Rain Gardens

Flooded Basement? Try a Rain Garden!

More and more, we are seeing large rainfalls in a short period. Climate scientists have come to a consensus that our warming atmosphere plays a big part.  Warmer air can hold more moisture, and the jet stream seems to be less stable and less able to keep weather fronts moving along. Therefore, fronts linger over one place.  

When these increasingly powerful storms hit, some Riverside residents get water in their basements, and many more have backyards that turn into ponds. Although pumping excess water out to the street is one solution it does nothing to help with overloaded sewers.
Most of Riverside’s sewers date to the late 19th century – and are the “combined” type. This means that the “sanitary” sewer that carries household waste and the storm sewer grates in the streets that collect rain water are combined in one system. Newer towns have separate sanitary and storm sewers. The last thing anyone wants is to have the sewer system completely full of water, or clogged, and have excess rainwater carry sewage back into our basements. In a worst-case scenario Riverside would dump waste water into the Des Plaines River. Chicago recently had to let water from the Chicago River flow into Lake Michigan.  

Keeping refuse, including leaves and grass clippings from blocking sewer entrance gratings is important to prevent backups in the street, and important to prevent these materials from entering the sewers and causing blockages within the sewers. As a reminder homeowners and landscapers are prohibited from depositing leaves and yard waste into the streets. Riverside’s waste hauler accepts an unlimited amount of yard waste for pickup.
 One way to help alleviate flooding from heavy rain falls is to install a rain garden.  A rain garden collects excess surface water in the lowest part of the yard and holds it temporarily allowing it to gradually soak into the ground.  To create a rain garden, start by figuring out how to channel the water to a low spot. That low spot can then be enlarged and deepened to hold greater amounts of water.  Riverside has a layer of clay, so plan on digging down at least a few feet. Be sure to do a percolation test – how long does it take for water to percolate through the soil. If the water does not percolate quick enough, the rain garden won’t be as effective. Plant native plants with long roots and marsh plants that will filter and absorb much of the water. This helps prevent runoff water from filling the overloaded sewer system and seeping into your basement; or ponding which can make a mosquito breeding site.

A rain garden is not a permanent swampy area. When it’s not raining, the garden looks pretty much like any other garden with grasses and flowering plants. When it does rain a lot, there might be standing water in the garden for a couple days or so. Another benefit of a rain garden with native plants is that these plants are host plants for some species of butterflies and they provide a food source for native bees.   Some plants that like boggy conditions will grow much better in a rain garden than in a traditional flower bed – I’m looking at you Lobelia.  Some Riverside residents have already installed a rain garden. You can view what the problem was, what they did and how it helped here

Changing driveways and patios from solid concrete to permeable pavers also helps water find its way into the ground, rather than into the sewers.  

Will a rain garden solve all of your water problems? Maybe not. Will it help to alleviate some of your water problems? Yes. When we get a rain like we did on July 2, 2023, you will probably still have some water issues. If a two inch rain causes issues, then a rain garden is very likely to make a big difference.

Download an excel spreadsheet that can help you figure out how much material you may need to build a rain garden.

Links for additional resources and information

Rain Gardens

The Green Neighbor Guide – Green Infastructure Projects to Manage Storm Water at Home

University of Illinois - Rain Gardens

Rain Garden Native Plant List

Rain Gardens: A How To Manual For Homeowners
Rain Garden Presentation Slides

Rainfall in Storms and Climate Change 

Rainfall Intensity Index 
Weather and Climate Extreme Events in a Changing Climate
Extreme Weather Events 

Jet Streams 

The Jet Stream
Waves and The Jet Stream