CLEVELAND -- Parts of northeast Ohio got 2 inches of rain in just one hour and flooding resulted. But why can't the sewers handle that much water?

NewsChannel5 investigator Ron Regan reported that northeast Ohio has what is called a combined sewer, and that spells trouble.

Giant sewer pipes, such as one located at Edgewater Beach, overflowed Tuesday for the first time in two years, spewing raw sewage all over the beach.

When storm drains and sewer lines combine and you throw in the amount of rain northeast Ohio had, the lines simply overflow.

Wastewater from homes, industry and storm drains all flow into the same pipes.

NewsChannel5's created a computer-generated map to show how many such pipes there are in the Cleveland area.

Our investigation found the top five locations that overflow roughly 80 times each year:

• I-90 East of Eddy Rd at Shaw Brook
• East 40th at King, North of Aviation High School
• Burke Brook at the Cuyahoga River
• Mary Street, east of West 3rd at the Cuyahoga River
• Kingsbury Run at the Cuyahoga River

NewsChannel5 also found sewage levels in Lake Erie are so high that scores of health advisories have been posted since May.

At Villa Angela and Euclid State Park there have been 34 advisories each, and there have been 10 at Edgewater Park.

For all Lake Erie Beaches from Toledo to Ashtabula there have been 134 advisories warning bathers to swim at their own risk.

The Northeast Ohio Regional Sewer District's Erwin Odeal is warning that Cleveland's Sewer will overflow.

"We do have combined sewers and they will overflow and even storm water, the material that's been on parking lots and streets, animal waste and so forth, all that is going to end up in our water," said Odeal. "So clearly, it would not be safe from a health standpoint to be in any of these streams for the next couple of days."

The sewer district said it has invested $900 million in projects to reduce sewer overflows, all part of 30 projects to renovate the aging system.

It will also be working to create a storm drainage plan on which the area is decades behind.