By Nancy Vogel
California Department of Water Resources

Fears that the Bay Delta Conservation Plan will make Delta water salty enough to destroy the region's farm economy are apparently unfounded. The most thorough examination yet of salinity changes tied to a project that diverts Sacramento River water around the Delta finds a decline of less than one percent in crop revenue in the region, or an estimated annual loss of $2.3 million.

That finding surprised even the researchers themselves at the UC Davis Center for Watershed Sciences. They modeled the movement of water and salt in the Delta under different scenarios, analyzed how the salinity of irrigation water would affect Delta crops, and estimated the effect on the overall Delta farm economy. They studied salinity changes tied to the BDCP's proposal to divert water from the Sacramento River in the northern Delta. They also examined the salinity effects of sea level rise. They found minor costs to the farm economy.

Their explanation? The islands most vulnerable to salinity grow irrigated pasture and other low-value crops. These crops are relatively salt-tolerant. And salinity spikes in the late summer and fall, after most crops are harvested.

Changes in salinity are one of the potential impacts that the BDCP is studying and must mitigate.

But the latest research indicates that California can modernize its major water diversion point in the Delta without causing significant salt damage to local farms.