Cadillac Desert: The American West and Its Disappearing Water

by Marc Reisner

Trinity Tunnel, which would spin water out of the bottom back side of the reservoir and carry it to the Central Valley, would be sixty miles long, Its shape would resemble a horseshoe, and its diameter would be thirty-seven feet. There would be no tunnel remotely like it anywhere in the world. The Delaware Aqueduct, stretching from the Catskill Mountains to Westchester County, is eighty-five miles long, but its diameter is only fourteen feet. Trinity Tunnel could hold four passenger trains operating on two levels. It alone would cost nearly half a billion dollars, in 1951, and it was merely the longest and biggest of numerous tunnels. The Tehachapi Tunnel, forty miles long, would move the water through the Transverse Ranges, which cordon off Los Angeles from the rest of the state. Seven known fault zones would be crossed along the aqueduct route, and one of them, the San Andreas Fault, would present a fracture zone at least two miles wide in the middle of the Tehachapi Tunnel which could pose “unusual construction problems.” An ordinary tunnel would shear if the fault slipped—it slipped nearly twenty feet in the 1906 quake—leaving Los Angeles unwashed and unquenched. “Extra-heavy supports would be required throughout this zone.”