20090195 Ver 1_More Info Received_20090420

Dq.0195
TO:
FROM:
DATE:
RE:
ENVIRONMENTAL SERVICES, INC.
1022 Grandiflora Drive Suite 250
Leland, North Carolina 28451
910-383-6021 / Facsimile 910-383-6049
www.environmentalservicesine.com
MEMORANDUM
Joanne Steenhuis
Matt Smith
!1?K °' 2;i! cj
CF.r7R - WATEn GUA.LITY
VIET! A ,'DS R ID. S'"ORMI-7WE4 Ef -??;CH
17 April 2009
Cypress Village Subdivision Section 404 PCN Application.
USACE Action ID 2008-02703.
Please find attached supplemental information requested by the U.S. Army Corps of Engineers in
regards to the road and stormwater designs for the Cypress Village Subdivision.
Please feel free to call me at [phone] if you require any additional information.
Cc: Mickey Sugg, N.C. Division of Water Quality
Services
April 16, 2009 /

US Army Corps of Engineers
Attn: Mr. Mickey Sugg - Project Manager
69 Darlington Avenue
Wilmington, NC 28403-1343
Re: Cypress Village Subdivision
Masontown Road SR 1127
Newport, NC 28570
CIVIUSANITARY ENGINEERS
Engineering
Company, P.A.
Dear Mr. Sugg:
It was a pleasure meeting you in the field on April 7t' to discuss your concerns over the need to maintain
cross drainage near station 7+00 on Cypress Lane in the above subdivision. You also stated concern
over the potential for the roadside drainage system to drain the weltand located on the south side of
Cypress Lane. As you know I described the engineering logic used to design the system making the
following point:
1. The entire drainage system of the subdivision outlets to a pond whereby the spillway of the
pond serves as a dam therefore no water will drain from the ditch system until the water level of elevation
26.50 is reached.
2. The pond is lined with an impermeable liner therefore the pond can not drain it will remain
flooded except for the effects of evaporation; therefore it is similar to an extended detention basin as it will
cause the shallow roadside ditches to trap and retain the surface water runoff.
3. The roadway just west of the wetlands includes a 100 foot long, deep retaining wall which is
constructed from elevation 22.0 to elevation 28.0. The lowest elevation of the wetlands on the south side
is elevation 25.5 therefore the roadside retaining wall also serves as a dam preventing the natural draining
of the wetlands towards the highway 70 corridor.
4. The ditch system was designed to retain the stormwater from a 25yr storm therefore the stored
water level in the ditch after any rain would be equal to the spillway at 26.50 and the stored water from
more intense storms will be to elevation 27.10.
5. The existing ground at the wetlands crossing is elevation 27.5 and the bottom of the roadside
ditch is about elevation 26.0, the road shoulder is at elevation 28.33 therefore water will store in the ditch
up to elevation 27.10. We now are including 2 each - 6" HDPE corrugated drain lines proposed to be at
an invert of 26.50 which will be gravel packed to support the roadway, the drains will allow for stormwater
to cross the roadway to provided interconnectivity directly at the existing road crossings.
6. We also pointed out the roadside ditch system will actually draw more water to the wetlands
area then currently exist thereby providing more of a groundwater recharge then is present currently on
the site.
7. We enclosed a crude sketch showing the spillway heights and expected water storage level
and our commitment to construct the cross drainage pipe.
We appreciate your attention to this matter and look forward to working with you to protect the waters and
wetlands in the area. Please let me know should you require any additional information or drawings.
Sincerely,
Mic elle L. Ben
ton, PE
Project Manager
PO Box 97, Gamer, North Carolina 27529 [phone]
PO Box 828, Morehead City, NC 28557 [phone] PO Box 349, Boone NC 28607 [phone]

OPERATIOWCONSTRUCTION QA/OC
Municipal
C ?[ I CALCULATION
PROJECT
CLIENT
SUBJECT cM ?1
PROD. NO.
DATE
DES. BY
CHK. BY
Municipal Engineering Services Co., PA wti?(. min
? P_0. Box 828, Morehead City, North Carolina 28557 [phone] '-p Im4 rif I I
? P.O. Box 97, Gorner, North Carolina 27529 [] [phone] P.O. Box 349, Boone, North Carolina 28607 [phone]
DO
so