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Mousam Watershed

Public Swimming Beaches

The Mousam River Watershed drains 122 square miles from portions of Acton, Shapleigh, Waterboro, Sanford, Alfred, Lyman, and Kennebunk, Maine. The watershed can be divided into three main portions. In the western part, the Mousam River flows from Square Pond and Mousam Lake in Shapleigh, and gathers water from numerous small ponds, streams, and wetlands as it flows through Sanford. This area is rural with thousands of acres of wetlands, forests and agricultural land, which include scattered areas of significant habitat for inland waterfowl and wading birds. Development near the headwaters of the Mousam River is concentrated along the shores of the lakes and ponds. The densest development occurs around the river as it passes through the center of Sanford. An extremely high percentage of impervious surface causes increased flows of stormwater to the river here. The outfall for the Sanford Wastewater Treatment facility flows into the Mousam, and its retention ponds are popular bird watching spots.

In the eastern part of the watershed, the Middle Branch of the Mousam River flows out of Waterboro and gathers water from Shaker Brook, Littlefield River, and other small streams and wetlands as it passes through Alfred and joins the Mousam River at Estes Lake. The surrounding area is characterized by large tracts of forest and scattered agricultural land, which includes significant habitat for the endangered Northern Black Racer, Ringed Boghunter, and Blandings Turtle, as well as the threatened Spotted Turtle, and significant deer wintering habitat. Development is highest along the Middle Branch where it passes the town centers of Waterboro and Alfred.

The combined volume of the two branches flows from Estes Lake and passes through Kennebunk, where it is joined by a few small streams before meeting the Gulf of Maine. The main stem of the river is 24 miles long from its source at Square Pond in Shapleigh, to its mouth in Kennebunk. The Kennebunk Wastewater Treatment Facility outflow empties into the river just below the last dam. The surrounding watershed narrows as the river flows south. While the percentage of impervious surface increases significantly in this southern portion of the watershed, there are scattered areas of forest and agriculture land that provide significant habitat for the endangered Northern Black Racer, White-topped Aster, and Flowering Dogwood. Several parcels of conservation land are located in the lower portion of the Mousam River watershed including state and federally managed lands as wells as privately held easements. The river encounters ten dams along its course, several of which generate electricity. The Kennebunk Wastewater Treatment Facility outflow empties into the river just below the last dam in Kennebunk Upper Village.

The Mousam River passes through a tidal estuary and empties into the Gulf of Maine at Parsons Beach. A broad saltmarsh borders the river within the Rachel Carson National Wildlife Refuge. This area is significant habitat for numerous coastal wading birds, waterfowl, and shorebirds including the endangered Piping Plover. The beach is also a popular swimming and fishing spot and human activities can often impact wildlife there.

Non-point source pollution
Intensifying shore front development
Ongoing Projects:
Best Management Practices for controlling runoff around Mousam Lake.
Key Resource(s) for Mousam Watershed:
(Click the Title of the entry below to learn more.)
Kennebunk Land Trust
Community Assistance Providers
A land trust serving Kennebunk, Arundel, and Lyman.
Three Rivers Land Trust
Community Assistance Providers
A regional land trust for Acton, Alfred, Lebanon, Sanford, and Shapleigh in Maine
Towns located in Watershed:
Acton [ME]
Alfred [ME]
Kennebunk [ME]
Lyman [ME]
Sanford [ME]
Waterboro [ME]
Counties located in Watershed:
York [ME]
 Website: www.co.york.me.us
 Phone: 207-324-1571
 Population SWIM Towns: 121,400
 Total County Population: 202,232 (U.S. Census Est. 2006)
 Area SWIM Towns: 645.3 square miles
 Total County Area: 1002.6 square miles
Waterbodies located in Watershed:
(WC-watercourse, WB-waterbody)

Bunganut Pond [WB]; Carll Branch [WC]; Cold Water Brook [WC]; Day Brook [WC]; Estes Lake [WB]; Fernald Brook [WC]; Hamlinton Brook [WC]; Hay Brook [WC]; Heath Brook [WC]; Littlefield Pond [WB]; Littlefield River [WC]; Loon Pond [WB]; Middle Branch Mousam River [WC]; Middle Branch Pond [WB]; Moody Pond [WB]; Mousam Lake [WB]; Mousam River [WC]; Northwest Pond [WB]; Number One Pond [WB]; Old Falls Pond [WB]; Round Pond [WB]; Scotsman's Brook [WC]; Shaker Brook [WC]; Shaker Pond [WB]; Square Pond [WB]; Stump Pond [WB]; Trafton Brook [WC]

The Town of Sanford (population 21,000) rose to industrial prominence in the 1800s on the power provided by the River. The large brick mill complexes still line the waterway through the community. Several of the 10 dams along its length are still used for generating electrical power.
Most of the agriculture that supported this region for two centuries has disappeared leaving only hayfields, abandoned orchards, and stone walls through forests.

Nearer the coast the development in the watershed intensifies. Kennebunk (population 10,500) saw a population increase of 31% in the past decade. This is in addition to a tourist based economy that sees thousands of visitors during the summer and increasingly spring and fall seasons.
The Wells National Estuarine Research Reserve at Laudholm Farm, Wells, Maine Copyright 2006 All rights reserved. Collaboration with NOAA CSC, Charleston SC