Before city council and the public received updates on the EBMUD Reservoir Tower retrofit from the Citizens Advisory Committee, City Manager Niroop Srivatsa provided a brief summary of the project's history.
"In January 2023, East Bay Municipal Utility Disctrict (EBMUD) staff presented the Lafayette Reservoir Tower Seismic Retrofit Project to the Lafayette City Council featuring a tower shortened by 40 feet. The City Council and the community expressed concerns about the proposed design and the potential loss of the iconic tower that has symbolized our city for decades. A group of Lafayette residents with extensive expertise in seismic structural retrofit design, structural engineering, architecture, and construction volunteered to review EBMUD's technical reports, analyses, and plans to determine if the tower could be seismically strengthened in its place in its original configuration rather than by shortening the tower. The committee presented its first report to you in July of 2023."
Since that time, the committee she said had "spent countless hours" reviewing technical studies and other materials provided by EBMUD. Speaking at the meeting May 28 held on Tuesday due to the Memorial Day holiday, Srivatsa said efforts made to work collaboratively with EBMUD and its consultant AECOM to identify alternatives and mitigations have been extensive.
The committee has concluded that the city would be best served if the existing reservoir tower remained and received seismic improvements. Specifically, they concluded that instead of shortening the tower, a retrofit of the upper one half of the existing tower using a modest addition of steel reinforcements would address seismic risk, life safety, code compliance, cost effectiveness, environmental sensitivity, while preserving the iconic structure. In their final report to council, the committee stated that EBMUD's proposed shortening of the tower would actually increase the seismic risk for downstream residents of Lafayette in the event of a major earthquake.
Structural Engineer and 50-year Lafayette resident Loring Wyllie summarized the committee's conclusion that EBMUD's shortening the height of the tower would reduce bending forces, but could cause it to shake violently and increase the lateral sheer forces at its base. While the tall tower would also shake during an earthquake, a shorter tower would move at an accelerated rate and potentially decrease safety of residents located downstream.
Committee chair Gordon Chong emphasized that the committee's study of the issues involved in retrofitting the tower was based entirely on EBMUD's structural design thinking and data. He said their primary goal was to protect Lafayette residents downstream of the reservoir from the negative impacts of a major earthquake. Chong said the collaborative intentions of the committee had not been mirrored by EBMUD and their consultants. For that reason, the committee had pivoted after months of effort to search for alternative mitigation and design proposals to reduce seismic risk.
Response to EBMUD positions related to repairing conduits to the tower and not designating the tower as a protected historic landmark appeared in the final report. The committee's presentation also included mention of letters sent by EBMUD to the city accusing the committee of misrepresenting data and ignoring vital information. For example, the publicly posted letter accuses the committee of ignoring updates following a 1995 ICEC report.
Council member Karl Anduri asked the committee to respond to the relevancy of EBMUD's statements. The committee concluded the core engineering principles remained the same and shortening the tower-regardless of the data used-would still result in unknown, increased risk. Of equal concern was what Wong said was constant rebuttal, defensiveness, and rejection of the committee's suggestions, indicating EBMUD's disinterest in collaborating and underscoring their position of having sole authority in the retrofit. For that and other reasons, he said the committee had no interest in continuing the conversations with EBMUD.
Council member John McCormick asked about the cost effectiveness of adding reinforcements to the tower instead of to the conduit at its base. Wyllie said the increased tower costs would be negligible and would shift the cost of work done on the conduits.
In public comments, a representative of EBMUD expressed disappointment in the committee's final report conclusions and disputed several of its positions. Working in ways he said were "responsive and collaborative," he stressed that EBMUD is accountable to the community and to the California Division of Safety of Dams and would, as a result, continue with plans to shorten the tower.
Vice Mayor WEi-Tai Kwok said the city's relationship with EBMUD had been positive for many years and was surprised and disappointed the committee and EBMUD had come to loggerheads. He suggested bringing in an adjudicator to move the project forward.
Anduri suggested the council list and develop options and consider placing the topic on the agenda for the meeting June 10. The latter action would allow time for pubic input. In the meantime, staff would be authorized by council to send a letter to EBMUD requesting that work cease on the designs for a shortened tower.
Council member Susan Candell recused herself from the discussion and left the meeting because she is involved in a separated, unrelated lawsuit with EBMUD. After she departed the meeting, the four remaining council members considered three options:
1. Agree to EBMUD's retrofit Plan B with a shortened tower. Pros: No demand on city resources or dollars, maintains good relationships with EBMUD, risk exists but is low because it would take a simultaneous maximum earthquake and precipitation event to result in significant damage. Cons: The committee assessed this is risky and city would lose the iconic structure.
2. Maintain tower without retrofit. Anduri predicted this would require a large effort, time and expense and have little chance of success.
3. Improve safety while maintaining height. This would involve changes from EBMUD and Division of Safety of Dams. Pros: If the effort is successful, Anduri said they would "have the best of both worlds: lower risk and our iconic tower." Cons: Expensive in time and money to pursue it. Cost estimates from EBMUD for this option indicate it would cost $7.6 million more than shortening the tower.
Kwok favored option three, along with asking an impartial adjudicator to examine estimated cost and safety elements before issuing recommendations for proceeding. He proposed the council ask Srivatsa to draft a letter to EBMUD requesting they pause their plans to shorten the tower. Discussion of issuing a request that he and Anduri meet as council representatives with an EBMUD board member and a second action directing city staff to draft a letter to Division of Safety of Dams summarizing the city's position and requesting a meeting had the council deciding the EBMUD letter will be issued and the item will not be added to the agenda for future council meetings until EBMUD's response is received.
