When Mike Gutow bought his home on Lake St. Clair in May of 2011, it was with fond childhood memories of fishing, swimming and skiing its clear waters.

“Paradise,” he said. “It’s the best way to describe it. Lake St. Clair was paradise.”

A few days after he moved in, a heavy rain fell, and two or three days later, “this glob appeared at the seawall that was about three-feet thick,” Gutow said. “Mixed in was a lot of dead fish. At first it was like, what the heck is this? I’d never seen anything like it before, but, bad as it was to look at, the smell was even worse.”

He now knows what he was seeing and smelling was the result of a sanitary and storm sewer system that is outdated, underfunded and unable to handle the amount of stuff flowing through its pipes, especially in a moderate or heavy rainfall.

Take a drive along Michigan’s streets and highways, and you’ll know many roads are in poor condition. But buried beneath them are the equally deteriorating pipes that are meant to deliver water for drinking and washing and to carry away the waste. Some of those pipes have been in the ground for more than a century — well beyond their expected lifespans. In some cities, sewage still flows through hollowed out logs, although no one knows exactly where.

“Out of sight, out of mind, right?” said Ronald Brenke, executive director of the Michigan section of the American Society of Civil Engineers. “People don’t think about it, because it’s underground.”

Much of Michigan’s water and sewer infrastructure has been neglected for years, threatening public health and in desperate need of repair, an undertaking that experts say could cost $17.5 billion over the next two decades. That price tag doesn’t include the cost of replacing lead service pipes across the state, a peril exposed by the ongoing water crisis in Flint.

How shaky is Michigan’s overall water infrastructure? Consider our faltering network of sewers. In 2013 and 2014, nearly 25 billion gallons of partially treated and untreated storm and sanitary sewage flowed into Michigan’s waterways. How much is that? One billion gallons is enough to fill more than 1,500 Olympic-sized swimming pools.

In its most recent report card, released in 2009, ASCE gave Michigan a D+ for its storm water sewers and a C for those that carry waste water. Even worse, the report card gave the state’s drinking water system a D.

“A significant portion of the state’s primary (water) distribution system is nearing 100 years old,” the report said, adding, “Much of the delivery system, including piping, valves and hydrants, are reaching the end of their anticipated design life, and routine replacement has been postponed for too long.”