to TNWs
® Relatively permanent waters2 (RPWs) that flow directly or indirectly into TNWs
? Non-RPWs that flow directly or indirectly into TNWs
? Wetlands directly abutting RPWs that flow directly or indirectly into TNWs
? Wetlands adjacent to but not directly abutting RPWs that flow directly or indirectly into TNWs
? Wetlands adjacent to non-RPWs that flow directly or indirectly into TNWs
? Impoundments of jurisdictional waters
? Isolated (interstate or intrastate) waters, including isolated wetlands
b. Identify (estimate) size of waters of the U.S. in the review area:
Non-wetland waters: 400 linear feet: 3 width (ft) and/or NA acres.
Wetlands: acres.
c. Limits (boundaries) of jurisdiction based on: 1987 Delineation Marl"
Elevation of established OHWM (if known):
2. Non-regulated waters/wetlands (check if applicable):3
Potentially jurisdictional waters and/or wetlands were assessed within the review area and determined to be not jurisdictional.
Explain:
' Boxes checked below shall be supported by completing the appropriate sections in Section Ill below.
Z For purposes of this form, an RPW is defined as a tributary that is not a TN W and that typically flows year-round or has continuous flow at least "seasonally"
(e.g., typically 3 months).
s Supporting documentation is presented in Section HIT.
I
SECTION III: CWA ANALYSIS
A. TNWs AND WETLANDS ADJACENT TO TNWs
The agencies will assert jurisdiction over TNWs and wetlands adjacent to TNWs. If the aquatic resource is a TNW, complete
Section III.A.1 and Section III.D.1. only; if the aquatic resource is a wetland adjacent to a TNW, complete Sections III.A.l and 2
and Section 111.D.1.; otherwise, see Section III.B below.
TN W
Identify TNW: NA.
Summarize rationale supporting determination:
Wetland adjacent to TNW
Summarize rationale supporting conclusion that wetland is "adjacent": NA.
B. CHARACTERISTICS OF TRIBUTARY (THAT IS NOT A TNW) AND ITS ADJACENT WETLANDS (IF ANY):
This section summarizes information regarding characteristics of the tributary and its adjacent wetlands, if any, and it helps
determine whether or not the standards for jurisdiction established under Rapanos have been met.
The agencies will assert jurisdiction over non-navigable tributaries of TNWs where the tributaries are "relatively permanent
waters" (RPWs), i.e. tributaries that typically flow year-round or have continuous flow at least seasonally (e.g., typically 3
months). A wetland that directly abuts an RPW is also jurisdictional. If the aquatic resource is not a TNW, but has year-round
(perennial) flow, skip to Section III.D.2. If the aquatic resource is a wetland directly abutting a tributary with perennial flow,
skip to Section III.D.4.
A wetland that is adjacent to but that does not directly abut an RPW requires a significant nexus evaluation. Corps districts and
EPA regions will include in the record any available information that documents the existence of a significant nexus between a
relatively permanent tributary that is not perennial (and its adjacent wetlands if any) and a traditional navigable water, even
though a significant nexus finding is not required as a matter of law.
If the waterbody4 is not an RPW, or a wetland directly abutting an RPW, a JD will require additional data to determine if the
waterbody has a significant nexus with a TNW. If the tributary has adjacent wetlands, the significant nexus evaluation must
consider the tributary in combination with all of its adjacent wetlands. This significant nexus evaluation that combines, for
analytical purposes, the tributary and all of its adjacent wetlands is used whether the review area identified in the JD request is
the tributary, or its adjacent wetlands, or both. If the JD covers a tributary with adjacent wetlands, complete Section III.B.1 for
the tributary, Section III.B.2 for any onsite wetlands, and Section III.B3 for all wetlands adjacent to that tributary, both onsite
and offsite. The determination whether a significant nexus exists is determined in Section III.C below.
1. Characteristics of non-TNWs that flow directly or indirectly into TNW
(i) General Area Conditions:
Watershed size: acres
Drainage area: acres
Average annual rainfall: inches
Average annual snowfall: inches
(ii) Physical Characteristics:
(a) Relationship with TNW:
? Tributary flows directly into TNW.
? Tributary flows through Pick List tributaries before entering TNW.
Project waters are Pick List river miles from TNW.
Project waters are Pick List river miles from RPW.
Project waters are Pick List aerial (straight) miles from TNW.
