Hopkinton Reservoir

Hopkinton Reservoir is the lake at the center of Hopkinton State Park, in Hopkinton, Massachusetts, one of the reservoirs built on the upper Sudbury River for Boston's water supply. Today it is a DCR recreation lake: you can swim at Reservoir Beach in season, paddle or sail anywhere boats are allowed (no motors of any kind), fish from shore, and walk out to the historic earthen dam, which DCR says has some of the best views in the park year-round. Its smaller neighbour, the Swimming Pond, holds Main Beach.

A Reservoir Built for Boston

The Massachusetts Water Resources Authority's history of the regional water system explains why there is a reservoir here at all. Boston outgrew its first supplies in the 1800s, and in 1878 the main stream of the Sudbury River was diverted through the Sudbury Aqueduct to Chestnut Hill Reservoir. Between 1875 and 1898, MWRA says, seven major reservoirs were built in the upper Sudbury River watershed. The Friends of Whitehall, a volunteer group at a neighbouring reservoir, list Hopkinton among them, alongside Sudbury, Whitehall, Ashland, Stearns, Brackett and Foss.

The Sudbury system was later overtaken by Wachusett and then Quabbin. MWRA lists the Sudbury Aqueduct as emergency-only today, and says DCR still manages the reservoir watersheds in partnership with MWRA.

The Earthen Dam

DCR singles out the park's historic earthen dam as offering some of the best views in the park, year-round. On DCR's trail map, the dam runs between the reservoir and the Swimming Pond on the east side of the main recreation area, near Main Beach and the Beach Pavilion, and a path crosses it. It's an easy walk from any of the eastern lots and the best spot for a long look down the water.

Swimming on the Reservoir

DCR's map shows Reservoir Beach on the reservoir shore near the boathouse. Like Main Beach on the Swimming Pond, it is lifeguarded seasonally and open for swimming late May through Labor Day. You may swim only at the designated beaches; the rest of the shoreline is off-limits to swimmers, and floats are banned. Swimming guide.

Paddling and Sailing

No motorized watercraft of any kind are allowed, so the reservoir is all paddles and sails. Regatta Point Community Sailing, the park's rental operator, describes it as wind-protected and good for beginners, and rents kayaks, canoes, paddleboards, pedal boats and sailboats from its boathouse in season (rentals and prices). You can launch your own car-top boat at the ramp, or at the canoe launch on Cedar Street shown on DCR's map.

Walking the Shore

There is no single trail all the way around the water on DCR's map. On the west side, the Arborvitae and Vista trails run near the shore by the entrance. On the east side, Reservoir Run follows the shore toward Cedar Street. Combine them with park roads for a longer outing. Hiking trails.

Wildlife

Regatta Point mentions herons, hawks and deer among the wildlife paddlers see on and around the reservoir.

Fishing

DCR lists fishing, including accessible fishing, and links MassWildlife's trout stocking report from the park page. Fish from shore or from a non-motorized boat with a Massachusetts license. Fishing guide.