Sewer project to disrupt traffic in downtown Des Moines

Details: The WRA's Ingersoll Run project is a sewer separation, stretching from around 22nd and High Streets, through a section of Locust Street and along MLK from 15th Street to Principal Park.

• Groundwork begins in January, and the completion date is anticipated to be around June of 2024.

Between the lines: Modern sewers are typically built so that raw sewage is carried in a separate line from rainwater runoff.

• Some of DSM's sewers are more than 100 years old, and the city had 20 systems with combined lines. That's a problem because they can exceed capacity and discharge untreated wastewater into rivers or streams.

Flashback: The project is part of an agreement DSM made with environmental regulators back in 2003 to continue operating the WRA facility on the city's southeast side.

• The following year, DSM started citywide sewer separations under a five-phase, $338 million plan that's expected to continue for another four years. Ingersoll Run is one of the last projects.

Of note: DSM is the only city in the metro with combined sewers, and regulators have agreed to keep one downtown because it's too costly to separate.

• Thirteen others in Iowa, mostly river towns, are dealing with similar issues.
• Nationally, there are 772 cities with such systems, according to the Environmental Protection Agency.