Are We Ready for Water Shortages in Western States?

The rivers are rising as spring arrives in the Rocky Mountain West. In the annual pattern that sustains the environment and much of the economy of this region, water generated from melting snow feeds the streams, soaks the soil, and is diverted into ditches and reservoirs to serve millions of people and water their landscape. Here at the crown of the continent, the snowcapped peaks are far more than a pretty picture -- they are an interest-bearing savings account we draw on throughout the year.

Unfortunately, the principal of this account is being depleted by the increasingly obvious impacts of global climate change. Even this winter's abundant snowfall fails to overcome decades-long trends of increased temperatures and altered patterns of precipitation and spring runoff. The latest documentation of these impacts is the U.S. Environmental Protection Agency's National Water Program Strategy: Response to Climate Change.

The EPA, which is seeking public comment on the report by May 27, 2008, provides an overview of the effects of observed and projected climate change on national water resources, with a focus on water quality and aquatic species. The draft National Water Program Strategy offers a whopping 46 "key actions" that the federal agency proposes to implement in response, ranging from water and energy conservation incentives to new and modified water quality regulatory programs. The proposed national actions are organized into four major goals:

• Use water programs to contribute to greenhouse gas mitigation
• Work with states and tribes to adapt water programs to projected new conditions due to climate change
• Strengthen the link between water programs and research activities
• Educate water professionals and stakeholders about projected climate change impacts on water resources.

Like many reports on water issues from Washington, however, the EPA's National Water Program Strategy offers precious little detail about the projected conditions and appropriate policy responses to those projected conditions for the arid West. In part, this is explained by the frustrating lack of regional- or local-scaled modeling to project more accurately the effects of climate change on our western river basins and watersheds. The EPA proposes further work to better define projected conditions and responsive policies in particular regions of the country, including special attention to issues of drought and water supply in the West.

The world's leading climate change research consortium, the Intergovernmental Panel on Climate Change, is working to produce the finer-scaled regional models that will inform the EPA in this follow-up work. In the meantime, the IPCC's 2007 report documented substantial changes already underway in the western United States, among them:

• Earlier runoff of snowmelt, stressing some reservoir systems
• Decreased spring and summer snow cover
• Increased annual precipitation falling as rain rather than snow
• Threats to reliable supply complicated by high population growth rates in western states where many water resources are at or approaching full utilization
• Increased wildfire potential
• Lowered levels of streamflow, which has already decreased by about 2 percent per decade in the central Rocky Mountain region over the last century
• Additional stress from decreased recharge to heavily utilized groundwater-based systems in the Southwest

Given these significant changes, the most pertinent sections of the EPA's National Water Program Strategy propose actions that would stretch our limited water resources further through federal and state policies to encourage or require water conservation, re-use, and efficiency improvements. It is particularly encouraging to see the EPA emphasize the link between water and energy use -- a notable sign of progress since the Natural Resources Defense Council exposed the astounding amount of energy consumed by water infrastructure in its 2004 report, Energy Down the Drain.