Analysis of ground water level fluctuations and borehole extensometer data from the Baytown area, Houston, Texas

Former use of ground water in the Baytown area in Houston, Texas has been about equally divided between public supply and industry. In this area piezometer wells and borehole extensometers have been constructed by the U.S. Geological Survey. The extensometer (LJ 65-16-930) was completed at a depth of 131 meters (431 feet), and another extensometer (LJ 65-16-931) was completed at a depth of 450 meters (1475 feet). A continuous record of the water levels in piezometers exists for different depths. Continuous records of consolidation (compaction) between the land surface and the depth of each extensometer also exist. This data was used to generate stress-strain diagrams. The head decline and the recovery (stress changes) plotted against compaction (strain) generates a series of open loops that represent the elastic and inelastic parts of the consolidation curve. Fourteen years of continuous records were analyzed for each of the clay layers in the Baytown area to compute important properties such as the storage coefficient for either the elastic range or the inelastic range and the vertical hydraulic conductivity.