20200533 Ver 2_More Info Received_20210326

MEMORANDUM
Sue Homewood
North Carolina Division of Water Resources
Department of Environmental Quality
Bob Zarzecki - S&EC
Chuck Smith - Preston Development Company
From: Robert Oldham, PE LEED AP
Date:
Project
Subject
March 26, 2021
Chatham Park North Village - Pittsboro, Chatham County, NC
Revised Individual Permit Application - Response to Comments
Dear Ms. Homewood:
Chatham Park Investors LLC (CPI) is submitting this Memorandum in response to North Carolina Division
of Water Resources (DWR) request for information to address certain comments submitted to North
Carolina Division of Water Resources (DWR) by North Carolina Wildlife Resources Commission (WRC) in a
Memorandum dated March 15, 2021 and by United States Fish and Wildlife Service (FWS) in a letter
dated March 19, 2021. This Memorandum summarizes measures for protection of downstream waters
applicable to construction activities in the approximately 2,224 acres of property in what is known as
"North Village" in Chatham Park Planned Development District (Chatham Park) in the Town of Pittsboro,
Chatham County, North Carolina, together referred to herein as the "Protection Measures". CPI believes
that sufficient information previously has been submitted by CPI to address the other comments in the
WRC Memorandum FWS letter. This Memorandum also addresses whether the Protection Measures
comply with the conditions outlined in 15A NCAC 04B .0124 Design Standards in Sensitive Watersheds,
even though those standards are not applicable to the receiving waters for Chatham Park.
NCAC 04B .0124 Design Standards in Sensitive Watersheds
(a) Uncovered areas in HQW zones shall be limited to a maximum total area of 20 acres;
Chatham Park is not within a High Quality Water (HQW) watershed as defined by the State and it is
important to note that this project is not subject to these Design Standards. Any of these Design
Standards applied in Chatham Park exceeds Local, State, and Federal requirements applicable to Chatham
Park. Given the type of development and existing topography and the need to balance earthwork, limiting
denuded areas to 20 acres is not practical, feasible nor required. North Village will be a phased
development estimated to be completed over the next 15 years. The 401 permitting being considered by
DWR is related to an Individual Permit application for North Village submitted by CPI to the U.S. Army
Corps of Engineers. CPI believes that the planning that has been in connection with the Individual Permit
application, which has included routing of roadways around streams rather than through them, has
resulted in approximately one quarter of the stream impacts that would have occurred if, for example, the
land in North Village were to be developed as twenty-two separate 100-acre developments.
North Village will have approximately 600 acres of riparian buffers, nature parks, and open space that will
remain mostly undisturbed and an additional 100 - 200 acres that will remain undisturbed due to
topography and tree protection requirements. Currently, Chatham Park is the only development in the
Town of Pittsboro that has tree protection requirements. Therefore approximately 1,500 acres of North
Village will be developed. There is limited existing infrastructure serving North Village and it will take years
to extend roads, water, and sewer, which will naturally extend the development timeline and reduce the
ability to develop in large phases at any one time.
55 Grant Drive, Suite DI Pittsboro, NC 27312
t: 919.469.3340 1 f: 919.467.6008 1 w wv.withersravenel.com License No. C-0832
Asheville Cary ! Greensboro l Pittsboro l Raleigh l Southern Pines l Wilmington

