Water policy

This memo presents the results of a literature search conducted in May-June 2007 as a preliminary step toward the study of how climate change-induced variations in the hydrograph (i.e. earlier snowmelt and peak flows) may impact the temporal elements of water rights.

This report surveys the water sources available to a study area that includes Arizona and Southern California and the legal rights of water users in the two states. It assesses the security of those sources and how the various interests served by them will be affected during prolonged water shortages.

Several studies demonstrate that the hydrographs of many western rivers are changing in response to climate change, with one of the most pronounced changes being earlier runoff. This trend is most pronounced in low elevation basins. For example, in many basins of the Pacific Northwest, annual spring snowmelt is now occurring more than 20 days earlier than a half-century ago. This trend is less evident in high elevation watersheds, but even in those...