The first workshop of the water resources sector was held from September 14-16, 1998, in West Palm Beach, Florida. The workshop summarized and prioritized water resources issues from the regions and other sectors in the assessment. Regional issues identified at the workshop included:

Central Great Plains: The Central Great Plains rely on water imported to the region. The main transbasin water diversions are the tunnels drilled through the Rockies to bring supplies of water from the Colorado River to the Great Plains. Irrigated agriculture is a main end use in this region, and this demand is increasing (although there are some shifts underway from agriculture to urban development). The biggest regional issue is the lack of surplus capacity in regional water supplies. For example, water from the Arkansas River serves multiple uses as it passes through the different states. The resulting conflicts over allocation of limited groundwater and surface water supplies have led to a number of lawsuits in the region.

Eastern Midwest: The eastern Midwest includes some of the largest river systems in the nation, and this region is also strongly affected by drought and flood. Drought brings on low flow and depletion of groundwater. Flooding causes crop and property damage, erosion, and sedimentation. In addition, agricultural runoff from the region is causing hypoxia (a reduction in aquatic oxygen concentration to levels where life cannot be sustained) within the Gulf of Mexico. On the bright side, floods increase the fish population. Generally, the region has plenty of water, but the effectiveness of the distribution systems varies, resulting in water shortages during droughts.

Great Lakes: The Great Lakes, while making up 95% of the fresh surface water in the United States, are a shared resource with Canada. The potential for degradation IN water quantity, quality, associated ecosystems, and coastline is a concern for both nations. Anticipated impacts associated with climate change and variability include increased air temperatures, changes in precipitation, increased evaporation from lakes, increased evapotranspiration from plants, decreased tributary flows, decreased net water supplies, and lower lake levels. Seasonal and interannual changes are also projected to lead to a factor of three increase in the normal variability of water level in the lakes. Regional needs include a serious consideration of sustainability, the development of a robust water-management plan including groundwater supplies, and an assessment of water-quality and ecosystem impacts on the 121 watersheds around the Great Lakes.

Metropolitan East Coast: Although many communities in this region have their own water supply systems, they are generally small compared to that for New York City. water supply here is comples issue which is linked to many others. Climate change would occur on top of these other dynamics with unknown effects to the water supply. A rise in sea level could also cause a major impact because it would result in saltwater intrusion into the long island aquifer, causing increased strain on the New York City system. New institutional forms and changes will be needed, as will new infrastructure systems. The quality of effluent waters has improved significantly; water quality will not be affected to a large extent by climate change unless large increases occur in upstate precipitation or there is a large sea-level rise.

Mid-Atlantic: The Middle Atlantic region is an area with significant climate variability and large vulnerabilities. During the past few decades, the region has experienced both severe drought and flooding produced by winter storms and summer hurricanes. The region includes several metropolitan areas which rely on water systems that are highly sensitive to climate variation. A large portion of the population obtains water from private wells which are potentially impacted by climate variability. As a result, water management in dry periods is a major issue here.

Pacific Islands: The Pacific Islands cover a vast expanse of ocean but have a relatively small population and vulnerable economic and ecological systems. Water-resource systems are made up of (1) low-lying atolls with no groundwater, and (2) high islands with the runoff from mountains being collected for subsequent use. The extant models of these systems are relatively weak, and limited historical climate data exist for the area. Research and information that are needed include: reinstatement of streamflow monitoring, better understanding of climate-system processes, information and education campaigns, and involvement of the industrial sector in overall water use planning.

Pacific Northwest: As temperatures go up, snowpacks in the mountains go down, and those snowpacks supply most of water resources to the area east of the Cascades. Late fall snow turns into flood-producing rains under warmer climate scenarios, leaving less snowpack to augment water flows during the summer. Because the Columbia River watershed has already experienced demands on too little water, a potential decrease in water availability is a major concern. Another regional issue is the length of time required for fish to travel downriver with all the reservoirs in place and related degradation in fish habitat.

Rio Grande: Water shortage is a concern for the entire region, yet at the same time the region is experiencing rapid urban and population growth. With the population doubling every 20 years, aquifers are being depleted rapidly. Conflicts are arising between Indian tribes and the rest of the community, resulting in legal battles in many cases. Border river water is being allocated to agriculture, yet no drought-management plan is in place. With in-stream flows as low as 20% of historical levels, the ecology of the region is also threatened. one potential answer to supply problems is increased efficiency of agricultural water use.

South Atlantic Coast and Caribbean: Some parts of the region (such as the southeastern states) have abundant water; but others (such as the Caribbean Islands) have no groundwater. Water management policy is critical because of the strong pressure for further development in the region. Demographic impacts also play an important role in water management and use in this area because of the high population densities along the coast and because of large seasonal swings in population. In addition, some health hazards are also associated with water resources.

Southeast: The Southeast regional workshop identified agriculture, forestry, and ecological systems as the main areas of concern, especially with respect to water quality and availability. To assess how climate change and variability might affect those resources, institutions and agencies are performing climate-model simulations and biophysical-response models relating to water resources for agriculture, forests, and land use.

- D. Briane Adams, USGS