West Brook

A view of the West Brook.

With its headwaters in Whately and Conway, the West Brook watershed spans 7,018 acres and flows through one of the largest tracts of unfragmented forest in Massachusetts.

During the 18th and early 19th West Brook, with its steep gradient and nearly two dozen waterfalls, was considered one of the most valuable power streams for its size in Massachusetts. Early settlers built built dams at nearly every waterfall (or privilege) and small mills flourished along the watercourse. But by the late 19th century, the mills were in decline. Their demise was due to a combination of events--the opening of the West, the lure of factory jobs in the cities, and floods that damaged the millworks. By the turn of the century, the few remaining mills were forced to close when the City of Northampton built an 18-million gallon reservoir above their dams.

West Brook: Northampton's Main Source of Drinking Water

A reservoir within Mill River.

Sixty years later after the construction of the West Whately

Reservoir, the City of Northampton built a much larger dam to form the 720-million gallon Ryan Reservoir. Together the West Whately and Ryan Reservoirs provide an average of 1.58 million gallons of water per day to the residents and business of Northampton. The Northampton Water District is registered to withdraw 3.96 million gallons of day.

In order to protect the quality of its drinking water, the City of Northampton has an active land acquisition program and has secured over 2000 acres of land surrounding the reservoirs and their tributaries. At its northwestern boundary, the City-owned watershed land abuts the 1,946-acre Conway State Forest,

A black bear resting in a tree.

creating a large block of forested habitat for wildlife, from bear and moose to tropical migratory birds, like wood thrushes and scarlet tanagers. Many of these tropical migrants depend on big forest patches to avoid cowbirds and nest successfully, and their numbers have seriously declined due to forest fragmentation in North America.

In addition to wildlife, the western portion of the West Brook watershed includes pockets of rich, mesic woods, where lush swaths of maidenhair fern, blue cohosh, squirrel corn and isolated stems of the state-listed American ginseng can be found.

Other Water Supply Connections
In addition to drinking water reservoirs, West Brook appears to play a significant role in helping to recharge the narrow, confined aquifer tapped by Whately and Hatfield public wells. Not far from its confluence with the Mill River, West Brook flows over an old glacial delta. It is likely that some of the river water sinks down into the permeable sands and gravels, helping to replenish the aquifer at the base of the delta. Hazardous waste spills or other contaminants from residences built on the delta could threaten the safety of the aquifer.

Water Quantity & Fish Issues

Because of the height of the City of Northampton's dam on the West Whately Reservoir, little to no water flows over into West Brook in the summer. During this time, all the water in the West Brook comes from surfacing groundwater and smaller tributary streams, such as Jimmy Nolan Brook and Potash Brook. These low flows have serious consequences for the downstream aquatic community. However, because so much of the brook is forested and fed by groundwater, its waters remain cold and well-oxygenated throughout the year. These conditions made West Brook a logical choice for a detailed, multi-year study on the habits of young Atlantic salmon, which are annually stocked as fry in the brook. The Salmon study, which is sponsored by the US Fish & Wildlife Service, has marked every Atlantic salmon with a personal identification tag (PIT) in a 1-kilometer stretch of brook. Each month researchers use nets and electro-shockers to catch, measure, weigh and photograph every salmon living in this section. Preliminary results show that salmon have a high fidelity to their home site. However, when spring comes, most of the 2-year old salmon (smolt) move en masse down river to the Atlantic Ocean.

Although the Hatfield Dam on the Mill River and a large waterfall on West Brook prevent salmon from returning to the waters of West Brook, it is stocked each May with approximately 7000 salmon fry.