California’s worsening drought is raising the stakes for a $15 billion plan endorsed by Governor Jerry Brown to build two 30-mile (48-kilometer) water tunnels under an ecologically sensitive river delta east of San Francisco Bay.
The tunnels, each as wide as a two-lane interstate highway, would ship water more reliably from northern California to thirsty farms and cities in the south. They would also bolster the ecosystem of the Sacramento-San Joaquin River Delta, which is on the verge of collapse from feeding water to 25 million people and 750,000 acres (304,000 hectares) of farmland.