November 06, 2024| Community, Environment
By: Holly Odgers
Each year the water level on Lake Hopatcong is lowered to allow for waterfront maintenance and to protect private property from ice damage. The lake level is managed by Hopatcong State Park staff through adjustments in the four sluice gates at the dam within the park. These adjustments are made in accordance with the New Jersey Department of Environmental Protection’s (NJDEP) Lake Hopatcong Water Level Management Plan along with the amendment to that plan, the 2016 Lake Hopatcong Water Level Management Pilot Program, which reduced the level of the annual drawdown to 22 inches.
The drawdown initiation dates are determined by assessing recent rainfall and current lake levels. Due to this fall’s unusually dry weather, the lake level has already declined significantly. State Park officials will initiate the drawdown as necessary to meet the 22-inch target, or a gage height of 7.16 feet, by December 15. The graph below displays the timeline and water level targets for the drawdown process. The U.S. Geological Survey (USGS) monitors water level, outflow, and rain data on Lake Hopatcong. Their data can be viewed HERE.
The water level will then be maintained until a spring thaw has softened the ice on the lake sufficient to avoid ice damage to private property. Once the spring thaw is underway, the flow will be reduced at the dam to a level to both maintain sufficient flow to the Musconetcong River and allow refill of the lake, given adequate rainfall, to the elevation of 9 feet.
