SACRAMENTO (AP) — State water officials say they may dam parts of the Sacramento-San Joaquin Delta in an emergency measure to protect freshwater used by millions of Californians. The Department of Water Resources said Monday that if the drought persists they may build temporary rocky barriers blocking three channels on the Delta. They say the dams would decrease the amount of water released from upstream reservoirs to keep saltwater from creeping inland from the San Francisco Bay, contaminating the Delta.