WaterSense is a water efficiency rating system, much like Energy Star. Lots of states and communities throughout the U.S. offer rebates to encourage people to buy high efficiency toilets or other WaterSense products. It’s not just dry towns worrying about their water either – my hunch is that New Berlin, WI, Charlottesville, VA, and Concord, MA, all get a fair bit of rain and they all offer rebates.
So what about Illinois and Indiana? Scroll through the rebate finder on the WaterSense and you don’t see any, though I know that in Illinois both Aurora and Batavia do offer rebates. What about your town? If you don’t have one, talk to your community leaders and see if they’d be interested.