To: Board of Directors, Sonoma County Water Agency
Department or Agency Name(s): Sonoma County Water Agency
Staff Name and Phone Number: Dale Roberts 707-547-1979
Vote Requirement: Majority
Supervisorial District(s): Countywide
Title:
Title
Engineering and Design of River Diversion Structure Modernization Project
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Recommended Action:
Recommended action
Authorize Sonoma County Water Agency’s General Manager to execute the First Amended and Restated Agreement for Engineering and Design of the River Diversion Structure Modernization Project with Brelje & Race Engineering Consultants, in a form approved by County Counsel. The amended agreement increases the amount by $378,210, expands the scope of work to include additional seismic structural design, geotechnical investigation, and engineering analysis for a new not-to-exceed agreement total of $835,110. There is no change to the term end date of August 30, 2027.
end
Executive Summary:
Sonoma County Water Agency’s (Sonoma Water) River Diversion Structure (RDS) facility was originally constructed in 1975 for supplementary recharging of the alluvial aquifer. The RDS’ primary pumping, electrical, and control equipment has reached the end of its useful life and requires replacement. During the initial project review of design concepts, several additional necessary project elements emerged that require work not currently included in the scope of work for the agreement including, but not limited to, a portion of the additional work requiring geotechnical engineering services.
Discussion:
HISTORY OF ITEM/BACKGROUND
Sonoma Water’s water supply is largely comprised of water drawn from the Russian River (River). Sonoma Water has six collector wells at the River that extract groundwater from an alluvial aquifer that is adjacent to the River. The River naturally recharges the alluvial aquifer that feeds these collector wells, but in 1975 Sonoma Water constructed the RDS as a supplemental recharge facility to increase the volume of the riverbank infiltration aquifer from which the collector wells can draw. The RDS diverts water from the River into a series of infiltration ponds that recharge the alluvial aquifer that feeds collectors 3, 4, and 5.
The RDS is operated during the dry season (approximately April through October) in conjunction with the Mirabel inflatable dam (Dam). The Dam increases the water elevation/hydraulic head in the River so that the RDS pumps can operate and divert water from the River to the infiltration ponds. During the wet season (approximately October through April), the RDS is not operated because water levels are sufficiently high to recharge the aquifer to meet water supply demands.
The equipment in the RDS has reached the end of its useful life and needs to be replaced (Project). Originally, it was thought that the equipment in need of replacement included, but was not limited to, the following: medium-voltage step-down transformer; motor control center; three vertical turbine pumps; facility lighting; heating, ventilation, and air conditioning; and a programmable logic controller.
During a Project site visit, additional design requirements for seismic structural modifications were identified that exceeded the scope and budget of the original agreement. The Project design is nearing 30 percent completion.
Sonoma Water and Brelje & Race Engineering Consultants (Consultant) entered into an agreement for engineering and design of the Project, dated October 27, 2022, in the amount of $456,900.
SELECTION PROCESS
Consultant was selected from a competitive selection process. Attached is a memo that explains the competitive selection process.
SERVICES TO BE PERFORMED
Under the amended agreement, Consultant will continue to conduct Project meetings; prepare a design report; provide complete engineering design and construction documents, including specifying new equipment to replace the existing equipment; redesigning the existing RDS equipment; designing new ingress and egress to and from the RDS; and optimizing the operations with a new programmable logic controller; providing assistance during bidding and construction of the Project; and other related services. In addition, Consultant will provide the necessary geotechnical work at the site and additional design engineering for completion of the Project.
The additional cost is $378,210, for a new not-to-exceed agreement total of $835,110. There is no change to the end date of August 30, 2027.
California Environmental Quality Act
The General Manager has determined that the project is categorically exempt from the California Environmental Quality Act (CEQA) pursuant to CEQA Guidelines Section 15306, Information Collection, as it consists of basic data collection, research and resource evaluation activities that do not result in a serious or major disturbance to an environmental resource, it is strictly for information gather purposes and is part of a study leading to an action which a public agency has not yet approved, adopted or funded.
County of Sonoma Strategic Plan Alignment
N/A
Sonoma Water Strategic Plan Alignment
Goal: Planning and Infrastructure
Strategy: Fund and implement the planned capital and maintenance projects on schedule to ensure reliable services.
Action: Fund Capital Improvement Program budgets to meet infrastructure needs.
Funding and implementing the River Diversion Structure Modernization project will improve the reliability of the water transmission system by replacing aging infrastructure with resilient and redundant equipment. The controls for the system will be modernized to allow for additional data to be collected that will be used to improve efficiency and operations.
Racial Equity:
Was this item identified as an opportunity to apply the Racial Equity Toolkit?
No
Prior Board Actions:
08/02/2022: Approved agreement between Sonoma Water and Brelje & Race Engineering Consultants for engineering and design of the River Diversion Structure Modernization Project. Cost $456,900; term end August 30, 2027.
Fiscal Summary
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Expenditures |
FY23-24 Adopted |
FY24-25 Projected |
FY25-26 Projected |
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Budgeted Expenses |
$378,210 |
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Additional Appropriation Requested |
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Total Expenditures |
$378,210 |
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Funding Sources |
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General Fund/WA GF |
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State/Federal |
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Fees/Other |
$378,210 |
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Use of Fund Balance |
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General Fund Contingencies |
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Total Sources |
$378,210 |
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Narrative Explanation of Fiscal Impacts:
Budgeted amount of $378,210 is available from FY 2023/2024 appropriations for the Common Facilities fund. No additional appropriation is required.
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Staffing Impacts: |
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Position Title (Payroll Classification) |
Monthly Salary Range (A-I Step) |
Additions (Number) |
Deletions (Number) |
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Narrative Explanation of Staffing Impacts (If Required):
N/A
Attachments:
Consultant Selection Memo
Draft Agreement
Related Items “On File” with the Clerk of the Board:
None.