Project waters are Pick List aerial (straight) miles from RPW.
Project waters cross or serve as state boundaries. Explain: NA.
Identify flow route to TNW5:
Tributary stream order, if known:
a Note that the Instructional Guidebook contains additional information regarding swales, ditches, washes, and erosional features generally and in the and
West.
Flow route can be described by identifying, e.g., tributary a, which flows through the review area, to flow into tributary b, which then flows into TNW.
(b) General Tributary Characteristics (check all that apply):
Tributary is: ? Natural
? Artificial (man-made). Explain:
? Manipulated (man-altered). Explain:
Tributary properties with respect to top of bank (estimate):
Average width: feet
Average depth: feet
Average side slopes: Pick Lid.
Primary tributary substrate composition (check all that apply):
? Silts ® Sands ? Concrete
? Cobbles ? Gravel ? Muck
? Bedrock ? Vegetation. Type/%cover:
? Other. Explain:
Tributary condition/stability [e.g., highly eroding, sloughing banks]. Explain:
Presence of run/riffle/pool complexes. Explain:
Tributary geometry: Pick List
Tributary gradient (approximate average slope): %
(c) Flow:
Tributary provides for: Pick M
Estimate average number of flow events in review area/year: Pick List
Describe flow regime:
Other information on duration and volume:
Surface flow is: Pick List. Characteristics:
Subsurface flow: Pick List. Explain findings:
? Dye (or other) test performed:
Tributary has (check all that apply):
? Bed and banks
? OHWM6 (check all indicators that apply):
? clear, natural line impressed on the bank ?
? changes in the character of soil ?
? shelving ?
? vegetation matted down, bent, or absent ?
? leaf litter disturbed or washed away ?
? sediment deposition ?
? water staining ?
? other (list):
the presence of litter and debris
destruction of terrestrial vegetation
the presence of wrack line
sediment sorting
scour
multiple observed or predicted flow events
abrupt change in plant community
E] Discontinuous OHWM.' Explain:
If factors other than the OHWM were used to determ
High Tide Line indicated by:
? oil or scum line along shore objects
? fine shell or debris deposits (foreshore)
? physical markings/characteristics
? tidal gauges
? other (list):
ine lateral extent of CWA jurisdiction (check all that apply):
Mean High Water Mark indicated by-
El survey to available datum;
? physical markings;
? vegetation lines/changes in vegetation types.
(iii) Chemical Characteristics:
Characterize tributary (e.g., water color is clear, discolored, oily film; water quality; general watershed characteristics, etc.).
Explain:
Identify specific pollutants, if known:
6A natural or man-made discontinuity in the OHWM does not necessarily sever jurisdiction (e.g., where the stream temporarily flows underground, or where
the OHWM has been removed by development or agricultural practices). Where there is a break in the OHWM that is unrelated to the waterbody's flow
regime (e.g., flow over a rock outcrop or through a culvert), the agencies will look for indicators of flow above and below the break.
'Ibid.
r
For each wetland, specify the following:
Directly abuts? (Y/N) Size (in acres) Directly abuts? (Y/N) Size (in acres)
Summarize overall biological, chemical and physical functions being performed:
C. SIGNIFICANT NEXUS DETERMINATION
A significant nexus analysis will assess the flow characteristics and functions of the tributary itself and the functions performed
by any wetlands adjacent to the tributary to determine if they significantly affect the chemical, physical, and biological integrity
of a TNW. For each of the following situations, a significant nexus exists if the tributary, in combination with all of its adjacent
wetlands, has more than a speculative or insubstantial effect on the chemical, physical and/or biological integrity of a TNW.
Considerations when evaluating significant nexus include, but are not limited to the volume, duration, and frequency of the flow
of water in the tributary and its proximity to a TNW, and the functions performed by the tributary and all its adjacent
wetlands. It is not appropriate to determine significant nexus based solely on any specific threshold of distance (e.g. between a
tributary and its adjacent wetland or between a tributary and the TNW). Similarly, the fact an adjacent wetland lies within or
outside of a floodplain is not solely determinative of significant nexus.
Draw connections between the features documented and the effects on the TNW, as identified in the Rapanos Guidance and
discussed in the Instructional Guidebook. Factors to consider include, for example:
• Does the tributary, in combination with its adjacent wetlands (if any), have the capacity to carry pollutants or flood waters to
TN Ws, or to reduce the amount of pollutants or flood waters reaching a TNW?
