Moosup River Dam Removals

In 2013, American Rivers, CTDEEP Fisheries, and Natural Resources Conservation Service began collaborating on an effort to remove up to five dams as part of a long-term project to restore connectivity to the Moosup River, prized trout-fishing stream in the Town of Plainfield. Princeton Hydro was contracted with RiverLogic Solutions to provide design-build and permitting services.

As part of this larger effort, the most downstream barrier, Hale Factory Dam, was removed in 2014. The remnants of the toppled Griswold Rubber Dam (approximately 2 miles upstream) were removed in 2015. The removal of Brunswick Mill Dam #1 (approximately 0.75 miles upstream) was completed in 2017.

Princeton Hydro developed a design-build approach for the project in collaboration with RiverLogic Solutions, a contractor highly specialized in the removal of dams. Princeton Hydro prepared design plans and project permitting, as well as supervised construction for the three dams. RiverLogic Solutions provided design and constructability input, and the construction services to remove each dam.

Princeton Hydro proposed a low-cost, low-impact approach to the removal of the Hale Factory Dam that involved the full removal of the structure, the re-use of boulders from the dam for random in-channel placement to enhance aquatic habitat, and the passive recovery of the channel. Griswold Rubber Factory Dam Removal involved the demolition and removal of concrete slabs and the creation of a natural gravel/cobble riffle coupled to the existing pools upstream and downstream of the former spillway to provide enhanced fish habitat. In addition to restoring aquatic organism passage, the Brunswick Mill Dam #1 removal, also provided for removal of a large floodplain constriction and a public safety hazard, and stabilization of an eroding bank.

While dam removal is becoming a more common mode of restoring rivers, efforts like this – to remove multiple barriers on a single river – are rare. When clustered on a single river, the ecological benefits to restoring aquatic organism passage and enhancing aquatic habitat are substantially magnified.