Lake Cochichewick

Lake Cochichewick is North Andover's drinking water supply, about two miles long, and its use is tightly limited: boating is only for town residents with a permit from the Department of Public Works, in hand-powered or electric boats, and anglers need a Massachusetts fishing license. Swimming and wading are not allowed. The easiest way for anyone to enjoy it is on foot, along the shoreline trails at The Trustees' Weir Hill.

The Lake

The Town of North Andover's page on the lake says it was the main reason settlers came to the area: the Cochichewick Plantation was chartered in 1634 and settlement around the lake, then called Great Pond, began in the 1640s. The lake drains through the Cochichewick River, which passes through Stevens, Osgood and Sutton Ponds to the Merrimack River. The Trustees describe it as two miles long.

The lake sits in a 2,700-acre watershed. The town says less than a third of its water falls directly on the lake as rain; the rest runs off or seeps in through neighborhoods. About 40 percent of the shoreline is conservation land: Weir Hill, Osgood Hill, Half-Mile Hill and the Stevens Estate on the west side, and Mazurenko Farm to the north.

Why the Rules Are Strict

In 1986, the town says, polluted runoff led to giardia in the lake, a state boil-water order and a new $19.9 million water treatment plant. Cyanobacteria (blue-green algae) blooms have appeared several times since 2000, including in summer 2020; the town notes that fertilizer runoff and pet waste are major causes and asks pet owners in the watershed to leash and pick up after their animals. Tap water is treated and safe to drink even during a bloom.

Boating

North Andover's Lake Access Committee drafted the current lake rules in 2001 and the town updated them in 2016. The town's page says:

• Hand-powered boats and electric boats are allowed.
• You need either a day permit or a lake use and boat storage permit from the town's Department of Public Works.
• Boating is limited to North Andover residents with permits.

The town's notices give the boat storage season as April 15 to November 1, and the town's bylaws keep boats and anglers at least 100 yards from the water treatment plant. The Trustees add that canoes and kayaks reach the lake from the town launch near Weir Hill's Pleasant Street entrance.

Fishing

Fishing requires a state fishing license, according to the town. Anyone 15 or older needs one; see fishing for 2026 costs. The town notes that state studies in the 2000s found much lower mercury levels in the lake's fish than in the past. Nonresidents cannot boat here, so fishing is from shore where shoreline access is allowed.

Swimming and Dogs

Swimming and wading are not allowed, and The Trustees restrict dog access to the lake. For a swim nearby, see DCR's Berry Pond in Harold Parker State Forest or Andover's Pomps Pond.

Walking the Shore at Weir Hill

The Trustees' Weir Hill reservation follows more than a mile of the west shore. Its 2.3-mile yellow loop takes the Edgewood Farm, Cochichewick, Alewife and Stevens Trails along the water to Stevens Beach and the Pleasant Street entrance, and its hilltop trails look across the lake. Free, sunrise to sunset, dogs on leash. See Weir Hill.

Lake Cochichewick and Harold Parker

The lake is in the northeast part of North Andover; Harold Parker State Forest is in the south of town and Andover. Harold Parker is the place to paddle without a residency permit: DCR lists non-motorized boating there, and its planning summary names Field and Stearns Ponds as popular for canoeing and boating. See the ponds.