Eliana Brown is a Water Resources Outreach Specialist at the Illinois-Indiana Sea Grant College Program. She says Illinois has a flooding problem. The data agrees.

Evidence from the Illinois Flooding Awareness Act Report in 2015 shows that between 2007 and 2014, nearly $2.4 billion was lost on flooding damages in Illinois alone. Precipitation in Illinois has increased by 10% over the last century, mostly due to more intense storms. The problem is expected to continue and worsen due to climate change, which will cause more heavy rain events in the future.

In early 2019, record high flooding in the Midwest killed at least three people and emergency declarations were issued in Iowa, Nebraska, South Dakota, and Wisconsin.

While flooding near human structures is obviously damaging and emotionally straining, floods can also cause significant damage to ecosystems and habitats. Water management infrastructure has been developed to help with stormwater management.

Conventional stormwater management infrastructure is known informally as “Grey Infrastructure.” This term encompasses infrastructure such as storm sewers and gutters which are effective at swiftly moving water off of undesirable areas, such as roofs or roads.

A common example of grey infrastructure (Image/Memphis Storm Water)

For the first years after installation, grey infrastructure is inexpensive and requires little maintenance. It is out of sight of the public, and it therefore keeps the problem of stormwater management out of the public’s mind. Unfortunately, as years go by, grey infrastructure may become clogged or worn down, and the maintenance required is difficult and pricey.

Grey infrastructure also severely disrupts the normal hydrology of a system.

In natural systems, water flows from where it lands to the river very gradually, meaning the rise in river level is slow and it happens over a long time period. But in grey infrastructure systems where the water moves quickly into the stream or river, the water levels levels rise rapidly and drastically, causing erosion and a change in hydrology. This damages habitat and ecosystems.

Pointing out flood damage to a river (Image/Duluth News Tribune)

Green Infrastructure (GI) is currently used as an ancillary system to grey infrastructure. GI involves the use of civil engineering technology and natural systems to intelligently manage stormwater in ways that are nearer to nature. GI can be as simple as a grassy swale that stores water until it can percolate into the ground, or it can be as complex as placing permeable pavement next to a curated rain garden in order to save a road from flooding.

The below image shows permeable pavement that is sloped toward a grassy swale. These practices both soak up water and slow it down on its way to a storm gutter or a nearby stream.

Green roofs, which are essentially green spaces on the roofs of buildings, can soak up rainwater that would otherwise be shuttled down a gutter. This practice captures water and slows its movement to reduce the risk of flooding.

GI systems have bonus benefits as well. Rain gardens provide habitat for small animals and insects, while stormwater wetlands may provide homes for waterfowl and amphibians. Green roofs can work to mitigate the urban heat island, increasing the longevity of a roof and keeping a building cool. Many people believe that GI installations have aesthetic value.

With the increased threat of climate change looming, there will be more severe rainstorms in the Midwest, as well as more rain overall. States in the region that are already struggling with floods would be wise to prepare.

One political solution may be a ‘GI’ Bill at the state level, which could offer municipalities financial incentives to implement and maintain green infrastructure across their cities. This bill, while imposing an up-front cost, would recoup some or all of those costs over time through reduced flood damage, healthier ecosystems, and the wide breadth of side benefits that different variants GI provide.

The record flooding in the Midwest and the evidence-based warnings of things to come suggest that smart policy-makers should take action sooner rather than later.

-Ben Chapman