This is part four of an eight-article series by We are Water Evanston, a community-based participatory research project that explores our relationship with and concerns about water. For more information on this series, click here.
This past year, flooding has wreaked havoc across the globe, from Bangladesh to Germany, New York City to Louisiana. Evanston itself experienced several flash flood warnings due to severe storms this summer. As climate change brings heavier rainfall to the region, the city’s drainage system will be put to the test.
We Are Water Evanston, a community-based participatory research project, found that 60% of survey respondents expressed concern about street flooding. With the impact of climate change bearing down on us, the question is: What can we do about it? But in order to know what can be done, we first need to know what’s happening right now.
Where does our wastewater go?
Evanston has a combined sewer system, which means the water flushed down the toilet and the water that flows into a storm drain on a rainy day all end up in the same place. Most of the time, this mix of sewage and stormwater travels to a wastewater treatment plant, where it is cleaned and discharged into the Chicago River.
However, during big storms the system can get overwhelmed with large amounts of water entering over a short period of time. When this happens, untreated sewage is released directly into the river, in what’s called a combined sewer overflow (CSO). Heavier rainfall could mean the combined system is overwhelmed more frequently, leading to more flooding, more CSOs and this more beach closures. These can all affect residents’ quality of life at a local scale. However, there are many solutions that can help reduce these impacts.
Local flooding solutions
Most flooding solutions fall into two categories: gray infrastructure or green infrastructure.
Gray infrastructure includes what we often think of as typical engineering projects, sea walls and tunnels – for example, the Deep Tunnel project, which provides additional water storage during heavy rain events to prevent the drainage system from being overwhelmed.
In recent years, there’s been a shift toward more natural solutions, like green infrastructure, that “let nature do the work”, as Julia Bunn, local landscape designer and owner of The Spirited Gardener, puts it.
Green infrastructure, which includes natural green spaces like woodlands and marshes, and engineered green spaces like residential rain gardens, captures and absorbs water before it enters the drainage system, reducing the burden on the city’s infrastructure during heavy rain events.
Green infrastructure also can provide benefits beyond reducing flooding. It can provide habitat for endangered species like the rusty patched bumble bee and in some cases, can help reduce exposure to harmful air pollutants that exacerbate COVID-19, which has disproportionately affected people of color in Evanston.
In interviews for the We Are Water Evanston project, residents expressed support for both gray and green solutions to flooding. Some residents mentioned in-home solutions for flooding, such as sump pumps. However, these preventative strategies can cost more than $1,000, making them too expensive for many households. Interviewees also suggested improving storm drain and sewer maintenance and installing more storm drains, particularly in areas where excess water pools on the streets.
Stormwater can often be temporarily stored on streets by design, to prevent the sewer system from being overloaded during heavy rain events and to keep water out of residents’ basements. However, some residents we spoke with, especially those with mobility issues, told us that this has made navigating these streets quite challenging.
Green infrastructure generally received positive reactions from the interviewees, with one civic leader stating, “I think the more green infrastructure we can have, the better.” Many residents were also unfamiliar with the role green infrastructure and natural systems can play in flood prevention and others expressed concerns ranging from costs to appearance.
“I mean, a lot of my neighbors can spend $3,000 to $4,000 on landscapers coming in, but we can’t,” one Sixth Ward resident said. “You know, we’re looking at native plant places and thinking about the amount of plants we need to put in for grasses. And it adds up. So, you know, there’s the expense of making those changes.”
While some types of green infrastructure can be expensive there are also low-budget options, like DIY backyard rain gardens.
Interviewees also expressed concern about the cost of green infrastructure maintenance and who would be responsible for it, particularly on public land. “If you’re going to start a project, you’ve got to make sure it’s maintained, or otherwise, it’s just kind of useless,” a First Ward resident remarked. However, urban forestry expert Cherie LeBlanc Fisher told us, “The costs of maintenance are sometimes brought up as a reason not to use green infrastructure, but all infrastructure needs maintenance, including gray infrastructure like storm drains.”
Many residents also recognized tensions around land use for housing versus green infrastructure. But some suggest that while green infrastructure is not a silver bullet for all flooding problems, that doesn’t mean it’s not worthwhile. “It’s not going to solve problems at the global level, but this is something we can do at the neighborhood scale,” said Wendy Pollock, Co-Chair of Evanston’s Environment Board.
Policy action for flood resilience
Both green and gray infrastructure will be critical to addressing flooding in Evanston. However, we also need to address the root cause of these increasingly frequent flood events: climate change.
Many residents expressed concern about the impacts of climate change, ranging from heat waves to poor air quality. Some were worried about how climate change would affect future flooding events. As communities of color tend to be most affected by the results of climate change, reducing the risk for those on the front lines of flooding is an important issue of equity.
Evanston has taken several steps to plan and prepare for the impacts of climate change. In 2018, the city approved the Climate Action and Resilience Plan (CARP), which set forth goals for climate mitigation and climate resilience, including steps toward building a more flood resilient Evanston, such as promoting green infrastructure and enhancing existing stormwater systems.
As mentioned in our previous article, the city is also in the process of completing a hydraulic and hydrologic study with the help of Hey and Associates, a local engineering consulting firm. The study, which will help identify risks from future storms, is expected to be completed by this spring.
Upon completion, the city plans to develop a Capital Improvement Plan including projects to address current and future flooding risks identified by the study. Other cities with combined sewer systems, such as Philadelphia and Bloomington, Illinois, have implemented stormwater utility fees to fund stormwater projects. These fees are based on the amount of impervious surface, like pavement, asphalt and rooftops, on the property. The cost for a residential property in cities like Philadelphia and Bloomington ranges from $6 to $16 per month.
What can residents do?
One tangible way to address local flooding is by reducing personal water consumption on rainy days. By delaying noncritical water-intensive activities like laundry or running the dishwasher until after the rain stops, residents can reduce the amount of water flowing into the combined sewer system, allowing the sewers to better handle the influx of water.
Evanston residents can even sign up for a rain alert to remind them to delay these tasks till later by visiting https://www.cityofevanston.org/rain or by texting COE RAIN to 468311.
Residents who are interested in installing green infrastructure on their own property can also visit the city’s website or contact firstname.lastname@example.org for more information on how to build a residential rain garden.
Flooding can have long-term impacts on our health and wellbeing, from mold growth and mosquitoes to the loss of priceless keepsakes. With the effects of climate change becoming more pressing every day, taking action to address its causes and adapt to the new normal has never been more urgent.
Residents looking to get more involved in taking local action on climate change can connect with organizations like Citizens’ Greener Evanston, Environmental Justice Evanston, the Evanston Environmental Association and E-town Sunrise.
(This story has been updated to replace an Oakton Elementary School photo with an image of the correct garden.)
We are Water Evanston is a collaboration between researchers at the Northwestern Center for Water Research and community water activists in the Watershed Collective, a subcommittee of Citizens’ Greener Evanston. Follow We are Water Evanston on Instagram (@wearewaterevanston) and Twitter (@waterevanston).