• Does the tributary, in combination with its adjacent wetlands (if any), provide habitat and lifecycle support functions for fish and
other species, such as feeding, nesting, spawning, or rearing young for species that are present in the TNW?
• Does the tributary, in combination with its adjacent wetlands (if any), have the capacity to transfer nutrients and organic carbon that
support downstream foodwebs?
• Does the tributary, in combination with its adjacent wetlands (if any), have other relationships to the physical, chemical, or
biological integrity of the TNW?
Note: the above list of considerations is not inclusive and other functions observed or known to occur should be documented
below:
Significant nexus findings for non-RPW that has no adjacent wetlands and flows directly or indirectly into TNWs. Explain
findings of presence or absence of significant nexus below, based on the tributary itself, then go to Section III.D:
Significant nexus findings for non-RPW and its adjacent wetlands, where the non-RPW flows directly or indirectly into
TNWs. Explain findings of presence or absence of significant nexus below, based on the tributary in combination with all of its
adjacent wetlands, then go to Section III.D:
Significant nexus findings for wetlands adjacent to an RPW but that do not directly abut the RPW. Explain findings of
presence or absence of significant nexus below, based on the tributary in combination with all of its adjacent wetlands, then go to
Section III.D:
D. DETERMINATIONS OF JURISDICTIONAL FINDINGS. THE SUBJECT WATERS/WETLANDS ARE (CHECK ALL
THAT APPLY):
TNWs and Adjacent Wetlands. Check all that apply and provide size estimates in review area:
TN Ws: linear feet width (ft), Or, acres.
d Wetlands adjacent to TNWs: acres.
RPWs that flow directly or indirectly into TNWs.
Tributaries of TNWs where tributaries typically flow year-round are jurisdictional. Provide data and rationale indicating that
tributary is perennial:
Tributaries of TNW where tributaries have continuous flow "seasonally" (e.g., typically three months each year) are
jurisdictional. Data supporting this conclusion is provided at Section III.B. Provide rationale indicating that tributary flows
seasonally:

(iv) Biological Characteristics. Channel supports (check all that apply):
? Riparian condor. Characteristics (type, average width):
? Wetland fringe. Characteristics:
? Habitat for:
? Federally Listed species. Explain findings:
? Fish/spawn areas. Explain findings:
? Other environmentally-sensitive species. Explain findings:
? Aquatic/wildlife diversity. Explain findings:
2. Characteristics of wetlands adjacent to non-TNW that flow directly or indirectly into TNW
(i) Physical Characteristics:
(a) General Wetland Characteristics:
Properties:
Wetland size: acres
Wetland type. Explain:
Wetland quality. Explain:
Project wetlands cross or serve as state boundaries. Explain:
(b) General Flow Relationship with Non-TNW:
Flow is: Pick List. Explain:
Surface flow is: Pick List
Characteristics:
Subsurface flow: Pick List. Explain findings:
? Dye (or other) test performed:
(c) Wetland Adjacency Determination with Non-TNW:
? Directly abutting
? Not directly abutting
? Discrete wetland hydrologic connection. Explain:
? Ecological connection. Explain:
? Separated by berm/barrier. Explain:
(d) Proximity (Relationship) to TNW
Project wetlands are Pick List river miles from TNW.
Project waters are Pick List aerial (straight) miles from TNW.
Flow is from: Pick List.
Estimate approximate location of wetland as within the Pick List floodplain.
(ii) Chemical Characteristics:
Characterize wetland system (e.g., water color is clear, brown, oil film on surface; water quality; general watershed
characteristics; etc.). Explain:
Identify specific pollutants, if known:
(iii) Biological Characteristics. Wetland supports (check all that apply):
? Riparian buffer. Characteristics (type, average width):
? Vegetation type/percent cover. Explain:
? Habitat for:
? Federally Listed species. Explain findings:
? Fish/spawn areas. Explain findings:
? Other environmentally-sensitive species. Explain findings:
? Aquatic/wildlife diversity. Explain findings:
3. Characteristics of all wetlands adjacent to the tributary (if any)
All wetland(s) being considered in the cumulative analysis: Pick List
Approximately ( ) acres in total are being considered in the cumulative analysis.
