Massive storm overwhelms sewer systems

Times-Herald Newspapers

DEARBORN — City workers still were checking drain lines and investigating claims late last week after a recent torrential storm caused widespread flooding across the city.

As of Thursday more than 250 homeowners had reported basement flooding, while several more reported outdoor flooding. About 80 had requested claims forms from the city’s Legal Department, while about three actually had filed them.

The June 5 storm dumped more than 3 inches of rain in a matter of hours late that night and early June 6. Tornadoes south of here caused massive destruction, while some local roadways and low-lying areas were awash for days in rainwater and overflowed sewage.

The majority of flooding occurred on the city’s east side, where drainage systems are engineered only to handle a once-in-five-years storm. But this diluvian downpour was 10 times that, city officials said, amounting statistically to a once-in-50-years storm.

City officials believe basement flooding at more than 80 southeast Dearborn houses is related to a pumping station malfunction in Detroit. Any flood claims would be to the insurer of the station, said Corporation Counsel Derbra Walling, but the city will help to facilitate them.

But flooding also occurred simply because the city’s drainage systems weren’t engineered to withstand such a heavy rain. Even in the west end of Dearborn, where more recently constructed drains are rated for a once-in-10-years storm, the sudden and abrupt nature of the recent system was just too much to handle.

“The rain fell so hard, so quickly, that the water had nowhere else to go,” said Dean Montrief, superintendent of the Water and Sewer Department. “With the (city) drain lines at capacity, the water looks for somewhere to go, and a lot of times it will find its way up the drain connectors to houses into low-lying basements.”

The flooding was the worst Montrief has seen in more than 20 years with the city. But even as claim forms still were be requested, as of Thursday none of the flood cases that had been investigated indicated any malfunction or blockage of the city’s drain lines, Montrief said.

He also said that combined sewage overflow construction, the massive project to stop storm runoff and untreated sewage from dumping into the Rouge River, didn’t affect the drain capacity, because drain flow hasn’t been changed by any of the ongoing work.

With the storm causing so much trouble, Montrief offered a suggestion to homeowners.

“If you live on the east side where you could have problems like this once every five years, or even once every 10 years on the west side, I don’t think I would want to get my basement finished,” he said.