Despite opposition, there's precedent for using Lake Michigan to supply New Berlin
As current law works in the Great Lakes states, any city that wants to divert Great Lakes water out of the basin must get the nod from all eight Great Lakes governors. The problem is that the system is considered too arbitrary to hold up in court.
During the summer, word leaked that the Wisconsin DNR was quietly working with New Berlin on a plan to take water over the basin dividing line before the compact is formally adopted and that it had been floating the idea past water officials in the other Great Lakes states. That didn't go over well with conservation groups, the City of Milwaukee or the State of Michigan, where Gov. Jennifer Granholm reacted with a swift no.
A year ago, the governors released a new batch of proposed diversion rules, formally known as the Great Lakes-St. Lawrence River Basin Sustainable Water Resources Compact. Those rules, which still must be adopted by the legislatures of all eight Great Lakes states and then ratified by Congress, include a provision that specifically allows "straddling" communities, such as New Berlin, to access Great Lakes water.