SW6090701_Response to Comments_20110829

29 August 2011
Mr. Michael Lawyer
NCDENR
Division of Water Quality
McBride
Hess
Design
Group, P.A.
Fayetteville, NC Landscape Architecture
Campus Planning
Re: Grays Creek Middle School Land Planning
In response to your letter dated 9 August 2011. We have reviewed your document, discussed with you your
concerns and walked the site. We respond as follows
SW Measures
.Additional Outlet pipe observed going directly into the main pond.
This was a pipe added by the owner at the end of the project to capture a low turf area.
Corrective Measure
At this time the pipe is draining only the turfed area which is established. In that the pipe is only
draining a turf area, the Owner will re grade the outlet ditch to eliminate the undercut and fill
back in the ditch. We will use the soil that is at the edge of the pond to fill the ditch thereby
reestablishing the pond depth. Additional soil will be brought into complete the ditch fill. We will
then install a rip rap outlet apron to slow the outlet water.
At this time we would prefer not to add pipe and cause the opportunity for new erosion.
We, will in addition, stabilize the inlet of the pipe by re -grading and adding sod to stabilize the
entrance.
Outlet structure had two openings which are lower than allowed.
Corrective Measure
The school system will weld over the opening to create the storage required and according to the
approved drawings. Top of the new plate will be at ELEV. 158.07 or 1.07' Above the bottom of the
permanent pond pipe
In regards to the openings. The drawings indicate (3) 12"H X 30"W openings for a total of 7.5 Sq.
Ft. Because the riser is 36" in diameter this is not possible. We will therefore provide the same
area of opening by cutting two square holes in the riser that are similar location as the existing
openings. The two openings will begin at Elevation 158.07 and be 1'-8"H and 2' W for a total of
7.5 SQ. FT. The use of two openings will maintain the integrity of the riser pipe. The square
footage of the opening(s) will therefore be equal to the design.
Operation and Maintenance
Erosion observed along the slopes and around the rip rap inlets. Head cutting below the added pipe
Corrective Measure
• The school system will rework the ditch as described above. In that there are rills in slopes the
School System will fill in the rills, seed, and mulch as per your request.
• The Outlet apron will be cleaned on the Existing 42" RCP. As per your comment, the School will
back fill around the top and sides of the pipe and add Rip -Rap around its side and top.
1073 Bullard Court 13 Raleigh, North Carolina 27615 13 919.954.8200 (F) 919.954.8299 13 mcbridehess.com

Additionally, the school system will provide a rip rap apron on the ditch which is the outlet to a
long and shallow ditch at the back of the ball field site. This should eliminate the erosion on this
bank.
Re -vegetation of the vegetative shelf
Corrective Measure
The school system would like to observe the vegetative shelf for one year following the
modification of the outlet structure. If Mother Nature has not self -vegetated the shelf within one
year following the raising of the outlet as noted above the school system will re vegetate the
shelf.
Time Line
The school system will have the above measures corrected by December 1", 2011, or 90 days from Sept 1" at
the latest. We will contact you once the measures are complete for your observation. If desired we will inform
you when the work is taking place so that you might observe the correction process..
We thank you for your observations and trust these measures reflect your desires. Please feel free to contact us
if you need additional information or would like to discuss these responses.
With Kindest Regards,
Tim Hess
President
McBride Hess Design Group, P.A.
1073 Bullard Court 11 Raleigh, North Carolina 27615 13 919.954.8200 (F) 919.954.8299 0 mcbridehess.com