Flood Control

The Roslindale Wetlands provide a buffer against flooding

For many years, local residents of the Peters Hill area have recognized the role played by the Roslindale Wetlands in handling rainwater runoff from heavy storms. Runoff flows downhill to the low-lying wetlands, where it can pool until it is reabsorbed by the soil and flow into the Charles River basin. The Boston Water and Sewer Commission recognizes the wetlands' importance and has infrastructure in place directing stormwater overflow into the area.

With changes in the climate, the number of severe storms has increased, and this upward trend is expected to continue. Hundred-year flood levels were reached in 2010 and 2012. When the City of Boston developed its interactive Climate-Ready Boston map, the Roslindale Wetlands showed up as one of the wettest areas, shown in dark blue. The City's climate action plan cautions that "rising sea levels and extreme precipitation will exacerbate stormwater flooding."

flooding map detail

In addition to more frequent storms, climate scientists expect higher sea levels, which can have effects even far from the coast. Backflow could occur if sea levels rise to the point of overtopping the Charles River Dam, which would raise water levels throughout the entire Charles River watershed. Because water in the Roslindale Wetlands drains into the Charles River, backflow would cause accumulated water in the wetlands to reach higher levels and take longer to reabsorb. The Climate Ready Boston plan recognizes that "stormwater outfalls may not be able to discharge or may even backflow" (p. xxv).

Green infrastructure as a climate resilience strategy

A strategy recommended in the City's climate action plan is to "expand the use of green infrastructure and other natural systems to manage stormwater, mitigate heat, and provide additional benefits" (p. xl). It goes without saying that existing green infrastructure such as the Roslindale Wetlands must be preserved in order to achieve a net gain in buffer areas against the consequences of a warming climate.

Mass Audubon also recommends preserving open, natural spaces as a buffer against the effects of extreme weather events. "Preserving forested lands in urban areas helps to soak up water, reducing sudden flows of runoff that lead to flash floods during heavy rains" (Explore newsletter, Oct-Dec 2018).

Photos from recent floods