Lake Hopatcong Water Level

The approved Lake Hopatcong Water Level Management Plan 2011 has been issued by NJ DEP.  NJ DEP also provided responses to public comment on the draft plan

2012 Lake Hopatcong Water Level Management Report

The Lake Hopatcong Commission is not responsible for managing the water level of Lake Hopatcong nor is it responsible for updating the Lake Hopatcong Water Level Management Plan. 

The U.S. Geological Survey (USGS) sites below are available to monitor the lake level, outflow into the Musconetcong River and precipitation at the Hopatcong State Park.

Citizen Advisory Committee

Meeting Minutes 9-13-12 & 10-10-2012


Q&As About Lake Hopatcong Water Level

  1. How can I monitor the water level in Lake Hopatcong?
  2. Who controls the water level for Lake Hopatcong?
  3. When is the lake lowered in the fall and raised in the spring?
  4. What determines if there is a "SLOW SPEED - NO WAKE" restriction on Lake Hopatcong?

How can I monitor the water level in Lake Hopatcong?

The New Jersey Department of Environmental Protection  funds the operation and maintenance of gages on Lake Hopatcong and at the outflow into the Musconetcong River through an agreement with the U.S. Geological Survey (USGS).  The lake level gage is located near the dam at the Hopatcong State Park in Landing, New Jersey. 

Back to Top

Who controls the water level for Lake Hopatcong?

Mother Nature and Hopatcong State Park personnel control the water level in Lake Hopatcong.  Hopatcong State Park personnel manage the lake level as outlined in the Lake Hopatcong Water Level Management Plan 2011 The goal of the plan is to protect the environmental health and the natural and scenic resources of Lake Hopatcong/Musconetcong River System, maximize recreational opportunities, minimize the potential for damage to property and waterfront structures, while maintaining the minimum flow requirements necessary to protect downstream uses, including but not necessarily limited to: aquatic biota, historic resources and water quality.  Each year the NJ DEP Division of Parks and Forestry - State Park Service follows procedures to to manage the level of Lake Hopatcong.  However, the annual precipitation does effect the raising or lowering of the lake.  A gage to monitor the precipitation is also funded by the NJ DEP through a USGS agreement.

Back to Top

When is the lake lowered in the fall and raised in the spring?

Both the 26 inch annual drawdown and the 60 inch (five foot) drawdown dates will vary depending on the water level.  See the Lake Hopatcong Water Level Management Plan 2011 for dates. 

The 26 inch annual drawdown begins on or after November 12 except when the 60 inch drawdown occurs every fifth year.  Starting in late winter or early spring, depending on when the ice breaks away from the docks, rainfall is allowed to raise the lake level.

The 60 inch (five foot) drawdown is scheduled every five years and begins on or after September 22.    During the 60 inch drawdown from December through February, when ice conditions permit, the lake is allowed to rise but not higher than the 26 inches below the spillway elevation.  The next 60 inch drawdown is scheduled for September 2013.

Back to Top

What determines if there is a "SLOW SPEED - NO WAKE" restriction on Lake Hopatcong?

The water level determines when there is a "SLOW SPEED - NO WAKE" restriction on the Lake.   This "SLOW SPEED - NO WAKE" restriction shall exist until the water level recedes below a measurement of 9.50 as gauged from the dam at the Hopatcong State Park.  "SLOW SPEED- NO WAKE" is defined as minimal speed to make headway in a the prevailing conditions.  The New Jersey State Police enforce all Lake Hopatcong boating regulations

Back to Top

Crest of Dam/Spillway at Hopatcong State Park flowing into Musconetcong River - Fall, 2003 (60 inch drawdown)

Lake level reading of 9.00 feet on the Lake Hopatcong gage is 923.70 feet above mean sea level or the top of the spillway.

Crest of Dam/Spillway at Hopatcong State Park from Lake Hopatcong - Fall, 2003 (60 inch drawdown)

 
Revised: 04/19/16.