The New Year has brought much needed rainfall to the Sunol Valley. Despite the winter weather, our teams are continuing the important work to seismically upgrade the facilities that deliver drinking water to 2.6 million Bay Area customers. These projects are part of the $4.8 billion Water System Improvement Program (WSIP). The San Francisco Public Utilities Commission (SFPUC) is the owner and operator of the Hetch Hetchy Regional Water System. In addition, other work, such as work on the Alameda Creek Watershed Center and upgrades to our Sunol Yard, are also underway this year.
Calaveras Dam Replacement Project
Work is still underway to replace the existing dam with a seismically-robust dam in order to restore its historic storage capacity. Rebuilding this dam and filling the reservoir is crucial to the reliable water supply of our customers. Over seven million cubic yards of earth and rock materials have been excavated. We have started to construct the new dam. Crews have constructed a new tower and shaft with five adits which connect outlet pipelines to the reservoir. The new 1550 ft spillway was completed in April 2016. The dam and all the outlet works have been designed to withstand the force of a 7.25 magnitude maximum credible earthquake from the nearby Calaveras Fault. The project is over 78% complete.
Due to recent storm impacts, portions of Calaveras Road remains closed to the public on 7 days a week. Please visit sfwater.org/Calaverasroad for more specific details regarding the closure.
Fish Passage Facilities within the Alameda Creek Watershed
Construction for the Fish Passage Facilities within the Alameda Creek Watershed began earlier in 2016. The Calaveras Reservoir collects water from Alameda Creek by means of the Alameda Creek Diversion Dam (ACDD), a 1.8-mile-long Alameda Creek Diversion Tunnel from other streams that flow directly into the Reservoir.
The project will improve the current facility and develop fish passage facilities within the Alameda Creek Watershed. This important work will support restoration of steelhead trout to the Watershed. The project will construct a fish ladder to facilitate fish passage around the existing Alameda Creek Diversion Dam. The project is approximately 30% complete and project completion is expected in Fall 2018.
Alameda Creek Recapture Project
The proposed project would recapture a certain volume of water that would be released and bypassed at Calaveras Dam and Alameda Creek Diversion Dam. The recaptured water would be pumped from an existing quarry pit (Pit F2) in the Sunol Valley, downstream of the compliance points for the bypasses and releases below the ACDD and Calaveras Dam, respectively.
The project would utilize the natural infiltration of water into the ground in the vicinity of Pit F2, and the recaptured water would be transferred to the SFPUC water system via either the San Antonio Reservoir or the Sunol Valley Water Treatment Plant. The recapture operation would be conducted within the SFPUC’s existing pre-1914 appropriative water rights.
The Draft Environmental Impact Report was released in November 2016. Construction is expected to begin in Fall 2017 and last for approximately 18 months.
Sunol Yard & Alameda Creek Watershed Center
Construction of upgrades to our Sunol Corporation Yard (located on SFPUC lands near the Sunol Water Temple) are expected to begin in February 2017 and last approximately 22 months.
Please note that the Sunol Water Temple will be closed during construction to protect the safety of members of the public passing through the area. The Sunol AgPark will remain open to farmers during construction.
Alameda Creek Watershed Center in Sunol and work on the Education Master Plan for the Center continues in 2017. The Center design continues to undergo value engineering, and results are expected in early 2017. Construction of the Native Plant Nursery for the plants that will be in the new Sunol Yard and Watershed Discovery Trail at the Center will also begin in 2017.