Provide estimates for jurisdictional waters in the review area (check all that apply):
Tributary waters: linear feet width (ft).
Other non-wetland waters: acres.
Identify type(s) of waters:
Non-RPWss that flow directly or indirectly into TNWs.
Waterbody that is not a TNW or an RPW, but flows directly or indirectly into a TNW, and it has a significant nexus with a
TNW is jurisdictional. Data supporting this conclusion is provided at Section III.C.
Provide estimates for jurisdictional waters within the review area (check all that apply):
[ Tributary waters: linear feet width (R).
? Other non-wetland waters: acres.
Identify type(s) of waters:
4. Wetlands directly abutting an RPW that flow directly or indirectly into TNWs.
? Wetlands directly abut RPW and thus are jurisdictional as adjacent wetlands.
Wetlands directly abutting an RPW where tributaries typically flow year-round. Provide data and rationale
indicating that tributary is perennial in Section III.D.2, above. Provide rationale indicating that wetland is
directly abutting an RPW:
Wetlands directly abutting an RPW where tributaries typically flow "seasonally." Provide data indicating that tributary is
seasonal in Section 111.13 and rationale in Section III.D.2, above. Provide rationale indicating that wetland is directly
abutting an RPW:
Provide acreage estimates for jurisdictional wetlands in the review area: acres.
5. Wetlands adjacent to but not directly abutting an RPW that flow directly or indirectly into TNWs.
Wetlands that do not directly abut an RPW, but when considered in combination with the tributary to which they are adjacent
and with similarly situated adjacent wetlands, have a significant nexus with a TNW are jurisidictional. Data supporting this
conclusion is provided at Section III.C.
Provide acreage estimates for jurisdictional wetlands in the review area: acres.
Wetlands adjacent to non-RPWs that flow directly or indirectly into TNWs.
? Wetlands adjacent to such waters, and have when considered in combination with the tributary to which they are adjacent and
with similarly situated adjacent wetlands, have a significant nexus with a TNW are jurisdictional. Data supporting this
conclusion is provided at Section III.C.
Provide estimates for jurisdictional wetlands in the review area: acres.
Impoundments of jurisdictional waters.9
As a general rule, the impoundment of a jurisdictional tributary remains jurisdictional.
El. Demonstrate that impoundment was created from "waters of the U.S.," or
Demonstrate that water meets the criteria for one of the categories presented above (1-6), or
? Demonstrate that water is isolated with a nexus to commerce (see E below).
E. ISOLATED (INTERSTATE OR INTRA-STATE] WATERS, INCLUDING ISOLATED WETLANDS, THE USE,
DEGRADATION OR DESTRUCTION OF WHICH COULD AFFECT INTERSTATE COMMERCE, INCLUDING ANY
SUCH WATERS (CHECK ALL THAT APPLY):"
? which are or could be used by interstate or foreign travelers for recreational or other purposes.
? from which fish or shellfish are or could be taken and sold in interstate or foreign commerce.
? which are or could be used for industrial purposes by industries in interstate commerce.
? Interstate isolated waters. Explain:
? Other factors. Explain:
Identify water body and summarize rationale supporting determination:
"See Footnote # 3.
9 To complete the analysis refer to the key in Section 11I.D.6 of the Instructional Guidebook.
10 Prior to asserting or declining CWA jurisdiction based solely on this category, Corps Districts will elevate the action to Corps and EPA HQ for
review consistent with the process described in the Corps/EPA Memorandum Regarding CWA Act Jurisdiction Following Rapanos:
1
Provide estimates for jurisdictional waters in the review area (check all that apply):
? Tributary waters: linear feet width (ft).
Other non-wetland waters: acres-
Identify type(s) of waters:
Wetlands: acres.
F. NON-JURISDICTIONAL WATERS, INCLUDING WETLANDS (CHECK ALL THAT APPLY):
If potential wetlands were assessed within the review area, these areas did not meet the criteria in the 1987 Corps of Engineers
Wetland Delineation Manual and/or appropriate Regional Supplements.
Review area included isolated waters with no substantial nexus to interstate (or foreign) commerce.
? Prior to the Jan 2001 Supreme Court decision in "SWANCC," the review area would have been regulated based solely on the
"Migratory Bird Rule" (MBR).
