California, known for its geographic diversity and its role as one of the most iconic states in the United States, is facing a critical environmental challenge in which they are being forced to deal with significant water issues. In recent decades, the situation has worsened dramatically, and what used to be a state where the sun shone brightly and farmland flourished is now on the verge of becoming a bleak landscape, affected by drought and soil subsidence. According to the NASA, California is sinking due to the way groundwater has been extracted to cope with the drought crisis. This massive water extraction has had severe effects at ground level, particularly in the San Joaquin Valley, which is a critical area for agriculture in the state.
In a report from the Jet Propulsion Laboratory, subsidence in the San Joaquin Valley was indicated as particularly worrisome. California Department of Water Resources Director William Croyle noted that "subsidence has long plagued several regions of California, but the current level endangers an infrastructure serving millions of peopleThis means that the critical infrastructure that supports the state's water supply is at risk due to excessive groundwater extraction.
The San Joaquin Valley is a vital area that extends from the delta of the rivers Saint Joaquin y Sacramento to the north, to the Tehachapi Mountains to the south and the Coastal Sierras to the west. This valley is essential not only for the state's agriculture, but also for providing drinking water to millions of Californians. However, constant water extraction has led to a drastic decline in water levels in this region. Since 1920, the water level in the valley has dropped 8,5 meters, which has led to the degradation of aquifers and the loss of groundwater storage capacity.
The cost of this crisis is high: damages caused by subsidence are estimated at hundreds of millions of dollars due to the need to repair and maintain affected water systems and infrastructure. This not only represents an economic burden but also raises serious concerns about future water supplies. In a state where agriculture represents a crucial sector of the economy, the water crisis jeopardizes agricultural production and, consequently, food security.
As the drought persists, reliance on groundwater has increased, leading to a vicious cycle where over-extraction results in ground subsidence that exacerbates drought conditions. As mentioned above, the San Joaquin Valley has experienced subsidence at a rate of approximately 25,4mm per year between 2006 and 2022, according to a recent study published in Communications Earth and EnvironmentThis phenomenon has been partially attributed to a lack of data and previous studies that had not adequately quantified subsidence in this region, making it difficult to implement effective measures to mitigate the problem.
The implications of the sinking are severe, not only for the natural environment but also for the economy. The rapid and uneven decline in elevation has forced multimillion-dollar repairs to canals and aqueducts that carry vital water to Southern California cities, leading to criticism of water management and questions about the current agricultural model. This has damaged thousands of groundwater wells and exacerbated water supply problems in one of the most agriculturally productive regions in the world.
La subsidence It occurs due to the extraction of water from aquifers, which are underground reservoirs of water found between sediments such as sand, gravel, and clay. Water fills the pores within these sediments, and when it is extracted excessively, the soil structure is compromised and compacted, resulting in a lowering of the ground level. Between 1925 and 1970, intensive groundwater pumping, driven by a boom in agriculture and population growth, led to more than 10,359.95 km² of land to sink by more than 30 cm in some places, a phenomenon described in a report as "one of the largest alterations of the Earth's surface attributed to humanity."
In the current context, where climate change is also exacerbating droughts and tensions in water supplies, subsidence rates have increased dramatically. Researchers such as Rosemary Knight They have warned that ground subsidence is not only an immediate problem, but also poses long-term challenges for water management and agriculture in California. Groundwater levels have, in many cases, reached historic lows, and the intensifying drought has led to an increased reliance on these sources, which in turn accelerates ground subsidence.
Recent research has discussed how changing water policies and management is crucial to addressing the crisis. Farmers and water managers must adopt a more sustainable approach that includes aquifer recharge and water conservation, which has been essential to mitigate the effects of climate change in many regions. Implementing water harvesting and storage technologies, as well as using conservation agriculture techniques, are essential to mitigate the effects of overpumping, which is linked to the climate changeIn some case studies, aquifer recharge, such as the system implemented by Don Cameron on his ranch in Fresno, has been shown to help restore groundwater levels.
As more people realize the importance of conserving water, efforts are being made to educate the public about the need to manage water resources more effectively. Public policies must also align with the need for sustainability and water stewardship, ensuring that measures are taken to protect California's water sources.
The current situation in California is a wake-up call about the need to address the water crisis not only through infrastructure, but also through a cultural shift in how water is perceived and used. The survival of one of the most productive agricultural regions in the world depends on its inhabitants' ability to adapt to changing climate conditions and their water management practices. This means rethinking the way water is extracted, adopting more efficient technologies, and ensuring that future generations can enjoy the state's most vital resource.
