Nancy Vogel, a Department of Water Resources employee blogging for the Bay Delta Conservation Plan (BDCP), has thrown the agency’s support behind a study that minimizes the effect of reduced water quality on agriculture in the Delta. She cites a study by the U. C. Davis Center for Watershed Sciences that found the cost of salinity changes on agriculture would be less than one percent of the Delta’s total crop revenue.
But the Center came up with a model that used averages for water conditions that we haven’t seen since 2000. The model assumed that only part of average annual exports would go through peripheral tunnels, with the rest being pulled through Delta channels. That isn’t what the BDCP proposes.
The model also left out the multiplier effect of agriculture on the overall economy of the region. And because they decided to focus on South Delta agriculture, the modelers weren’t looking at costs to coastal salmon fishing or to the recreational fishing economy as a result of changes in salinity in the Bay-Delta Estuary and upstream.
So the model really just tells us what we already knew: That decades of declining water quality in some parts of the Delta have already forced farmers to grow lower-value crops on prime farmland, while farmers in Westlands grow high-value crops in tainted soil.
As with Dr. Sunding’s original cost-benefit analysis and the original effects analysis that led to the “red flag” document, the Watershed Sciences study found a model that would tell BDCP planners what they want to hear. BDCP can force this whole project to pencil out and make sense if they keep selecting data sets that give them the answers they’re looking for.