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ARS Home » Southeast Area » Jonesboro, Arkansas » Delta Water Management Research » Research » Publications at this Location » Publication #334775
Title: Groundwater trends during 1985 to 2019 in a critical groundwater area of northeastern Arkansas

Author
item Leslie, Deborah
item Reba, Michele
item Godwin, Ian
item YAEGER, M.A. - University Of Memphis

Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/10/2021
Publication Date: 9/1/2021
Citation: Leslie, D.L., Reba, M.L., Godwin, I.A., Yaeger, M. 2021. Groundwater trends during 1985 to 2019 in a critical groundwater area of northeastern Arkansas. Journal of Soil and Water Conservation. 77(1):67-77. https://doi.org/10.2489/jswc.2022.00170.
DOI: https://doi.org/10.2489/jswc.2022.00170

Interpretive Summary: Groundwater depletion is a concern in eastern Arkansas, where agriculture is the dominant economic sector. Irrigation is primarily sourced from the shallow Mississippi River Valley alluvial aquifer. Groundwater levels in the alluvial aquifer have been monitored by federal and state agencies since the 1980s to collect information about its status and the effect of extraction for irrigation on water levels. Many water level measurements in critical groundwater areas recorded consistent annual declines. In response to the declining water levels, many producers invested in alternate surface water irrigation through on-farm reservoir – tailwater recovery systems in the 2000s. This study compares groundwater trends before and after the implementation of these water conservation methods by using consistent and focused water level measurements. The recent groundwater trends show groundwater level improvements compared to previous measurements before several on-farm reservoirs-tailwater recovery systems were implemented. This work contributes evidence that these water conservation methods are reducing the dependency on groundwater and alleviating groundwater decline in a critical groundwater area.

Technical Abstract: The Mississippi River Valley alluvial aquifer provides over 90% of irrigation water for agriculture in the Lower Mississippi River Basin. Overexploitation of the alluvial aquifer in the Cache River Critical Groundwater Area (CRCGA) in Arkansas started impacting crop production in the 2000s with previous historical data identifying sustained groundwater declines. Groundwater depletion resulted in many producers investing in on-farm reservoir- tailwater recovery systems to provide a more secure irrigation source. More focused and consistent water level measurements were necessary to identify any groundwater level changes. Groundwater trends focused on the CRCGA cone of depression were compared from twotime groupings: 1985 to 2012 and 2012 to 2019. On-farm reservoirs in the CRCGA were inventoried in 2015, and 90% of those inventoried were constructed by 2012. More frequent groundwater level data collection in the CRCGA started in 2012 as well. Groundwater levels during 1985 to 2012 had consistent decline rates of –0.17 to –0.44 m y–1. Groundwater levels during 2012 to 2019 varied with decline rates of =–0.10 to =–0.50 m y–1, but also areas of no significant change and recovery at rates of =0 to =0.25 m y–1. Trend differences between the two periods showed improved water level trends for most of the study area, with rates ranging =–0.30 to =0.50 m y–1. The measured improvements were attributed to less pumping due to greater precipitation and the use of surface water irrigation from 60 on-farm reservoir- tailwater recovery systems. Detection of these improvements is crucial to understanding the response and status of the alluvial aquifer within the agricultural area of the CRCGA. It is recommended that adding continuous groundwater monitoring stations in west Craighead and Poinsett counties would be beneficial to inform the status of the cone of depression, considering the importance of protecting the main agricultural irrigation supply for the state. If warmer temperatures occur in the future, higher temporal and spatial groundwater level data in the CRCGA will allow policymakers and water resource managers to make timely groundwater management decisions to ensure its supply for future generations.