Draft FY26-27_Water Transmission Summary_20260122_TAC — Cotati City Council, March 10, 2026

Sonoma Water i Draft 2/11/2026
Water Transmission FY 2026/2027 Draft Budget and Rates
Sonoma Water Background
Sonoma Water is a wholesale water supplier to nine cities and water districts that serve more than 600,000 residents in portions of Sonoma and Marin counties. The Russian River provides most of Sonoma Water’s water supply with groundwater supply from the Santa Rosa Plain as a secondary source.

Under agreements with the U.S. Army Corps of Engineers, Sonoma Water manages the water supply storage in Lake Mendocino and Lake Sonoma to provide a reliable water supply and maintain minimum instream flow requirements for fish and wildlife protection and recreation in the Russian River and Dry Creek. Sonoma Water holds water-right permits issued by the State Water Resources Control Board that authorize Sonoma Water to store up to 122,500 acre-feet per year of water in Lake Mendocino and up to 245,000 acre-feet/year of water in Lake Sonoma.

The primary points of Sonoma Water’s diversion facilities near Forestville include six radial collector wells that extract Russian River underflow that has been filtered through approximately 100 feet of natural sand and gravel. This highly efficient, natural filtration process, with chlorination treatment, produces high-quality, potable water. This water is then fed directly into Sonoma Water's aqueduct system.

The Water Transmission System extends from Sonoma Water’s Russian River diversion facilities located near Forestville to the Santa Rosa, Petaluma, and Sonoma valleys. The Water Transmission System consists of over 85 miles of pipelines, seven booster-pump stations, and 18 storage tanks with a combined storage capacity of 128.8 million gallons. The major pipelines that comprise the system and range in diameter from 16 to 54 inches are:
the Santa Rosa Aqueduct (built in 1959), the Sonoma Aqueduct (built in 1963), the Petaluma Aqueduct (built in 1962), and the Cotati Intertie (built in 1977).

Sonoma Water remains dedicated to serving our communities and securing our future through responsible resource and environmental stewardship, continued technical innovation, investment in critical infrastructure and effective fiscal management.

Recent Highlights
A few highlights of programs and projects that Sonoma Water accomplishes in collaboration with the water contractors and other partners that benefit the community are summarized below. More information can be found on Sonoma Water’s website at: https://www.sonomawater.org. • Santa Rosa Plain Water Supply Resiliency: Reactivated three Santa Rosa Plain Wells, utilizing $6.9 million in Department of Water Resources grant funding for two of the wells, and implemented Aquifer Storage and Recovery for additional water supply reliability and alleviate drought impacts to the water contractors and their customers.
• Regional Water Supply Resiliency: Sonoma Water has worked collaboratively with the water contractors to improve the region’s water supply reliability during periods of water supply shortage due to drought, seismic, and other hazard events. Using Sonoma Water's transmission system as the backbone, Sonoma Water is pursuing development of a Regional Water Bank Implementation Strategy to integrate the most significant regional water storage facilities (Lake Sonoma, groundwater basins, Lake Stafford, and Marin Water reservoirs).

Sonoma Water ii Draft 2/11/2026
• Hazard Mitigation: Sonoma Water and its water contractors have invested substantially in efforts to protect water supply infrastructure with continued emphasis on implementing high priority seismic and flood hazard mitigation projects.
• Sonoma-Marin Saving Water Partnership (SMSWP): Sonoma Water is administering a $4 million regional drought resiliency program with a $2 million United States Bureau of Reclamation grant that is being passed through to the water contractors to implement critical drought resiliency programs. • Water, Stormwater, and Energy Education Program: Sonoma Water collaborates with the SMSWP and Sonoma Clean Power to bring its education program annually to more than 16,000 local students. • Dry Creek Habitat Enhancement: Sonoma Water, the water contractors, and the U.S. Army Corps have completed 5 miles of restoration to date. The U.S. Army Corps agreement with Sonoma Water provides a 65 percent cost share to complete fishery habitat restoration work in Dry Creek. • 2025 Russian River Biological Opinion: On April 29, 2025, the National Marine Fisheries Service (NMFS) issued a second Russian River Biological Opinion to the USACE, Sonoma Water, and the Mendocino County Russian River Flood Control and Water Conservation Improvement District. The 2025 Russian River Biological Opinion has a ten-year term and covers the USACE and Sonoma Water’s operations and maintenance activities, including water supply, flood control, channel maintenance and habitat restoration in the Russian River watershed.