"In January 2023, East Bay Municipal Utility Disctrict (EBMUD) staff presented the Lafayette Reservoir Tower Seismic Retrofit Project to the Lafayette City Council featuring a tower shortened by 40 feet. The City Council and the community expressed concerns about the proposed design and the potential loss of the iconic tower that has symbolized our city for decades. A group of Lafayette residents with extensive expertise in seismic structural retrofit design, structural engineering, architecture, and construction volunteered to review EBMUD's technical reports, analyses, and plans to determine if the tower could be seismically strengthened in its place in its original configuration rather than by shortening the tower. The committee presented its first report to you in July of 2023."
Since that time, the committee she said had "spent countless hours" reviewing technical studies and other materials provided by EBMUD. Speaking at the meeting May 28 held on Tuesday due to the Memorial Day holiday, Srivatsa said efforts made to work collaboratively with EBMUD and its consultant AECOM to identify alternatives and mitigations have been extensive.
The committee has concluded that the city would be best served if the existing reservoir tower remained and received seismic improvements. Specifically, they concluded that instead of shortening the tower, a retrofit of the upper one half of the existing tower using a modest addition of steel reinforcements would address seismic risk, life safety, code compliance, cost effectiveness, environmental sensitivity, while preserving the iconic structure. In their final report to council, the committee stated that EBMUD's proposed shortening of the tower would actually increase the seismic risk for downstream residents of Lafayette in the event of a major earthquake.
Structural Engineer and 50-year Lafayette resident Loring Wyllie summarized the committee's conclusion that EBMUD's shortening the height of the tower would reduce bending forces, but could cause it to shake violently and increase the lateral sheer forces at its base. While the tall tower would also shake during an earthquake, a shorter tower would move at an accelerated rate and potentially decrease safety of residents located downstream.
Committee chair Gordon Chong emphasized that the committee's study of the issues involved in retrofitting the tower was based entirely on EBMUD's structural design thinking and data. He said their primary goal was to protect Lafayette residents downstream of the reservoir from the negative impacts of a major earthquake. Chong said the collaborative intentions of the committee had not been mirrored by EBMUD and their consultants. For that reason, the committee had pivoted after months of effort to search for alternative mitigation and design proposals to reduce seismic risk.
Response to EBMUD positions related to repairing conduits to the tower and not designating the tower as a protected historic landmark appeared in the final report. The committee's presentation also included mention of letters sent by EBMUD to the city accusing the committee of misrepresenting data and ignoring vital information. For example, the publicly posted letter accuses the committee of ignoring updates following a 1995 ICEC report.
Council member Karl Anduri asked the committee to respond to the relevancy of EBMUD's statements. The committee concluded the core engineering principles remained the same and shortening the tower-regardless of the data used-would still result in unknown, increased risk. Of equal concern was what Wong said was constant rebuttal, defensiveness, and rejection of the committee's suggestions, indicating EBMUD's disinterest in collaborating and underscoring their position of having sole authority in the retrofit. For that and other reasons, he said the committee had no interest in continuing the conversations with EBMUD.
Council member John McCormick asked about the cost effectiveness of adding reinforcements to the tower instead of to the conduit at its base. Wyllie said the increased tower costs would be negligible and would shift the cost of work done on the conduits.
In public comments, a representative of EBMUD expressed disappointment in the committee's final report conclusions and disputed several of its positions. Working in ways he said were "responsive and collaborative," he stressed that EBMUD is accountable to the community and to the California Division of Safety of Dams and would, as a result, continue with plans to shorten the tower.
Vice Mayor WEi-Tai Kwok said the city's relationship with EBMUD had been positive for many years and was surprised and disappointed the committee and EBMUD had come to loggerheads. He suggested bringing in an adjudicator to move the project forward.
Anduri suggested the council list and develop options and consider placing the topic on the agenda for the meeting June 10. The latter action would allow time for pubic input. In the meantime, staff would be authorized by council to send a letter to EBMUD requesting that work cease on the designs for a shortened tower.
Council member Susan Candell recused herself from the discussion and left the meeting because she is involved in a separated, unrelated lawsuit with EBMUD. After she departed the meeting, the four remaining council members considered three options:
1. Agree to EBMUD's retrofit Plan B with a shortened tower. Pros: No demand on city resources or dollars, maintains good relationships with EBMUD, risk exists but is low because it would take a simultaneous maximum earthquake and precipitation event to result in significant damage. Cons: The committee assessed this is risky and city would lose the iconic structure.
2. Maintain tower without retrofit. Anduri predicted this would require a large effort, time and expense and have little chance of success.
3. Improve safety while maintaining height. This would involve changes from EBMUD and Division of Safety of Dams. Pros: If the effort is successful, Anduri said they would "have the best of both worlds: lower risk and our iconic tower." Cons: Expensive in time and money to pursue it. Cost estimates from EBMUD for this option indicate it would cost $7.6 million more than shortening the tower.
Kwok favored option three, along with asking an impartial adjudicator to examine estimated cost and safety elements before issuing recommendations for proceeding. He proposed the council ask Srivatsa to draft a letter to EBMUD requesting they pause their plans to shorten the tower. Discussion of issuing a request that he and Anduri meet as council representatives with an EBMUD board member and a second action directing city staff to draft a letter to Division of Safety of Dams summarizing the city's position and requesting a meeting had the council deciding the EBMUD letter will be issued and the item will not be added to the agenda for future council meetings until EBMUD's response is received.
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Lamorinda Weekly, Moraga CA