15 CAR § 23-507 – Reservoir drain conduit

(a) All proposed dams must include a permanent facility for draining the reservoir.
(b)
1. (1) Such conduit shall have a minimum diameter of:
  1. (A) Twelve inches (12”) for watershed areas less than one (1) square mile; and
  2. (B) Eighteen inches (18”) for watershed greater than one (1) square mile.
2. (2) Such conduits must be capable of lowering the surface of the reservoir at a rate not less than two inches (2”) per day (at normal pool) while inflow to the reservoir is twice the annual average daily flow.
(c) Operating equipment for the drain facility must be accessible from above the maximum design water surface, unless inlet design is such that the conduit is flowing at capacity at a lower elevation.