Sonoma Water leverages partnerships to implement programs funded from other sources that also benefit the water contractors and the community they serve:
• Quagga Mussels: Sonoma Water collaborates with the U.S. Army Corps of Engineers, the California Department of Fish and Wildlife, and the California Department of Boating and Waterways on a boat inspection strategy to prevent invasive mussel infestations in Lake Mendocino and Lake Sonoma. • Forecast Informed Reservoir Operations (FIRO): FIRO is an ongoing collaborative program with Sonoma Water, the U.S. Army Corps of Engineers, and a multi-agency steering committee that began in 2012.

FIRO is a flexible water management approach that uses data from watershed monitoring and improved weather forecasting to help water managers selectively retain or release water from reservoirs for increased resilience to droughts and floods. A significant accomplishment in 2025 was the incorporation of FIRO into updates to the water control manual for Coyote Valley Dam and Lake Mendocino. The revised manual redefines the operating rules around flood control schedules for the first time in the dam’s 66-year history by incorporating the principles of modern-day forecast-informed reservoir operations, or FIRO, to enhance the facility’s dual mission of flood risk management and water supply security.
• San Francisco Bay Advanced Quantitative Precipitation Information System (AQPI): The AQPI system provides X-Band and C-Band weather radar information that will increase the accuracy of weather forecasting and response systems throughout the Bay Area. A $20 million grant from the Department of Water Resources awarded in 2016 to Sonoma Water and its partners to install four weather radars in the Bay Area to provide improved precipitation and hydrologic information to water agencies, flood control managers, and emergency personnel. The C-Band radar installation was accomplished in late 2025. The radar data will result in improved management of water supply reservoirs, and improved operations of wastewater systems and flood protection facilities.

Challenges
Sonoma Water, our water retailers, and the industry at-large are facing very similar challenges including aging infrastructure, rising operating and maintenance costs, and water usage fluctuations resulting in lower revenues.

These challenges drive rate increases which have a financial impact on end users but are necessary to upgrade infrastructure and ensure reliable service. Similar to the water contractors, Sonoma Water has deferred maintenance and capital projects to keep water rates as low as possible while providing clean, reliable, essential water for the benefit of the water contractors and the 600,000 customers they serve every day. These challenges Sonoma Water iii Draft 2/11/2026
will continue to put pressure on rates given the significant needs of the system in the coming years as additional infrastructure investments are required.

Aging Infrastructure
Our critical infrastructure, including aqueducts, pipelines, pump stations, storage tanks, and wells are gradually aging after decades of reliable service. A significant portion of these assets are approaching the end of their useful lifespan. Preliminary assessments of the water production/transmission systems indicate that a large portion is in less than acceptable (i.e. fair, poor, or failed) condition. The age of the infrastructure and current condition of assets, combined with substantial levels of deferred maintenance, present a significant challenge for Sonoma Water in the near term. The draft FY 2026/2027 Water Transmission Budget supports Sonoma Water’s five-year strategic plan by continuing investments to upgrade critical aging infrastructure and systems that supply essential water to all the water contractors and ultimately 600,000 residents in Sonoma and Marin County.

To address this challenge, Sonoma Water has developed an Asset Management Program and is also currently preparing a 20-year Comprehensive Water Master Plan on the water production/transmission system. The assessment data collected under the Asset Management Program will be incorporated, along with recommendations of other current seismic and regional resilience planning efforts, into the 20-year Comprehensive Water Master Plan. These efforts will provide crucial information on system health and we anticipate these efforts will identify additional system needs on both the near and long-term timeframes.