Waters do not meet the "Significant Nexus" standard, where such a finding is required for jurisdiction. Explain:
Other: (explain, if not covered above):
Provide acreage estimates for non jurisdictional waters in the review area, where the sole potential basis of jurisdiction is the MBR
factors (i.e., presence of migratory birds, presence of endangered species, use of water for irrigated agriculture), using best professional
judgment (check all that apply):
Non-wetland waters (i.e., rivers, streams): linear feet width (ft).
? Lakes/ponds: acres.
? Other non-wetland waters: acres. List type of aquatic resource:
? Wetlands: acres.
Provide acreage estimates for non-jurisdictional waters in the review area that do not meet the "Significant Nexus" standard, where such
a finding is required for jurisdiction (check all that apply):
[] Non-wetland waters (i.e., rivers, streams): linear feet, width (ft).
? Lakes/ponds: acres.
Other non-wetland waters: acres. List type of aquatic resource:
Wetlands: acres.
SECTION IV: DATA SOURCES.
A. SUPPORTING DATA. Data reviewed for JD (check all that apply - checked items shall be included in case file and, where checked
and requested, appropriately reference sources below):
Maps, plans, plots or plat submitted by or on behalf of the applicant/consultant:
Data sheets prepared/submitted by or on behalf of the applicant/consultant.
? Office concurs with data sheets/delineation report.
? Office does not concur with data sheets/delineation report.
? Data sheets prepared by the Corps.
? Corps navigable waters' study:
? U.S. Geological Survey Hydrologic Atlas:
? USGS NHD data.
? USGS 8 and 12 digit HUC maps.
ED U.S. Geological Survey map(s). Cite scale & quad name: Quad.
ER USDA Natural Resources Conservation Service Soil Survey. Citation: .
? National wetlands inventory map(s). Cite name:
? State/Local wetland inventory map(s):
? FEMA/FIRM maps:
? 100-year Floodplain Elevation is: (National Geodectic Vertical Datum of 1929)
? Photographs: ? Aerial (Name & Date):
or ? Other (Name & Date):
? Previous determination(s). File no. and date of response letter:
? Applicable/supporting case law:
? Applicable/supporting scientific literature:
? Other information (please specify):
B. ADDITIONAL COMMENTS TO SUPPORT JD: This form is for the perennial stream which is impacted by a road crossing and for
Indian Creek which a sewer line installation will be termporary impacting.
WITHERS RAVEN EL
STORMWATER MANAGEMENT
PLAN
Montvale Phase 11
Cary, North Carolina
Prepared For:
BRANSTON, LLC
PO Box 30o6
Cary NC 27519
Prepared By:
WITHERS & RAVENEL, INC
111 MacKenan Drive
Cary, North Carolina 27511
June 2007
Revised August 2007
Revised September 2007
W&R Project No. 2040409.1
k CAR
?n??.??
Q? $
63
1, s
5tephanie A. Hall, PE
MONTVALE PHASE II
STORMWATER MANAGEMENT PLAN
CARY, NORTH CAROLINA
INTRODUCTION
Montvale Phase II is a ±52-acre site in the Jordan Lake Watershed in Cary. The development was
chosen to be the first Low Impact Development (LID) site in Cary and is being used as a pilot study
by the town staff. The overall goal of Low Impact Development is to minimize structural BMPs such
as large detention ponds and disperse smaller BMPs throughout the site closer to the source of
runoff. These dispersed BMPs are meant to mimic the pre-development hydrologic regime by
treating stormwater close to the source and maximizing infiltration wherever possible.
The purpose of this study is to document pre- and post-development peak stormwater discharges
for the i-year storm event and to evaluate the affect of the lo-year design storm for erosion control
purposes on the proposed stormwater management devices that required routing analyses. The
goal is to use a Low Impact Development strategy to provide best management practices (BMPs)
adequate to maintain a discharge less than or equal to the 1-year pre-development peak discharges
after the site has been developed.
There are several stormwater Best Management Practice (BMP) proposed for the site to meet peak
attenuation requirements. This includes two bioretention basins, grassed swales within the right-
Montvale Phase II 1 W&R Project 2040409.1
Stormwater Management Report September 2007
Figure i. Site outlined in red on 2005 Aerial Photograph.
MONTVALE PHASE II
STORMWATER MANAGEMENT PLAN
CARY, NORTH CAROLINA
of-way with check dams to provide storage and infiltration, and a bio-swale with check dams
adjacent to the greenway trail.
