Outflow hydrology of tailwater recovery systems with comparisons to a control catchment*

Abstract Conservation practices termed tailwater recovery (TWR) systems are being installed throughout the Lower Mississippi River basin to mitigate damage from agricultural production. Many of the costs and benefits of these systems have yet to be documented; therefore, the objective of this study is to assess whether TWR systems have the potential to impact on the hydrology of downstream systems. In this study, we compare hydrologic parameters of two TWR systems—one with an on‐farm storage reservoir (TWR‐OFS) and one without (TWR‐D)—and a control ditch (CTRL). Systems were monitored at one outflow location each using flow meters. Estimated percentage differences between TWR‐D and CTRL sites were determined, in which the CTRL site was found to have greater values reflected in the parameters, including length of event median 94% and mean 60%; time to peak median 80% and mean 70%; time to base median 88% and mean 60%; peak flow median 86% and mean 67% and discharge median 134% and mean 101%. The TWR‐D and TWR‐OFS sites differed in peak flow, with TWR‐OFS being 40% greater. Evidence from this investigation shows that TWR systems have the potential to influence downstream hydrology by retaining water.