Eric D. Lawrence

Detroit Free Press

Thursday's flooding of freeways around metro Detroit raises an obvious question:

Why does it keep happening?

The answer might not be simple and raises additional questions about the region's infrastructure and the willingness to address underlying problems or pay for those fixes.

It was only last month that similar scenes of flooded underpasses played out across the region, and minor flooding, slowing commutes, regularly occurs during heavy rains. That's not even taking into account the historic flooding of August 2014 when 4 to 6 inches of rain pounded the area, not only closing interstates, but also stranding cars and inundating basements, government buildings and even the GM Tech Center in Warren with water.

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Pump houses — those concrete bunkers on the sides of metro Detroit's notoriously low-lying freeways — have been recent targets of blame. The structures, which remove excessive water from the roads, failed because of power failures or mechanical issues in 10 different locations last month, contributing to the flooding. In fact, only 29% of the 140 pump houses in Macomb, Oakland or Wayne counties are rated as good with 52% in poor condition, and much of that infrastructure is 40 and 50 years old.

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But then, as now, the Michigan Department of Transportation, pointed to other factors, including highway debris that can clog the pump houses:

Heavy rains saturate the ground and overwhelms the local drainage system, but because the pump houses rely on the local drainage system in order to remove the water, flooding can arise.

"We can't pump into a bathtub that’s already full," MDOT spokeswoman Diane Cross said, noting that she was unaware of any pump house failures related to this storm.

The Free Press recently toured one of the pump houses that stopped working during last month's highway flooding. That pump house -- overlooking I-94 in Macomb County near Eastpointe's Spindler Park and the St. Clair Shores Civic Arena -- has electronic equipment, which functions like a circuit breaker in a house and it shut down at some point to prevent system damage because it had been working so much.

Matthew Chynoweth, MDOT's deputy region engineer, noted an increasing frequency of heavy storms, which could be caused by climate change. The infrastructure simply was not built to handle this new reality. In the case of the I-94 pump house, the "1965" stamped on several pipes highlights the challenge. But Chynoweth described an obvious complication.

"We could make this able to handle a monsoon, but we'd still be limited by how much we can pump into the local system," Chynoweth said.

Still, MDOT does have a goal of upgrading its pump houses to 90% good by 2035. With all highway projects, however, the budget is limited — $3 million per year, and each pump house rehab costs about $1.5 million.

A comprehensive, long-term solution, which would involve not only MDOT but also local communities and a host of other stakeholders, however, does not appear to be in the works.

Cross pushed back against speculation from Free Press readers that lack of maintenance or a failure to adequately clean up highway debris by the department were the issue in the current flooding. She said highway debris cleanup is part of regular MDOT maintenance, but that heavy rains always collect additional debris so the department is in a constant battle.

"Water carries all debris. Should we get more rain that is forecasted, all of that water will carry more debris into the low-lying areas. and we cannot control that or determine what location that will be," Cross said.

Some of the factors that contribute to street flooding, however, are less complicated.

The City of Detroit issued a news release pointing to clogged catch basins. That release also noted that flooding of locations, such as the Lodge Freeway under Cobo Center, is MDOT's responsibility.

"Clogged catch basins from leaves can also result in blocked basins that encourage flooding of streets. As the rain volume decreases and basins are cleared, the standing water will recede," the release said. "Today’s flash flooding is a reminder that residents and businesses can minimize street flooding by ensuring leaves, twigs, grass clippings and other debris are cleared from the street and in front of their property. Left remaining on the street, these items will clog the catch basins that cause flooding. DWSD encourages residents and businesses to use rakes, shovels and brooms to remove the debris and place in a proper refuse bag."

Contact Eric D. Lawrence: elawrence@freepress.com. Follow him on Twitter: @_ericdlawrence.

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