New & Noteworthy

 Press Release: Deficit in Nation's Aquifers Accelerating

 MODFLOW-USG: An Unstructured Grid Version of MODFLOW

 USGS Threatened and Endangered Stations

 Report to Congress: Progress Toward Establishing a National Assessment of Water Availability and Use

 Fact Sheet: Understanding and Managing the Effects of Groundwater Pumping on Streamflow

  Annotated List of Classic Pre-1980 USGS Groundwater Papers on Quantitative Groundwater-Flow Analysis

  WaterNow: Get current water conditions by text or email

  Circular: Streamflow Depletion By Wells: Understanding and Managing the Effects of Groundwater Pumping on Streamflow

USGS Groundwater Watch

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

USGS in Your State

USGS Water Science Centers are located in each state.

Archive of USGS Groundwater Technical Procedures Documents

The most current versions of the GWPDs are always available online as USGS Techniques and Methods Report (TM) 1-A1 at http://pubs.usgs.gov/tm/1a1/

A series of groundwater technical procedures documents (GWPDs) has been released by the U.S. Geological Survey (USGS), Water-Resources Discipline, for general use by the public. Because a goal of this series of GWPDs is to remain current with the state of the science, and because procedures change over time, the report has been released in an online format only. As new procedures are developed and released, they will be linked to the online report.

This web site is an archive of superseded versions of the GWPDs. The superseded GWPDs on this site are no longer used or supported by USGS. These documents are provided for historical reference only and may contain outdated methods, broken links, and (or) incorrect contact information.

Superseded Versions of GWPDs from Techniques and Methods Report 1-A1

There are no superseded versions of TM1-A1 at this time.

Note: Some or all of this information is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of the free Adobe Reader from the Adobe web site.  Visit http://www.adobe.com/accessibility/  for free tools that allow visually impaired users to read PDF files.