Iran and US: Two Countries and the Pistachio Between Them

In southeastern Iran, Armin's pistachio orchard is suffering from hand-width cracks that have rapidly spread over the past five years, causing the ground to sink and swallow precious water. The region has long been a major supplier of Iran's prized pistachios, which are used in various culinary delights. However, a combination of drought and groundwater extraction for irrigation has led to one of the fastest-sinking areas in the country, with parts of the ground dropping by up to 37 centimeters annually.

A similar situation is unfolding in California, where some pistachio farmers are also experiencing sinking ground. Joe Coelho, the director of sustainability at American Pistachio Growers, explains that while his family's farm in Fresno is not directly affected, growers are aware of the risk. Some nearby areas are facing serious water problems, he says, highlighting the link between growers in the two countries that dates back to the 1960s when U.S. farmers started building a pistachio industry using an Iranian variety called Kerman.

The similarities between the two regions extend beyond the shared issue of sinking ground. Both California and Iran rely heavily on groundwater for irrigation, with water being pumped from underground aquifers for crop irrigation exceeding the amount flowing back into the aquifers. This imbalance has led to land subsidence, a man-made hazard that cannot be undone once the aquifer collapses.

While California has implemented the Sustainable Groundwater Management Act (SGMA) to address the issue, regulations are currently awaiting government approval in Iran. The SGMA requires water agencies to balance pumping and recharge in groundwater basins by 2040, with managed aquifer recharge being one method used to achieve this goal.

Some progress has been made in California, with groundwater levels rising in four out of 10 monitored wells. However, large parts of the Central Valley continue to sink, and experts believe that aligning crop water demand with the long-term water available under a warmer and more variable climate will be necessary to overcome the challenges posed by land subsidence.

In Iran, awareness of groundwater management and subsidence has grown in recent years, but action remains limited due to political constraints. Ali Beitollahi, who leads subsidence research at Iran's Road, Housing and Urban Development Research Center, believes that swift action could help manage the problem, as demonstrated by Tokyo's experience.

However, given the current political situation in Iran, immediate action is unlikely. One urgent step, Beitollahi suggests, is to change the way farmers water their fields immediately, teaching them why it matters. Most of Rafsanjan's orchards still use flood-irrigation methods, resulting in significant water loss due to evaporation before reaching plant roots.