Groundwater overdraft, especially at the pace and scale now underway in the southern part of California’s Central Valley, has substantial costs – in terms of lost water availability and ground subsidence. But the discussion of those costs often occurs in a vacuum, without a discussion of the very real costs incurred by fixing the problem. People were doing something with that water that was valuable to them, and they’ll either have to stop doing it, do less of it, or find an alternative water source.

One of the most interesting findings in a new paper by a team of UC Davis researchers is the increased pressure on the Sacramento Delta, one of the alternative water sources for the region. Here the authors explain:

The analysis used a hydro-economic optimization model for California’s water resource system (CALVIN) that suggests operational changes to minimize net system costs for a given set of conditions, such as ending long-term overdraft. Based on model results, ending overdraft could induce some major statewide operational changes, including significantly greater demand for Delta exports, more intensive conjunctive-use operations to increase artificial and in-lieu groundwater recharge, and greater water scarcity for Central Valley agriculture.