Stormwater Flood Resilience
Managing Local and Regional Flood Damage
Photo credit: Ram Subramanian
Theory of Change
Climate risks
We recognize that flooding doesn’t stop at municipal boundaries and that there is a need for managing precipitation-based flooding on a watershed scale. 17 RMC communities are working together on a range of strategies from constructed wetlands to new zoning.
Where we are
We use a watershed-wide hydrologic model to predict future precipitation-based flooding and flood damage. We found 120 viable sites for stormwater wetlands and have begun designing and constructing the first six. In doing so, we found that these wetlands made a much bigger difference in local vs. regional flood management.
What we’re doing
Recognizing that we can’t prevent stormwater flooding to the 2070 10% storm, we’re focusing on preventing flood damage, especially to those who can least afford it. We are now looking at how zoning and other policies and communications can help people and critical resources get or stay out of harm’s way.
Progress to Date
Constructing Stormwater Wetlands
Partnering with state and local agencies and consultants from Kleinfelder and Stantec, the RMC completed tabletop assessments of 465 open space parcels three acres or more across the Mystic River Watershed. Ranked by physical, equity, and feasibility characteristics, the team narrowed the list down to 140, then 18, then a first six locations to move to “shovel ready” design.
Preventing Flood Damage to Vulnerable Residents and Resources
After realizing that we would not be able to prevent stormwater flooding in Mystic Watershed communities, we turned to focus on preventing flood damage. The hydrologic model we developed shows where flooding is expected to occur across the 17 communities located above the Amelia Earhart Dam (Lower Mystic communities are focused on managing coastal flooding).
Using funds from the state MVP program, we are documenting where stormwater flood damage is expected to occur and comparing that to measures of social, economic, and infrastructure costs, especially to low-income residents of color. This exposure analysis will allow individual municipalities and the RMC to prioritize local and regional flood mitigation projects to minimize harm. It will also help us develop and coordinate land use policy changes across the watershed that go beyond large place-based interventions.