Legislation Details

File #: 2026-0536   
Type: Consent Calendar Item Status: Agenda Ready
File created: 4/17/2026 In control: Sonoma County Water Agency
On agenda: 6/2/2026 Final action:
Title: Engineering and Design Services for Warm Springs Dam Hydropower Retrofit
Department or Agency Name(s): Sonoma County Water Agency
Attachments: 1. Summary Report, 2. Draft Sixth Amended Agreement with Integrated Engineers & Contractors Corporation
Related files: 2019-1254, 2021-1134, 2021-0716

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 Services for Warm Springs Dam Hydropower Retrofit

End

 

Recommended Action:

Recommended action

Authorize Sonoma County Water Agency’s General Manager to execute the Sixth Amended and Restated Agreement for Engineering and Design Services for Warm Springs Dam Hydropower Retrofit Project with Integrated Engineers & Contractors Corporation, in substantially the form as the draft presented to this Board.  The amended agreement increases the amount by $143,380, expands the scope of work to include design revisions regarding the generator step-up transformer and inclusion of an optional task, and extends the agreement term by two years for a new not-to-exceed agreement total of $1,146,557 and term end date of June 30, 2028.

end

Executive Summary:

Sonoma County Water Agency (Sonoma Water) owns, operates, and maintains the Warm Springs Dam Hydropower Facility (Hydropower Facility), which a condition assessment performed in 2017 recommended be modernized and retrofitted. Integrated Engineers & Contractors Corporation (Consultant) was selected from a competitive selection process and began the design phase for recommended updates for the Warm Springs Dam Hydropower Retrofit Project (Project) in 2018. Design modifications are necessary to address recent PG&E requirements to the electrical transformer.

 

Discussion:

HISTORY OF ITEM/BACKGROUND

Warm Springs Dam, located in Geyserville, California, was completed by the United States Army Corps of Engineers (USACE) in 1984, creating Lake Sonoma which stores water used for both domestic purposes and recreation. USACE owns and operates the dam and is responsible for controlling the releases when the water levels in the reservoir exceed specified flood level elevations. Sonoma Water manages the reservoir releases when the water levels are below the flood level elevations.

 

Since the Hydropower Facility was constructed in 1989, it has produced approximately 9,000 MWh-16,000 MWh per year and has performed well with minimal repairs over the years. The Hydropower Facility is now over 37 years old. Although it has not had major performance issues, in 2017 Sonoma Water performed a condition assessment of the Hydropower Facility with the aim of improving efficiency, resiliency, and useful service life.

 

Sonoma Water and Consultant first entered into an agreement for engineering and design services for Hydropower Facility retrofit in July 2018 in the amount of $644,484. At the 60% design stage, Consultant recommended that additional facility protection instrumentation be included to address code compliance requirements, new interconnection requirements required by Pacific Gas & Electric (PG&E), and to increase overall Hydropower Facility functionality. The agreement was first amended to increase the amount by $264,853, expand the scope of work, and extend the agreement term by two years for a new not-to-exceed agreement total of $909,337 and end date of December 31, 2021.

 

The Project was advertised for bids on February 16, 2021, and bids were opened on May 25, 2021. The two bids received were approximately $500,000 more than the engineer’s estimate. At Sonoma Water’s recommendation, the Board of Directors rejected the bids on August 17, 2021.

 

The difference in bids was mostly attributable to limited electrical switchgear equipment options that can fit into the relatively tight space within the Warm Springs Dam control structure, while still maintaining compliance with current National Electric Code requirements and California Division of Occupational Safety and Health (Cal/OSHA) requirements. These requirements became effective only after the original hydroelectric facility was constructed in 1988 -1989.

 

To address the size constraints of the site, Sonoma Water conducted a solicitation to purchase custom electrical switchgear equipment uniquely fabricated to fit the tight space requirements. A second amended agreement, approved by the Board on November 16, 2021, increased the agreement amount by $93,840 for a new not-to-exceed total of $1,003,177 and extended the agreement by two years to December 31, 2023, to include switchgear solicitation, purchase assistance, and design revisions.

