NHDES Response to Hermit Lake Drawdown

The State does not regulate or guarantee the operation of private wells and unfortunately some wells rely on the artificial groundwater table created by dams.  These issues regarding wells can happen when a dam, which is a man-made structure, needs repair and the water level is temporarily lowered.  With the understanding of these impacts, NHDES tries to limit the frequency of drawdowns that could have an effect on wells.  Currently there is no mechanism for the NHDES Dam Bureau to reimburse homeowners for impacts caused by fluctuating water levels. 

Also, Hermit Lake Dam was last reconstructed in 1980/1981.  At that time, the pond was drained starting in the late spring of 1980 and was refilled during the winter of 1981.  With the last major rehabilitation of the dam occurring over 40 years ago, there is a high likelihood that at some point in the future, possibly the next 10 to 15 years, that Hermit Lake Dam will need to go through a similar rehabilitation process to meet new regulatory criteria, repair deteriorated concrete and to control water seeping through the earth embankment.  When this rehabilitation occurs, Hermit Lake will likely need to be drained for at least 1 year.  At that time residents who rely on the water will need to seek other means of securing a sustainable water source.  Therefore, it would be in their best interest to start that process before dam rehabilitation occurs.

If you have any further questions please do not hesitate to reach out,

Dan

Dan Mattaini, PE
Operation & Maintenance Engineer
Water Division/Dam Bureau

New Hampshire Department of Environmental Services
29 Hazen Drive, PO Box 95
Concord, NH 03302-0095
Tel: (603) 271-8867