By Robert Marcos
The excessive pumping of aquifers in the San Quintín Valley in Baja California is threatening the long-term reliability of tomato and berry exports to the United States. Because the freshwater aquifers sit near the ocean, the overpumping has resulted with an intrusion of saltwater.
Groundwater in the San Quintín Valley, Baja California, is critically overexploited and heavily contaminated by saltwater intrusion. Pumping rates exceed natural recharge by millions of cubic meters annually, causing declining water tables and rendering underground sources too brackish for normal agricultural use or human consumption. 1
The San Quintin Valley faces one of Mexico’s most acute water crises. Located in an arid area in the northwestern region of the country, the valley lacks freshwater bodies and is structurally disconnected from other regional supply sources. To meet the water demand in the region, water is drawn from local underground aquifers, which have been subjected to increasing pressure due to overpumping and prolonged drought conditions. Current underground sources are insufficient and do not have the required water quality. The Colorado River is the region’s only other potential source of water, but it is 167 miles away and its viability is in question. 2
In 2024, the Mexican National Water Commission (CONAGUA) published three technical studies confirming the overexploitation of the four aquifers in the SQV—San Simon, San Quintin, Camalu and Vicente Guerrero—by a volume of 68.5 million cubic meters per year, jeopardizing the long-term viability of these sources. The groundwater has high levels of total dissolved solids, ranging between 1,540 and 11,000 parts per million (ppm), which is between 1.5 and 11 times higher than the maximum limit of 1,000 ppm established by Official Mexican Standard NOM-127-SSA1-2021 for water intended for human consumption. It is important to note that, due to insufficient water distribution infrastructure, low population density and overexploitation of the aquifers in the SQV, the local water utility, Comisión Estatal de Servicios Públicos de Ensenada (CESPE), is only able to supply potable water intermittently to 56% of the population through the distribution system, while the rest of the community relies on hauled water for their supply. This sporadic service increases the risk of cross-contamination within the pipelines due to backflows and leaks, as well as through the water storage methods used by residents, further compromising the safety of the water
available for human consumption.3
Desalination considerations
A public desalination plant would provide a reliable source of clean, affordable drinking water to over 110,000 residents in San Quintín, drastically improving public health and daily life by reducing reliance on expensive, privately trucked water tankers (pipas). Because local groundwater wells are heavily contaminated with saltwater and unsafe for domestic use, this plant would bypass the degraded aquifers to deliver potable tap water directly to homes through a new macro-distribution pipeline network. 4
However, implementing desalination in San Quintín faces several steep hurdles:
- Power Grid Limitations: The regional Federal Electricity Commission (CFE) power grid lacks the high-voltage capacity required to run a large-scale desalination facility, necessitating massive energy infrastructure upgrades before the plant can operate.
- Brine Disposal: Safely discharging the highly concentrated leftover saltwater (brine) back into the ocean requires careful management to prevent destroying the fragile marine ecosystems and local fisheries.
- High Operational Costs: Desalination is an energy-intensive process, making the final tap water expensive to produce and requiring long-term government subsidies to keep it affordable for low-income residents.
- Financing and Bureaucracy: The project has historically suffered from prolonged political shifts, contractual re-negotiations, and delays in securing international development bank funding.