By Rich Anderson
June 19, 2006

Albuquerque (NM) Mayor Martin J. Chavez, Chairman of the Urban Water Council, convened a meeting of the Council on June 2, in conjunction with the Conference of Mayors Annual Meeting in Las Vegas. Chavez welcomed three experts who addressed global warming and community water resources. The experts offered a sobering view of future water management challenges.

Brad Udall, Director of Western Water Assessment at the University of Colorado Regional Integrated Science Center, discussed ongoing joint research with the National Oceanic and Atmospheric Administration. Udall stated that we are currently experiencing a period of global warming, although he could not say with great certainty how long the current warming trend might last. Evidence of warming is based on a 30 percent elevation of atmospheric carbon dioxide since 1800; global temperatures up by 1°F since 1970; and, a rise in sea level of 4-8 inches since 1900. He also mentioned that 985 of 1000 Alaskan Glaciers are receding and only 15 are growing, due mainly to a 3°F increase during the 20th Century.

According to Udall’s review of published research future warming may range between 2.5°F to 10°F. The estimated range is broad due to uncertainty about future emissions from human activities and because of scientific uncertainty. The impacts of global warming include: higher maximum temperatures, greater frequency of extreme hot days, higher minimum temperatures. Additionally, coastal cities can expect rising sea levels of four inches to as much as three feet due to the thermal expansion of sea water and melting glaciers. Udall stated that cities can expect average precipitation increases and greater variation in rain intensity.

Water managers facing familiar challenges such as population gains and losses, normal climate variability and competition for finite water supplies will face the additional challenges posed by global warming. He stated that climate is not static, and planning on past patterns may be shortsighted. Water managers should reconsider how they incorporate extreme weather events in planning and forecasting. Udall suggested that water conservation is critical to water supply resiliency and to reduce water shortage vulnerability.

Dr. Joel Scheraga, EPA National Program Director for Global Change Research Program, agreed that a warming trend is in effect. He stated concern about community water resources because climate is the dominant factor governing the occurrence, distribution, and movement of water within watersheds. Understanding the risks posed by climate variability to water systems is a central focus of water resources management. Such an understanding will be critical for our ability to meet future water supply needs, comply with water quality regulatory requirements, design and properly plan water infrastructure, and protect our fragile ecosystem.

Scheraga talked about an assessment tool that EPA has developed for communities that would help reduce the likelihood of future community water resources impacts. The tool, named “CAT”, is intended to aid cities in developing strategies to “adapt” to future climate change conditions. The tool relies on inputs of local watershed information. It can help water managers: assess how increases in precipitation of 10 percent, 20 percent, 30 percent, etc. over historical conditions will influence non-point pollution loading to a stream; assess the flooding caused by an historical extreme weather event given recent increases in urban development within the watershed; assess the future effectiveness of a proposed water quality limit implementation plan under a projected climate change scenario.

Ken Albright, Director of Groundwater Resources for the Southern Nevada Water Authority (SNWA) provided examples of water management in stressed regions that suffer from naturally arid conditions, drought events and the new pressures related to global warming and climate change.

The Authority was formed in 1991 to address Southern Nevada’s unique water needs on a regional basis. It is responsible for regional water supplies, ensuring water quality, and developing and administering conservation programs.

In response to the long'standing area drought, the Authority accelerated development of Colorado River water resources, in'state water resources, and continues to emphasize conservation. Albright oversees the coordinated operation of Lakes Powell and Mead as the major water supply sources. He plans to avoid shortage conditions with programs intended to create a water surplus. This is accomplished through system efficiency projects; tributary conservation; acquiring water from non-Colorado River sources. One of the most important water supply arrangements is the “Return-Flow credits” program for in'state groundwater discharged to Lake Mead. For every treated gallon of water returned to Lake Mead the Authority is granted equivalent supplies in the future.

Another example of progressive planning at SNWA is their water conservation plan. Unlike many communities that focus conservation efforts on lowering indoor use of water consumption, SNWA places greater emphasis on curbing outdoor water use. The critical program is a cash incentive to property owners to convert traditional landscaping in favor of desert landscaping. The Authority promotes this activity by making over $30 million in cash incentives annually; and it conserves significant volumes of water.

Chavez announced two upcoming meetings including a special work shop on water infrastructure disaster recovery in Biloxi (MS) June 28-29; and the Urban Water Summit will be held in Santa Barbara (CA) September 13-14.