Rising operating and maintenance costs
Operation and maintenance costs continue to rise due to several factors including inflation, labor costs, and increasing regulations. Economic and operational pressures include significant increases in the price of electricity, chemicals, and treatment supplies. In addition, tariffs cost increases are starting to materialize and are creating additional uncertainty in regard to future costs.

Water Usage Fluctuations/Volumetric Rate
The terms of the Restructured Agreement for Water Supply require that budgeted deliveries be the lesser of the preceding twelve months of water delivered, or the average annual amount of water delivered during the preceding 36 months. This requirement is to ensure Sonoma Water can meet its obligation to set rates at an amount that covers the projected costs for the following year. Sonoma Water must also generate sufficient revenue to cover debt obligations and maintain a debt coverage ratio as stipulated in outstanding bond issuances.

Deliveries remain low by historical standards and trends show negative or flat growth both in the near and long term. Sonoma Water’s rate is fully volumetric meaning that lower deliveries drive rates higher. Year-to-year differences in budgeted deliveries averaged over the 3-, 5-, and 10-year periods have been negative, even when including the deviation proposed and approved in FY 2024/2025 to use the higher of the delivery numbers. Yearto-year differences in actual deliveries inherently have more variability but have also shown negative growth when averaged over 5-year period. The 3-year and 10-year periods show growth, but this is skewed by the fact that both FY2015/2016 and FY2022/2023 set records as our two lowest delivery years on record, meaning the 3- year and 10-year figures have abnormally low starting points.

Difference in Year-to-Year Budgeted
Deliveries
Difference in Year-to-Year Actual
Deliveries
3-year
average
5-year
average
10-year
average
3-year
average
5-year
average
10-year
average
-2.39% -0.49% -1.46% 5.50% -3.35% 1.14%
Sonoma Water iv Draft 2/11/2026
* Increase in actual deliveries in FY20-21 was partially due to the backfilling of Stafford Lake by NMWD. In FY21-22, MMWD took excess winter instream flows. FY22-23 was an historic low at 36,032 AF.

Multiple years of drought and mandated conservation measures resulted in low water deliveries, low water sales revenue, and reduced fund balance reserves. The FY budgeted deliveries of 41,776 AF represent a 1.49% decrease (631 AF) from the FY 2025/2026 budget.
35,000
40,000
45,000
50,000
55,000
60,000
65,000
70,000
Acre-Feet
Fiscal Year
Water Deliveries - Budget to Actual
Budget Actuals Linear (Actuals)
Sonoma Water v Draft 2/11/2026
Draft Proposed Budget
This draft FY 2026/2027 Water Transmission Budget has been developed based on the prior 12-month of water deliveries of 41,776 Acre-Feet (AF) and is shown below.

The proposed rate increases are 8.21% to 8.97% for prime contractors served from the three aqueducts. See page xi which includes more details and also includes rates for Town of Windsor, NMWD, and MMWD.

Sources of revenue including water sales and charges for services, federal and state grants, existing fund balances, contributions, interest, and bond financing are detailed below:

Revenues
FY 2026/2027
Draft Budget
Increase/(Decrease)
over FY 2025/2026
Water Sales & Charges for Services $65,423,715 7.28%
Power Sales 300,000 200.00%
Operating Grants 34,871 (52.23%)
Capital Grants 0 0%
Contributions 740,370 24.67%
Interest & Investment Earnings 1,394,278 27.75%
TOTAL $67,893,234 8.04%
*Capital Grant figure only reflects new awards. Most capital grants are multi-year projects and project revenues/expenses will be rolled forward into the adjusted budget. New awards not known at budget time will be added to the adjusted budget. *Contributions include TOW diverted revenue and WUE Passthroughs.

