20221160 Ver 1_More Info Received_20221026

Baker, Caroline D
From: Kevin Martin <[e-mail]>
Sent: Thursday, October 27, 2022 4:01 PM
To: Rowland, Kelsey S
Cc: Max Klietsch; Jay Colvin
Subject: [External] Add Info #2022-1160 Berry Property
Attachments: Rough Alternate Layout.pdf, Culvert Calculations.pdf, DRB21001x- Culvert DA.pdf,
permissble velocity.png; Post Hydrology.pdf
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Kelsey, the engineer's responses to your other questions are below with supporting docs
attached. I would add that a significant amount of impervious surface from the upstream
school and Leesville road is directed into the site. When the school was built, according to the
delineation of the Berry property done for the sewer line, there were no wetlands on the
property except one small pocket. The increased stormwater runoff from the school and
Leesville road improvements for the school caused the wetlands that are present today to be
"created" in my professional opinion. Let me know if you have further questions
From: Max Klietsch <[e-mail]>
Sent: Thursday, October 27, 2022 1:48 PM
To: Kevin Martin <[e-mail]>
Cc: Jay Colvin <[e-mail]>; Nick Williamson <[e-mail]>
Subject: RE: Add Info #2022-1160 Berry Property
Kevin,
please see the attached supporting documents and additional info questions 2 thru 5 that
DWR asked.
2. The road crossing is not feasible at the most southernmost tip of the wetlands mainly
because of the horizontal and vertical roadway design constraints. An alignment navigating
towards the southern tip of the wetlands would not be a safe or acceptable design. Roadway
design constraints are limited to those of a local neighborhood street, outlined by the city of
Raleigh Street Design Manual section 6.10, 6.11 and the values provided in table 6.11A where
1

a minimum horizontal curve centerline radius of 150' is required along with a K value 12 in
crest and 26 in sag. These values are based on a 25mph design speed . Another aspect of
feasibility would be the economics. Realigning the road to the south would make a large
portion of the site undevelopable and cut the number of proposed lots in half. The layout that
would conform to an alignment to the south would force the SCM's near the bottom of the
wetland, taking up usable space and forcing pockets of inaccessible area to the north where
tree conservation must be accounted for. This also results in a net reduction of 30 lots. NOTE:
The provided rough layout exhibit does not represent a feasible horizontal or vertical layout
and its purpose is only to roughly represent a sketch of usable space. It is arguable that the
road crossing is at the narrowest part of the wetland and provides a safe, feasible design.
3. Proposed utilities are proposed within the roadbed doghouse manholes are proposed
within the roadbed to connect to existing City of Raleigh sewer outfall. No additional impacts
to the wetlands or streams will be necessary.
4. The rip rap dissipater pad is shown because the potential velocity through the culvert during
a 10-year storm event could be considered erosive. Drainage area map and calculations have
been provided to show the extent of what is captured into the culvert. The calculated velocity
is 8 ft/s during a 10 year storm event (design) and the provided graphic shows any more than
about 2 ft/s is erosive
5. Retaining walls are set back at least 5' from the boundary of the wetlands, while the limits
of disturbance follow the wetland boundary. This buffer was given for constructability to
ensure no temporary impacts are necessary.
Please let me know if this additional info is sufficient or if you need anything else.
Many thanks!
Max
9 ' Max Ket
designer II,, residential
Direct 919-287-0726
[e-mail]
2905 Meridian Parkway, Durham, NC 27713
www.mcadamsco.com
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061

From: Rowland, Kelsey S <[e-mail]>
Sent: Tuesday, October 25, 2022 1:16 PM
To: berry*[e-mail]; Kevin Martin <[e-mail]>
Cc: Phillips, George L CIV USARMY CESAW (USA) <[e-mail]>
Subject: Add Info #2022-1160 Berry Property
Hi Mr. Martin,
We sent an additional information request for Project #2022-1160 (Berry Property) via our automated system on
October 3rd. Following up to make sure you received that.
Best,
Kelsey
Kelsey Rowland, MEM
Environmental Specialist, Division of Water Resources
North Carolina Department of Environmental Quality
[phone]
[e-mail]
1617 Mail Service Center, Raleigh, NC 27699-1617