Abstract for:Irrigation efficiency implications for regional hydrologic resilience in drought

Irrigation withdrawals are a main concern when water scarcity becomes a common issue. Paradoxically, increased efficiency in irrigation practices does not necessarily lead to water conservation due to multiple factors such as corresponding increases in irrigation frequency and decreased groundwater recharge. Before making water policy decisions to invest in improving irrigation efficiency (IE), a comprehensive consideration is necessary which will include the connectivity between surface water and groundwater, non-consumptive values of irrigation and the effect of high IE at the regional scale in a no-analog future. An integrated model presented here was developed for the Lower Rio Grande Region in New Mexico which includes water, irrigated land, capital, and population. The model tested the recharge contribution of irrigation to explore the performance of different IE and groundwater conditions. Results reveal that a high IE does not necessarily improve the resilience of groundwater especially under the condition of mega drought which creates higher dependence on groundwater for irrigation. Popular and well-intentioned water conservation and management policies, including those that encourage the adoption of more efficient irrigation technology, may have unintended and negative consequences if policy-makers do not account for comprehensive effects.