Eight years ago, we each were involved in our respective state's passing of the historic Great Lakes Compact. As tankers were moving into the Great Lakes to ship drinking water to China, and as climate change led to drier conditions across the continent, the region reacted in a rare moment of bipartisan regional solidarity to protect the Great Lakes. It required all eight states (Minnesota, Wisconsin, Michigan, Illinois, Indiana, Ohio, Pennsylvania and New York) to pass legislation to ban diversions of water outside the Great Lakes Basin. Congress later ratified the interstate compact, and President George W. Bush signed it into law.

The compact does allow communities just outside the basin to apply for an exemption to the ban on diversions, if the community has no other reasonable alternatives and strict guidelines are met.

Waukesha, Wis., is the first community to test the compact's ban on diversions ("Waukesha deserves a shot at Lake Michigan water," Dec. 12). It will set a precedent for how future proposals to siphon Great Lakes water outside the basin are treated.

Getting this decision right is not just about Waukesha; it is about ensuring that the protections in the Great Lakes Compact will hold up. We are about to find out if the historic compact can live up to the promise of its protections.

Minnesota should care for two reasons: First, the decision could affect proposed diversions from Lake Superior and water levels necessary for successful commercial shipping; second, Gov. Mark Dayton has to review the Waukesha proposal and either approve or deny it. In fact, under the rules of the compact, all eight governors must approve any exemption from the ban on diversions.

The Waukesha proposal is flawed and not supported by Wisconsinites. Waukesha seeks to more than double its customer-service area and send its treated sewage into an already-impaired river, and the proposal fails to meet the conservation requirements under the compact.

In addition, the Wisconsin Department of Natural Resources received over 3,600 comments on the proposed diversion; 3,300 of them were opposed; 300 were in favor. Polling released just last week from Marquette University in Milwaukee showed that 51 percent opposed the diversion, while 38 percent supported it.

Minnesota led the way by being the first of the Great Lakes states to pass the compact legislation. It can lead again by being the first state to uphold the environmental standards of the compact and deny Waukesha's ill-conceived proposal. We are calling on Dayton to do just that.

Ann Rest, DFL-New Hope, is a member of the Minnesota Senate. Cory Mason, D-Racine, is a member of the Wisconsin Assembly.