The Project’s flood control objective will be accomplished by removing restrictions in the river so that flooding during major storms (such as the flood of 1996) does not damage adjacent properties or transportation infrastructure. Existing restrictions include the growth of invasive vegetation, such as tall reeds (Phragmites), the build-up of sediments in the riverbed, and limiting water movement by forcing the river through undersized pipes.
After the construction of the dam on the Charles River, the Fens and the Muddy River were no longer subject to tidal flushing. Today, there is only a one-foot drop in water level between Leverett Pond and the Charles River Basin. As a result, over the years, flow in the Muddy River has diminished as silt and sediment (e.g. sand) from roadways and other development have filled in the waterway. Other flow restrictions have occurred over the years as sections of the river were filled and pipes were installed. This occurred at the Fens Bridge and Brookline Avenue where pipes were installed and the river was filled in the 1940s in anticipation of roadway widening. In front of the Landmark Center, the river was filled for a parking lot. These pipes or culverts also restrict flow in major storms events, contributing to the flooding. Invasive vegetation, particularly Phragmites reeds, has grown up along the banks and in shallow open waters resulting in a narrowing of the watercourse.
Flood control strategies will address the three problems that restrict the capacity of the river:
- The built-up sediment will be dredged to restore the original depth and width of the river;
- A combination of “daylighting” and the installation of larger culverts (pipes) will occur in areas where the river has been filled;
- Invasive vegetation will be completely removed and the historic shoreline restored.
What is “daylighting?”
Daylighting exposes sections of the river that have been diverted through underground pipes and opens them up to the daylight. The fill and the pipes will be removed. In their place, the river will be restored as an open stream.
Muddy River rises March 14, 2010
(U.S. Army Corps of Engineers photos)
Project Phase 1
(U.S. Army Corps of Engineers photos)
