Gibraltar Farm

In the early 1900s the City of Santa Barbara had exhausted its local water supplies, and looked to the drainage basin of the nearby Santa Ynez River, which is much larger than any of the city's local streams. In 1904 construction began on the Mission Tunnel which was bored under Mission Canyon in the Santa Ynez Mountains, to tap surface and ground water in the Santa Ynez basin. for which a $40,000 contract was awarded to Arthur S. Bent Construction Co. In 1917 a concrete "thrust block" was poured on the south side of the canyon to take the weight of the future dam, as the rock on this side was not high enough to support the structure. Because there was no road to the site, workers and…

Gibraltar Dam is a constant radius concrete arch dam 194.5 ft high and 600 ft long. Downstream of Gibraltar, the Santa Ynez flows into the much larger Lake Cachuma, owned by the U.S. Bureau of Reclamation. The spillway is designed so that overflow water cascades down the natural sandstone face adjacent to the dam, creating a 150 ft high waterfall. The original design capacity of Gibraltar Reservoir was 15374 acre feet. Water is drawn from the reservoir via an intake structure near the south end of the dam into the 3.7 mi Mission Tunnel, which transports water beneath the Santa Ynez Mountains to a small regulation basin, Lauro Reservoir. The water is either treated at the Cater Water…

Although the dam and reservoir are open to the public, only official vehicles are allowed on the narrow winding dirt roads leading to the dam. The shortest way to reach the dam on foot is a 6 mi round trip hike along the Santa Ynez River from Red Rock Campground. It can also be reached from several trails originating at Camino Cielo Road. The Gibraltar Trail follows the southern edge of the reservoir from the dam, and several other trails branch around the reservoir into the backcountry of Los Padres National Forest. Boating, fishing and swimming are not allowed at the reservoir since it is a public water supply.