Great Lakes Compact
|Long title||Great Lakes--St. Lawrence River Basin Water Resources Compact|
|Enacted by the||110th United States Congress|
|Effective||December 8, 2008|
The Great Lakes-St. Lawrence River Basin Water Resources Compact is a legally binding interstate compact among the U.S. states of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin. The compact details how the states manage the use of the Great Lakes Basin's water supply and builds on the 1985 Great Lakes Charter and its 2001 Annex. The compact is the means by which the states implement the governors' commitments under the Great Lakes-St. Lawrence River Basin Sustainable Water Resources Agreement that also includes the Premiers of Ontario and Quebec.
The Council of Great Lakes Governors serves as secretariat to the Governors' Compact Council created by the Compact.
Following approval by each of the eight member state legislatures, the compact was signed by Minnesota Gov. Tim Pawlenty on February 20, 2007; Illinois Gov. Rod Blagojevich on August 17, 2007; Indiana Gov. Mitch Daniels on February 20, 2008; New York Gov. Eliot Spitzer on March 4, 2008; Wisconsin Gov. Jim Doyle on May 27, 2008; Ohio Gov. Ted Strickland on June 27, 2008; Pennsylvania Gov. Ed Rendell on July 4, 2008; and Michigan Gov. Jennifer Granholm on July 9, 2008. The U.S. Senate passed the compact on August 1, 2008, and the U.S. House of Representatives followed on September 23, 2008. President George W. Bush signed it on October 3, 2008. The compact became state and federal law on December 8, 2008.
In 2013, the city of Waukesha, Wisconsin applied for permission from the State of Wisconsin to withdraw water from Lake Michigan. Water historically drawn from an aquifer reached radium levels exceeding federal standards. After protest and later negotiation with state officials, Waukesha became obligated to find a new source of water by 2018. The city lies 1.5 miles outside of the Lake Michigan drainage boundary; however the county in which it resides straddles both the Mississippi and Great Lakes watersheds. 
- "Legislative record for S.J. Res 45". Library of Congress. Retrieved 2009-04-09.
- "Great Lakes-St. Lawrence River Basin Water Resources Compact Implementation". Council of Great Lakes Governors. Retrieved 2010-06-05.
- "IMPLEMENTATION", Great Lakes-St. Lawrence River Water Resources Regional Body, Retrieved September 21, 2009.
- "City of Waukesha Water Diversion application". Wisconsin Department of Natural Resources. Retrieved 2013-11-19.
- "City's Water Problems Test Great Lakes Agreement". The Wall Street Journal. Retrieved 2013-11-19.
- Great Lakes—St. Lawrence River Basin Water Resources Council
- Great Lakes—St. Lawrence River Water Resources Regional Body
- Navigating Wisconsin's Obligations Under the Public Trust Doctrine