Flood Damage Reduction
The Project is designed to eliminate flood risk for a 20-year storm event—equivalent to the 1996 storm that caused significant damage to adjacent properties and transportation infrastructure.
- The built-up sediment has been removed from 12 key choke points to improve stormwater conveyance. Approximately 90,000 cubic yards of sediment has been removed.
- The paved-over sections of the River have been daylighted (brought above ground). Larger culverts (pipes) were installed in key areas.
- Invasive vegetation, whose spread led to a narrowing of the River channel, is being removed and the historic shoreline restored.
- Regular monitoring of ongoing sedimentation rates ensure that the benefits of dredging will last long into the future.
Water Quality Improvement
Urban stormwater runoff carries sand, organic waste, and various chemical pollutants from streets and parking areas into the Muddy River. The Project aims to achieve “Class B” surface water quality standards (as set by the Massachusetts Department of Environmental Protection) and “contribute to fishing and recreational uses in the Muddy River.”
- Contaminated sediment in the River and ponds is being removed.
- Best management practices have been established for street sweeping, catch basin cleaning, and illicit discharge detection and elimination.
- Regular water quality testing (both at stormwater outfalls and at designated sites within the River itself) will provide prompt feedback to public works departments.
- A growing number of sewer pipes are being lined with plastic to minimize contamination of stormwater and groundwater.
- Green infrastructure projects, such as infiltration basins and bioswales, will help ensure that stormwater flowing into the Muddy River is freer of contaminants.
Aquatic and Riparian Habitat Enhancement
Pollution, sedimentation, vegetation loss, and invasive species overgrowth have compromised the Muddy River’s habitats for birds, mammals, invertebrates, fish, amphibians, and reptiles. The Project includes efforts to enhance habitats in and along the River.
- Migratory fish passage and protection of turtle nests have been carefully protected during the entire construction process.
- Invasive plant species (Phragmites, Japanese knotweed, and purple loosestrife) have been removed.
- A diverse cross section of plantings, including wetland species, low and high shrubs, and upland trees, have been installed.
- Newly planted vegetation has been protected from herbivores and pedestrian traffic.
- “Habitat logs” have been placed along the river banks to create more varied homes for vertebrate and invertebrate species.
- New plantings are regularly monitored and maintained.
Historic Landscape Rehabilitation
Frederick Law Olmsted prioritized the human experience in his visions for the landscape. Rehabilitation of the Muddy River requires a balance of engineering solutions and landscape design.
- Planning has incorporated Olmsted’s vistas, pedestrian access, and integration of natural and built elements.
- New shrub and tree plantings reflect Olmsted’s original vision for the Emerald Necklace.
- Pedestrian paths, bridges, and buildings are key elements in the restored landscape.
- The Carlton Street Footbridge is being rehabilitated as a historically important entry point to the Riverway.
- The historic islands in the River channel have been restored.
Best Management Practices (BMPs) Implementation
A watershed-wide goal has been to reduce the quantity of sediment and other solid material entering the Muddy River through storm drains by at least 30%.
- Regular reporting by government agencies helps ensure that street sweeping and catch-basin inspection and cleaning are thorough and consistent.
- The public agencies have committed to undertake steps—including more frequent street sweeping and storm drain cleaning—to prevent sediment and contaminants from reaching the River.
- Damaged or non-functional stormwater outfalls will be replaced in a form consistent with the Olmsted landscape aesthetic.
- Where possible, bio-retention areas, sand filters, and swales will be installed to reduce the level of stormwater contaminants that reach the River.
Plus a Sixth Goal: Tree Stewardship
With input from the MMOC and its member organizations, the US Army Corps of Engineers has established a comprehensive plan for minimizing the impact of construction on healthy trees and maximizing the landscape rehabilitation in areas affected by the dredging work.
- Once landscaping is completed, 130 trees, more than 3500 emergent wetland plants, 6500 ferns, and 9000 shrubs will have been planted in the Project area.
- All of the newly planted trees derive from Olmsted’s original list of native species.
- The Project’s tree stewardship plans were presented at a meeting for the public held on June 30, 2020.
Long-term Maintenance and Management
The Emerald Necklace Parks Master Plan was developed by a program funded by the 1983 Open Space Bond Bill. The program in the Commonwealth of Massachusetts Department of Environmental Management was known as the Olmsted Historic Landscape Preservation Program. The Master Plan was completed in 2005 and remains the guiding document guiding maintenance activities along the River.
The primary goal of the Plan is to implement a superior performance standard maintenance and an effective system of management—and to ensure that the significant public investment in the Project is protected.
The Plan aims to strengthen the ongoing cooperation among the Massachusetts Division of Conservation and Recreation (DCR), City of Boston, Town of Brookline, park staff, volunteers, and park partners. It provides a blueprint for management and maintenance of the parks, as well as the coordination of capital projects and the maintenance they require. As the landscape matures and further restoration projects are completed, the Plan will provide guidance for responding to changing conditions and proposed capital improvements.
THE MASTER PLAN
Goal #1: Promote the enhancement, protection and preservation of the historic and natural landscape of the Muddy River park system.
- Rehabilitate and maintain the historic landscape and features in an appropriate and sensitive manner.
- Develop treatment recommendations that preserve and respect the historic and natural landscape features, circulation patterns, and the uses and structures that have been determined through research and documentation to be integral components of the Muddy River landscape.
- Minimize alterations or additions that are not consistent with the historical integrity of the area, while also recognizing contemporary needs and community priorities.
Goal #2: Advocate for public funding for ongoing management and maintenance of landscape features, uses, and structures that will guide park managers, administrators, and park partners who are responsible for the stewardship of the Muddy River parks.
- Develop a maintenance plan for the vegetation and historic landscape of the Muddy River.
- Provide guidelines for the use, rehabilitation, and maintenance of the historic structures in the parks.
- Prioritize projects for implementation by park partners.
- Analyze existing staffing and provide recommendations to realize an increased maintenance standard.
- Develop a budget as required by environmental documents that will support a higher performance standard of maintenance.
Goal #3: Promote the stewardship, use, and awareness of the Muddy River parks as a unique historic landscape.
- Support ongoing efforts of volunteer and community groups to preserve the historic landscape of the parks.
- Develop educational programs that reflect the significance and variety of resources within the Muddy River landscape.