Thornton Composite Reservoir Nears Capacity, Raising Concerns
With the Thornton Composite Reservoir nearing capacity, residents in the southern suburbs express concern over potential flooding and unpleasant odors. Following heavy rains over the weekend, the reservoir reached 94% capacity, a record since its 2015 inception, according to the Metropolitan Water Reclamation District of Greater Chicago. By Tuesday morning, the level receded to 93%, equivalent to 7.3 billion gallons, as reported on the district’s website. Previously, the highest level was 54.5% in 2019.
Thirteen communities contribute to the reservoir’s inflow, including parts of Chicago and several nearby towns, hosting about 556,000 people. It is the world’s largest combined sewer reservoir. Residents nearby have long dealt with odors which are now intensified by the reservoir’s high capacity. Thornton Village Clerk Nikki Kitakis describes the stench as overwhelming, wishing she could convey its severity through a ‘Smell-O-Vision.’ Despite the water reclamation district’s mitigation efforts, the issue remains daunting.
The district is actively managing both the Thornton and McCook Reservoirs to lower water levels, serving multiple Chicago suburbs. To alleviate the situation, the district uses gravity to transfer water through a tunnel to the Calumet Water Reclamation Plant, located five miles north. There, the water is pumped, treated, and returned to the environment.
Residents fear additional rainfall could exacerbate the situation, increasing flood risks. At a recent Dolton Village Board meeting, residents and officials discussed flooding issues. Dolton Mayor Jason House empathized with concerned residents, acknowledging the village’s infrastructure limitations. An estimated $50 million overhaul would be necessary to update the flood management system. Public Works Superintendent Matt Stacy urged cooperation and vigilance, anticipating more rain based on forecasts from the National Weather Service.
Flossmoor recently recorded 6.37 inches of rain, highlighting the region’s weather challenges. The Thornton reservoir still has a capacity for 600 million more gallons. However, uncertainty looms, waiting on how impending weather events will influence the situation. Still, as of a follow-up, the district hadn’t provided a timeline for water drainage completion.