Common Waters, Diverging Streams: Linking Institutions and Water Management in Arizona, California, and Colorado. By William Blomquist, Edella Schlager, and Tanya Heikkila. Washington, D.C.: Resources for the Future, 2004. 210p. $70.00 cloth, $30.95 paper.

Water supply and allocation is a problem that has plagued the West for most of its history. Water marketing, a greater emphasis on conservation, and surface water augmentation projects are all methods that have been used to address the problem. Another approach that has been around for quite some time but has been pushed to the forefront in recent years is the idea of conjunctive use management. In its broadest sense, conjunctive use management is simply linking surface and groundwater together and managing them as a common water supply pool. Rather than having one set of groundwater users and one set of surface water users, all are bound together by the need for more water. By doing so, excess surface water can be stored beneath the ground during wet times, and these same users can draw on the underground supply during times of drought. Similarly, the storage will increase the amount of water available underground so that overdraft conditions are diminished. In theory, this means that there will be an overall gain in the amount of water available for all users and that supplies can be managed on a more sustainable basis. In practice, Wiliam Blomquist, Edella Schlager, and Tanya Heikkila point out, existing institutions play a major role in determining the push for conjunctive use management and the form that it takes.