Chicago experienced a series of sewer geysers after heavy storms pounded the city on Monday. Jets of water were seen bursting into the air from manhole covers in the Loop, West Loop, and Pilsen. The phenomenon, dubbed ‘urban geysers,’ has become increasingly common in cities across the country as heavier rainfall due to climate change stresses aging sewer infrastructure.

Causes of Urban Geysers

Susannah Drake, a landscape architect, explained that climate change is leading to more powerful downpours over shorter time periods, forcing large volumes of water into the sewer faster than the city’s pipes were designed to handle. This creates trapped air pockets and pressure differentials, which force air and water upward through a manhole, lifting its cover and producing a geyser-like eruption.

Most sewers in Chicago were built over a century ago and were designed to drain sanitary flow and a limited amount of stormwater directly to the river before wastewater treatment existed. Today, Chicago’s combined sewer system carries household wastewater and rainwater to treatment plants, where it is treated before being released into waterways.

Drake suggested that cities like Chicago should expect to see urban geysers occur more frequently with heavy storms, unless officials devise strategies for redirecting excess rainwater. One solution is to implement green infrastructure to absorb surface water runoff, such as Chicago’s ‘green alleys’ that act like a sponge and a runway for rainwater.

Original reporting: Block Club Chicago — read the source article.