The proposed bioretentions were sized per DWQ standards although we are not claiming nutrient
removal credit for the devices. The grassed swales within the right-of-way are used for conveyance
of the io-year storm per typical roadway drainage design standards. However, they were widened
and flattened to provide storage opportunity for a portion of the i-year design storm. Check dams
are provided every ioo feet of Swale for this storage. Small weep holes are designed as part of the
check dam system to prevent extended periods of standing water in the ditches. The bio-swale is an
adaptation of the bioretention system. The design below the surface is exactly the same as a
bioretention system. However, this bio-swale surface will be covered in grass sod instead of mulch.
Check dams are proposed intermittently to provide adequate infiltration through the bio-swale.
METHODOLOGY
The stormwater study was conducted using the natural drainage features as depicted by the Wake
County aerial topographic information (2-ft contours), field survey data and proposed development
within the drainage areas. The scope of work included the following analyses:
Hydrolol;y
? Simulation of the i-year and io-year rainfall events for the Cary area.
? Formulation of the i-year and io-year peak flows for the pre- and post-development
conditions of the site.
Hydraulic
? Modifying i-year and io-year post-development peak flows to account for storage
provided by proposed BMPs.
The results of the hydrologic calculations are used in the hydraulic analyses for the design of the
BMPs.
HYDROLOGY
The SCS Method was used to develop runoff hydrographs for the 24-hour duration, i-year storm
event in the Cary area.
Curve numbers were based on soil type and land use. Soil types were delineated from the Soil
Survey of Wake County, North Carolina (November 1970). Land use for all conditions was based on
the most recent site plans for the proposed site. The curve numbers used in this study are listed in
the appendix of this report.
Times of concentration were calculated using methods described in the SCS publication "Urban
Hydrology for Small Watersheds, TR-55" and based on proposed site plans and field survey data.
HYDRAuucs
For the pre- and post-development 1-year design storm calculations - the cumulative storage of the
bioretentions, grassed swales, and bio-swale were used to adjust the post-development curve
number by applying the equation from the Maryland Dept of Environment guidance for "Modeling
Infiltration Practices using TR-20." This equation adjusts the post-development curve number and
therefore reflects the post-development runoff after infiltration and storage devices are applied.
Montvale Phase II 2 W&R Project 2040409.1
Stormwater Management Report September 2007
MONTVALE PHASE II
STORMWATER MANAGEMENT PLAN
CARY, NORTH CAROLINA
Since the curve number adjustment is relative to the precipitation depth for each design storm,
different adjusted curve numbers were determined for the i-year and zo-year storms. The final post-
development peak flows were calculated using this adjusted curve number.
CONCLUSIONS
Based on the hydrologic study, the post development peak discharge from the entire site is less
than or equal to the pre-development peak for the z-year design storm. The section in the appendix
entitled "Hydrologic Calculations" provides the pre- and post- development discharges as well as
the supporting calculations. Design details are located in the construction drawings.
The post development nitrogen export for this parcel is below the 3.6 lbs/ac/yr and therefore meets
the nitrogen rules for the Town of Cary in the Cape Fear River Basin. The nitrogen export calculations
are provided in an appendix to this report.
