U.S. GEOLOGICAL SURVEY GROUND WATER CLIMATE RESPONSE NETWORK

Scientists are striving to improve the timeliness and accuracy of drought forecasting. One area of current research is the integration of ground-water data with other hydrologic information that historically has been used in drought analysis. The U.S. Geological Survey (USGS) measures water levels in nearly 24,000 wells each year for a variety of objectives. Approximately 500 of these wells supported by the USGS Ground-Water Resources Program and in cooperation with state and local agencies under the USGS Cooperative Water Program meet the criteria necessary to be included in a “Climate Response Network” of wells designed to illustrate the response of the ground-water system to climate variations.

A Climate Response Network well must be completed in a single unconfined aquifer or near-surface confined aquifer that responds to climatic fluctuations. A Network well also must show little or no effect from pumping or other human activity. Three types of water-level data are available from these wells--periodic (279 wells), which are ground-water levels measured by hand; continuous (83 wells), levels measured by an automatic sensing device; and real-time (238 wells), levels that are continuous data transmitted from the well at least once per day. Each of the 50 states and Puerto Rico has at least one well in the Network, and most states have two or more Network wells.

The Climate Response Network web pages provide water-level data for all wells in the Network, in addition to a monthly statistical summary of ground-water levels for wells that have at least 10 years of water-level measurements in a given month. Water-level distributions greater than or equal to the 90th percentile, 75th-89th percentile, 25th-74th percentile, 10th-24th percentile, and less than the 10th percentile are presented, and current measurements are compared against this distribution. A U.S. map provides a broad overview of water-table conditions across the nation. State maps provide a more local picture of ground-water conditions. Individual well pages provide the details about a specific well, and all water-level data. Data from the Climate Response Network represent a potentially important addition to the hydrologic data needed for drought monitoring and forecasting. These data can be combined with data from other Federal, State, and local agencies to support drought planning, response, and mitigation efforts.