Fish Ladder at the Center Falls Dam

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Updates from the Conservation Commission

Herring Observations in the Aberjona 2019

The Fish Ladder at the Center Falls Dam 

Winchester’s fish ladder is a critical passageway connecting river herring habitat above and below the Center Falls Dam, located at the Mill Pond in Winchester Center. The dam, which blocks herring from swimming upstream, now has a fish ladder that provides river herring a safe passage to enter the Mill Pond and continue their migration upstream.

A fish ladder allows fish to migrate around a dam by providing enough water so that fish can swim up to the other side of the dam. The velocity of water is controlled to prevent pushing fish back downstream. The fish ladder is located on the right side of the dam, facing upstream. Look for the metal grating by the side of the bridge to see the concrete channel of the ladder underneath, the flowing water, and the herring during migration.

River Herring 

Locally, we have two species of river herring, the Blueback Herring (Alosa aestivalis) and Alewife (Alosa psuedoharenous). Both spend most of their lives in the ocean, but return each spring to freshwater rivers and lakes to lay and fertilize their eggs. This is called spawning, and the adults return to the ocean after it is over. The young mature in freshwater and make their own way to the ocean in the late summer and fall.

 River Herring and the Food Web 

The ability to navigate around the Center Falls Dam provides river herring new habitat and spawning areas, helping their survival and the survival of species that feed on them. The herring are the foundation of several food webs and provide food for many species, including birds (herons, gulls, cormorants, ospreys, and eagles), other fish (striped bass, tuna and cod), and mammals (river otters, foxes and raccoons).

 The Migration Pathway: From Saltwater Through Winchester’s Rivers and Lakes 

In terms of numbers of fish, the Mystic River Watershed herring migration is one of the largest in Massachusetts. There is a camera that counts the fish using the Winchester Fish Ladder to pass upstream. There is also a counting program at a fish ladder installed at the dam between the Mystic Lakes. The fish ladder allows the herring to reach Horn Pond in Woburn. Herring have also been observed in the Aberjona River, upstream of the underground culverts in Skillings field.

 Fish in our Past: “Herring Swarmed in our Waters” 

Records show that herring actively ran in Winchester in the past. In 1870, Winchester built a fish ladder at the Center Falls Dam. By 1872, people wrote that the herring “swarmed in our waters.” But river pollution and artificial obstructions killed off the herring by the early 1900s. When the Town built the current semi-circular Center Falls Dam in 1914-1915, the original fish ladder was not replaced.

A century later, in November of 2016, the new fish ladder was installed. It was dedicated on Winchester Town Day, in June of 2017.


The Fish Ladder was created by the Town of Winchester, with support from the Mystic River Watershed Association, the Massachusetts Division of Marine Fisheries, the performing parties at the Industri-Plex Superfund Site, and the En Ka Society.

For more information about river herring, visit