Drought Resiliency Solutions for Alluvial Wellfields

Shallow alluvial aquifers are particularly vulnerable to drought due to their dependency on recharge from surface water and precipitation. Northwest Iowa, a region with a multi-billion agribusiness industry, relies heavily on groundwater from alluvial aquifers, and saw this vulnerability firsthand. Iowa experienced a severe statewide drought starting in the fall of 2011 and continuing through most of 2012 and 2013. The drought put rural communities and agribusinesses at risk. One regional water supplier had to implement an emergency water plan. A temporary water-use permit was issued by the Iowa Department of Natural Resources to pump water from the Big Sioux River into a recharge basin to prevent the production wells from going dry. Public water utilities, like the one in northwest Iowa, are continuously looking for ways to increase their drought resiliency and manage water sustainability. One way to improve drought resiliency is to implement strategies that increase surface water (induced) recharge into the aquifer. The Iowa Geological Survey evaluated several drought strategies in Northwest Iowa, including recharge basins and rock riffles. The different strategies’ impact on groundwater quantity and quality will be presented. A framework for selecting a potential drought strategy for any given wellfield will also be discussed.