Montvale Phase II 3 W&R Project 2040409.1
Stormwater Management Report September 2007
HYDROLOGIC
CALCULATIONS
Stormwater Management Plan
Montvale Phase 2
Project No.: 2040409
Date: 7/31 /2007
Withers & Ravenel Designer: SAH
PRE-DEVELOPMENT CALCULATIONS
ICURVE NUMBER:
User Definec
User Definec
User Definec
User Definec
HSG Land-use CN Area acres %
C Pasture or Open Space, Good Cond. 74 4.63 8.95%
C Impervious 98 0.9 1.74%
C Woods, Good Cond. 70 46.19 89.31%
98
98
98
98
98
98
98
98
98

Totals: 51.72 100.00%
Pre-development CN = 71
1-year Storm Runoff (inches) = Q" = 0.76 inches
(TIME OF CONCENTRATION:
Sheet Flow:
Sheet Flow:
Shallow Flow:
Shallow Flow:
Channel Flow:
Channel Flow:
Length (ft) Slope (ft/ft) Surface Cover Tt (hrs)
100 0.06 Grass 0.14

605 L.063 Unpaved 0.04
__J __

Length (ft)
Slope (ft/ft)
n-value Flow
Area (ft 2)
Wetted Perimeter (ft)
Tt (hrs)
2570 0.0144 0.065 9.0 9.0 0.26

Pre-development Tc = 0.45 hrs
Stormwater Management Plan Project No.: 2040409
Montvale Phase 2 Date: 7/31/2007
Withers & Ravenel Designer: SAH
POST-DEVELOPMENT CALCULATIONS
ICURVE NUMBER:
Total Area of Lots: 33.3 acres
Number of Lots: 72
Impervious Area per Lot: 7000 sf
% Impervious on Lots: 34.75%
% Woods on Lots: 35%
Percent Impervious for Site: 28.64 %
Percent Total Impervious that is Disconnected: 85 %
HSG Land-use CN Area acres %
C Impervious 98 3.24 6.26%
C Open Space 74 3.79 7.33%
C Lots 81 33.3 64.39%
C Woods 70 11.39 22.02%

Totals: 51.72 100.00%
Post-Development CN = 75
1-year Storm Runoff (inches) = Q* = 0.96 inches
Stormwater Management Plan Project No.: 2040409
Montvale Phase 2 Date: 7/31/2007
Withers & Ravenel Designer: SAH
POST-DEVELOPMENT CALCULATIONS
E OF CONCENTRATION:
Sheet Flow:
Sheet Flow:
Shallow Flow:
Shallow Flow:
Channel Flow
Channel Flow
Length (ft) Slope (ft/ft) Surface Cover Tt (hrs)
100 0.06 Grass 0.14

605 0.0628 Unpaved 0.04

Length (ft)
Slope (ft/ft)
n-value Flow
Area (ft)
Wetted Perimeter (ft)
Tt (hrs)
2570 0.0144 0.065 9.0 9.0 0.26

Post-development Tc = 0.45 hrs
Stormwater Management Plan
Montvale Phase 2
Withers & Ravenel Project No.: 2040409
Date: 7/31/2007
Designer: SAH
PROPOSED STORAGE DEVICES
Storage Volume
Name/Location Type of Device Provided (ft) Additional Comments
1 Bioretention #1 Bioretention 731 Across from Lot 68
2 Bioswale Bioretention 12060 Greenwa Bioswale
3 Swale System Grassed Swale w/Check Dam 28845 Roadway Swales - 3' Flat Bottom w/12" CD's
4 Bioretention #2 Bioretention 1192 Cul-de-sac of Lots 37-41
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Total Volume Provided: 42828 ft
Total Volume Required: 37620 ft
Post-Development Curve Number Adiustment based on Volume Provided
Source: "Modeling Infiltration Practices Using TR-20", October, 1983, Maryland Department of the Environment
200
CNadj = (P+2Q+2) - (5PQ+4Q2)1/2
Where:
P = Rainfall (inches) = 3 inches
Q = Runoff Depth for Proposed CN (Q") - Volume Provided (inches)
Volume Provided (Inches) = 0.23 inches
Q' = 0.96 inches
Q = 0.73 inches
Post-Development CNadj (1 -year)= 70
Stormwater Management Plan Project No.: 2040409
Montvale Phase 2 Date: 7/31/2007
Withers & Ravenel Designer: SAH
1 -YEAR PEAK FLOW CALCULATIONS
ICURVE NUMBER:
Pre-development CN = 71
Post-Development CNadj (1 -year)= 70
ME OF CONCENTRATION:
Pre-development T, = 0.45 hrs
Post-development Tc = 0.45 hrs
PEAK FLOW:
Method: TR-55 Graphical Peak Discharge Method for Tvpe 11 Distribution
QP = quAmQ.
