People worried about basement flooding, closed beaches and tainted drinking water got good news last week.
On Thursday, the Cook County Watershed Management Ordinance went into effect after 10 years of work, quietly but thankfully. The new rules will go a long way toward keeping flooding and waterway pollution in the region from getting worse. The new rules also mean it’s time to step up other efforts to fix the stormwater problems we already have.
As the metropolis has grown, more and more land that once soaked up rainwater has been used for pavement or buildings. In Chicago, almost 60 percent of the land is covered. As a result, just an inch of rain in the city produces about 4 billion gallons of stormwater that has to go somewhere. Too often, it goes into our basements or causes a “Lake Michigan reversal,” when the locks separating the Chicago and Calumet rivers from Lake Michigan are opened, allowing combined stormwater and sewage to spill into the lake. You know, the same lake we swim in. And drink out of.
Now, any new construction in Cook County will have to conform with regulations on drainage, detention, volume control, floodplain management, wetland and environment protection, soil erosion and sediment. Similar rules already were in place in the collar counties. That should keep new development from dumping more stormwater into sewers and waterways that can’t handle what we already have.
But we still have a legacy of older development that pipes stormwater directly into sewer systems, where it carries runoff into local waterways along with so much fertilizer and other pollutants that it actually contributes to the creation of a dead zone where the Mississippi River flows into the Gulf of Mexico. To address that, we need a combination of old-fashioned “gray” engineering — bigger pipes and bigger detention ponds — and “green” engineering — land uses such as forest preserves, floodplains and wetlands that absorb rainwater, as well as rain barrels, rain gardens, porous pavements, “green” roofs, tree boxes and anything else that capture rainwater instead of sending it into sewers.
The best-known gray engineering project is the Metropolitan Water Reclamation District’s Tunnel and Reservoir Plan, also called the Deep Tunnel, which began in 1972 and is supposed to be finished in 2029. TARP, which eventually will be able to store 20 billion gallons of water, will make a big difference, but it won’t be enough.
In Chicago, green engineering got a boost last week when the city announced its $50 million Green Stormwater Infrastructure Strategy. The strategy calls for the Department of Water Management help make green infrastructure part of capital projects. In 2014, the department will spend $6.1 million on 39 projects to keep water out of sewers.
Meanwhile, the MWRD plans to distribute 15,000 rain barrels over the next few years, pay for rain gardens at schools and implement other plans to let rainwater seep into the ground, where it can recharge aquifers instead of adding to flooding. On the federal level, Chicago recently received $1 million worth of Shoreline Cities grants from the U.S. Environmental Protection Agency for green infrastructure.
We’ve come a long way from where we were in the 1840s, when primitive handling of sewage caused thousands of deaths from cholera and diphtheria. But we have a long way to go.
Last week was the best week for stormwater management the city has seen in a long time. We need more weeks like it.