How far can investment in efficient irrigation technologies reduce aquifer overdraft? Insights from an expert elicitation in Aguascalientes, Mexico

Abstract

Aquifer overdraft is a key public concern in arid and semiarid regions —where agriculture is responsible of most of the water extraction. To tackle this problem, policy interventions in those regions most frequently focus on investment in irrigation technologies. However, these investments are usually carried out without consideration of the effects on water extraction. Estimation of such effects tend to be expensive and time-consuming because they vary depending on technology- and location-specific conditions, and their interactions. Thus there is the demand for methodologies that can provide cheaper estimates, even if rough. This paper explores whether an expert elicitation can provide insights on the impacts that are reasonable to expect from specific efficient irrigation technologies. Our case study is the aquifer of Valle de Aguascalientes, Mexico —where extraction is more than 80% above of the natural recharge. We have learned that our experts in agronomy and hydrology do not expect that sprinkler or drip technologies will substantially reduce overdraft. These results are policy relevant because both types of technologies are at center of the strategies proposed by the policy makers aiming to solve aquifer overdraft in Aguascalientes.