Aurora/Fox Metro/Sierra Club/IEPA CSO Green Infrastructure Improvement ProjectThe City of Aurora uses sewer infrastructure that dates back to the 1880s in some of the most historic parts of the city. Unlike more modern sewer systems that separate wastewater and stormwater, these century-old systems accept liquid waste from homes and rain water from street gutters, roof tops and driveways, and send them both through the same pipes to the Fox Metro Water Reclamation Plant for cleaning.
Under normal conditions, these vintage combined sewers do an adequate job serving the needs of residents in older parts of Aurora, usually those neighborhoods closest to the Fox River. But during heavy rain storms, the sewers become surcharged. When waste water and rain water exceed the capacity of the pipes, the excess rain and sewage either overflows into the Fox River or backs up into residents' basements.
The problem is common among older cities across the country, and the U.S. EPA through the Clean Water Act mandates that cities take steps to reduce the overflows to preserve the health of our rivers. The City of Aurora is using several approaches to reduce the number of times sewage overflows and how much pollution goes into the Fox River, including updates to the sewer system. The rain gardens planned for the near East Side and the West Side are one piece of the solution per Aurora's Long Term Control Plan, which has been approved by the IEPA.
For the EnvironmentRain gardens are designed to hold rain water during storms by diverting that water from the sewer system and reducing how often the sewer system floods and overflows. Instead of going into the sewers, the rainwater is slowly infiltrated into the ground, and the water is cleaned naturally before it finds its way back into the Fox River. This natural cleaning - removing runoff contaminants like suspended solids (sand, dirt and grit), excess lawn fertilizer and chemicals from vehicles before they reach the river - helps reduce the volume of water treated by Fox Metro and helps the Fox River water quality.
For the NeighborhoodIn addition to their stormwater management advantages, the rain garden design used by the City of Aurora has other benefits to the immediate neighborhood. The gardens are natural traffic control devices that slow neighborhood traffic by narrowing intersections.
Narrow intersections automatically prompt drivers to be more cautious and to drive more slowly and shorten the cross walks where pedestrians are likely to be in the street. The gardens also feed important pollinators like butterflies and birds, and they look nice, too.
CostThe City's long-term plan to fully correct the problem of combined sewer overflows includes extensive infrastructure upgrades from replacing sewers to the construction of a new pump station. Such upgrades are estimated to cost about $120 million and will take about 20 years to complete. The gardens are a small fraction of that overall cost, at $1.7 million, paid for in partnership with the Fox Metro Water Reclamation District and the Valley of the Fox chapter of the Sierra Club and with a $1.45 million Illinois Green Infrastructure grant. The new sewers, rain gardens, and other federally mandated upgrades that together comprise Aurora's Long-Term Control Plan are funded through a combination of loans from the Illinois EPA, grants provided through the federal Clean Water Act, and a $6.90 charge on residents' bimonthly water bill.
If the City of Aurora did not comply with federal law and make mandated improvements, not only would our river and local environment as a whole suffer, our inaction would cost local taxpayers. The U.S. EPA could levy fines against the City of Aurora, at a rate of tens of thousands of dollars every day. Such fines have totaled hundreds of millions of dollars in cities around the country.
In carrying out the federal mandate to improve our sewer infrastructure, the City of Aurora is committed to implementing innovative, cost-effective, and sustainable upgrades like the rain gardens. Aurora is one of just a handful of major cities recognized nationwide by the Natural Resources Defense Council as an Emerald City for rethinking the design of municipal services and infrastructure with long-term sustainability in mind. Rain garden infrastructure is just one of the many projects the City of Aurora is implementing to protect our residents and improve our environment.
Rain DiversionRain gardens divert stormwater runoff from combined sewer systems. That reduces the volume of water in the sewer and reduces the likelihood that water and sewage will back up in basements or overflow into the Fox River. Because they can accommodate more water than gutters, they also help reduce street flooding during storms.
Traffic CalmingTraffic calming through rain gardens uses narrowed intersections to slow motorists in residential neighborhoods and discourage drivers from cutting through residential streets. Navigating narrower intersections takes more concentration than wider streets, so motorists naturally slow down, making neighborhood streets safer for children and pedestrians.
And, because traffic calming at intersections uses No Parking zones, few street parking spaces are lost. Combining traffic calming with rain gardens is environmentally sound and safer for residents. It's a win-win.