GROUNDWATER LEVEL MONITORING IN IOWA: RESURRECTED IN TIME TO REVEAL CURRENT AND FUTURE CHALLENGES

The United States Geological Survey and Iowa Geological Survey (IGS) collaborated in the 1980s to create an Iowa groundwater level monitoring network. This network experienced many changes during its timespan and was ultimately discontinued in 2007. In 2017, with funding from National Groundwater Monitoring Network (NGWMN), the IGS resumed monitoring a portion of the original network wells to document groundwater levels in several bedrock aquifers across the state. The IGS currently monitors 57 dedicated monitoring wells at 27 sites across Iowa. Groundwater depletions are observed in the deep Cambrian-Ordovician aquifer and in the Cretaceous Dakota sandstone aquifer due to overpumping. Levels in other bedrock aquifers fluctuate seasonally in response to climate and water use. Ongoing monitoring documented drought conditions over the last several years and record low water levels at over 50% of the sites. As the age of the IGS’ wells presents challenges to continuing the network, NGWMN funds provide the IGS with opportunities to change and enhance the network. The IGS has recently replaced several old wells, constructed new wells to monitor new aquifers, and installed pressure transducers to increase the resolution of the water level measurements. These improvements are allowing the IGS to better characterize Iowa groundwater resources and contribute to national assessments of groundwater levels.