Development of Water Budget for Tailwater Recovery Systems in the Lower Mississippi Alluvial Valley

Unsustainable groundwater use for agricultural irrigation has led to declining aquifer levels across the United States, necessitating implementation of water conservation practices. One conservation practice being implemented throughout the lower Mississippi River alluvial valley (LMAV) that collects and stores surface water for irrigation is a tailwater recovery (TWR) system. Accordingly, the overall objective of this study was to develop a water budget for TWR systems. Eight TWR systems were continuously monitored for water depth, allowing rates of water gain and loss to be quantified. Volumes of water movement were calculated based on change in water depth and system dimensions. Using water budgets derived from TWR systems the water volume was calculated and found to be gaining, except during months of irrigation. Extrapolating the water budget to all TWR systems shows a total offset of 15% of the annual groundwater deficit. Tailwater recovery system efficiencies show designs may be altered to improve the water savings and use of these systems.