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.
The EPA's National Water Program Strategy characterizes water conservation both as a mitigation measure for reducing greenhouse gas emissions and as an important adaptation to drier conditions in the future. And the EPA is not the only federal agency that recognizes the important link between water and energy. In a report just released by the U.S. Department of Energy that analyzed a scenario in which 20 percent of the nation's electricity is generated from wind power by the year 2030, the DOE noted that such a shift would reduce water use by approximately 8 percent. That's a significant savings, roughly equal to the average share of western water withdrawals claimed by urban users.
The EPA's National Water Program Strategy also acknowledges an important new way of thinking about our water and the rest of our environment in the face of what appear to be permanently shifting baseline conditions. The increasingly common droughts and extreme weather conditions will inevitably redefine what is "normal" as climate conditions continue to change. The EPA refers to this as a shifting "natural reference," by which it means emerging dynamic conditions today challenge all of our assumptions about what to expect in terms of stream flows, seasonal temperature patterns, and just about every other reference point that has until now been based on conditions in the past.
This is an important point, similar to the message in a short but pointed essay published in the February 1, 2008 issue of Science, "Stationarity is Dead: Whither Water Management?" The authors caution policymakers against making "grand investments" in new water infrastructure without acknowledging the realities of "an uncertain and changing environment." Their caution is well advised.
The annual onset of the Rocky Mountain snowmelt will continue to nurture welcome growth and renewal, but the seasonal changes may look very different to our children and grandchildren. It is encouraging to see the Environmental Protection Agency acknowledge the explicit effects of climate change on our precious water resources. It is essential to hold the agency accountable for implementing the action items outlined in its National Water Program Strategy, and to provide sufficient financial resources to support the additional regulatory, education, and research initiatives called for in this report.