Mill River Watershed Management Plan

The Mill River Watershed is located in Fairfield County in southwestern Connecticut. It has a watershed area of approximately 32 square miles, encompassing parts of six municipalities. The watershed is quite varied in many respects. At nearly 14 miles in length along the north-south axis, elevations range from sea level up to 630’. Because of its glacial geology, the topography includes low hills, while the main river valley features steep escarpments. The development patterns essentially divide the watershed in two: the developed southern and eastern portions of the watershed, and the rural headwaters to the north and west.

Princeton Hydro was contracted by Fairfield County, CT to develop the Mill River Watershed Management Plan (WMP). The Fairfield Conservation Commission, part of the municipal government for the Town of Fairfield, applied for a Clean Water Act Section 319(h) Nonpoint Source Program grant with CT DEEP to help address the TMDL and other nonpoint source (NPS) pollutant loading and stormwater management concerns in the Mill River. The grant was awarded for the development of this Watershed Management Plan (WMP). Princeton Hydro worked with project partners, including Connecticut DEEP, Harbor Watch, Trout Unlimited, Fairfield Shellfish Commission, FairPLAN, Mill River Wetland Committee, and Lake Hills Association, throughout the watershed planning process.

Mill River does not meet some of the water quality standards or designated uses. For example, in 2004 Mill River was added to the 303(d) List of Impaired Waterbodies, which is named after a section of the Clean Water Act that mandates tracking and reporting of impaired waters, for exceeding the standards associated with indicator bacteria. Mill River has had problems with excessive concentrations of Escherichia coli, more commonly E. coli.

The WMP was primarily intended to provide a path to improve water quality throughout the watershed. The plan followed the requirements for the Environmental Protection Agency’s watershed-based plans (WBP) that addresses nine specific elements. This type of plan therefore covered a wide range of topics including identification of water quality problems, determining the cause of those problems, identifying measures to correct the problems, securing the technical and financial assistance to implement the plan, and developing criteria, schedules, and a monitoring program to track progress. Throughout this process, Princeton Hydro routinely met with stakeholders to define their vision and refine the plan to meet the goals and objectives in an achievable manner.