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. At that time, it was the longest water tunnel in the world. The city sought to build a dam somewhere on the Santa Ynez River in order to increase the water supply available for Mission Tunnel. Between 1913 and 1919, revenue bonds totaling $820,000 were issued for the construction of the dam and water system.