N.H. Admin. Code § Env-Wq 1905.05

Current through Register No. 50, December 12, 2024

Section Env-Wq 1905.05 - Dam Management Plans

(a) Each affected dam owner within a WMPA that is subject to a water management plan under Env-Wq 1905.01, and each hydropower facility that is an affected water user, shall have an individual dam management plan that is prepared by the department in consultation with the affected dam owner or hydropower facility owner.

(b) Each individual dam management plan shall be incorporated into the water management plan for the WMPA.

(c) Each individual dam management plan shall:

(1) Include data and information from department sources, site visits, and interviews with each affected dam owner or their operator on characteristics and operational procedures of affected dams within the WMPA including:

a. The name of the dam;

b. The name of the town where the dam is located;

c. The name, address, email address, and telephone number of owner, operator or both;

d. The emergency contact person and phone number;

e. The dam's state ID number and Federal Energy Regulatory Commission exemption or license number, if applicable;

f. A description of the dam's typical annual operational schedule, including any routine drawdown and refilling events;

g. The name of the water body impounded by dam and the downstream river;

h. The primary use(s) of the impoundment;

i. The elevation, in feet, of the normal full pool;

j. The elevation, in feet, of the invert of all spillways and outlets;

k. The volume of water in the top 2 feet of the lake at full pool;

l. The elevation, in feet, of the top of the dam or dam height relative to the lowest spillway;

m. The height of the dam, in feet, from toe to the highest point on the dam;

n. The type and dimensions of spillway control(s) or outlet works;

o. The surface area of the impoundment at the normal full pool, in acres;

p. The drainage area, in square miles;

q. The normal storage, in acre-feet, which is the volume of water impounded above the natural pond or stream elevation when the water level is at the spillway crest;

r. The maximum unoperated discharge, in cubic feet per second (cfs);

s. The design storm discharge, in cfs;

t. The estimated 50-year flood flow, in cfs;

u. The estimated 100-year flood flow, in cfs;

v. Any contractual obligations, minimum flow requirements and flowage rights; and

w. A description of any expected water quality impacts to the impoundment as a result of implementing the dam management plan;

(2) Include a section describing:

a. The potential water available for release to maintain protected instream flows;

b. The ecological and other impacts to the impoundment and downstream river reaches which might restrict the use of such waters for augmentation flows; and

c. The potential for dam management to meet instream flow requirements, including dam operation patterns, physical structure, and needs as determined in (c)(1) above;

(3) For each affected dam in the WMPA, include an individual dam management plan so that the net effect of implementation of all individual dam management plans, in coordination with implementation of the water use plans, is maintenance of the protected instream flows;

(4) For each affected dam in the WMPA for which dam releases are specified in a dam management plan, include an assessment of how such releases could affect lakefront properties, recreational interests and lake ecology; and

(5) For each affected dam in the WMPA, include an implementation schedule, as provided in Env-Wq 1905.07.

(d) The department shall:

(1) Meet with each affected dam owner to discuss potential water management plan requirements necessary to protected instream flows; and

(2) Coordinate negotiations among affected dam owners, affected water users, and other applicable interests toward water use and dam management that will meet protected instream flows and support the primary uses of the impoundment.

N.H. Admin. Code § Env-Wq 1905.05

#7901, eff 5-29-03 (See Revision Note at chapter heading for Env-Wq 1900) (formerly Env-Ws 1905.05); ss by #9936, eff 5-28-11

Amended by Volume XXXIX Number 02, Filed January 10, 2019, Proposed by #12695, Effective 12/22/2018, Expires 12/22/2028.