MILWAUKEE, Wis. (WTAQ) - Over two billion gallons of raw sewage and storm water spilled into Metro Milwaukee’s lakes and streams after last Thursday’s torrential rains. That’s more than four times the capacity of the area’s Deep Tunnel sewage system.

The overflows were designed to prevent sewage from going into basements. But over six-thousand basements in the city of Milwaukee got flooded anyway. The metro sewerage district told the state DNR that the system’s relief points could not remove excess water from the over-burdened sewers fast enough.

That was after parts of Milwaukee got close to eight inches of rain in a six hour period. It was the fourth time this year the area had sewage overflows. But they were not nearly as big as the record of two point nine billion gallons spilled in June of 2008.