"Chicago-area residents asked to delay showers, use less water ahead of more storms," NBC 5
With more rain expected in the Chicago area this week, residents are being asked to use less water by delaying showers, running dishwashers less frequently, and more.
According to the Metropolitan Water Reclamation District, the organization in charge of managing stormwater and wastewater in the Chicago area, an “Overflow Action Day” has been declared for Monday, with more showers and thunderstorms potentially bringing several more inches of rain to the region.
The purpose of an “Overflow Action Day” is to call attention to the need to keep water out of the region’s sewer systems, as that water must be taken into the TARP, or “Deep Tunnel” system, processed, and then released into area waterways.
According to the latest estimates from the MWRD, reservoirs in the area are already filling up quickly after this week’s rains, including the McCook TARP Reservoir, which is at 95% capacity and holding nearly five billion gallons of water.
The Thornton TARP Reservoir is at 58% capacity, according to officials.
With more rain expected to enter that system, residents are being asked to reduce their water usage in an effort to divert it out of sewers and waterways.
Those steps can include reducing the amount of time residents spend in the shower, as well as running dishwashers less frequently, reducing the number of times toilets are flushed, and by delaying doing laundry until rain has excited the area.
If too much water enters the TARP systems, it can lead to flooding, including into the basements of residences and businesses.
If the system becomes too full of water, untreated sewage can make its way into area rivers and can overflow from sewers, leading to neighborhood and basement flooding. Officials may also be forced to release untreated water into Lake Michigan to alleviate pressure on the TARP system, which would lead to beach closures and potential health hazards.
The TARP system has expanded its capacity in recent years, but it’s still been heavily taxed this year by heavy rains in the region. According to MWRD officials, the McCook Reservoir has already hit capacity six times so far this year. It had only reached capacity five times in the previous five years combined, according to officials.
The Thornton Composite Reservoir set a record earlier this year by having 7.4 billion gallons of water stored.
The TARP system is also known as the “Deep Tunnel” system, and it serves to capture and process stormwater and sewage that would otherwise overflow into area rivers and lakes during rainstorms. The system then transfers that water to treatment facilities, where it is processed and then released back into area rivers and streams.
That water makes its way through approximately 110 miles of tunnels, which are 8-to-33 feet in diameter and located hundreds of feet underground through the Chicago area. Those tunnels carry water into three separate reservoirs, including the Thornton and McCook reservoirs, along with the Majewski Reservoir near suburban Elk Grove Village.
The forecast in the Chicago area is calling for more rain, and officials have expressed concern the current weather pattern will allow heavy rains to continue running over the same areas over and over again, leading to localized flooding and eye-popping precipitation totals.
There are chances of severe thunderstorms multiple times this week, which could further challenge the TARP system to keep untreated water out of area waterways.
Be sure to stay tuned to the NBC 5 Storm Team for all the latest weather news and information, and be sure to download the NBC Chicago app for real-time weather alerts sent to your phone.