There are two sections of North Village adjacent to Haw River. Section 1.1 is in the northeast corner of
North Village and is limited to residential development. As required by the Chatham Park Master Plan and
open space requirements, there is a 300' riparian buffer adjacent to Haw River that applies to Section 1.1.
Section 1.5 is designated as park land and, as required by the Chatham Park open space regulations has a
1,000' buffer requirement adjacent to Haw River. There is an area of State park land between the
southern portion of Section 1.1 and the northern portion of Section 1.5. In addition, with respect to
Section 1.1 the Chatham Park Master Plan has the following development density limitations moving away
from the 300' riparian buffer: (i) next 200', 1.0 dwelling unit per gross acre; (ii) next 250', 2 dwelling units
per gross acre; and (iii) next 250', 2.5 dwelling units per acre. The Chatham Park stormwater regulations
(separate and more extensive regulations than those that apply to other development in the Town of
Pittsboro) are based on an "Exceptional Design Evaluation" for development projects in Chatham Park,
which is required to be quantified through a scoring system for each sub -watershed that balances
between impacts to critical environmental resources and environmental uplift measures deployed within
the built environment. The minimum required sub -watershed score for most of North Village is 120 points.
However, within 1,000' of the top of bank of Haw River, the minimum required score is 130 points and
between 1,000' and 2,000' feet from top of bank of Haw River the minimum required score is 125 points.
The Chatham Park tree protection regulations (specific to Chatham Park - currently there are not any tree
protection regulations for development other land in the Town of Pittsboro) requires that existing trees be
retained on not less than 35% of the land in Chatham Park that is within 2,000' of the top of bank of Haw
River.
(b) Erosion and sedimentation control measures, structures, and devices within HQW zones shall be
planned, designed, and constructed to provide protection from the runoff of the 25-year storm;
Chatham Park is already using the 25-year storm event for design of erosion and sedimentation control
measures.
(c) Sediment Basins shall be designed and constructed to meet the following:
Use a surface withdrawal mechanism, except when the basin drainage area is Tess than 1.0 acre;
Chatham Park is already meeting this condition.
Have a minimum of 1800 cubic feet of storage area per acre of disturbed area;
Chatham Park is exceeding this condition by using 3,600 cubic feet.
Have a minimum surface area of 325 square feet per cfs of Q25 peak inflow;
Chatham Park is exceeding this condition by using 435 square feet.
Have a minimum dewatering time of 48 hours; and
Chatham Park is already meeting this condition.
Incorporate 3 baffles, unless the basin is less than 20 feet in length, in which case 2 baffles shall be
sufficient.
Chatham Park is already meeting this condition.
(d) Upon a written request of the applicant, the Director may allow alternative design or control measures
in lieu of meeting the conditions required ins Subparagraph (c)(2) through (c)(5) ...
Comment is noted but Chatham Park is already exceeding or meeting subparagraph (c)(2) through (c)(5)
requirements.
(e) Newly constructed open channels in HQW zones shall be designed and constructed with side slopes no
steeper than two horizontal to one vertical if a vegetative cover is used for stabilization ...
Chatham Park is already meeting this condition.
Page 2 of 3

Existing Chatham Park Conditions That Provide Additional Protection of Downstream Waters
Provide additional buffers that results in less denuded area and additional protection and buffering to
streams:
• Per the approved PDD Master Plan, provide 100' riparian buffers (50' required by State and Town
of Pittsboro regulations) on all perennial streams.
• 300' and 1,000' buffers along Haw River as previously described.
• Pursuant to an agreement among DWR, North Carolina Division of Energy, Mineral and Land
Resources, Town of Pittsboro, and CPI effective May 15, 2019, CPI agreed to provide 100'
riparian buffers on intermittent streams within approximately 2/3 of North Village (adjacent to the
Haw River. In addition, CPI agreed to provide access to DWR to a website maintained by CPI for
tracking stormwater control measures in Chatham Park.
Provide additional site stabilization strategies and compliance with local erosion and sedimentation control
program:
• Per the Chatham Park Stormwater Element, incentivize site stabilization strategies to provide
points in meeting the Exceptional Design Evaluation scoring requirements. These include the
following: exceed erosion control design volume, stabilize disturbed areas within 7 days, use
enhanced silt fence near protected areas, and use of flocculants.
• Compliance with Chatham County Soil Erosion and Sedimentation Control Ordinance (Chatham
County administers erosion and sedimentation permitting for the Town of Pittsboro).
Provide additional measures for low impact development resulting in less disturbance (list of measures
previously discussed):
• Per the Chatham Park Master Plan, require low -density development within 1,000' of the Haw
River.
• Per the Chatham Park Stormwater Element, require Exceptional Design Evaluation of all
development including public infrastructure on a sub -watershed basis that essentially requires
more protection and measures commensurate with the intensity of development.
• Per the Chatham Park Stormwater Element, require higher scores for the Exceptional Design
Evaluation for development within 1,000' and 2,000' of the Haw River.
• Per the Chatham Park Tree Protection Element, require up to 25% of Tree Coverage Area for
development.
• Per the Chatham Park Tree Protection Element, require at least 35% of existing trees to be
retained within 2,000' of the Haw River.
• Per the 2019 agreement among DWR et al., require additional stormwater tracking and
monitoring that includes web -based tracking of all SCMs and Sub -Watershed Exceptional Design
Evaluations.
Provide design that minimizes stream crossings:
• Per the current Individual Permit application, only 11 roadway impacts are proposed for North
Village with only one stream feature having more than one roadway crossing. That is equivalent
to one crossing per 200 acres that will be developed over 15 years or approximately one crossing
per year.
• Per the current Individual Permit application, only 4 greenway impacts are proposed with no two
on the same stream feature.
Page 3of3