A draw bridge is shown in the Sacramento San Joaquin River Delta near Walnut Grove, California September 3, 2013. California water officials have proposed redesigning two water diversion tunnels planned for the Delta, away from several small towns along the Sacramento River that Delta residents said would be threatened under the existing plan. Water from the tunnels would flow to urban areas in the Silicon Valley, Los Angeles and San Diego and farmers in the San Joaquin Valley. Picture taken September 3, 2013. REUTERS/Robert Galbraith (UNITED STATES - Tags: ENVIRONMENT AGRICULTURE SOCIETY)