Where:
QP = Peak Discharge (cfs)
q„ = Unit peak discharge (csm/in) TR-55 Appendix F
Am = Drainage Area (miZ)
Q" = runoff (inches)
Pre-development
qu = 484.84 csm/in
Am = 0.08 miZ
Q• = 0.76 inches
01-year= 29.79 cfs
Post-development
q„ = 484.80 csm/in
Am = 0.08 mil
Q" = 0.71 inches
01-year = 27.98 cfs
Stormwater Management Plan IProject No.:
Montvale Phase 2 (Date: 7/31
Withers & Ravenel Designer: SAH
10 -YEAR PEAK FLOW CALCULATIONS
Post-Development Curve Number Adiustment based on Volume Provided
Source: "Modeling Infiltration Practices Using TR-20", October, 1983, Maryland Department of the Environment
200
CNadj _ (P+2Q+2) - (5PQ+4Q2)1?2
Where:
P = Rainfall (inches) = 5.28 inches
Q = Runoff Depth for Proposed CN (Q*) - Volume Provided (inches)
Volume Provided (Inches) = 0.23 inches
Q* (10-year) = 2.67 inches
Q (10-year) = 2.44 inches
Post-Development CNadj (10-year)= 72
ICURVE NUMBER:
Pre-development CN = 71
Post-Development CNadj (10-year)= 72
ITIME OF CONCENTRATION:
Pre-development Tc = 0.45 hrs
Post-development Tc = 0.45 hrs
IPEAK FLOW:
Method: TR-55 Graphical Peak Discharge Method for TvDe II Distribution
Qp = qAr,,Q*
Where:
Qp = Peak Discharge (cfs)
q„ = Unit peak discharge (csm/in) TR-55 Appendix F
Am = Drainage Area (mi)
Q* = runoff (inches)
Pre-development
q„ = 484.84 csm/in
Am = 0.08 mi2
Q* = 2.33 inches
Q10-year = 91.31 cfs
Post-development
qu = 592.24 csm/in
Am = 0.08 mil
Q* = 2.42 inches
010-year = 115.61 cfs
NITROGEN
CALCULATIONS
Nitrogen Control Plan
Residential Subdivision with no known building footprints
Project Title: Montvale Phase II
Part I. Riparian Buffers
Area includes riparian buffers? [ ] No [X ] Yes [ ] Exempt
If yes, [X] 50 foot [ ] 100 foot
River Basin? [ ] Neuse [X] Cape Fear
Basis for Exemption
Show buffers on site plan.
Part II. Nitrogen Calculations (Method 1, Appendix C):
a. Subdivision Information
Number of lots 72
Total area of lots (excluding
RAN and open space) 33.3 ac
Number of lots / acre 2.16
Average lot size 20147 sf
Impervious area per lot 7000 sf
Amount of Right-of-Way 7.03 ac*.*
Percent of Right-of-Way
that is impervious area 46.14%
Amount of Right-of-Way
that is impervious area 3.24 ac
Total estimated impervious area 14.81 ac
b. Pre-development loading:
Type of Land Cover
Permanently protected undisturbed open
space (forest, unmown meadow)
Permanently protected managed open space
(grass, landscaping, etc.)
Impervious Area
TOTAL
Pre-development Nitrogen Loading Rate (Ibs/ac/yr) _
c. Post-development loading:
Residential
Type of Land Cover
Permanently protected undisturbed open
space (forest, unmown meadow)
Permanently protected managed open space
(grass, landscaping, etc.)
Right-of-Way (read TN export from Graph 1)***
Lots (read TN export from Graph 2)
TOTAL
Post-development Nitrogen Loading Rate (Ibs/ac/yr) = 3.56
Proposed BMP(s) No BMPs proposed for Nitrogen Removal since loading rate is below 3.6
Nitrogen Load after BMPs = 3.56 Ibs/ac/yr
Nitrogen Load offset by Payments = 0.00 Ibs/ac/yr
Net change in on-site N Load = 2.96 Ibs/ac/yr (Post BMP load less Pre-development N load)
Part III. Control of Peak Stormwater Flow (for 1 year, design storm)
Calculated Pre-development Peak Flow 29.79 cfs
Calculated Post-development Peak Flow 54.03 cfs
Proposed BMP(s) Grass Swales w/Check dams; Bio-swale; Bioretention
Post BMP Peak Flow 27.98 cfs
I, the undersigned, certify to the best of my knowledge that the above information is correct (affix seal).
TN Export
Area TN export coeff from use
(acresl llhe/ar/vrl /lhe/vrl
51.72 0.6 31.03
0 1.2 0
0 21.2 0
51.72 31.03
0.60
TN Export
Area TN export coeff from use
(acresl Ilhs/ar/vrl ll helvrl
11.39 0.6 6.83
1.08 1.2 1.30
7.03 8.5 59.76
33.30 3.6 119.88
52.80 187.77
Supply notes & details showing control of Nitrogen and peak stormwater runoff. 31812006