Fund Balance FY 2026/2027
Draft Budget
Increase/(Decrease)
over FY 2025/2026
Use of Fund Balance: $ 2,097,124 (73.56%)
Bond Funds FY 2026/2027
Draft Budget
Increase/(Decrease)
over FY 2025/2026
Use of Bond Funds $ 12,510,000 (5.33%)
FY25-26 FY26-27
Budget
(in Millions)
Budget
(in Millions)
Change
(in Millions)
Operations and Maintenance $45.87 $48.75 $2.88
Capital Projects $18.28 $10.90 ($7.38)
Biological Opinion Compliance, Water
Supply Planning, Water Conservation $8.80 $10.09 $1.29
Debt Service $9.07 $8.67 ($0.41)
Totals $82.02 $78.41 ($3.62)
Grants, Use of Fund Balance, and Bond
Proceeds $21.22 $14.64 ($6.58)
Sonoma Water vi Draft 2/11/2026
Budget Requirements:
• Maintain 3-month operating reserve.
• Maintain 1.15x debt coverage bond covenant.
• Rates collect 1.15x debt service in accordance with the provisions of the Water Transmission System Master Ordinance.

Changes made since January 22, 2026 Draft Water Transmission Budget:
• Increased Power Sales from $100,000 to $300,000 as we anticipate the Warm Springs Dam Hydo Project will be operational at end of Q3. In future years this amount will reflect Power Sales for the full 12 months.
• Added revenue of $300,000 in Common Facilities for the construction of the Warm Springs Dam Hydropower Retrofit Project. Revenue source is from Power and Water Resources Pooling Authority (PRWPA) P-3 funding.
• Fixed formula error in computation of O&M rate.
• These changes reduced rate increases:
o Santa Rosa Aqueduct/Town of Windsor reduced from 8.83% to 8.21% o Petaluma Aqueduct reduced from 9.58% to 8.97%
o Sonoma Aqueduct reduced from 9.28% to 8.72%
o North Marin Water District reduced from 10.01% to 9.42% o Marin Municipal Water District reduced from 8.23% to 7.68% • Various other typographical or sum errors not affecting the rate.

Factors affecting the Rate Increase:
• 1.49% decrease in deliveries
• Multiple years with actual water deliveries below budget reducing reserves. Total budget shortfall over prior three years is 7,888 AF.
• Erosion of fund balance available to offset rate increases. • Lack of budgeted grant funding.
• 4.41% decrease in overall budget from PY.
• 6.28% increase in O&M costs.
• 40.37% decrease in Capital Project costs (Capital program funded by loans, bonds, and fund balance) • 14.66% increase in Subfund costs.
• 4.52% decrease in debt service.
• 100% of the rate increase is attributable to the O&M and subfund (Water Management, Watershed Planning and Restoration, Recycled Water and Local Supply, and Water Conservation) budget the year. • Increases in material and equipment costs for aging infrastructure and priority maintenance projects that can no longer be deferred, supply chain disruptions, long lead times on equipment, and the current inflationary environment are putting continued upward pressure on the Water Transmission System budget.

Fund Highlights:

Operations and Maintenance (O&M)
Sonoma Water vii Draft 2/11/2026
• 7.3% increase in water sales revenue due to a decrease in deliveries and the rate needed to cover budgeted expenditures.
• 7.9% increase in budgeted expenditures. Budgeted expenditure increases are attributable to cost increases for maintenance equipment, permitting costs, SCADA system contributions, utilities, staff costs (tied to negotiated labor agreements), and the Tank Recoating Program. Note that the increase in FY26/27 request for the Tank Recoat Program is partially due to cuts to its budget in prior years that reduced our rate smoothing efforts.
• O&M budget has been already been reduced by $1.7 million, or 2.9%, by deferring maintenance costs, studies, and projects. Included in this amount is a $450,000 reduction to the Tank Recoat Program. This could result in a rate spike in future years as the project’s costs cannot be deferred indefinitely. • Deferring the maintenance projects above reduced the O&M rate increase from more than 12.32% to

8.21%.
• Budgeted projects have been thoroughly reviewed and edited and represent the budgeted work that can reasonably occur in FY 2026/2027. Budgeted maintenance projects are a priority, and further delays and cuts pose detrimental operational impact and risk.
• Must have sufficient net operating revenues to meet 1.15x debt coverage bond covenant requirement.

