Lexington Reservoir was created in 1878 by damming the Vine Brook, a tributary of the Shawsheen River. The reservoir covers an area of 35 acres. The reservoir is used for drinking water supply, recreation, and wildlife habitat. 

The Old Reservoir, locally known as “The Res,” was once a water source and is now a popular location for fishing and swimming. There is a sandy beach.

There is a fee for swimming at the beach.