 

A third, fourth, and fifth amended agreement, approved by the General Manager of Sonoma Water on August 24, 2023, October 17, 2024, and October 28, 2025, respectively, extended the agreement by a total of 2.5 years to June 30, 2026, with no change to agreement amount to continue design revision work. Additional time extensions were warranted following an equipment manufacturer’s unanticipated change in the terms of the purchase order, necessitating further refinement of procurement documents and resolicitation for the procurement of electrical equipment. Shop drawings and specifications of the customized equipment have since been received under separate equipment purchase agreement.

 

Upon ascertaining the manufacturer-supplied dimensions and specific interconnections of the customized electrical switchgear equipment, the installation design needed to be modified to suit the specifics of the new electrical switchgear. In addition, design modifications were necessitated for the existing electrical transformer to meet new system requirements mandated by PG&E.

 

SELECTION PROCESS

Consultant was selected through a competitive selection process conducted under the original agreement. A new competitive selection process was not conducted because this amended agreement covers design modifications to work already in progress, not a new scope of services.

 

SERVICES TO BE PERFORMED

Under the proposed amended agreement, Consultant will revise the design to reflect the updates to the generator step-up transformer.

 

The additional cost is $143,380, for a new not-to-exceed agreement total of $1,146,557. The new term end date is June 30, 2028.

 

Through the proposed amended agreement, the General Manager will be delegated the authority to approve a written amendment to extend the term of the agreement for up to two additional years by providing written notice to the other party thirty days in advance of the term end date and by executing an agreement amendment.

 

County of Sonoma Strategic Plan Alignment:

N/A

 

Sonoma Water Strategic Plan Alignment

Goal: Planning and Infrastructure

Strategy: Conduct planning that integrates and balances operational, maintenance, and infrastructure priorities.

Action: Continue to identify opportunities to implement renewable and efficiency-enhancing energy projects to meet energy policy objectives.

 

Retrofitting the Hydropower Facility allows Sonoma Water to more effectively use its renewable power generation to supply the local electric power network and minimize power imports.

 

Racial Equity:

 

Was this item identified as an opportunity to apply the Racial Equity Toolkit?

No

 

Prior Board Actions:

11/16/2021:                     Approved second amended agreement between Sonoma Water and Consultant for engineering and design services. The additional cost was $93,840, for a new not-to-exceed agreement total of $1,003,177 and term end date of December 31, 2023.

08/17/2021:                     Approved Sonoma Water’s rejection of all bids received on May 25, 2021, for the Warm Springs Dam Hydropower Retrofit Project.

09/10/2019:                     Approved first amended agreement between Sonoma Water and Consultant for engineering and design services. The additional cost was $264,853, for a new not-to-exceed agreement total of $909,337 and term end date of December 31, 2021.

07/10/2018:                     Approved agreement between Sonoma Water and Consultant for engineering and design services.  Cost was $644,484, and term end date was December 31, 2019.

 

Fiscal Summary

 Expenditures

FY25-26 Adopted

FY26-27 Projected

FY27-28 Projected

Budgeted Expenses

$143,380

 

 

Additional Appropriation Requested

 

 

 

Total Expenditures

$143,380

 

 

Funding Sources

 

 

 

General Fund/WA GF

 

 

 

State/Federal

 

 

 

Fees/Other

$143,380

 

 

Use of Fund Balance

 

 

 

General Fund Contingencies

 

 

 

Total Sources

$143,380

 

 

 

Narrative Explanation of Fiscal Impacts:

Budgeted amount of $143,380 is available from FY 2025/2026 appropriations for the Common Facilities fund.

 

No additional appropriation is required.

 

Staffing Impacts:

 

 

 

Position Title (Payroll Classification)

Monthly Salary Range (A-I Step)

Additions (Number)

Deletions (Number)

 

 

 

 

 

 

 

 

 

 

 

 

 

Narrative Explanation of Staffing Impacts (If Required):

N/A

 

Attachments:

Draft Sixth Amended Agreement with Integrated Engineers & Contractors Corporation

 

Related Items “On File” with the Clerk of the Board:

None.