Climate change isn’t just about warmer temperatures. It’s also changing the nature of storms. In our neighborhoods here in Illinois, we’re already seeing the impacts: more intense and frequent rainstorms. With more rain comes more stormwater, which means more potential floods and related stormwater issues.
While climate change can feel overwhelming, there are concrete steps we can take in our communities and at home to adapt to these new weather patterns.
How Climate Change is Increasing Stormwater in Illinois
Climate change may be a global issue, but its impact is already being felt at home. According to An Assessment of the Impact of Climate Change in Illinois, rainfall patterns are changing in a few ways and will continue to change in the coming decades:
- More rain overall: Average annual precipitation in northeastern Illinois has increased 15 to 20% over the past century.
- More heavy rainstorms: The number of days with precipitation exceeding two inches has increased by approximately 40% over the past century.
- More to come: Annual total precipitation is expected to rise even further, especially in northern Illinois, through the rest of the 21st century (Wuebbles et al. 2021).
To sum it up, we’re experiencing more rain overall and getting heavier downpours more often. This trend is expected to continue, bringing growing challenges for local communities.
More Rain, Greater Flood Risk: Neighborhood Impacts
With more rain, comes more stormwater to manage. In urban and suburban areas, rain that falls on impervious surfaces like roads and buildings can’t soak into the ground. Instead, storm drains and storm sewers systems collect and move stormwater out of our neighborhoods.
However, most stormwater infrastructure, especially in older neighborhoods, was not built for the increased rainfall we expect to experience in the coming decades. These new storms put strain on stormwater infrastructure, and if the amount of stormwater exceeds storm sewer capacity, we get flooding in neighborhoods.
In fact, claims and payouts under the National Flood Insurance Program have risen sharply in recent years (Winters et al. 2015). This brings the impact of the changing climate right to our doors—through flooded streets, homes, and basements.
More Rain, More Runoff: Environmental Impacts
Besides flooding, increased rainfall also worsens another stormwater issue: polluted runoff. When rain can’t seep into the ground due to pavement or compacted soil, it flows across the landscape, picking up pollutants like:
- Lawn fertilizers and herbicides
- Road salt (chlorides)
- Pet waste
- Litter
- Oil and fluids from vehicles
Polluted runoff enters storm sewer systems that eventually discharge the runoff directly into a local river or stream. Heavier rainfall increases the volume of stormwater runoff and pollutes waterways as a result.
Intense bursts of runoff also cause “flashy” streams, meaning these waterways experience quick changes in water level as stormwater is diverted into them. Stream flashiness causes streambank erosion, poorer water quality, and difficult conditions for wildlife.
A New Vision for Stormwater: Community Solutions
Fortunately, we can respond to more frequent and intense rainstorms at the community-scale. Some climate-smart stormwater management methods include:
- Integrating green infrastructure: Techniques like bioswales, rain gardens, green roofs, rainwater harvesting, native plant landscaping, and permeable pavement effectively soak up or collect rain where it falls.
- Expanding the urban tree canopy: Along with native plant landscaping, trees have a remarkable capacity to absorb and infiltrate stormwater, even in urban areas. Trees bring additional benefits like cleaner air, shade, and wildlife habitat—and of course, they mitigate climate change by pulling carbon dioxide from the air.
- Preserving and restoring open space: In northeastern Illinois, we are lucky to have an extensive forest preserve system. Continuing to protect open spaces improves water infiltration and water quality.
- Restoring streams: Stream restoration techniques like meanders, streambank stabilization, and floodplain restoration make waterways more resilient.
- Maintaining and upgrading infrastructure: Stormwater infrastructure only operates effectively if it is property maintained. As we upgrade stormwater infrastructure, we can design it with climate in mind.
A combination of these stormwater solutions reduces a community’s risk of flooding, improves the water quality of local streams, and creates greener neighborhoods.
What You Can Do at Home
We don’t have to wait for a large-scale project to make a difference. Individual actions add up to make a real impact. Ways to manage stormwater at home include:
- Plant native trees, shrubs, flowers, and grasses: Native plants have deeper roots that infiltrate stormwater and stabilize the soil. At the same time, native plants support healthy ecosystems by providing nourishment and habitat for birds, bees, and butterflies.
- Create a rain garden: Rain gardens collect and soak up stormwater. Rain gardens are specifically designed to reduce flooding in your yard by directing water from your downspout into an area planted with water-tolerant native plants.
- Attach a rain barrel to your downspout: Rain barrels allow you to collect rain to use later to water your gardens and landscaping.
- Clear neighborhood storm drains of leaves and debris: Blocked storm drains lead to faster flooding in your street. Take a minute to check and clear storm drains near your home.
Resilience Starts Where We Live
Along with a commitment to reducing causes of climate change, we can respond to its impacts in our community and at home. Climate-minded stormwater management adapts to expected increases in storm intensity and frequency, reducing the risk of flooding and protecting clean water in rivers and streams. Together, we can build neighborhoods that are ready for whatever the next storm brings.
References
- Wuebbles, D., Angel, J., Peterson, K., and Lemke, M. (2021). An Assessment of the Impacts of Climate Change in Illinois. The Nature Conservancy, Illinois, https://doi.org/10.13012/B2IDB-1260194_V1.
- Winters, B. A., Angel, J. R., Ballerine, C., Byard, J., Flegel, A., Gambill, D., Jenkins, E., McConkey, S. A., Markus, M., Bender, B. A., & O’Toole, M. J. (2015). Report For The Urban Flooding Awareness Act. Illinois Department of Natural Resources.
