Interbasin water transfers at the US-Mexico border city of Nogales, Sonora: Implications for aquifers and water security

Nogales, Sonora, on the US-Mexico border, employs interbasin water and wastewater transfers to address water scarcity in the context of a rising population, a warming climate, and cross-border institutional asymmetries. A unique feature of its geography and border context is Nogales's export of wastewater both north to the US and, starting with the August 2012 commissioning of a strategically positioned wastewater treatment plant, south to the Alisos basin, which is its principal drinking-water source. Thus, when the new plant is fully operational, it will result in indirect potable reuse of effluent via recharge of the source-water aquifer. This paper finds that such strategies contribute to increased water scarcity in Nogales, and to detrimental health, livelihood and environmental impacts in the source basin, thus raising questions about interbasin transfers as a principal water management strategy.