Access to Lake Michigan water has been critical to regional development and, if well managed, will continue to provide a sustainable supply of water into the future for much of the region. Illinois withdraws, uses, and then diverts Lake Michigan water out of the Great Lakes Basin to the Mississippi River system. This modification resulted in a U.S. Supreme Court Consent Decree that governs Illinois withdrawal of lake water, which is managed by the Illinois Department of Natural Resources (IDNR). As other parts of the region face water quality and quantity challenges, Lake Michigan communities can help make more of the state’s limited allocation available to others in the region by increasing conservation and efficiency and reducing water loss. In fact, advancing water conservation and efficiency are conditions of the Lake Michigan Allocation Program.
Reducing water loss is a key way to reduce water use and effectively increase the supply available for use. Twenty-one percent of Lake Michigan permittees face chronic water loss problems. Water loss is not only a waste of a valuable resource, but often results in a loss of revenue for the community water supplier, which can hinder their ability to maintain the water system. Communities can tackle water loss in a variety of ways, including use of the American Water Works Associations (AWWA) M36 water audit method. Partners in the region, including IEPA, Illinois Section AWWA, and MPC, among others, are providing critical assistance by helping communities advance asset management processes. Demand management – an approach that aims to conserve water by influencing demand – is a critical strategy that community water suppliers throughout the region should use to meet long-term water supply needs.
ON TO 2050 calls for an integrated approach to water resource management, where the region recognizes, values, and manages water as a singular resource that could be almost infinitely reusable if managed properly. Reuse of rainwater and graywater are key strategies to reducing demands on drinking water supplies while also addressing water quality and other wastewater management objectives. Within the Lake Michigan basin, stormwater that once flowed into Lake Michigan is now sent out of the basin by stormwater infrastructure and the altered river system. This stormwater volume, part of Illinois’ allowed diversion of Lake Michigan water, reduces the amount of the Lake Michigan allocation that can be used for domestic purposes. Local governments should promote green infrastructure and other stormwater management best practices that focus on infiltration to help decrease the Illinois diversion volume attributed to stormwater runoff.