Implications of environmental water allocation scenarios for agricultural water availability in a desert river basin

Authors: SAMIMI, MARYAM - Oklahoma State University; MIRCHI, ALI - Oklahoma State University; MANASARY, ABU - Oklahoma State University; ARSHAD, ARFAN - Oklahoma State University; Moriasi, Daniel; ALIAN, SARA - Oklahoma State University; HARGROVE, WILLIAM - University Of Texas - El Paso

Submitted to: American Geophysical Union Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/9/2022
Publication Date: 12/16/2022
Citation: Samimi, M., Mirchi, A., Manasary, A., Arshad, A., Moriasi, D.N., Alian, S., Hargrove, W. 2022. Implications of environmental water allocation scenarios for agricultural water availability in a desert river basin. American Geophysical Union Meeting Abstract. AGU Fall Meeting, Dec 12-16, 2022, Chicago, IL.

Interpretive Summary: Abstract only.

Technical Abstract: Protecting riparian ecosystems in the arid/semi-arid Rio Grande River basin is challenging due to over allocation of water to beneficial consumptive uses under an anthropocentric water management paradigm. Consequently, riparian forest galleries that provide habitat for endangered species like southwestern willow flycatcher have declined dramatically. A warm-dry climate scenario will exacerbate the chronic water scarcity. Newly planted native trees in restoration sites depend on irrigation, which is challenging owing to reduced river flow and groundwater levels. This study quantifies the water requirements for different scenarios of developing riparian forests along the main channel of the river in the middle section of the Rio Grande basin in a future warm-dry climate. For each scenario, we analyzed the potential tradeoffs of environmental water allocation in terms of impacts on irrigation water availability for high value perennial crops like pecan, using the Soil and Water Assessment Tool (SWAT). The results show that developing the minimum required riparian vegetation buffer zone would not significantly affect water availability for current pecan production in dry years. While the tradeoff is larger during severely dry periods, the amount of water required to sustain the riparian forests is only a small fraction of the total water use for agricultural irrigation. The environmental water allocation options and associated costs to acquisition of water from willing water rights holders provides useful information for decision makers to restore riparian forests based on available water resources and associated tradeoffs.