Things to know about California’s giant twin tunnels project

In this Tuesday, Feb. 23, 2016 photo, farmer Russell van Loben Sels inspect grape vines on his land in the San Joaquin-Sacramento River Delta, near Clarksburg, Calif. A $15.7 billion tunnel project promoted by Gov. Jerry Brown to build giant pipes underground to ship water south is splitting farmers and politicians throughout the state. "I do resent the fact they look at the delta as being sort of expendable to protect their farms," van Loben Sels says. (AP Photo/Rich Pedroncelli) In this Tuesday, Feb. 23, 2016 photo, farmer Russell van Loben Sels inspect grape vines on his land in the San Joaquin-Sacramento River Delta, near Clarksburg, Calif. A $15.7 billion tunnel project promoted by Gov. Jerry Brown to build giant pipes underground to ship water south is splitting farmers and politicians throughout the state. "I do resent the fact they look at the delta as being sort of expendable to protect their farms," van Loben Sels says. (AP Photo/Rich Pedroncelli)

By Associated Press March 18, 2016 2 min read

CLARKSBURG, Calif. (AP) – California is proposing its most ambitious water project in a half-century. At $15.7 billion, it would run two giant tunnels, each four stories high, for 35 miles under the Sacramento-San Joaquin River Delta in Northern California, sending water to cities and farms to the south. In size and cost, the feat would rival or dwarf the tunnel under the English Channel and Boston’s Big Dig.

Some things to know about the delta tunnels:

WHY IT’S PROPOSED

The way water is taken today from the delta has altered natural flows, making it run backward in parts and pulling migrating native fish off course. Once-bountiful stocks of Delta smelt, Chinook salmon and other native species have plummeted. At least 35 native fish, plants and animal species there are now listed under federal and state endangered-species acts. Environmental regulations limit how much water can be pumped from the delta.

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