Imperial Valley Precipitation & Groundwater Monitoring

ISWS, under contract to the Imperial Valley Water Authority (IVWA), has operated a network of rain gages in Mason and Tazewell counties since August 1992 and a network of groundwater observation wells since 1994. These networks collect long-term data to assess the aquifer’s recharge rate and how groundwater withdrawals affect the aquifer during dry periods and growing seasons.

Monitoring & Data

Precipitation

IVWA rain gages gather daily precipitation data.

Groundwater

View real-time water level hydrographs for Imperial Valley.

Monitoring Site Map

View Imperial Valley groundwater observation well locations via our interactive Illinois Groundwater Monitoring Network map.

Findings to Date

Transducers that enable near-continuous measurement of water levels in monitoring wells have allowed us to correlate rainfall timing with changes in aquifer levels. These data indicate that, depending on location and time of year, rainfall events can significantly affect aquifer recharge.

Water levels can change within a day of a rainfall event. We are collecting data to establish relationships among water table depth, time of year, and the magnitude of rainfall events to better predict aquifer recharge.

Project Letters & Publications

Here you’ll find all the publications from the Imperial Valley project: 

• project letters and updates from 2007 to present,
• contract reports from 1992-2007, and 
• IVWA Precipitation Network monthly progress reports from 2016 to present.

Yearly Project Letters & Updates

In 2009, ISWS began providing annual project update letters to the Imperial Valley Water Authority instead of Contract Reports.

Contract Reports

IVWA Precipitation Network Monthly Progress Reports

Monthly progress reports for the IVWA Precipitation network are available from January 2016 through February 2021.