THE IMPORTANCE OF WATER AVAILABILITY INFORMATION FOR LARGE-SCALE EFFORTS TO PROTECT AND RESTORE THE GREAT LAKES

The Great Lakes are vast natural resources that contain about eighteen percent of the world's fresh unfrozen surface water with an additional large volume of water in the ground-water system. The ecosystems in the Great Lakes watershed rely to a large extent on that water. Humans, animals, and plants have adapted to this general abundance of water. Yet, even in this water-rich area, water withdrawals, diversions, and use sometimes conflict with other users' needs or with the ecosystem needs in the basin. In response to these conflicts and potential future conflicts, several large collaborative efforts have formed to deal with water and water-related issues in the Great Lakes. These collaborations can be associated with four main issues: 1) diversion of Great Lakes water outside of the watershed and interbasin transfer of water within the watershed, 2) ecosystem protection and restoration, 3) water quality, and 4) fisheries.

Issues related to diversion of Great Lakes water are being addressed by the Great Lakes Charter which is overseen by the Governors of U.S. states and Premiers of Canadian provinces in the watershed. Ecosystem issues are being addressed by the Great Lakes Regional Collaboration that was formed in 2005. Water-quality issues are addressed by the Great Lakes Water Quality Agreement that was agreed to by the U.S. and Canada in 1972 and was last amended in 1987. Currently, a new amendment of this agreement is being discussed. Fisheries issues are addressed by the Convention on Great Lakes Fisheries between the U.S. and Canada that is overseen by the Great Lakes Fishery Commission. All of these high-level collaborations require water-resource assessments to evaluate the issues being addressed. Many of these quantitative water-resource assessments are being developed as part of a U.S. Geological Survey pilot project on Water Availability and Use in the Great Lakes Basin.