The DNR Iowa Geological and Water Survey (IGWS) recently completed a groundwater study and predictive model for the Silurian aquifer in east-central Iowa. Information from thousands of well records, hundreds of water production tests, current and historic water levels, and water withdrawal records were incorporated into a groundwater model. The completed and tested model will give estimates of the changes in water levels into the future for a wide range of anticipated or possible future demands.
“The Silurian aquifer is an important groundwater source in eastern Iowa,” said Mike Gannon, an IGWS research geologist who coordinated development of the model. “It’s widely used by cities, industries, farms and rural communities, and also supplies geothermal wells.”
As the study was being completed, the model was used to assist Marion and Coralville in assessing long-term additions to their water supplies.
The Silurian study follows work done on the Dakota aquifer in northwest Iowa, shallow alluvial aquifers in several parts of Iowa, and the deep Jordan aquifer across the state.
“This effort is the key to long term management of our underground water supplies” says Iowa’s State Geologist Bob Libra. “The decisions we make about water development today will be with us for decades, and this work helps assure the investments made for water will pay off for the long run. The studies will also allow us to assess and predict the impacts of developing drought conditions in western Iowa.”
The report on the aquifer is available at: ftp://ftp.igsb.uiowa.edu/igspubs/pdf/WRI-5.pdf