IOWA CITY – The DNR’s Geological and Water Survey recently completed a detailed investigation of the sand and gravel aquifer associated with the lower reach of the Raccoon River near Des Moines.
The DNR used a predictive groundwater model to evaluate the aquifer for future water supply development. The evaluation indicates increased water supplies could be developed.
The lower reach of the Raccoon River aquifer is one of the most intensely used aquifers in the state. Current water use is approximately 14.6 billion gallons per year. More than half of that comes from the area studied by the DNR.
Staff estimated maximum sustainable pumping rates under severe drought conditions using a groundwater model. DNR hydrologists were able to identify the best areas for future wells based on aquifer permeability and recharge rates.
The modeling and geologic information is a major step forward in developing and protecting water supplies, evaluating drought impacts, and addressing groundwater and stream water quality concerns. This study is important to assure the long-term sustainability of Iowa’s groundwater resources.
A full technical report is available at ftp.igsb.uiowa.edu/igspubs/pdf/WRI-7.pdf
The study is the seventh in a series of water resource reports authorized by the legislature in 2007 because of concerns about the availability of water to existing users. Find other reports at www.igsb.uiowa.edu/GroundwaterResources/WaterResourcesManagement/WaterResourcesManagement.htm