March 06, 2012

Musconetcong River channel restoration projects completed

TU’s Musconetcong Home Rivers Initiative Coordinator, Brian Cowden, reports that a total of one mile of the 42 mile Musconetcong River was restored in late February using Natural Resource Conservation Service’s WHIP (wildlife habitat incentive program) funds and NJTU state council funding on 3 sites on the upper and middle river in Mansfield and Washington (Warren Cty). 

These projects were chosen for their impact to restore sections of river channel greatly affected by man’s interference over past decades. The 1/3 mile section of river restored in lower Mansfield Township behind the Cliffdale property (most recently Cassia Grill) has widened by as much as a third since heavy development was allowed along the river to facilitate large scale box stores within 150’ of the river upstream of this project site.  All of that impervious cover flashes the river during run-off, causing it to widen, shallow and fill with sediment.  At the downstream site in Washington and Hampton below route 31, the river channel was actually straightened (channelized) most likely during the 1920s and 30s when such practices were common in an attempt to reduce flooding.  This wreaks havoc on the channel in the straightened reach as well as far downstream, causing widened and shallow channels that are ““simplified”” and lack structure that holds both aquatic macro invertebrates as well as trout and bait fish. These sections were chosen for their unique restoration needs as demonstration projects in the watershed under the Musconetcong Home Rivers Initiative.
During channel restoration, the river is narrowed where needed using control structures, digging out of pools, addition of boulders and restored point bars to keep the river flowing and transporting sediment during low water periods.  TU employed the state of the art services of Urbani Fisheries out of Bozeman, MT for their natural approach to channel restoration and bank stabilization methods.  The Urbani team utilizes their own machine operator who only works on river restoration implementation, making their approach unique in the field. 

Here are some photos of the work:

Channel bottom prior to restoration where sediment largely covers bottom cobbles.

underwater sediment

Channel bottom after restoration.

underwater after reconstruction

Here is a view of a typical section of this simplified channel where it was overly wide, shallow, sediment laden, and lacking fish habitat in the form of pools, riffles, or pocket water.

Washington looking down

Here is a section of the river recently restored.  Here you’ll note restored point bars which narrow the channel, boulder clusters to provide habitat, as well as deeper pools to hold fish of all species. 

Washington looking up

And one of our deeper pools to provide thermal refuge, dissolved oxygen, and fish holding structure.  In this photo, the very first canoeists enjoyed paddling this restored stretch during construction.

Newly restored deep pool habitat at Homeboy pool

Stay tuned for additional photos in coming days of work performed upstream as well as more from the 7/10 mile stretch on two properties in lower Washington Twp. in Warren County near route 31.