I
n the San Joaquin Valley, sinking land has become a significant issue, affecting home prices and causing economic losses. Researchers at UC Riverside found that homes in areas with subsidence have lower values than they would if the land were stable, resulting in losses of $6,689 to $16,165 per home. The study analyzed sales between 2015 and 2021 and discovered that land subsidence has lowered the value of homes across eight counties by $1.87 billion over six years.

    The economists found a strong correlation between areas with higher rates of subsidence and more dramatic drops in home values. They established causation by comparing pairs of similar homes, each sold twice during the period, one in an area with subsidence and one without. The study's lead researcher, Mehdi Nemati, said his team was surprised by their results, as land subsidence is a slow problem that can be difficult to visualize.

    The researchers attribute the issue to decades of groundwater overuse, which has caused underground clay layers to compact and alter the landscape. Agricultural wells have been drawing heavily on groundwater, leading to faster subsidence in some areas. The problem has worsened due to climate change-induced droughts. California's groundwater law aims to address overdraft by 2040, but researchers project that large portions of irrigated cropland will need to be left dry to comply with the restrictions.

    The study highlights the costly effects of chronic groundwater overpumping and warrants attention from local officials. Amanda Fencl, climate science director for the Union of Concerned Scientists, said the link between subsidence and home values should prompt action to protect homeowners and replenish groundwater. Nemati emphasized that the state's Sustainable Groundwater Management Act is crucial in combating land subsidence.

    Other experts, such as Brad Franklin from the Public Policy Institute of California, noted that other factors may also affect home values at the local level. Sen. Melissa Hurtado (D-Bakersfield) expressed concerns about the impact of groundwater depletion and subsidence on property values, particularly for agricultural land. She believes "bad actors" should be held accountable for their role in depleting groundwater resources.