New & Noteworthy

Press Release: Study Explores Groundwater and Geothermal Energy in Drought-Stricken Eastern Oregon and Neighboring States

Technical Announcement: USGS Issues Revised Framework for Hydrogeology of Floridan Aquifer

Press Release: High Plains Aquifer Groundwater Levels Continue to Decline

Regional Groundwater Availability Study Geospatial Data

Press Release: USGS Assesses Current Groundwater-Quality Conditions in the Williston Basin Oil Production Area

Past listings...

USGS Groundwater Watch

USGS maintains a network of active wells to provide basic statistics about groundwater levels.

Other Water Topics

 Water Resources

 Groundwater

 Surface Water

 Water Quality

 Water Use

USGS in Your State

USGS Water Science Centers are located in each state.

Water-Table Fluctuation (WTF) Method

Estimating the Water-Level Rise (DH(t_j))

Determination of water-level rise.

The water-level rise DH(t_j) is estimated as the difference between the peak of a water-level rise and the value of the extrapolated antecedent recession curve at the time of the peak. The recession curve is the trace that the well hydrograph would have followed had there not been any recharge. Extrapolation of the recession curve is not always straightforward.

At least two approaches can be used to estimate DH(t_j) in the WTF method: graphical extrapolation and calculation from a master recession curve (MRC). A third approach used to estimate DH(t_j), made on the basis of the computer code from the RISE program (A. Rutledge, U.S. Geological Survey, written commun., 2005), does not extrapolate for continuation of a hypothetical recession while the water table is rising. Because of the need for daily water-level data, the MRC and RISE approaches can be applied only at sites where water levels were continuously monitored.