Fishways have opened up hundreds of miles of river to migratory fish in the Connecticut River watershed! We know this because we count the number of fish passing through these structures. Knowing how many fish and what species use these fishways helps us make decisions on how to best restore our migratory fishes.

  • The Leesville Dam on the Salmon River in Connecticut is monitored only for Atlantic salmon. The Salmon River joins the Connecticut River 18 miles upstream of the Long Island Sound.
  • The Rainbow Dam in Connecticut is the first dam on the Farmington River, and is located 8 miles upstream of where the Farmington River joins the Connecticut River. The Farmington River joins the Connecticut River about 57 miles upstream of Long Island Sound.
  • The West Springfield dam (formerly called the DSI Dam) in Massachusetts is the first dam on the Westfield River, and is located 4 miles upstream of where the river joins the Connecticut River. Westfield River joins the Connecticut River 75 miles upstream of the Long Island Sound.
  • The Holyoke Dam in Massachusetts is the first dam on the mainstem of the Connecticut River, and is 87 miles upstream of the Long Island Sound.
  • The Turners Falls Dam fish ladder in Massachusetts is 122 miles upstream of the Long Island Sound; The Vernon Dam fish ladder is located in Vermont, 142 miles upstream of the Long Island Sound.
  • The Bellows Falls Dam fish ladder is located in Vermont, 174 miles upstream of the Long Island Sound.

Connecticut River Basin Fishway Passage Counts

Report Date: 09/14/2023

Fishway, River -
Data as ofAmerican shadAlewifeBlueback herringAtlantic salmonAmerican eelSea lampreyStriped bassGizzard shadShortnose sturgeonOther/ comment
Rogers Lake-CTFinal 1,245        
Mary Steube, Mill-CT


Final 7,636        
Mill Pond, Falls-CT (NEW Fishway)Final 127        
Moulson Pond, Eightmile-CT5/16 15117  15    
Leesville, Salmon-CTOpen          
StanChem, Mattabesset-CT5/16 239        
Rainbow, Farmington-CTClosed*          
W. Springfield, Westfield-MA5/141,674    1,306   730 white suckers
Holyoke, Connecticut-MA 277,367 2,211 10,18721,1681166047 
Easthampton, Manhan-MAOpen          
**Turners Falls-Gatehouse, Connecticut-MA7/533,753    rechecking    
Vernon, Connecticut-VT7/527,283    7,371   missing data for parts of 13 dates
Bellows Falls, Connecticut-VT          no counts was operated

Total to basin, only first barrier counts

Last year totals (2022) 191,6516,68137047,84523,0423146320 

* CTDEEP will not operate the Rainbow Fish Ladder due its documented poor performance and the lack of suitable downstream fish passage fish passage
Fish passage is the ability of fish or other aquatic species to move freely throughout their life to find food, reproduce, and complete their natural migration cycles. Millions of barriers to fish passage across the country are fragmenting habitat and leading to species declines. The U.S. Fish and Wildlife Service's National Fish Passage Program is working to reconnect watersheds to benefit both wildlife and people.

Learn more about fish passage
protection measures at the Stanley Works owned dam/project. Fish passage at this project has been the responsibility of the CTDEEP, due to FERC legal rulings and timing of that facilities construction. 

** Spillway Fish Ladder - at the dam xx shad, xx sea lamprey; Cabot Station Ladder, base of canal, xx shad, and xx sea lamprey. Note that at Turners Falls Project (Dam/Canal) fish must use one of these two fishways first before having the opportunity to pass the final required ladder (Gatehouse).

A - total collected from 3 eel ramp/traps at Holyoke in 2022

At Holyoke Fish Lift, operations were suspended from high flows/turbidity from 5/2 through 5/7, and reopened on 5/8 with 3,764 American Shad passed that day. Shad counts on the following days have increased nicely- 5/9 (4,082), 5/10 (9,830), and 5/11 (22,663), water temps are seasonally cool (14.6C or 58F) and discharge in main stem and tribs are close to long term averages. Other species, as shown are now also passing there. Historic, long-term annual (daily time step) data shows "approximately" 15% of the annual shad run is passed by 5/11 at HFL. Research by UMass/USGS Research Coop Unit has shown for Blueback Herring a shift in run timing at Holyoke starting and ending earlier. We plan to expand modeling work for the other species as climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

Learn more about climate change
studies have been demonstrating both shifts and compression of these life history "windows", with potential concerns for population resilience among others. My Office's river herring assessment work, showed an increase in Blueback Herring abundance in Wethersfield Cove, rates close to our 10 year average (vs. last year's time series lows). We also sampled fish in Massachusetts tribs at modest rates, with temps still on cool side. The Farmington River produced highly variable rates that over the day increased on each successive downstream run, suggesting fish just moving in (at least for the ~7 km we cover to near its mouth).



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Juvenile Northern Pike in aquarium at Gavins Point National Fish Hatchery, South Dakota
The Fish and Aquatic Conservation program leads aquatic conservation efforts for the U.S. Fish and Wildlife Service. We are committed to tackling the nation’s highest priority aquatic conservation and recreational challenges to conserve, restore, and enhance fisheries for future generations.