To: Board of Directors, Sonoma County Water Agency
Department or Agency Name(s): Sonoma County Water Agency
Staff Name and Phone Number: Grant Davis 707-547-1900, Dale Roberts 707-547-1979
Vote Requirement: Majority
Supervisorial District(s): Countywide
Title:
Title
Engineering and Design for River Diversion Structure Modernization Project
End
Recommended Action:
Recommended action
Authorize Sonoma County Water Agency’s General Manager to execute the Second Amended and Restated Agreement for Engineering and Design for River Diversion Structure Modernization Project with Brelje & Race Engineers, in substantially the form as the draft presented to this Board. The amended agreement increases the amount by $160,127, expands the scope of work, and extends the agreement term by one year for a new not-to-exceed agreement total of $995,237 and end date of August 30, 2028.
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. Sonoma Water proposes to amend the design agreement to add flow rate monitoring, relocate electrical equipment to the recently decommissioned Emergency Well Field Building, and prepare procurement documents to pre-purchase pumps and electrical switchgear due to their long lead times.
Discussion:
HISTORY OF ITEM/BACKGROUND
Sonoma Water’s water supply is largely drawn from the Russian River. Sonoma Water has six collector wells at the Russian River that extract groundwater from an alluvial aquifer that is adjacent to the Russian River. The Russian 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 Russian 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. The Mirabel inflatable dam increases the water elevation/hydraulic head in the Russian River so that the RDS pumps can operate and divert water from the Russian 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 medium-voltage step-down transformer; motor control center; three vertical turbine pumps; facility lighting; heating, ventilation, and air conditioning; and a programmable logic controller. Based on work completed to date, additional replacement or modification is needed.
The Project has been completed to the 90 percent design stage and is nearing advertisement for bids. Sonoma Water proposes amending the design agreement to add flow rate monitoring required by the State Water Resources Control Board to better measure Russian River withdrawal amounts, relocate electrical equipment to the recently decommissioned Emergency Well Field Building rather than on an outside platform, and prepare procurement documents to pre-purchase pumps and electrical switchgear due to their long lead times to more efficiently and cost effectively implement the Project.
Sonoma Water first entered into this Agreement on October 27, 2022, in the amount of $456,900.
The First Amended and Restated Agreement increased the amount by $378,210 and expanded the scope of work to include necessary geotechnical work at the site and additional design engineering for completion of the Project design for a new not-to-exceed Agreement total of $835,110. There was no change to the end date of August 30, 2027.
This Second Amended and Restated Agreement increases the amount by $160,127, expands the scope of work to include use of Wellfield Building, addition of meter and vault, and pre-purchase documents for a new not-to-exceed Agreement total of $995,237, and extends the Agreement term by one year for a new term end date of August 30, 2028.
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; redesign the existing RDS equipment; design new ingress and egress to and from the RDS; optimize the operations with a new programmable logic controller; provide assistance during bidding and construction of the Project; and other related services. In addition, Consultant will incorporate use of the Wellfield Building, add a meter and vault, and prepare pre-purchase documents.
The additional cost is $160,127, for a new not-to-exceed agreement total of $995,237. The new end date is August 30, 2028.
CALIFORNIA ENVIRONMENTAL QUALITY ACT
The General Manager has determined that the Project is categorically exempt from the California Environmental Quality Act (CEQA) pursuant to sections 15301(b), Existing Facilities, and 15302(c), Replacement or Reconstruction. The Project will consist of replacement of existing publicly owned utility systems involving negligible or no expansion of use by upgrading aging electrical equipment and infrastructure on the same site and have substantially the same purpose and capacity as the systems replaced. The Project does not have the potential to degrade the quality of the environment or cause a substantial adverse change in the significance of a historic resource.
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:
03/26/2024: Approved the First Amended and Restated Agreement for Engineering and Design of the River Diversion Structure Modernization Project with Brelje & Race Engineering Consultants. The amended agreement increased the amount by $378,210 to expand the scope of work for a new not-to-exceed agreement total of $835,110; term end August 30, 2027.
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 |
FY25-26 Adopted |
FY26-27 Projected |
FY27-28 Projected |
|
Budgeted Expenses |
$160,127 |
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|
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Additional Appropriation Requested |
$ |
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Total Expenditures |
$160,127 |
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|
|
Funding Sources |
$ |
|
|
|
General Fund/WA GF |
$ |
|
|
|
State/Federal |
$ |
|
|
|
Fees/Other |
$160,127 |
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|
Use of Fund Balance |
$ |
|
|
|
General Fund Contingencies |
$ |
|
|
|
Total Sources |
$160,127 |
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Narrative Explanation of Fiscal Impacts:
Budgeted amount of $160,127 is available from FY 2025/2026 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:
Attachment 1: Amended Agreement with Brelje & Race
Attachment 2: Consultant Selection Memo
Related Items “On File” with the Clerk of the Board:
None.