At a Glance
- A UC Riverside study found that land subsidence caused by groundwater pumping has significantly reduced home values in California’s San Joaquin Valley by 2.4% to 5.8% per property.
- This decline in property value translates to an estimated aggregate loss of $1.87 billion for homeowners across the entire region, indicating a significant economic impact that extends beyond the agricultural sector.
- Researchers used satellite-based radar data to measure sinking land and compared it with nearly 200,000 home sale transactions to establish a direct scientific link between the two.
- The study underscores the urgent need for effective policies, such as the Sustainable Groundwater Management Act, by assigning a clear dollar value to the damage caused by unsustainable water use.
- Beyond economics, the findings reveal a social equity issue where families lose home equity due to environmental factors that are entirely beyond their control.
A new study from the University of California, Riverside has revealed a direct link between sinking land in California’s Central Valley and declining home values, quantifying for the first time the economic toll of land subsidence on homeowners. The research, forthcoming in the journal Land Economics, found that excessive groundwater pumping has caused property values in affected areas to drop by as much as 5.8%, representing a cumulative loss of $1.87 billion. These findings underscore the far-reaching economic implications of unsustainable water management practices in one of the nation’s most crucial agricultural regions.
The scientific phenomenon responsible for this is known as land subsidence. It occurs when large amounts of water are pumped from underground aquifers, which are layers of rock and sediment that hold groundwater. This over-pumping causes the clay and silt layers within the aquifer to compress, leading to the gradual and often permanent sinking of the land surface above. Mehdi Nemati, a UCR assistant professor who led the study, compared the process to a sponge in a university press release: “If you squeeze water out and never let it soak again, it flattens and hardens. That’s what’s happening underground.”
To measure this effect, the research team employed advanced scientific methods. They used data from Interferometric Synthetic Aperture Radar, a satellite-based technique that can precisely measure subtle changes in the ground’s elevation over time. This land displacement data was then cross-referenced with nearly 200,000 home sale transactions across eight counties in the San Joaquin Valley. By applying sophisticated statistical models, including repeat-sales analysis, the researchers were able to isolate the financial impact of subsidence from other market factors, confirming that sinking land directly correlated with lower sale prices.
The study’s implications extend beyond real estate, touching on issues of water policy, environmental stability, and social equity. Researchers argue that by assigning a dollar value to the damage, their work provides a more substantial justification for investing in sustainable water solutions, such as California’s 2014 Sustainable Groundwater Management Act. The findings serve as a “wake-up call,” showing that the consequences of groundwater overuse are not limited to agriculture or infrastructure but also directly harm the financial well-being of families and communities, especially those living on sinking ground.
References
- Danelski, D. & University of California- Riverside. (2025, August 1). Groundwater depletion sinks home prices in California’s Central Valley. Phys.Org; University of California- Riverside. https://phys.org/news/2025-08-groundwater-depletion-home-prices-california.html
- Nemati, M., Sneed, M., & Dinar, A. (2025). Impact of land subsidence on housing sale values: Evidence from the san joaquin valley, california. Land Economics, 092324-0083R. https://doi.org/10.3368/le.102.1.092324-0083R
