This is a past event.

Environmental Engineering Graduate Seminar

Alex Mayer, Professor, Department of Civil Engineering Director, Center for Environmental Resource Management, University of Texas at El Paso

More than one-third of the world’s largest cities are in drylands. Water scarcity and vulnerability to climate change are hallmarks of modern cities in drylands. Populations in drylands are expected to grow substantially over the next half-century, putting further stress on water supplies already stretched beyond their limit.

We are examining the vulnerability of the El Paso (Texas, US) and Ciudad Juárez (Chihuahua, Mexico) to climate change and water scarcity. These two cities are emblematic of the southwest US and northern Mexico but are tied together due to their proximity along the US-Mexico border. We take a multiscale systems approach, starting with projections of surface water availability from the upper Rio Grande-Rio Bravo basin. Surface water storage estimates using downscaled global climate model projections through 2070 indicate that droughts will be longer and more severe. We couple these projections with econometric models predicting groundwater demand in local aquifers as a function of surface water storage and other variables. With pumping rates that are much higher than recharge, groundwater balance models predict that fresh groundwater may last only a few decades in a local aquifer.

We then examine impacts of climate- and demand-induced water scarcity on vulnerable households, in the form of rising costs of water service. We couple projections of future surface and groundwater availability, supply demands, and cost with socio-economic data at the census tract level to estimate the fraction of income paid for water service. The estimates indicate that, in a few decades, lowest income households in El Paso will be paying more than 10% of their income for indoor water use alone. Finally, ethnographic studies from households are revealing that poorer households are already strategizing to save indoor water use and are avoiding outdoor water use to avoid paying higher water and other utility bills.