As a water resources professional who regularly handles issues related to climate change and water planning, I have noted in past that one of the key missing data points in scientific studies related to climate change is a reliable projection of sea levels. This is important because sea level is a key input for determining the potential impact of climate change on coastal groundwater basins. Such basins frequently have both on-shore and off-shore areas, and intrusion of seawater into the on-shore portion is affected by the relative head of groundwater in the two areas. The head of groundwater in the off-shore portion is directly related to sea level, such that a rising sea level would increase the head in off-shore basins and tend to push seawater toward or into the on-shore portion. Seawater intrusion can be a significant problem for management of coastal basins and the water utilities, industries and individuals that rely on those basins for water supply.
Coinciding with population growth and several years of drought in the southeastern United States, the states of Alabama, Florida and Georgia have been litigating their respective rights in the Apalachicola, Chattahoochee and Flint Rivers in U.S. District Court in the case of In re Tri-State Water Rights Litigation. On 17 July 2009, Judge Magnuson issued a Memorandum and Order ruling that water supply is not an authorized purpose for U.S. Army Corps of Engineers operation of Lake Lanier in northeastern Georgia, despite the fact that the reservoir is the largest source of water for metro Atlanta. The ruling has created significant uncertainty for the future of Atlanta regional water supplies and resulted in a rush of manpower (if not any water yet) to put out the ensuing legal and political fire.