The Connecticut River is home to many types of wildlife that move throughout the river and rely on parts of the river and riverbanks during their life cycles. Tiger beetles lurk on river beaches in sandy hideouts to hunt for prey. Ancient shortnose sturgeon migrate from the estuary to areas upstream and congregate together on the river bottom in the winter. Dragonflies live as larvae in the water and emerge to transform into adults on the banks of the river each summer. Freshwater mussel larvae move around via “host fish” and then settle into sediment and filter the water during their adult lives. These animals have been around for thousands of years, and only in the last few hundred years have been impacted by the presence and patterns of hydropower facilities on the Connecticut River. Not surprisingly, many of them have suffered and are now listed as endangered or threatened under state or federal law.

Five hydroelectric facilities on the Connecticut River are renewing their operating licenses under the Federal Energy Regulatory Commission (FERC). Later this summer, the public will have an opportunity to weigh in on terms for these licenses that will impact more than 175 miles of the Connecticut River for the next 40-50 years. These facilities are the Wilder, Bellows Falls, and Vernon dams in VT and NH, and the Northfield Mountain Pumped Storage Project and Turners Falls Dam in MA.

The current operation patterns of these five hydro facilities impact fish and other aquatic life in many ways, primarily through rising and falling water levels in addition to the obvious barrier of a dam itself. All the facilities hold back some flowing water, then release it through turbines to generate energy when it’s needed and profitable to do so – a process called “peaking.” This leads to constantly changing water levels upstream and downstream of these facilities.

Dragonfly and damselfly species in the Connecticut River are listed as threatened or endangered in Massachusetts, Vermont, and New Hampshire in the project areas. When they are ready to transform to adults, the larvae crawl out of the river to the bank, shed their larvae body, and unroll their wings, which must dry out and harden before they can fly. During this time, they do not move and are extremely vulnerable. If the water level rises or a wave knocks them back into the water, they will drown and die. Puritan tiger beetles are federally threatened, and the cobblestone tiger beetle is protected under state law. These beetles burrow in sandy or cobble areas along the river edge. They can survive short amounts of time being submerged in their burrows, but hydropower operations have permanently flooded some former habitat while submerging other areas almost daily. The Fowler’s toad is protected in NH and VT and there is important habitat downstream of the Vernon Dam. This toad lays eggs in small, ponded areas along the river. Dewatering or flushing these small ponds can wipe out the eggs or tadpoles.

Rapid changes in river flows, when hydro facilities suddenly release water, are also problematic. The high velocity water can flush shortnose sturgeon eggs and larvae downstream of Cabot station at the end of the Turners Falls canal. The same thing can happen with young freshwater mussels before they plant themselves into river sediment. Shad spawning below the Turners Falls, Vernon, and Bellows Falls Dams get spooked when conditions change abruptly. When their reproduction is interrupted, it can reduce the number of times a fish can spawn in its lifetime or reduce the number of young fish produced in a season.

Requirements under new hydropower licenses can address these impacts. Great River Hydro worked with CRC and other stakeholders to propose a dramatic change to their operations. They will convert to an inflow-equals-outflow operations model most of the time that will keep river water levels more consistent, with fewer small “peaking” events allowed, depending on the season. FirstLight has proposed slowing the rate at which turbines come on or the rate of rising water levels. However, rather than shifting to a model like GRH, FirstLight still plans to operate Turners Falls dam and Northfield Mountain Pumped Storage in a harmful “peaking” manner.

Everyone who cares about wildlife should get involved to speak up for the river later this year. Insist that FirstLight make better changes to their operations like Great River Hydro has proposed to protect our precious natural heritage species. Learn more at and speak up at