Excessive groundwater pumping in Mexico’s San Quintín Valley is threatening the long-term reliability of tomato and berry production and exports to the United States. Overpumping of freshwater aquifers near the coast has led to saltwater intrusion, reducing water quality for agriculture and domestic use.
According to technical studies published by the Mexican National Water Commission (CONAGUA) in 2024, the valley’s four aquifers, San Simón, San Quintín, Camalú and Vicente Guerrero, are being overexploited by 68.5 million cubic metres of water per year. Total dissolved solids in groundwater range from 1,540 to 11,000 parts per million (ppm), exceeding the Mexican drinking water standard of 1,000 ppm.
San Quintín, located in an arid region of Baja California, has no freshwater surface sources and depends on groundwater. The Colorado River is the only alternative source but is located 269 kilometres away, and its long-term availability remains uncertain.
Limited water infrastructure also affects domestic supply. The Comisión Estatal de Servicios Públicos de Ensenada (CESPE) provides intermittent potable water through the distribution network to 56% of the population, while the remainder rely on trucked water. Intermittent service also increases the risk of contamination through pipeline backflows, leaks, and household water storage.
A proposed public desalination plant would supply potable water to more than 110,000 residents and reduce reliance on groundwater and trucked water. The project would require a new water distribution network because existing aquifers are unsuitable for domestic use.
However, several constraints remain. The regional electricity grid does not have sufficient capacity to operate a large-scale desalination plant, requiring upgrades before the facility can become operational. Brine disposal would also require management to limit impacts on marine ecosystems and fisheries. In addition, desalination has high operating costs and would require long-term government support to keep water affordable. The project has also experienced delays linked to financing, contract renegotiations, and political changes.