N.H. Admin. Code § Env-Wr 303.12

Current through Register No. 50, December 12, 2024
Section Env-Wr 303.12 - Meeting Discharge Capacity Requirements
(a) If a dam does not have adequate discharge capacity to pass the flood specified in Env-Wr 303.11 with one foot of freeboard, the owner shall submit a plan to the department to address the deficiency.
(b) The plan submitted pursuant to (a), above, shall:
(1) Specify the action to be taken, per (c), below;
(2) Specify the proposed timeframe for taking the action; and
(3) Include the results of hydrologic analyses completed pursuant to Env-Wr 403.05, assessing the floods and discharge capacity of the structure.
(c) The plan shall specify which of the following actions the owner intends to pursue:
(1) Increase the capacity of the dam to pass the flood with one foot of freeboard and without manual operations;
(2) Submit a stability analysis to the department showing that the dam is safe against sliding, overturning, or erosion by overtopping, as applicable, during the specified flood, using the methods outlined in "Engineering Guidelines for Evaluation of Hydropower Projects" published by the Federal Energy Regulatory Commission (FERC), Chapter 3 dated 2002 and Chapter 4 dated 1991, available as noted in Appendix B;
(3) Stabilize the dam so that it is safe under the specified flood conditions; or
(4) Modify the dam so that the hazard classification is lowered and the dam passes the appropriate flow for the new classification.
(d) The department shall approve the plan if the department determines that:
(1) The proposed action will bring the dam into compliance with Env-Wr 303.11;
(2) The work can be done in a way that will not:
a. Endanger life or property downstream of the dam; or
b. Cause environmental losses that are not reversible environmental losses; and
(3) The time frame for the work is reasonable under the circumstances, including the risk posed by the deficiency, the owner's financial resources, and the timing of the work in relation to other uses of the impounded water.
(e) The department shall notify the owner in writing of its decision. If the plan is not approved, the notice shall specify the reason(s) for the non-approval.
(f) If work under the plan as approved constitutes reconstruction of the dam, the owner shall submit an application in accordance with Env-Wr 400.

N.H. Admin. Code § Env-Wr 303.12

#8414, eff 8-20-05; ss by #10510, eff 1-22-14