River dam removal and in-channel restoration enhances fisheries
I wrote this piece for my Recorder Newspapers column last year.
51 dams were deconstructed in 2013 through a nationwide movement to return rivers to free, flourishing flows. Here in the Highlands, The Musconetcong River Partnership won the 2012 Presidential Coastal America Award for removal of Musconetcong River dams. The Partnership is a team of agencies, organizations, and individuals, including New Jersey Trout Unlimited, the Musconetcong Watershed Association, American Rivers, NJDEP-Division of Fish & Wildlife, US Fish & Wildlife Service, and many others, all honored by the Office of the President of the United States.
While the Musconetcong is getting the most attention through a process ancillary to dam removal—in-channel restoration—continuing this year, efforts in New Jersey to improve rivers aren’t limited to the Highlands. Somerset County’s Raritan River has had three dams removed, and soon the Millstone River will flow freely from the dam at Carnegie Lake in Princeton to the Raritan. Trout are a concern in the Highlands, but these three rivers share shad and herring in common as a migratory possibility. In fact, shad and herring have been videoed at the Raritan in recent years. Remaining are two Raritan dams: the 1995 Island Farm Weir constructed with fish ladder and video devices just below the Millstone confluence, and the Headgates Dam, located a short way below the South and North Branch Raritan Confluence by Old York Road in the northernmost reach of Duke Island Park. The Millstone River awaits the removal of Blackwell’s Mills Dam well upstream of the town of Millstone possibly this summer. The Weston Causeway Dam at Manville will go sometime soon. Both Millstone River dams are low head varieties, but do obstruct the migration of fish.
Two of the remaining dams on the Musconetcong River are anything but low head. The Hughesville Dam—expected to be deconstructed in 2015—is 10 feet high, the Warren Glen Dam an enormous 35 ½ feet tall. The latter will be an extremely difficult project, but Trout Unlimited Musconetcong Coordinator, Brian Cowden, is confident that The Musconetcong River Restoration Partnership will pull it off.
“We’re talking about multiple millions of dollars, and where will that money come from?” Cowden said. More daunting than money, perhaps, is dealing with the sedimentary results of (?) years of the river gorge being dammed—too many tons of mud to guess the number. “Removing the concrete is easy. How do we get that sediment out of there, and where do we put it?”
I’m sure ways will be found, since the political will behind the project is powerful.
“Everyone in the partnership wants that dam gone, including the owners,” Cowden said. “That’s gonna clean up the Musky Gorge for trout fishing. It’s also going to be good for kayakers and canoers. That habitat is phenomenal, and significantly more water will be flowing through than the Ken Lockwood Gorge. Over time, sediment has settled over those beautiful boulders at the river’s bottom behind that dam, and this will renew the gorge as it naturally was.”
At present, more than four miles of the Musconetcong between Finesville and the Delaware River have been opened and flow without obstruction. Six dams have been taken out, considering that the Partnership’s Riegelsville project involved two solid wood coffer dams and a hand built stone dam. Gruendyke Mill Dam, Seber Dam, and the Finesville Dam are also gone. Removal of the Bloomsbury Dam is under consideration, but Saxton Falls—way upstream above Hackettstown in Stephen’s State Park—is not a concern.
“That dam is part of the State Park System. We’re not even targeting that. Our focus is downstream,” Cowden said.
When Bloomsbury Dam goes, shad will have a long, free flowing revitalized river to travel and spawn well upstream. Wild trout will respond with a healthier population to increased oxygen, lower water temperatures, and better insect hatches. And river ecology is also improved by in-channel restoration.
Trout Unlimited has been overseeing restoration efforts on the Musconetcong. This year, 1/3rd mile of the Point Mountain Trout Conservation Area, a full mile of the Wattle’s Tract, 1/3rd mile at Asbury, and a section at Beatty Farm, as well as a half mile of tributary West Portal Brook, will be shaped into environmentally sound configurations. Channels are narrowed where they become too shallow and wide, because increased run-off from impervious surfaces like parking lots homogenize the river bed. Pools are dug, boulders added, and point bars shaped, all to keep the river flowing strong, transporting sediment, and producing more trout in these enhanced habitats.
While the river is spring fed, trout generally reproduce in protected feeder streams, which tend to carry more spring water by volume. Nevertheless, the long term effect of restored habitat is likely to increase trout numbers, because offspring will find fit places to mature.