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Greenwire <br />Page 2 of 2 <br />availability -- supplies of surface water and groundwater. Surface water indicators proposed in the <br />report are annual and five to 10 year measurements of stream flow, reservoir storage, and storage in <br />large lakes and glaciers. <br />Groundwater indicators favored by USGS include groundwater level indices for a range of land use <br />settings and geological environments, changes in groundwater storage due to withdrawals, and <br />saltwater intrusion and the total number and capacity of groundwater supply wells and man -made <br />recharge facilities. USGS hopes such indicators can add to its vast historical database on trends in <br />water usage to create a complete picture of national water consumption, according to the report. <br />Mat Maucieri, a lobbyist for the Association of California Water Agencies, said he welcomed the new <br />approach by USGS and expected such data collection would help states make decisions about <br />future water - consumptive development. "The [USGS] water use reports are great, but there's a <br />longstanding concern that the information would be much more valuable to decisionmakers if they <br />actually had a baseline number of how much water there is," Maucieri said. <br />At press time, officials at several municipal water utilities said they were still reviewing the document <br />and declined comment. <br />The report to Congress also provides background information on the factors affecting water <br />availability. For example, changes in surface water levels are typically affected by variances in <br />natural events such as rainfall and snowmelt, evaporation due to heat, and the formation or melting <br />of glaciers. Even more important in may regions, groundwater levels are affected by natural <br />recharge rates, water table evaporation and fluctuations in surface waters connected to aquifers, the <br />report says. <br />Human activities also can dramatically affect water availability through surface water withdrawals or <br />diversions, river flow manipulation for hydropower or navigation, construction of reservoirs and <br />stormwater retention ponds, stream channelization, drainage of wetlands and other actions. <br />Regarding dams alone, USGS estimates that 77,000 structures block flow on the nation's <br />waterways, creating 68,000 reservoirs. <br />Human activities that deplete groundwater stores include construction of groundwater wells, deep <br />well injection, aquifer depletion for irrigation, drainage of wetlands, dewatering of mines and tunnels, <br />reservoir leakage, and development of sewer lines and lawn watering systems, according to USGS. <br />DAILY ENVIRONMENT & ENERGY .; LAND <br />PUBLISHING, LLC <br />122 C. St. NW, Ste. 722 Washington, D.C. 20001 <br />E- mail :pubs@eenews.net * Phone: 202- 628 -6500 <br />All contents O 2004 E &E Publishing, LLC. <br />http: / /www.eenews. net/ GreenwireBackissues /052704/05270415.htm 5/27/2004 <br />