Spring Showers Bring Flooded Basements

By Rebecca Reeves, Stormwater Education and Outreach Manager

This spring has by all accounts, been a wet one. High precipitation levels in Rhode Island have caused flooding across the state, and our water table is saturated. And although this spring has been a particularly rainy season, this is not an isolated issue. Climate change continues to bring heavier, more frequent storms in our region and along with it, comes flooding.

When precipitation is this high and the water table rises, soils can only absorb so much, and excess water can run into homeowners’ basements. Many homeowners opt for basement sump pumps that can capture and discharge unwanted ground water.

But how clean is this water, and how should homeowners get rid of it once it’s been removed from their basements? Per the Rhode Island MS4 (municipal separate storm sewer system) permit, sump pump discharges from home foundations and basements are considered to be uncontaminated groundwater. The reasoning is that this water originates from saturated soils, where the water will have already conceivably benefitted from the soil’s filtration abilities. Therefore, in many Rhode Island municipalities, homeowners can discharge this sump pump water directly into the street, where it can run into nearby storm drains.

But despite this statewide policy, many municipalities in Rhode Island have already passed local ordinances that prohibit individuals from discharging sump pump water into their storm drain systems. The result is that some residents discharge their sump pumps into neighbors’ properties, where it can lead to erosion or flooding in those yards and can lead to civil conflicts between neighbors.

More research is required to discover how sump pump discharges could impact water quality. No one is quite sure how contaminated sump pump discharges could be. This water could potentially gather contaminants like oil or gas from basements, or it could already be contaminated before it even reaches residents’ basements. Additionally, sump pump discharges that enter the storm drain system may potentially run into nearby water bodies unfiltered, and could impact the water quality of these creeks, ponds, rivers, and eventually, Narragansett Bay. It’s also true that even if this water is uncontaminated, it could overwhelm the MS4 by taking up capacity designed only for stormwater during heavy rain events.

Research about best practices, both for sump pump use and for preventative flooding measures, would be helpful to homeowners, whether their municipalities allow discharge into the MS4 or not. Municipalities could also utilize this research to determine whether their ordinances are truly in the best interest of their residents and our broader coastal communities. As a coastal state, we all have a stake in our local water quality, and it’s important to identify any potential sources of pollution that enter our storm system – as it all eventually ends up in the same place.

Stormwater Innovation Center Director Ryan Kopp recently met with representatives from the Town of Barrington and the US Geological Survey to discuss potential research that could be conducted related to sump pump water quality. The topic is of interest to a variety of stakeholders, but funding would be required to begin conducting this research. The Stormwater Innovation Center will continue to learn more about the issue and meet with those communities that it impacts. As we learn more, future funding will be needed to gain further insight into how municipalities might best move forward.