The Water Resources Management program of the Iowa Geological Survey evaluates the availability and sustainability of Iowa’s groundwater resources. Numerical methods and modeling are used extensively to try to predict and reduce future impacts and conflicts between water users. The long-term management of groundwater resources is essential to promote economic growth, and at the same time preserve water resources for future generations.

In Iowa, more than 80 percent of Iowans, both urban and rural, depend on groundwater resources for their water supply.  Iowa’s many agribusinesses also rely on a dependable supply of groundwater for biofuels, livestock, production of agricultural fertilizers and chemicals, manufacturing of farm machinery, food processing, and irrigation. However, economic growth has put additional stress on Iowa’s groundwater resources. Declines in groundwater levels have increased and accelerated in parts of Iowa, as municipal water supplies compete with new or expanding industries for water. The expansion and concentration of Iowa’s livestock industry and the increased dependency of large livestock producers on rural water systems have created additional stress on shallow groundwater resources.

Groundwater Sustainability

IGS researchers have developed groundwater flow models have been developed for four of Iowa’s regional confined aquifers (bedrock model areas). Numerical methods can predict future impacts and overall water level declines caused by increases in water use. Proper management of Iowa’s deep confined aquifers is essential to balance current economic development with groundwater availability for future generations. Additional model development will need to focus on county or local scale predictability. More information on groundwater sustainability can be found on the following links:

Cambrian-Ordovician Aquifer

Lower Dakota Aquifer

Silurian Aquifer

Mississippian Aquifer

Drought Assessments

Reoccurring drought conditions across much of Iowa over the last 2 or 3 years have adversely impacted many of Iowa’s shallow aquifers. Drought assessments using local scale groundwater flow models have provided water managers and engineers the tools to properly space new production wells, optimize pumping rates, and increase the availability of induced recharge or surface water recharge. In addition, model output can be used to develop an early drought warning system so conservation measures or alternative water sources can be implemented. Additional information on drought assessments and local scale modeling can be found on the following links:

Shenandoah, Iowa Drought Assessment

Hudson Aquifer near Rock Valley, Iowa

Raccoon River near Des Moines, Iowa

Des Moines River near Emmetsburg, Iowa

For additional information on the Water Resources Management program at the Iowa Geological Survey, please contact Greg Brennan.