20181361 Ver 1_Additional Information Received_20190205

Mitchell, Robert K
From: Sam Just <[e-mail]>
Sent: Tuesday, February 05, 2019 2:39 PM
To: Mitchell, Robert K
Cc: 'Clement Riddle'; 'Martin Kocot'
Subject: [External] Glen Cove Lake Outflow Structures
Attachments: EX10-2-5-19.pdf; D4-2-5-19.pdf, Discharge Velocity Calcs.pdf
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Kevin,
It was good talking to you this afternoon. We've decided to simplify the design. Instead of the "overflow structure" we
will simply discharge from a 12" HDPE pipe into a rip -rap plunge pool alongside the creek. In order to get a positive slope
on our discharge pipe we are showing this rip -rap within the buffer, would this constitute an additional impact?
Discharging into a rip -rap plunge pool should also help raise DO levels before entering the creek. Additionally, the intake
and outflow are intended to refresh the entire pond volume over a 10 day cycle.
I've attached supporting calculations in a PDF. Based on our numbers, the primary outflow will discharge at a velocity of
2.45 ft/s for the 175 GPM pump rate. I've reworked the emergency spillway calculations and now have a discharge
velocity of 1.06 ft/s. Neither of these velocities should have high erosive potential.
Feel free to email or call with any questions.
Thanks,
Sam Just, El
LandWorks Ennineerinn, PUC
Civil Engineering & Land Planning
PO Box 1922
Asheville, NC 28802
(828).442.6136