Concord Gully Brook - Cumberland County

Working in partnership with CCSWCD.

Watershed Information
The main stem of Concord Gully Brook is approximately 1.5 miles in length and the watershed covers approximately 600 acres. The brook has three tributaries which ultimately drain into Allen Pond before entering the larger Harraseeket River Watershed at Porter’s Landing. The upper reaches of the brook watershed are relatively undeveloped but development does intensify along Lower Main Street (U.S. Route 1) and is expected to continue.

The Town of Freeport is taking a proactive approach in determining the causes of impairment of the Concord Gully Brook Watershed. In collaboration with the Cumberland County Soil & Water Conservation District, the Concord Gully Brook Watershed Survey project will identify, document and prioritize any soil erosion sites in the watershed and recommend conservation practices that can be installed to fix problems at these sites. In addition, a Stream Corridor Survey will also be conducted to identify potential areas that negatively impact aquatic life with issues such as lack of riparian buffers, lack of flood plain, potential sources of bacteria and opportunities for stormwater treatment.

Water Quality
Concord Gully Brook does not meet its Class B state water quality standards and is listed as an Urban Impaired Stream. Concord Gully is specifically listed as impaired because it does not provide for aquatic life due to degraded stream habitat conditions. Bacteria have also been an issue in the past with known documented violations.

According to the Maine DEP’s Impervious cover Total Maximum Daily Load (ICTMDL) December 2011 draft report, Concord Gully’s watershed has an impervious surface area of 24% compared to the 9% level that MDEP estimates is needed to support Class B aquatic life use. Pollutants in stormwater, excessive stormwater flow are the primary cause of impaired water quality.

Impervious cover or surface is any area that prevents rain/stormwater to infiltrate into the ground. Common impervious surfaces include parking lots, roads, driveway and rooftops. The amount of polluted runoff increases in relation to the extent of impervious surface that could result in water quality degradation.

Concord Gully Brook has been listed as an urban impaired stream by the Maine Department of Environmental Protection because it is not meeting State water quality classifications due to polluted runoff and increased storm flow volume from impervious surfaces such as rooftops, parking lots and roads.