The Muddy River is a small waterway located in the Boston metropolitan area. Most of the 5.6 square mile watershed is located in the city of Boston and the town of Brookline, with a small portion located in the city of Newton. The 3.5 mile long Muddy River flows through the heart of Frederick Law Olmsted's famed "Emerald Necklace," one of the most carefully crafted park systems in America and the oldest remaining linear urban park system in the United States.

As a result of multiple floods, Boston's Parks and Recreation Department, working with the Boston Water and Sewer Commission, the Commonwealth of Massachusetts, the town of Brookline, the Federal Emergency Management Agency, and non-profit community groups such as the Emerald Necklace Conservancy and Fenway Alliance developed a comprehensive master plan to identify and address issues affecting the Muddy River.

Concurrent with actions by the local communities, the Corps of Engineers was authorized to study the Muddy River by a series of legislative acts. The Water Resources Development Act of 1999 authorized the Corps to evaluate the city of Boston's 1999 Master Plan to determine whether the proposed flood risk management and environmental restoration improvements were in the Federal interest. The Corps' Draft Evaluation Report, dated June 2000, determined that the City's Master Plan met some of the requirements of a Federally-implementable plan. However, continued Corps involvement would require preparation of a decision document that evaluated alternatives, identified the plan that maximized net National Economic Development benefits, and satisfied the requirements of the National Environmental Policy Act (NEPA).

Continued participation by the Corps was directed by Section 522 of the Water Resources Development Act of 2000. This Act authorized the Corps to carry out the project for flood damage reduction and environmental restoration, Muddy River, Brookline and Boston, substantially in accordance with the plans, and subject to the conditions, described in the Corps' draft evaluation report. In 2016 the aquatic ecosystem restoration element was deauthorized. The flood risk management portion is currently under construction.

The recommended plan consists of a combination of the 20-year flood risk management plan and extensive environmental dredging. The major features of the federally recommended plan include: improvements to protect against a flood with a return frequency of 20 years to include channel improvements, removal of undersized culverts, installation of two new culverts, and daylighting two sections (about 700 linear feet) of the Muddy River; dredging approximately 200,000 cubic yards of sediment from the Fens, Riverway, Leverett, Willow and Wards Ponds (the material will be dewatered on site and disposed of in licensed upland landfills); eradication of Phragmites from wetland and riparian areas by dredging and cutting/herbicide treatment; and preservation and restoration of the historic park shoreline and vegetation in construction areas.

The Commonwealth of Massachusetts, the city of Boston and town of Brookline will be the local sponsors of the project and will be responsible for long-term operation and maintenance of the project. This will include monitoring water quality, removal of future accumulations of sediment to maintain flood control, water quality, and sediment benefits, and monitoring to guard against recolonization by Phragmites.

For more information, please contact the Project Manager, by e-mail or by calling 978-318-8015.

- Updated: 27 January 2020