Lafayette Reservoir Tower Seismic Retrofit Project

Project Information

The Lafayette Reservoir Tower and the conduits at the base of the tower together function as a spillway and outlet to control the reservoir levels. In the event of an earthquake, the tower is likely to sustain significant damage due to the lack of steel reinforcement in the concrete, and the conduits at the base of the tower would sustain damage from bending forces. The tower was originally built in 1929 and is 40 feet too high due to a change in the dam height during construction. It currently does not meet modern seismic design standards and would bend and break in an earthquake. The conduits at the base of the tower would also become damaged so that the tower and conduits would not be able to function as an outlet and spillway. This presents a dam safety concern. The California Division of Safety of Dams, the state agency that regulates dam safety, has required EBMUD to address the seismic safety of the tower and conduit and to add an onshore valve operating system to improve response time in an emergency.  

The seismic deficiencies were identified in a comprehensive structural evaluation of the tower and conduit system using state-of-the-art finite element numerical modeling and dynamic response-spectrum analysis. Based on these results and after conducting an alternatives analysis, EBMUD plans to address the seismic risk to the tower by shortening it. This is required to ensure the safety of the facility and allow on-going operations as a recreational facility and emergency water source. The new tower will be 40 feet shorter which is appropriately sized for the height of the dam. Additional details are included in EBMUD’s March 2019 Lafayette Tower Alternative Selection Report. EBMUD is currently working with a consultant on the architectural details of the tower, but it is expected to have an architecturally detailed parapet wall, with a beveled platform and corbels, which will ensure functionality. EBMUD has also received community input and is evaluating the feasibility of a platform with a metal operating house. ​​​

Schedule 

Construction is expected to begin in Spring 2024 and last approximately one year. 

Construction Impacts

Construction impacts are expected to be minimal. Some parking spaces will be temporarily used to store equipment. There may be a need to temporarily suspend access to the reservoir for short periods of time during large equipment deliveries. This will be communicated to users beforehand and should be brief. There will be no need to drain the reservoir. Minor tree work is anticipated, along with some temporary, localized widening of the access road.

Community Outreach

• Presentation on design Alternatives to Lafayette City Council- December 2017
• Meeting with Lafayette City Staff – December 2022
• Presentation to Lafayette City Council- January 9, 2023
• Presentation to the Lafayette City Council - May, 2023
• Presentation to the Lafayette City Council - June 12, 2023

Presentations to community groups:

• Lafayette Rotary - March 8, 2023
• Lafayette Chamber of Commerce- March 13, 2023
• Community Engineers and Design Consultant Meeting - May 30, 2023

Contact information

Community Affairs
Email: construction-east@ebmud.com
Phone: 510-287-2053

Publications and Additional Documents