Note that an estimated $32.96M bond issuance is occurring in FY25/26. • Water Sales Revenue Budget to actuals:
o FY 2021/2022: -$1M
o FY2022/2023: -$10.2M
o FY 2023/2024: -$1.6M
o FY 2024/2025: $2.6M
o FY 2025/2026: -$0.7M (current estimate)
• FY 2025/2026 expenditures are anticipated to align with the adjusted budget. Unspent non-routine project budget is rolled forward to subsequent budget years to avoid being included in the rate calculation more than once.

See pages 18-25 for details on major services & supplies, maintenance – equipment, and consulting/contractual services occurring in FY26/27.

Capital Projects
Capital Projects: FY 2026/2027 draft budgeted expenditures of $10.90 million decreased by $7.38 million or 40%.

The capital program is fully funded by grants, bonds, and use of fund balance. See detailed list of capital projects on page xvii.

The Capital budget has been thoroughly reviewed and represents the budgeted work that can reasonably occur in FY 2026/2027 or will need to be encumbered in FY26/27 utilizing bond funds, capital charges, and fund balance.

Hazard mitigation projects ($3.55 million) and infrastructure improvement projects/drought resiliency projects ($7.36 million) are fully funded by Water Revenue Bonds, Grants, and Fund Balance.

Construction: Hazard Mitigation Projects $1,859,215
Bennett Valley Fault Crossing 50,220
River Diversion Structure (RDS) Upgrade Project 598,625 Seismic Retrofit of Storage Tanks – Ralphine 1 13,100
Seismic Retrofit of Storage Tanks – Sonoma 1 648,360
Sonoma Water viii Draft 2/11/2026
Wilfred Booster Station 548,910
Design: Hazard Mitigation Projects $1,686,640
Seismic Retrofit of Storage Tanks - Sonoma 2 480,600
Seismic Retrofit of Storage Tanks – Ralphine 2 453,100
Seismic Retrofit of Storage Tanks – Other Tanks 752,940 Construction: Other Capital Projects $178,054
Warm Springs Dam Hydropower Retrofit 178,054
Design Other Capital Projects $7,179,471
Kawana-Ralphine SBS Pipeline 267,136
Mirabel/Wohler Storage Building 4,600,995
Water Treatment System Modernization - Shone Farm & FBS 1,273,640 Water Treatment System Modernization - Wohler Facility 1,037,700 Watershed Planning/Restoration (Biological Opinion)
• 99.81% increase in revenue due to an increase in costs associated with the 2025 Russian River Biological Opinion and the rate needed to cover budgeted expenditures coupled with a decrease in available fund balance to offset rate increases.
• $2.4 million in Use of Fund Balance reduces rate increase from 234.43% to 108.74%. • 108.74% rate increase compared to 14.14% increase in FY 2025/2026 when $3.2 million in Use of Fund Balance was budgeted.
• Expenditures are anticipated to range from $3.5 million to $5.6 million annually in this subfund. A rate of $95.41/AF at 41,776 AF generates $3.99 million in revenue. This gets us to the lower end of the anticipated expenditure estimate. There is a need to increase revenue in this fund to cover a greater portion of annual costs as we continue to utilize fund balance to keep the rate low. If more fund balance were used, there would be a significant rate spike in subsequent years to generate sufficient revenue for the subfund. The rate increase is intended to smooth future rate increases. • See pages 27-28 for list of consulting/contractual services occurring in FY26/27.

