Taxing Groundwater Is a Sure Way to Preserve It: Mark Gongloff

Without really meaning to, farmers in a small California valley have spent the past 30 years in an experiment to see what happens when the groundwater they pump to their crops is taxed. The results are in, and they are striking. They could point the way to preserving a precious resource under threat worldwide.

But the experiment also highlights the difficult trade-offs that preparing for a sustainable future on a heating planet will bring.

In the 1980s, strawberry farmers in the Pajaro Valley pumped so much groundwater that salt water from nearby Monterey Bay infiltrated their aquifers, spoiling their crops. In ...