The Montecito Water District completed construction of Juncal Dam and Jameson Lake in 1930. Water is diverted to the Montecito area through the Doulton Tunnel. Construction of Doulton Tunnel began in 1924 and initially penetrated only the first mile of the Santa Ynez Mountains due to substantial groundwater inflow. The tunnel was finally completed in 1928. Groundwater inflow to Doulton Tunnel currently averages approximately 440 AFY. For more information on the Jameson Reservoir visit the Montecito Water District website.