The Caplina Aquifer at Risk: Scientific Evidence and Urgent Reforms to Prevent the Collapse of Tacna’s Groundwater System

Abstract

The Caplina aquifer, one of the main sources of Tacna’s water supply, is in a critical state of overexploitation that threatens its sustainability. Scientific evidence has shown that the balance between recharge and extraction was disrupted in the 1980s, reaching a deficit of -177 hm³/year by 2024, with the extraction rate approximately five times higher than natural recharge. This situation, exacerbated by the expansion of the agricultural frontier, informal land occupation and weak regulatory enforcement, compromises regional water security. In this policy brief, we propose the strengthening of the monitoring and control of groundwater extraction, the implementation of land-use planning to limit agricultural expansion, a review of water-use licenses, and the establishment of high-efficiency irrigation systems, in order to reduce pressure on the aquifer.