Groundwater Depletion Affects Pistachio Farming in Iran and California

Pistachios sold in the United States have historical ties to Iran, as California's trees originate from the region. Both areas are currently facing challenges due to groundwater depletion, leading to land subsidence. In southeastern Iran, cracks have formed in Armin's pistachio orchard, damaging irrigation systems and causing water loss. He has observed these cracks expanding over the past five years and is concerned about the future of farming for his children. Armin, whose real name is withheld for security reasons, resides in Rafsanjan, a region known for its pistachio production. However, drought and excessive groundwater extraction have made Rafsanjan one of the fastest-sinking areas in Iran, with some parts dropping by up to 37 centimeters (14 inches) annually. This decline is impacting pistachio production. In California, pistachio farmers are also experiencing land subsidence, particularly in the San Joaquin Valley. Joe Coelho, a farmer in Fresno, notes that while his farm is not directly affected, nearby areas face significant water challenges. The pistachio industry in the U.S. began in the 1960s using an Iranian variety known as Kerman, which is now prevalent in California orchards. California has surpassed Iran as the world's largest pistachio producer, with the Central Valley being a key growing region. Farmers in California are increasingly reliant on groundwater as surface water availability declines. Coelho reports changes in soil structure and water movement due to these conditions. In the Central Valley, pistachio orchards consume about 4% of the region's agricultural water, while in Rafsanjan, over 90% of groundwater is used for pistachio farming. As groundwater levels decrease, aquifers collapse, leading to land subsidence. Ali Beitollahi, a researcher in Iran, states that land subsidence is primarily a man-made issue, and once an aquifer collapses, it cannot retain as much water as before. Farmers in Rafsanjan have to drill deeper for water, with some reaching depths of 300 meters. Many orchards have been abandoned due to dried-up wells. Despite the global demand for pistachios, Iranian farmers struggle due to international sanctions and competition. In California, the Sustainable Groundwater Management Act (SGMA) aims to balance groundwater use and recharge by 2040, with managed aquifer recharge being one method employed. Progress has been noted, but significant challenges remain. Experts suggest that aligning crop water demand with available water resources is crucial for sustainability. In Iran, awareness of groundwater management is growing, but effective regulations are still pending government approval. Beitollahi believes that immediate changes in irrigation practices are necessary for farmers. Many orchards in Rafsanjan still use flood irrigation, which leads to water loss. Coelho emphasizes the need for improved water policies and infrastructure in California. Both regions face the interconnected challenges of financial, water, and environmental sustainability. Armin reflects on the significance of pistachios, viewing them as a representation of his family's history and livelihood.