Last Wednesday, your trusty blogger accompanied Center for Limnology post doc, Peter Levi, as he headed to Milwaukee for his research on what is, frankly, an under-served ecosystem in limnological circles – the urban river.
Most metropolitan areas have a sordid history with their rivers. The waterways that first made them appealing for settlement, soon made them indispensable to industry, as turn of the century (and some much more recent) developments like paper mills, steel plants and feed lots used the rivers as a convenient way to flush waste downstream. As a result, many cities turned their back on their rivers and the prime real estate migrated far from their banks.
In many cases, cities also “improved” rivers by straightening their course and “channelizing,” or lining the river in concrete. They become little more than straight-as-an-arrow throughways designed to get water out of town.
The problem, as the city of Milwaukee discovered, is that, when you have all of the impervious surface of a city, combined with a massive rain event and nothing but concrete channels, well, rivers rise fast, resulting in dangerous floods. Milwaukee realized that letting a river wander actually slowed the flow of water and let downstream areas drain before a new wave of stormwater came pouring in. So the city, primarily the Milwaukee Metropolitan Sewerage District (MMSD), reversed course and put the bend back in its rivers. Nowhere is the effect as dramatic as on the Kinnickinnic.
The Kinnickinnic is almost entirely an urban river. 93% of its watershed lies in city limits. It has had a long and problematic history of flooding and, over the last several years, it has begun to look like a real river again as the MMSD bought up houses on the bank, bulldozed them down and began restoring a more “natural” flow. The MMSD also restored tributaries, like Villa Mann Creek, that feed water into the Kinnickinnic.
While the process of relocating area residents wasn’t always easy or, in some cases, popular, it has dramatically reduced flooding, saving nearby homeowners from what was becoming an annual headache.
Levi is working on a project to see what the ecological impacts of the restored river has been. What lives there now? Is the food web building back up? Is water quality improving? All of these are questions Levi hopes to answer over time.
Levi is also considering the social and economic benefits from these restorations. And, as we discovered on our day in Milwaukee, for kids at the 16th Street Community Health Center’s summer camp, at least, river restoration has been a positive social development.
We had “boat races” and compared travel times down channelized and restored sections of the river. We talked about watersheds and how what’s upstream impacts everything else. And, most importantly, we got the kids out in the river. For many of them, it was the first time in their lives wading in a river and, as you can imagine, from the first crayfish sighting to the first loud “Ewww!” reaction to a leech, they were hooked.
