Ground Water Levels

The IDWR Hydrology Section maintains a database of information on ground-water levels in Idaho. The IDWR database, known as Hydro.Online, contains data gathered by a number of sources including measurements taken by the U.S. Geological Survey (USGS), the U.S. Bureau of Reclamation (USBR), IDWR contractors, IDWR staff, and other public and private entities. The Hydrology Section analyzes these data to determine regional ground-water level trends. These trends are used to evaluate ground-water availability for new water uses, evaluate and identify areas with declining ground-water levels that may need administrative action, such as ground-water management areas or critical ground-water areas.


Until recently, the IDWR had a cooperative program with the USGS to measure depth to water in approximately 320 wells throughout the state. Beginning in July 2009, measurements in most of these wells were shifted to IDWR staff. The USGS continues to measure seven of the wells, as well as other wells for specific projects under their control. USGS data is maintained in the National Water Information System (NWIS), and data for Idaho is periodically downloaded and stored in the Hydro.Online database.


IDWR also maintains several networks of wells with installed pressure transducers to provide near-continuous water level measurements. Measurements are collected and stored in data loggers for periodic download. These networks are used to support specific planning, modeling, and managed recharge projects in Ada County, Rathdrum Prairie in North Idaho, and in the Egin Bench, Aberdeen, and North Side Tract areas of the Eastern Snake Plain Aquifer (ESPA). Future plans include increasing the number of instrumented wells and equipping some wells with telemetry to provide real-time reporting of the data.


IDWR staff currently measure over 800 wells on a semi-annual to monthly basis. The USBR measures 70 wells on a semi-annual or monthly basis in the Eastern Snake River Plain and the USGS Idaho National Laboratory Project Office measures about 200 wells at varying frequencies on the ESPA. This makes a total of nearly 1100 monitoring wells in Idaho measured on a regular basis.


Public access to ground-water measurement data is available at Hydro.Online or by contacting IDWR staff.

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To request information about a specific area, please email our Ground Water Levels staff.

  • Please include as much information as possible about your request.
  • Add the legal description for the area, including the Township, Range, Section and quarter-quarter.
  • If you don't know the legal description, we can use a general description.
  • Be sure to include what kind of specific information you are looking for.
  • Your contact information.