more rumblings on compact in Indiana

Businesses and environmental groups in Northwest Indiana have already said they oppose water diversions from the Great Lakes. But the strength of their support for the Great Lakes Compact may depend on whether Indiana makes it mandatory or voluntary for existing water users to conserve water.

http://www.post-trib.com/news/579007,glcmeet.article

Why is it so burdensome to save water, which can also reduce costs and increase profits?