This report depicts 2000–2004 water-level changes in the Chicot and Evangeline aquifers in the Houston-Galveston region (figs. 1 and 2). The Houston-Galveston region comprises Harris, Galveston, Fort Bend, Waller, and Montgomery Counties and adjacent parts of Brazoria, Grimes, Walker, San Jacinto, Liberty, and Chambers Counties. The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District and the Fort Bend Subsidence District. The U.S. Geological Survey (USGS) has published annual reports of water-level altitudes and water-level changes for the Chicot and Evangeline aquifers in the Houston-Galveston region since 1979 and separate similar annual reports for the Fort Bend subregion since 1990. Beginning with 2002, the separate annual reports were combined into one report.