WorldWide Drilling Resource

Work is Underway to Raise the Height of Shasta Dam Compiled by Caleb Whitaker, Associate Editor, WorldWide Drilling Resource ® Shasta Lake, located in northern California, is the largest reservoir in California and second largest in the United States. Preconstruction work is underway at the Shasta Dam and reservoir in advance of a project to raise the dam 18.5 feet. Since the 1980s, talks to raise the dam have been ongoing. The feasibility and environmental impact statement was sent to Congress in 2015, with approval for the project and $20 million for the preliminary work coming in March 2018 from the Water Infrastructure for Improvements to the Nation (WIIN) Act. Enlarging the reservoir will provide an additional 630,000 acre-feet of stored water for the environment and for water users. It will also improve water supply reliability for agriculture, munici- pal, industrial, and environmental uses. Additionally, flood dam- age will be reduced, and water temperatures and water quality in the Sacramento River below the dam will be improved for survival of fish which swim upstream. Crews are currently performing exploratory drilling and con- crete coring to gather strength data for designers to complete the design. Holes are being drilled in the dam and into the bedrock beneath the dam. The project will require moving homes, a railroad, and a mari- na, with the dam scheduled to be finished and storing water by February 2024. The goal is to get the construction contract awarded by December 2019. The WIIN Act funding will not require congressional authorization, but does require 50% of the construction costs come from private stakeholders. In addition to raising the height of the dam, the project also includes raising the height of the approaches to the dam. The roundabout on the east side of the dam will need to be removed and replaced with a new approach. The three drum gates on the spillway will be replaced with eight vertical gates. The massive temperature curtain on the lake side of the dam will have to be removed and raised. Heavy equipment associated with concrete and soil construction, such as excavators and mobile cranes, are expected to be used on-site. A concrete batch plant will be built nearby. The contractor may also utilize a barge to help facilitate construction. ! " # ! C&G Shasta Dam, courtesy of the Bureau of Reclamation. 49 WorldWide Drilling Resource ® APRIL 2019