This is a continuation of annual progress reports giving the results of discharge measurements made in the Santa Ynez Mountains between Refugio Canyon on the west to San Marcos Pass and the Painted Cave area on the east. This portion of Santa Barbara County has been designated as the "Tecolote Tunnel Area" because a tunnel by that name, now being built by the Bureau of Reclamation, passes through it. The purpose of this tunnel is to divert flood runoff from the Santa Ynez River, stored in Cachuma Reservoir, to the city of Santa Barbara and adjacent areas.
During the construction of this tunnel, the seepage from the south portal has averaged 6.4 second-feet for the year ending April 30, 1952, the average being 8.7 second-feet for the last 6 months of that period. Both of these values exceed the average total discharge prior to April 30, 1951, for more than 120 springs measured in the Tecolote Tunnel Area.
As, it was not known what effect the seepage from this tunnel might have on the flow of springs and streams in the immediate vicinity, the Santa Barbara County Water Agency requested the U. S. Geological Survey to institute an observational program. This program was started in 1948—about 2 years before work was started on the tunnel. The area covered by the observational program was made sufficiently large to include all the springs that could possibly be affected, as well as certain border springs believed to be outside the zone of influence.
The purpose of this, the fourth progress report, is to make available factual data obtained during the year ending April 30, 1952. This program is operated under a cooperative agreement between the U. S. Geological Survey and the Santa Barbara County Water Agency whereby each pays half the cost of the investigation.
