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U may have heard that May was the wettest on record for northern Illinois since we started measuring rainfall in 1871, outstripping the prior record, which occurred just last year. Cook Co recorded 8.25” of rain in May, roughly 20% of the total annual rainfall in 1 month! 1/
During the month of May, the Metropolitan Water Reclamation District’s Tunnel and Reservoir system intercepted nearly 13.6 billion gallons of combined sewer overflows (CSOs). 2/
That’s sewage & waste water from homes, businesses & industries combined w/ rain washing over streets collecting oil, pet poop, brake dust & fertilizer from lawns & gardens that otherwise would have flowed directly in2 nearby rivers & streams, polluting them significantly. 3/
From January through May 31, the @MWRDGC Tunnel and Reservoir system captured 42.56 billion gallons of combined sewer overflows. Think about that: if that amount of water covered the surface area of Chicago, we’d be wading in 10.5” of stormwater mixed with sewage. 4/
Remarkably, given the record rains, there have been NO REVERSALS of CSOs to Lake Michigan since October 2017. 5/
Even though we've seen breaking rainfall records, we’ve avoided lake reversals, the Albany Park diversion tunnel has saved that area from flooding & CSOs are down. The reason? The 1st phase of the McCook Reservoir, which can capture & hold 3.5 bil gallons, went online Dec '17. 6/
Thanks are due not only to huge pipes and tunnels, but also to the heroic efforts by MWRD staff to lower water levels in the Chicago Area Waterways system in advance of storms to give the system as much capacity as possible to capture stormwater. 7/
During the late May storms, the gates releasing water at MWRD’s Lockport Powerhouse were open as wide as possible & the flow recorded there was 20,000 cubic feet per second (cfs). By comparison, Chicago can legally withdraw only 3,200 cfs/day of freshwater from Lake Michigan. 8/
Here's a fascinating fact: one cubic foot of water weighs 62.5 lbs. Thus, the flow of 20,000 cfs at Lockport equaled 625 tons of water per second flowing through the Powerhouse gates. 9/
The high flows on the Chicago Waterways also brought commercial barge traffic to a standstill in recent months. Beginning on May 7th, the US Coast Guard halted barge traffic on the Illinois River (which receives flows from the Chicago Waterways). 10/
And our soils are soaked! The soil moisture in Cook County is now higher than 99 percent of the historical record, according to NOAA and the National Weather Service. Saturated soils mean much less capacity to absorb rain when it comes. 11/
The Great Lakes have responded 2 this record-setting weather. According 2 Army Corps of Engineers, which tracks Great Lakes water levels, Lakes Erie & Superior reached new monthly mean high water levels in May, & Lake Ontario surpassed its all-time record high level this week 12/
As of the first week of June, Lake Michigan is 13” above its average level and is expected to continue rising through this summer. Lake Michigan is currently just 2” below its all-time record height for June, set in 1986. 13/
What’s to be done with all this water? First, expect the unprecedented. Predictions for the climate crisis in northeastern Illinois include more intense, less predictable rain and snowstorms. These are likely to be our new normal. 14/
Warmer air in IL means more H2O evaporates & coalesces into violent storms, while warmer air in Arctic destabilizes jet stream, leading Great Lakes 2 freeze over & lake levels to rise when ice melts. Cook Co sits at crux of these forces, with all variability that entails. 15/
Second, let’s do everything we can to give the land more absorptive capacity. We should install rain gardens, bioswales, permeable pavement, and green roofs everywhere we can to capture rain and keep it out of the sewers. 16/
But we may also need to un-finish our basements and expect them to take on water now and then -- the way things used to be. (A harsh reality, I know, but we live in a flat, wet world. There’s no downhill to move water away from us.) 17/
Finally, let’s get creative about ways to capture (and reuse) rain. Let's think about repurposing rail tank cars for stormwater capture next to big box stores and warehouses. Let's install community cisterns block by block and re-green vacant lots as wetlands. 18/
Let's convert parkway patches into prairie grass stands. Bring your ideas to your local representatives and push for action. Folks, we need all hands on deck because we’re taking on water! Final/
