SW4240902_BUA Allocations_20241004

NC Design Solutions, Inc.
6701 Carmel Road
Suite 205
Charlotte, NC 28226
Design Solutions Phone: [phone]
NC PE Firm C-4245
August 29, 2024
NC-DEQ ��� H • 0 i,/
Stormwater Program ;_ F �•o'•
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512 North Salisbury Street SE —
1612 Mail Service Center 71 •
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Raleigh, NC 27699-1612
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Re: NOVer: NOV-2024-PC-0214 �� �/ � io\
Site
NumbeWT 3553 ► F • �\\
Project Name: Bryson Park 1-3 8.29.2024
County: Davidson
Dear Mr. Michael Lawyer,
This letter is in response to the above-mentioned NOV that Clinard Farm Partners, LLC received
from your office on April 11, 2024. As I was not the original design engineer for this project, all
information, calculations, etc. are based upon information provided by Kat Lyons, a representative
of Clinard Farm Partners, LLC. As you will see in the provided narrative below, I have been able
to determine, to the best of my knowledge, upon review of the information that I was given, that
Bryson Park 1-3 qualifies as a low-density project as defined in 15A NCAC 02H .1003.
Background
On August 15, 2024, NC Design Solutions was contacted by Kat Lyons, a representative Clinard
Farm Partners, LLC regarding a notice of violation they received from Tamera Eplin, PE, Regional
Engineer, Land Quality Section, on April 11, 2024. Her direction was to determine how they could
get Bryson Park 1-3 in compliance with NC DEQ post-construction stormwater regulations and
obtain a State Stormwater Management Permit that was never obtained by the original project
design engineer.
Original Design Intent
Upon review of the approved construction drawing package, issued by Jamestown Engineering
Group, Inc., sealed by Thomas R. Glover, PE on October 28, 2019, it appears that the project
never intended to be classified as a high-density project. This can be deduced due to the omission
of permanent BMP measures, design of ribbon pavement along the roadways, vegetated swales
with driveway pipes, etc. All ponds shown on the construction drawings are sediment ponds and
no post-development plans or calculations could be found.

Low-Density Considerations
Per 15A NCAC 02H .1017 (4)
A project shall be considered a low-density project if it meets the low-density criteria set forth in
Rule .1003(2) of this Section and contains no more than 24 percent built-upon area or no more
than two dwelling units per acre; otherwise, a project shall be considered high density. Low density
projects shall comply with the requirements set forth in Rule .1003(2) of this Section.
Low-Density - Density Determination
The first exercise performed by NC Design Solutions was to determine if the site was planned
and designed to be less than two dwelling units per acre. Per Sheet 1 of the previously mentioned
approved plan set, under the Site Data Table, the total site area is listed as +/-208.10 acres with
440 proposed lots. This data results in a density of 2.11 dwelling units per acre.
Furthermore, by using the CAD file provided, the overall site area for Phases 1-3 was determined
to be 125.51 acres with 257 proposed lots. This data results in a density of 2.05 dwelling units
per acre.
Given the data for both the overall site (Phases 1-5) and phases 1-3 separately, it can be
summarized that Bryson Park does not meet the density requirement of less than two dwelling
units per acre.
Low-Density—24% Built-Upon Area Determination
Since the approved plans did not provide a built-upon area calculation, the CAD file was used to
determine the built-upon area for all 5 phases of the project. The built-upon area was also
assumed to be 3,000 sf for each lot which can be considered conservative compared to the largest
plot plan provided by the home builder. The largest plot plan provided totaled 2,208 sf of built-
upon area and an even smaller plot plan totaling 1,910 sf was also provided. These plot plans
are available upon request. Because the NOV clearly lists Phases 1-3, the built-upon area can
be summarized as follows:
Square Feet Acres
Total Site Area 9101237 208.94
Site Area Deeded to Adjoining Owners 37597 0.863
Total Adjusted Site Area 9063640 208.07
Phase 1 Site Area 1874483 43.03
Phase 2 Site Area 2340303 53.73
Phase 3 Site Area 1252344 28.75
Phase 4 Site Area 1988668 45.65
Phase 5 Site Area 1607842 36.91

Phase 1 Built Upon Area
Item Area (sf) Area (ac)
Roads 77659 1.78 4.14%
Pads 279000 6.40 14.88%
Driveways (93) 23715 0.54 1.27%
Phase Total 380374 8.73 20.29%
Phase 2 Built Upon Area
Item Area (sf) Area (ac) 0/0
Roads 86146 1.98 3.68%
Pads 318000 7.30 13.59%
Driveways (107) 27285 0.63 1.17%
Amenity 52799 1.21 2.26%
Phase Total 484230 11.12 20.69%
Phase 3 Built Upon Area
Item Area (sf) Area (ac) 0/0
Roads 35509 0.82 2.84%
Pads 171000 3.93 13.65%
Driveways (57) 14535 0.33 1.16%
Phase Total 221044 5.07 17.65%
Phases 1-3 Built Upon Area Summary
Item Area (sf) Area (ac) 0/0
Roads 199314 4.58 3.65%
Pads 768000 17.63 14.05%
Driveways (257) 65535 1.50 1.20%
Amenity 52799 1.21 0.97%
Phase Total 1085648 24.92 19.86%
These calculations assume the following:
1. All roads are constructed per the approved plans
2. All plot plans do not exceed 3,000 sf of built-upon area
a. Largest plot plan provided by builder does not exceed 2,208 sf
3. The Amenity area does not exceed 1.21 acres of built-upon area
Given the data from the Phases 1-3 Built Upon Area Summary Table above, it can be summarized
that Bryson Park does meet the "under 24% built-upon area" requirement and qualifies as a low-
density project based on having a calculated built-upon area of less than 20%.

Low-Density— Dispersed Flow
Per 15A NCAC 02H .1003 (2b)
Projects shall be designed to maximize dispersed flow through vegetated areas and minimize
channelization of flow;
Per the approved plans, it appears that the project attempted to meet this requirement. The plans
show riprap aprons that should disperse the flow from the sediment basins and dissipate the
stormwater velocity leaving the designed CMP outlet pipes. It also appears that the outlet pipes
are designed to outfall into vegetated areas as required.
Note: No site visit was performed by anyone at NC Design Solutions to verify this requirement.
This summary is only being made from the approved plans.
Low-Density—Vegetated Conveyances
Per 15A NCAC 02H .1003 (2c)
Stormwater that cannot be released as dispersed flow shall be transported by vegetated
conveyances. A minimal amount of non-vegetated conveyances for erosion protection or piping
for driveways or culverts under a road shall be allowed by the permitting authority when it cannot
be avoided. Vegetated conveyances shall meet the following requirements:
(i) Side slopes shall be no steeper than 3:1 (horizontal to vertical) unless it is
demonstrated to the permitting authority that the soils and vegetation will remain
stable in perpetuity based on engineering calculations and on-site soil
investigation; and
(ii) The conveyance shall be designed so that it does not erode during the peak flow
from the 10-year storm as demonstrated by engineering calculations.
Per the approved plans, it appears that the project follows this requirement. The project designed
vegetated swales along the roadways as shown in the chart on Sheet 37. All swales have been
designed with a 3:1 (horizontal to vertical) and nearly all the swales show a calculated velocity of
5.0 fps from the 10-year storm.
Note: No site visit was performed by anyone at NC Design Solutions to verify this requirement.
This summary is only being made from the approved plans.
Please let me know if you have any questions or comments.
Sincerely,
Robert L. Frost, PE
Principal Engineer
704-614-8359
[e-mail]