Chronicle: Groundwater law hasn’t stopped subsidence

By Tom Elias

Drive almost any road in the vast San Joaquin Valley and you’ll see irrigation pipes several feet high amid fields and orchards, pipes that were once underground.

These metallic artifacts are emblematic of the total failure of a 2014 law once billed by the government of the day. Jerry Brown as a milestone achievement. The ubiquitous drains, often unnoticed by speeding motorists, are symptoms of subsidence, the result of decades of excessive groundwater pumping in all of California’s frequent drought conditions, up to this time.

Pumping their deeper and deeper wells has been about the only way for the state’s huge and vital agribusiness community to sustain production of everything from peaches to peas, broccoli to pistachios, tomatoes to citrus, from cotton to cauliflower, when the snowpack was thin at the top. The Sierra Nevada Mountains and the state’s two major aqueducts have reduced their deliveries to mere drops – as they have had to do this summer.

The 2014 law was actually a rather mundane, crisis-free approach to something that was already a big deal years before the law was passed. The law’s timetable has increased the counting of wells drawing groundwater, but leaves no limit to what anyone can pump until 2030, by which time it may be too late.

For, as a new study from Stanford University shows, not only are the state’s groundwater supplies disappearing, but it’s becoming less and less likely that they can ever be restored to previous historic levels. or that the land subsidence that leaves irrigation pipes above the land they water can never be completely reversed.

The heartwarming idea behind the deepening of water wells as farms seek new groundwater supplies has always been that recharging natural storage basins below ground level will eventually replace whatever is being used.

The study, from the Stanford School of Earth, Energy and Environmental Sciences. suggests that is not the case. In fact, research suggests that the ground can continue to sink even if groundwater levels are stable or rising. Indeed, when water is extracted from the ground, the simple weight of the earth above the storage pond causes a partial collapse of the underground rocks around the storage spaces, called aquifers.

Even filling these spaces above capacity – not a realistic possibility in the near future – cannot completely reverse this effect. Stanford research indicated that it is unrealistic to expect ground levels to rise more than about a third of the distance they fell.

Slump levels vary a bit, but so far generally total about 20 feet over the past 65 years, gradual but now very noticeable. It only becomes disastrous when it affects things on the surface, like cracking roads and bridges and shifting the foundations of houses and other buildings.

The 2014 law, called the Sustainable Groundwater Management Act, required local water districts to develop plans to prevent further “significant and unreasonable” subsidence. There was no need for these agencies to figure out how to prevent conflicts between farmers or cities when one well owner drilled deeper and siphoned off others’ supplies.

This very phenomenon has caused at least two episodes where portions of towns in the Central Valley suddenly saw their taps dry up, forcing them to import supplies from neighboring unaffected areas. It can be both costly and unfair, but owners of suddenly dried up wells often can’t do anything about it. For one thing, farmers and towns whose wells are drying up can’t always tell where their water went or who took it. They can only be sure that it was flowing down and away from them.

All of this makes it very clear that the 2014 law was far too soft when it was passed and that more serious action to regulate and reduce groundwater use is needed.

But that’s not a priority for the current legislature, dominated by coastal and urban politicians whose voters are unaffected by what’s happening beneath the ground where their food supplies are grown. Central Valley lawmakers also haven’t done much, not wishing to offend commercial farms that often donate big campaign dollars.

Which means more fields will lie fallow in the next few years, more wells will dry up, more cities will take emergency action to find water supplies, and the ground will likely sink lower and lower.

Email Thomas Elias at [email protected] His book, “The Burzynski Breakthrough, The Most Promising Cancer Treatment and the Government’s Campaign to Squelch It,” is now available in a fourth edition hardcover. For more Elias columns visit www.californiafocus.net