To: Board of Directors, Sonoma County Water Agency
Department or Agency Name(s): Sonoma County Water Agency
Staff Name and Phone Number: Brad Sherwood (707) 547-1927, Hailey Norman 707-806-7860, Devin Chatoian, 707-524-3783
Vote Requirement: Majority
Supervisorial District(s): All
Title:
Title
Invasive Mussel Inspection Programs at Lake Sonoma and Lake Mendocino
End
Recommended Action:
Recommended action
A) Adopt a Resolution ratifying and approving the signing and filing of a grant application to the California Department of Parks and Recreation Division of Boating and Waterways and taking other actions related to the administration of the grant and implementation of the 2026 Lake Mendocino Mussel Infestation Prevention Program.
B) Authorize Sonoma County Water Agency’s General Manager to increase the cumulative amount for consultant agreements funded by the U.S. Army Corps of Engineers cost-share Aquatic Invasive Species Program, as executed under a five-year Project Partnership Agreement and annual Statements of Work, to a new cumulative not-to-exceed amount of $2,971,294.
end
Executive Summary:
Quagga and zebra mussels are an invasive mussel that, if introduced into a waterway, can devastate the natural environment, clog water and flood protection infrastructure, and cost millions of dollars in maintenance. Mussels are transported between waterways by watercraft, primarily recreational boats.
Sonoma Water has self-funded infestation prevention efforts at both Lake Mendocino and Lake Sonoma since 2012, and in 2020 was able to successfully obtain funds from the California State Parks Division of Boating and Waterways (DBW) to support these efforts. DBW offers competitive two-year grants to eligible applicants on an annual basis. Sonoma Water offsets applications for Lake Mendocino and Lake Sonoma by one year as required by the funding agency. The application for Lake Sonoma was awarded for the 2025 funding cycle. Applications for the 2026 funding cycle were due April 17, 2026, and Sonoma Water submitted an application for a $400,000 grant to fund inspection programs at Lake Mendocino. If awarded, program guidelines require a resolution authorizing application, execution of grant agreement, and related actions from the applicant’s governing Board to be signed and submitted prior to executing a funding agreement.
DBW grants only fund watercraft inspections for a portion of the day and additional funding is necessary to provide all-day inspections and complete tasks (mussel monitoring, decontaminations and outreach) necessary to ensure both lakes remain mussel-free. To address the remaining program needs, in 2025 Sonoma Water and the U.S. Army Corps of Engineers (USACE) executed a 5-year Project Partnership Agreement (PPA) under USACE’s cost-share Aquatic Invasive Species (AIS) Program, with the goal of expanding watercraft inspections at Lake Sonoma and Lake Mendocino. Under the PPA, Statements of Work (SOW) are executed annually as formal acceptance of the work plan and budget for the year. On November 4, 2025, the Board authorized a not-to-exceed amount of $850,000 to execute consultant agreements in furtherance of the 5-year PPA and annual SOWs. Sonoma Water is now requesting to increase the not-to-exceed amount to $2,971,294 in order to maximize USACE funding received under the 5-year PPA through December 1, 2030.
Discussion:
HISTORY OF ITEM/BACKGROUND
The Russian River Basin, including Lake Sonoma and Lake Mendocino, are at risk of a dreissenid infestation due to the mobility of watercraft transported overland between and within watersheds. In addition, the high survival rate of dreissenids once established, their ability to be hidden on or inside of boats and other structures, and the high fiscal and environmental costs of infestation present serious problems to those who live, work, or recreate in the Russian River Basin. Lake Sonoma and Lake Mendocino are currently mussel free; however, mussels have infested a waterway south of Mendocino and Sonoma counties, in San Benito County. This waterway, the San Justo reservoir, was closed to all public use since the mussels were first discovered in 2008 and remains closed 17 years later. It will cost an estimated $6.5 million to eradicate the zebra mussel over five years once an eradication plan is implemented; however, the actual costs of closing the reservoir to recreational use are much higher.
CURRENT QUAGGA AND ZEBRA MUSSEL INSPECTION PROGRAM AT LAKE SONOMA AND LAKE MENDOCINO
The existing watercraft inspection program in the Russian River Basin is managed by Sonoma Water. Current activities include inspecting watercraft at access points (boat ramps) within Lake Mendocino and Lake Sonoma, both of which are owned by the U.S. Army Corps of Engineers (USACE) and jointly operated by USACE and Sonoma Water. Watercraft requiring decontamination are currently directed to Clear Lake and Lake Berryessa, California (outside of the Russian River Basin), where decontamination equipment is available. Federal and State participation in the program provides an opportunity to further enhance the ongoing prevention program and support additional activities to prevent the spread of invasive mussels into Lake Sonoma and Lake Mendocino.
Current State Parks Division of Boating and Waterways (DBW) funding for Lake Mendocino’s Mussel Infestation Prevention Program will expire in 2026. In order to extend this funding source at Lake Mendocino, Sonoma Water applied for a $400,000 grant to extend and enhance the Lake Mendocino program through 2028. If the grant is awarded, the funds will be used to continue the existing invasive mussel prevention program at Lake Mendocino. Funds will be used to enhance watercraft inspections at Lake Mendocino, in order to reduce the number of vessels entering the lake outside of inspection hours. Community education and outreach activities also will be conducted through popular community events frequented by the boating public, and a survey will be conducted to gauge public knowledge of Mussel Infestation issues.
