Lake Mamanasco is located in the Town of Ridgefield, Fairfield County, Connecticut. It is 4,750 feet long, 1,500 feet wide, and has an approximate area of 96 acres. The deepest part of the lake, located in its central basin, is 10 feet, and it has an average depth of 5 to 6 feet. It is maintained by water from tributary flows, direct precipitation, stormwater inputs, and groundwater seepage.
Originally the lake was about 1/3rd its current size, but two impounding structures dating back to 1716 have increased it to its present surface area. Since that time, there has been a progression of dam and mill structures occupying the original outlet site. The final mill to have utilized Mamanasco Lake was a paper mill erected in the 19th century, whose abandoned works can still be seen today off of Pond Road.
The watershed area of a lake refers to the total area of the land which contributes water to that lake. The means by which water is contributed can include surface runoff, piped storm drainage or groundwater seepage. The ecological habits of all the residents of a watershed in regard to lawn fertilization, useage of certain cleaning agents, and septic maintenance can, therefore, directly affect the condition of the lake. The Mamanasco Lake Improvement Fund MLIF with the co-operation of the Town of Ridgefield and the state DEP, has launched a long-term program to restore the lake. It includes chemical treatments as a short term solution to the aquatic weed problems, and a watershed management plan that will eventually reduce the flow of pollutants into the lake from its watershed. Find out about this ambitious undertaking by clicking Restoration Plans.
The watershed of Lake Mamanasco covers an area of 537 acres and contains about 440 homes. It is bounded on the southeast by Tackora Trail, to the southwest by Barrack Hill Road, and to the north by North Salem Road. In addition to the private residential homes, the state maintains a boat ramp and parking area, while Richardson Park makes the town of Ridgefield the largest single lakefront property owner.
The lake is the center of many recreational activities including swimming, fishing, sailing and ice fishing. The major beach located on the western shoreline is the Mamanasco Beach Club, a private beach operated by the Eight Lakes Community Association. The most prolific game fish is largemouth bass. Boats may access the lake from the state owned boat launch located on the southwestern end of the lake. Gasoline motors are prohibited on Lake Mamanasco, so boating is primarily by rowboats, canoes, or boats with electric motors or sails. Snowmobiles and jet skis are also prohibited.