WAUKESHA, Wis. -- The city of Waukesha is encouraging homeowners to switch to ultra-efficient toilets, which can save 20,000 gallons of water every year.

The city has been dealing with a severe water shortage for years. Although it's about 15 miles from Lake Michigan, it hasn't been allowed to tap into that water.

The recently approved Great Lakes Compact could change that, but Dan Duchniak, of the Waukesha Water Utility, said conservation is still important.

Waukesha is offering a $25 rebate to homeowners who upgrade older toilets. About half of U.S toilets use at least 3.5 gallons per flush but newer ones can use about one-third that volume.

A family of four using a newer model can save 20,000 gallons a year.