In 2025, Sonoma Water and the USACE executed a 5-year Project Partnership Agreement (PPA) under USACE’s cost-share Aquatic Invasive Species Program. On November 4, 2025, the Board authorized a not-to-exceed amount of $850,000 to execute consultant agreements throughout the 5-year term of the PPA. Sonoma Water is now requesting to revise the recommended not-to-exceed amount to be $2,971,294 for the 5-year term, in order to maximize funding received under the 5-year PPA with USACE through December 1, 2030. State funding will be applied to meet cost-share requirements and USACE funding will reimburse most or all of the $2,971,294 not-to exceed amount. An increase to the not-to-exceed amount is being requested because the original inspection budget was developed early in the program, when the available funding, scope of work and program requirements were still uncertain. With clearer guidance related to eligible project costs and available funds, and a well-defined five-year work plan now in place, staff have been able to refine the budget and more accurately estimate the level of effort required for necessary watercraft inspection coverage. The requested increase aligns with the work anticipated under the contract for the remainder of the PPA and will ensure sufficient funding to complete the planned scope of work.
NEXT STEPS
If the Board adopts the resolution as requested, Sonoma Water’s grant application to DBW will be able to compete for the grant funds. If the Board chooses not to adopt the resolution, the grant application will be rejected by the state funding agency.
In the event that the Lake Mendocino project is awarded DBW grant funds, Sonoma Water will follow all state laws and local policies and procedures to select a qualified consultant to perform inspections and other program related activities and execute a services agreement in a form approved by County Counsel. Grant awards are currently planned to be announced by September 2026.
Separately, if the Board authorizes the new not-to-exceed amount for consultant agreements, Sonoma Water will be able to maximize federal funding received from USACE for the inspection program. If the Board chooses not to authorize the new not-to-exceed amount for consultant agreements, Sonoma Water will be limited in the amount of federal funding it will be able to accept under the five-year PPA with USACE.
CALIFORNIA ENVIRONMENTAL QUALITY ACT
Sonoma Water’s General Manager determined that the on-going project activities are exempt under California Environmental Quality Act (CEQA) pursuant to CEQA Guidelines Section 15309, Inspections, because the activities are limited to watercraft quagga and zebra mussel inspections, inspection trainings, and education and outreach activities that help prevent the potential for infestation at Lake Mendocino. Pursuant to Public Resources Code (PRC) Section 21083, the project does not have the potential to degrade the quality of the environment, have a cumulatively considerable effect, or cause substantial adverse effects on human beings, either directly or indirectly. Pursuant to PRC Section 21084, the project would not cause a substantial adverse change in the significance of an historic resource or tribal cultural resource.
County of Sonoma Strategic Plan:
N/A
Sonoma Water Strategic Plan Alignment
This item directly supports Sonoma Water’s Strategic Plan and is aligned with the following goal, strategy, and action item.
Goal: 3. Environmental Stewardship - Protect and sustain our watersheds to maintain water resources, ecosystems, and communities.
Strategy: 3.2 Protect, enhance, and monitor natural resources, watershed conditions, and ecosystem health that are vital to the Russian River, Petaluma River, and Sonoma Creek watersheds.
Action Item: 3.2.2 Conduct fisheries, wildlife, and water quality monitoring through existing programs and use of new technologies.
Work performed under this grant agreement will support efforts to further protect the Russian River watershed from the introduction of invasive species. Protecting the watershed is critical to ensuring that the region’s water supply remains resilient for today and future generations.
Racial Equity:
Was this item identified as an opportunity to apply the Racial Equity Toolkit?
No
Prior Board Actions:
See Attachment 1
Fiscal Summary
|
Expenditures |
FY26-27 Adopted |
FY27-28 Projected |
FY28-29 Projected |
|
Budgeted Expenses |
$908,500 |
$908,500 |
$908,500 |
|
Additional Appropriation Requested |
|
|
|
|
Total Expenditures |
$908,500 |
$908,500 |
$908,500 |
|
Funding Sources |
|
|
|
|
General Fund/WA GF |
|
|
|
|
State/Federal |
$808,500 |
$808,500 |
$808,500 |
|
Fees/Other |
$100,000 |
$100,000 |
$100,000 |
|
Use of Fund Balance |
|
|
|
|
General Fund Contingencies |
|
|
|
|
Total Sources |
$908,500 |
$908,500 |
$908,500 |
Narrative Explanation of Fiscal Impacts:
Budgeted expenditures of $908,500 are available from FY2026/2027 appropriations for the Russian River Projects fund with offsetting state revenue of $200,000 from the CA Dept of Boating and Waterways and $608,500 in federal revenue from the US Army Corps of Engineers. Within this amount, $575,000 is allocated for the consultant work funded through USACE Aquatic Invasive Species Program under the existing PPA, and $333,500 is allocated for the consultant contract supporting the continuation of the Lake Mendocino Mussel Prevention Program, if awarded. For FY 2027/2028, FY2028/2029, and future years for the duration of the PPA, revenue and expense appropriations will be made in those fiscal years.
Narrative Explanation of Staffing Impacts (If Required):
N/A
Attachments:
Attachment 1: Prior Board Actions
Attachment 2: Resolution 2026 Lake Mendocino Mussel Prevention Grant
Related Items “On File” with the Clerk of the Board:
None.