Water Conservation
• 9.05% increase in revenue due to the rate needed to cover budgeted expenditures and lower anticipated grant revenue partially offset by increased revenue from Town of Windsor diverted water charges. • 6.92% increase in expenditures.
• $160,000 in Use of Fund Balance. Reduces rate increase from 19.00% to 13.00%. o FY 2025/2026 Adopted Budget used $210,000 in Fund Balance to reduce the Water Conservation Rate Increase to 7.20%.
o Without the Use of Fund Balance in the FY 2025/2026 Adopted budget, the Water Conservation rate increase would have been 15.51%.
• See pages 30-31 for list of consulting/contractual services occurring in FY26/27.

Similar to last year, the Water Conservation Subfund budget is only inclusive of what is needed to maintain existing successful regional programs of the Partnership, including the Water Education Program, Green Business Program, Garden Sense Program, Water Loss Working Group and Validation Services, QWEL Program, EcoFriendly Garden Tour, and WaterSmart Plant Label Program.

Sonoma Water ix Draft 2/11/2026
Water Management Planning
The Water Management Planning rate is decreasing from the previous year as FY2025/2026 budget included costs for the 2025 Urban Water Management Plan (UWMP). The next UWMP will be issued in 2030. Sonoma Water attempts to smooth the cost for this 5-year report to avoid rate spikes, but rate reduction efforts in prior years resulted in the removal of the smoothing efforts. The FY2026/2027 budget request includes costs to smooth the rate for the 2030 UWMP. Sonoma Water was able to use $50,000 in Fund Balance to help reduce the FY2026/2027 rate.
• See pages 26 for list of consulting/contractual services occurring in FY2026/2027.

Recycled Water and Local Supply
Recycled Water and Local Supply costs have historically been for Sonoma Water’s share of the groundwater sustainability agency’s contributions. Sonoma Water’s share of mandatory fees has been included in the Agency Operating fund since FY 2024/2025. The is sufficient fund balance to set the rate at $0.00/AF this year and still cover depreciation which is currently the only expense.

Debt Service
Debt Service Expenditures decrease by $.41M or 4.52% as a result of debt issuance costs for the planned $32.96M in 2026 Water Revenue Bonds being captured in the Prior Year Budget. A list of capital projects that we anticipate funding with revenue bond proceeds in the 3-year required time frame is shown in the Long-Range Financial Plan.

Summary
Sonoma Water, our water retailers, and the industry at-large are facing very similar challenges including aging infrastructure, rising operating and maintenance costs, and water usage fluctuations resulting in lower revenues, forcing many wholesalers and retailers to raise rates beyond historical averages to address maintenance and capital needs. These challenges drive rate increases which have a financial impact on end users but are necessary to upgrade infrastructure and ensure reliable service. Similar to the water contractors, Sonoma Water has deferred maintenance and capital projects to keep water rates as low as possible while providing clean, reliable, essential water for the benefit of the water contractors and the 600,000 customers they serve every day.

The proposed draft budget for FY 2026/2027 is based on accomplishing the required elements of the Biological Opinion, maintenance of facilities, continued implementation of hazard mitigation and reliability projects, and projects to maintain, replace, and improve critical infrastructure. The FY budgeted deliveries of 41,776 AF represent a 1.49% decrease (631 AF) from the FY 2025/2026 budget, and the combination of low reserves, increasing operations and maintenance costs to keep pace with critical system needs, and capital projects to replace aging infrastructure, has contributed to needed rate increases.

Sonoma Water recognizes the profound impact of natural hazards, the remnants of the COVID-19 pandemic, inflationary pressures, and other economic circumstances to many residents, businesses, and our retail water contractors. In response to the far-reaching financial hardships, Sonoma Water has made a conscious effort to propose reasonable rate increases while continuing to maintain system reliability and public health and safety.

The many challenges we face will continue to put pressure on rates given the significant needs of the system in the coming years as additional infrastructure investments are required.

