MWA led the effort to remove the badly deteriorated Gruendyke Mill dam that partially blocked the Musconetcong immediately upstream from the Route 46 bridge at the border of Hackettstown and Mount Olive Township. The Gruendyke Mill dam was one of the many obsolete dams blocking the river. The removal of this dam was the first step in a long-term effort to restore the river's natural flow, improve water quality and enhance fish migration.

The photo on the left shows the Gruendyke Dam in the Fall of 2007.   Dams and the pools behind them may make a pretty scene to the casual observer with geese floating about amid lovely purple loosestrife flowers and the phragmites that look like feathered cattails. However, that lovely scene reveals a local environmental mess. When the dams were built they created an artificial pool that changed the local landscape. Native plant, fish and bird species lost their natural home. The pool of standing water created by the dam replaced wetlands, river banks and marshes that could no longer support the flora and fauna that formerly thrived there. Removing a dam is the first step in restoring the natural environment.

In March 2008 the first notch was cut in the Gruendyke Dam. On June 16, 2008 removal of the Gruendyke Dam began.

The photo on the right shows the dam in May 2008, after about 2 months of de-watering through the notch cut on March 11th, 2008. You can see a considerable drop in the dam pool.

In the photo below you see the dam on June 5, 2008. Note the riffle that has appeared above the dam, it is visible behind  MWA President Bill Leavens and National Park Service representative Paul Kenney. (A riffle is a small rapid caused by rocks extending across a stream bed.) Riffles provide excellent habitat for aquatic insects and good hunting grounds for fish, and in turn for the animals that come to hunt fish. The Musconetcong River is a National Wild and Scenic River, hence the National Park Service interest in the project.

Old dam leaves a mess in its wake June 26, 2008 by Tehani Schneider (Lots of pictures!)

The June 16, 2008 removal of half of the dam revealed something that we never could have guessed. For the most part, the consequences of damming our rivers are invisible. High temperature, concentrated pollutants and lower oxygen degrade aquatic habitat. But removal of the Gruendyke Dam revealed something that we could not have imagined - have a look at the river bed behind the dam! Yes, you are looking at the Musky!

An Emergency Clean Up coordinated by Brian Cowden, Trout Unlimited Musconetcong Home Rivers Initiative Coordinator was held on June 25, 2008 to remove the tires and other debris that were revealed under the former Gruendyke Mill Dam pool. Trout Unlimited members came out in force from several chapters to help. MWA Trustees and members, NJ hatchery workers, family of dam owners Rodger and Eileen Cornell and many others came out to help. Lunch for the volunteers was provided by the Pump House Restaurant. By the way, the entire project is in full view of the outside eating area at the Pump House Restaurant, 2 Highway 46 Hackettstown, NJ 07840.

For an informative video developed by the Hydropower Reform Coalition on the environmental and social impacts of dams on our waterways go to

For information about dam removals across the county check out Clearinghouse for Dam Removal Information

Older articles about the Gruendyke Mill Dam removal -

A Dam Irritation by Fred J. Aun Star-Ledger, Sunday October 26, 2007

Aiming to take down dam Hackettstown officials considering Seber Dam's demise By LYNN OLANOFF The Express-Times , Saturday, July 14, 2007

Conservation group says: Remove obsolete dams by John Monteith Hunterdon County Democrat Thursday, July 12, 2007

River's future looks rocky without help by Fred J. Aun Star-Ledger Wednesday, July 11, 2007

Group after dam-free river by Lynn Olanoff Express Times Monday, July 02, 2007

Putting the Wild Back Into the River by Kevin Coyne Sunday New York Times June 17, 2007 New Jersey Section Page 1

The saviors of the dammed Returning a river to a wild state by Brendan Berls Star-Ledger, Thursday, April 12, 2007


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  • Musconetcong Watershed Association
  • 10 Maple Ave. PO Box 113
  • Asbury, NJ 08802
  • 908-537-7060