INDIANAPOLIS, (WOWO): Central Indiana may get up to four inches of water once the rain is done.

Citizens Energy Group says four inches of rain will likely cause 800 million gallons of raw sewage overflows. That‘s the same as 1200 Olympic sized pools. Citizens is building a 25-mile underground tunnel system. It's designed to capture and store 250 million gallons of raw sewage.

Meanwhile, the Indianapolis Department of Public Works has crews out assessing flooding in numerous areas. Spokesperson Lesley Gordon says they've posted high water signs in the appropriate areas. She urges drivers to heed signs and drive with extra caution. Gordon says they also have free sandbags at the West Street Garage available to residents who may need them to offset flooding on their property.