Thanks in part to Environment Illinois’ legislative and grassroots advocacy, Illinois is on track to become the second state to adopt the historic Great Lakes Water Resources Compact, an agreement between the Great Lakes states to ensure that the lakes remain as great as they are now for future generations.

Although vast, the Great Lakes are vulnerable to the removal of water at rates faster than can be naturally replenished. Each year, rainfall and snowmelt replenish only about 1 percent of Great Lakes water; the other 99 percent is nonrenewable. All of the waters in the Great Lakes Basin are interconnected, so lower water levels can drain ponds, dry wetlands, and damage fragile ecosystems.

Lake Michigan currently supports Illinois’ economy through industry, shipping, recreation, tourism, and by providing drinking water to Chicago and 124 suburbs. But these demands on the finite Great Lakes water supply compete with proposals for new in-basin uses as well as schemes to export Great Lakes water—like the proposals to refill the western U.S.’s Ogallala Aquifer or produce bottled water for sale in Asia.

With 33 million people drinking Great Lakes water everyday, it surprises many people to learn that current law provides no assurances of the long-term supply of this vital resource.

The product of five years’ negotiation and 15,000 public comments, the Great Lakes Compact is an agreement among the eight Great Lake states to ensure sustainable use of Great Lakes water. The Compact prohibits most new or increased out-of-basin diversions, establishes uniform standards for new in-basin water uses, enhances public notices, and requires Great Lakes states to develop water resource inventories and efficiency programs.

In Illinois, a House bill to establish the Compact passed the House unanimously on March 29 and a separate Senate bill passed the Senate on April 25. To become law, one of those bills must pass both chambers and be signed by the governor.

Illinois’ passage of the Compact helps clear the way for its implementation, but to become law, it must pass the state Legislatures of all eight Great Lakes states, as well as the U.S. Congress.