Things haven't let up. June was the ninth wettest month on record for southeast Michigan since 1874, according to the National Weather Service. The city released more than 2 billion gallons of partially treated sewage and 82 million gallons of diluted sewage into the Detroit River in June alone.
The city reported 55 combined sewer overflow discharges to the Detroit River in 2011, which means too much rain overwhelmed the system and partially treated or untreated wastewater discharged into river. There have been 31 discharges in 2013 so far.
Record algae bloom
Overflows can cause a number of problems. The water carries harmful E. coli bacteria, which can make people sick if exposed to the water.
The Detroit River empties into Lake Erie, which had its worst algae bloom ever in 2011. The bloom was due to a confluence of factors, including record farm runoff, but overflows from Detroit affect the entire Great Lakes basin, said Joel Brammeier, president of the Alliance for the Great Lakes, a nonprofit environmental organization.
"The 'dump sewage into the Great Lakes' approach to sanitation should have been left behind a long time ago," Brammeier said. "But policy and infrastructure haven't caught up."
And it's not just Detroit. Other large Midwest cities are facing the need for major infrastructure upgrades.
During the heavy rain year of 2011, Hammond, Ind.; Toledo, Ohio; Buffalo, N.Y.; Chicago and Cleveland – all saddled with aging combined sewer systems – each spewed more than a billion gallons of sewage into either the Great Lakes or a nearby watershed.
A year ago, fellow Great Lakes city, Duluth, Minn., experienced its worst flood ever: Up to 10 inches of rain fell over two days, causing massive sinkholes, damaging roads and bridges, flooding homes and killing 14 animals at the Lake Superior Zoo.
Nine counties in northeastern Minnesota were declared disaster areas. Damages were estimated at $108 million, and sewage overflowed in both Duluth and nearby towns.
Detroit's woes are particularly compounded by a shrinking population. The nation's sixth largest metropolis three decades ago, with a population of 2 million, the city today has plunged to 18th, with just 700,000 people. Entire neighborhoods sit abandoned, the tax money gone. But the need for working pipes remains.
The city's wastewater system serves Detroit and 76 nearby communities – about 3 million people over 946 square miles. As pipes and other parts of the system age, the cost to maintain them increases, Schechter said. "Funding is a continual challenge for Detroit."
The infrastructure has already collapsed in certain parts of the city, said Nancy Love, an engineering professor at the University of Michigan. "When there is a big storm event there's a big flush – leaves, dirt, and stuff collect in the system from deteriorating parts of city."
It's unclear how much of the city's collection system is currently inactive, Schechter said.
But the city stopped street sweeping a few years ago because there's no money. "So now, when there's a big rain, we get more trash clogging up the system," he said. "That certainly doesn't help matters."
In a city that is more than 83 percent black and has a median household income 42 percent lower than the state, heat waves, flooding and other climate change challenges are an environmental justice issue, said Kimberly Hill Knott, a senior policy manager at Detroiters Working for Environmental Justice.
"It's a poor city and people are going to have to dip into their pockets to deal with climate change impacts," Knott said, referring to higher energy costs and taxes to help strengthen city infrastructure.