Lake Cochichewick is the source of drinking water for the 28,000 residents of North Andover. At 560 acres, it’s the largest lake in Essex County, over twice the size of the local Merrimack College campus.

The lake and the surrounding water bodies were a major reason for early settlements in the area, with Cochichewick Plantation being chartered by the state in 1634. The settlement around Lake Cochichewick, which was colloquially known as Great Pond, began in the 1640s. The lake was popular for recreation then, as it is today. The lake is drained by the Cochichewick River, which passes through Stevens, Osgood, and Sutton Ponds before reaching the Merrimack River. As populations and industry grew in the region, these water bodies attracted mills and other businesses that would benefit from access to the water.

The Lake sits in a 2,700-acre bowl of land, the watershed, that drains into the lake. Near the airport, the watershed boundary is only seven hundred feet from the lakeshore. In other areas of the town, such as Barker and Bradford Streets, Lisa Lane, or Coventry Lane, the watershed extends a full mile from the lake, draining down through many neighborhoods and into the lake through the ground, in runoff, streams, and wetlands.

About forty percent of the shoreline is conservation land, including Weir Hill, Osgood Hill, Half-Mile Hill, the Stevens Estate on the west side of the lake, and Mazurenko Farm to the north. This conservation land helps protect and filter water draining into this part of the lake. Large institutional landowners on the east shore of the lake include the North Andover Country Club, Rolling Ridge Conference Center, and Brooks School. There are 43 residential parcels on the lakeshore and about 800 property parcels in the watershed.