Determining a water budget for an established tailwater recovery system in the Mississippi Alluvial Plain

Authors: Nelson, Amanda; RODRIGUE, PAUL - Natural Resources Conservation Service (NRCS, USDA); Moore, Matthew; Delhom, Christopher

Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/23/2025
Publication Date: 5/28/2025
Citation: Nelson, A.M., Rodrigue, P., Moore, M.T., Delhom, C.D. 2025. Determining a water budget for an established tailwater recovery system in the Mississippi Alluvial Plain. Agrosystems, Geosciences & Environment. 8,Issue 2. https://doi.org/10.1002/agg2.70137.
DOI: https://doi.org/10.1002/agg2.70137

Interpretive Summary: Tailwater recovery (TWR) systems are an important best management practice used to address both water quality and quantity issues in the Mississippi Delta region. TWRs are systems for capturing surface water runoff to be later used for irrigation. The objective of this study was to quantify the reduction of groundwater use in an established TWR system when using the collected tailwaters as an alternative source for irrigation. To meet this objective, runoff flow from crop fields, irrigation withdrawals, tailwater relift pumping volumes, and water levels in the tailwater ditch were measured for two years. The study site was a TWR system established in 2013 in Sunflower County, MS. This study found that groundwater use was reduced by 22% with the use of the collected tailwater runoff. During the 2023 growing season, 84.5% of the water applied to the crop through irrigation or precipitation was retained in the soil, utilized for plant growth, or was recirculated within the tailwater recovery system. After a decade of use, the studied TWR system is meeting its dual purposes of reducing groundwater pumping and preventing the release of potentially nutrient and sediment-rich runoff waters from entering downstream waterbodies.

Technical Abstract: In the Mississippi Alluvial Plain, also known as the Delta, tailwater recovery (TWR) on-farm storage (OFS) systems are an important best management practice to address both water quality and quantity issues. TWR/OFSs are surface water capture and irrigation reuse systems, consisting of a ditch to capture surface water and often a reservoir to store captured water, and pumps to move surface water from the ditch into either an OFS reservoir or to irrigate nearby fields. To determine if established TWR systems are an effective way to reduce groundwater use, a 10 year old, ditch-only TWR system in Sunflower County, MS was equipped with velocity and flow meters, water level loggers, and rain gauges. The objective of this study was to determine a fully measured water budget for an older TWR system. This study found 22% of the total applied irrigated water over two growing seasons was from the collected tailwater runoff. During the 2023 growing season, only 15.5% of the input water was lost from the system through the outflow pipe, indicating that 84.5% of the input water (precipitation plus irrigation) during the growing season was retained in the soil, utilized for plant growth, or was recirculated in the tailwater recovery system. After a decade of use, the studied TWR system is meeting its dual purpose of reducing groundwater pumping and retaining potentially nutrient and sediment-rich runoff waters within the system, thereby preventing it from entering downstream waterbodies.