IIHR Models Sewer System for St. Louis

November 22, 2016

The IIHR team stands in front of the St. Louis models

The IIHR team with the St. Louis model.

Researchers at IIHR—Hydroscience & Engineering are among the world’s leaders when it comes to modeling and design of sewer and stormwater conveyance systems. Many of the world’s largest cities have turned to IIHR for expertise in this area, including London, Abu Dhabi, and now St. Louis.

IIHR has extensive experience constructing physical models that help solve water issues, including the reduction of air in sewer systems with underground tunnels. A build-up of air in the tunnel can cause geysers that blow manhole covers into the sky—a rare but dangerous situation.

Working with Jacobs Engineering and the Metropolitan St. Louis Sewer District, IIHR researchers and staff constructed a 1:16 physical model of a portion of the project. The IIHR model includes a vortex dropshaft that, when constructed, will be one of the largest in the world at 20 feet in diameter.

Dropshafts are just one important aspect of the project’s complex network of tunnels, conduits, and interception chambers that transfers sewage and stormwater to the tunnels and onwards for treatment before it is eventually released to the river. Each structure is unique and presents its own design difficulties.

A vortex dropshaft

The vortex dropshaft is one strategy to help remove air from the water flow through the sewer

Troy Lyons, IIHR’s director of engineering services, led a team that included Professor of Civil and Environmental Engineering Jacob Odgaard, Hydraulic Engineer Andy Craig, Shop Manager Brandon Barquist and his staff, and even students such as Kory Miller, an undergraduate student in civil engineering.

Lyons says it’s been a very rewarding project and one that will positively impact the environment by preventing sewage overflows into the river during heavy rainfall. “Modeling a system like this provides an opportunity to optimize the design, analyze how the system deals with extreme flows, and reduce risk, all while meeting the larger environmental objectives.”

Lyons says that many larger cities are adopting similar strategies to deal with combined sewer overflows. And IIHR is ready, with expertise and experience to help.