Groundwater-level altitudes and long-term groundwater-level Changes in the Chicot, Evangeline, and Jasper aquifers, Houston-Galveston Region, Texas, 2020

The U.S. Geological Survey (USGS) in cooperation with the Harris?Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, and Lone Star Groundwater Conservation District produced this dataset of groundwater?level altitudes and groundwater?level altitude changes in the Chicot, Evangeline, and Jasper aquifers in the Houston?Galveston region, Texas. This dataset documents current?year (2020) groundwater?level altitudes for each aquifer, 5?year (2015?20) groundwater?level changes for each aquifer, long?term (1990?2020 and 1977?2020) groundwater?level changes for the Chicot and Evangeline aquifers, and long?term (2000?2020) groundwater?level change for the Jasper aquifer. The groundwater?level measurements from which the dataset were built are stored in the USGS National Water Information System (NWIS) (http://dx.doi.org/10.5066/F7P55KJN) and are accessible through the NWIS Web Interface. In 2020, groundwater-level-altitude contours for the Chicot aquifer ranged from 150 feet (ft) below the North American Vertical Datum of 1988 to 200 ft above datum. Groundwater-level-altitude contours for the Evangeline aquifer ranged from 250 ft below datum to 200 ft above datum. Groundwater-level-altitude contours for the Jasper aquifer ranged from 200 ft below datum to 250 ft above datum. In each aquifer, the highest and lowest groundwater-level altitudes were measured in relatively small, isolated areas. This dataset was created by the U.S. Geological Survey to provide resource managers, public officials, researchers, and the general public with ready access to accurate, impartial, scientific information regarding groundwater?level changes and altitudes in Harris, Galveston, Fort Bend, Montgomery, Brazoria, Chambers, Grimes, Liberty, San Jacinto, Walker, and Waller Counties, Texas. These digital data accompany a U.S. Geological Survey Scientific Investigation Report by Braun and Ramage (2020).