Texas Water Science Center
Texas Drought Watch
Below normal 7-day average streamflow compared to historical streamflow for the day of the year
Based on about 280 USGS sites in Texas having at least 30 years of record. The data used to produce this map are provisional.
Click image to view larger, interactive version of the map.
The U.S. Geological Survey Texas Water Science Center continuously monitors the status of the State's principal rivers, reservoirs, and selected aquifers. Stations with long-term continuous record are used to compare existing streamflows, reservoir storage, and ground-water levels with normal and extreme recorded values to measure the potential for drought, or the severity of an existing drought.
Texas Drought Publications
Definitions of Drought
Droughts do not have the same meaning or significance to all people. No generally accepted definition is adequate, nor is one practical, because drought is the result of many different factors. Three common definitions are:
Assessing Hydrologic Drought Severity
In general, when the water content in streams, reservoirs, aquifers, or soils falls below the long-term average, a pending or potential hydrologic drought may exist. The severity of a hydrologic drought is not always obvious until these water supplies are seriously depleted. The USGS network of long-term continuous record stations is important in measuring the severity of an existing or potential drought and making projections of subsequent drought conditions.
Text modified from Hanson, R. L., 1987, Base flow as an indication of drought occurrence. In: S, Subitzky (ed.), Selected Papers in the Hydrologic Sciences: U.S. Geological Survey Water Supply Paper 2330. pp. 115-129.
1 Huschke, R.E., ed., 1959, Glossary of meteorology: Boston, American Meteorological Society, 638 p.
2 Rosenberg, N.J., ed., 1979, Drought in the Great Plains- Research on impacts and strategies: Proceedings of the Workshop on Research in Great Plains Drought Management Strategies, University of Nebraska, Lincoln, March 26-28: Littleton, Colorado, Water Resources Publications, 225 p.
3 Yevjevich, Vujica, Hall, W.A., and Salas, J.D., eds., 1977, Drought research needs, in Proceedings of the Conference on Drought Research Needs, December 12-15, 1977: Colorado State University, Fort Collins, Colorado, 276 p.