Significant efforts have been made to propose a responsible budget. The proposed rate increases are 8.21% to

8.97% for prime contractors served from the three aqueducts. See page xi for more details on prime contractors’ rates and the rates for Town of Windsor, NMWD, and MMWD.

Sonoma Water x Draft 2/11/2026
Sonoma Water continues to have one of the lowest wholesale water rates in the San Francisco Bay Area. The chart below compares the proposed FY26/27 rate per AF on the SR AQ to the current rates of other wholesale water agencies in the Bay Area.
* Valley Water rates for FY26/27 are not available as of 1.22.26. FY25/26 rates are used as a placeholder. *Zone 7 and Contra Costa Adjust rates on a Calendar Year. 2026 Rates are listed $-
$200
$400
$600
$800
$1,000
$1,200
$1,400
$1,600
$1,800
$2,000
$2,200
$2,400
$2,600
$2,800
Sonoma
County Water
Agency
Zone 7 Water
Agency
Contra Costa
Water District
Valley Water San Francisco
Public Utilities
Commission
Sonoma Water xi Draft 2/11/2026
Proposed rates are shown in the table below:

Charge / Aqueduct Santa Rosa Petaluma Sonoma
Deliveries (Acre-Feet) 41,776
O&M $1,106.05 $1,106.05 $1,106.05
Water Management Planning $2.63 $2.63 $2.63
Watershed Planning & Restoration $95.41 $95.41 $95.41
Recycled Water and Local Supply $0.00 $0.00 $0.00
Water Conservation $72.13 $72.13 $72.13
Total O&M $1,276.22 $1,276.22 $1,276.22
Storage & Common Bond/Loan Charges $228.65 $228.65 $228.65 Petaluma Aqueduct Bond/Loan Charge $27.55
Sonoma Aqueduct Bond/Loan Charge $166.46
Prime Contractors $1,504.87 $1,532.42 $1,671.33
Discretionary Charges
Capital Charges - to build fund balance for
future projects
$11.00 $10.00 $34.90
Total Prime Contractors $1,515.87 $1,542.42 $1,706.23
Total Overall Increase: 8.21% 8.97% 8.72%
Entity Rate per AF Rate Increase
Town of Windsor $1,515.87 8.21%
Town of Windsor (Diverted Water) $170.18 48.94%
NMWD 1,611.15 9.42%
MMWD $1,886.15 7.68%
• Deliveries: (Budget Packet Pages 9-14):

FY 2023/2024
Budget
FY 2023/2024
Actuals
FY 2024/2025
Budget
FY 2024/2025
Actuals
FY 2025/2026
Budget
FY 2026/2027
Est. Budget
12-months 3-year average 3-year average 12-months
41,847 41,317 42,826 45,184 42,407 41,776

1.3% less than
budget

5.5% more
than budget
A/F Difference (530) 2,358
FY 2025/2026 Budgeted Deliveries vs FY 2026/2027
Budgeted Deliveries

1.5% decrease
FY 2024/2025 Actuals vs FY 2025/2026 Estimated Actuals 7.5% decrease Sonoma Water xii Draft 2/11/2026
• Operations and Maintenance (O&M) – Water Transmission O&M Fund (Budget Packet Pages 15-25):
o In accordance with the Restructured Agreement for Water Supply:
 The rate is calculated by dividing operations and maintenance expenditures (less specific cash and noncash revenues and expenditures) by budgeted deliveries.

O&M Fund
Increase
(Decrease)
in Dollars
Percent
Change Description
Rate per AF $76.89 7.47%
Increase is attributable to increased infrastructure maintenance needs including higher expenditures for Tank Recoat Program due to the partial removal of rate smoothing efforts in prior years.

Revenue $4,710,000 7.68% Increase in revenue is attributable to the rate increase, interest earnings, and anticipated power sales.

Expenditures $5,358,000 7.89%
Increase is attributable to cost increases for maintenance equipment, permitting costs, SCADA system contributions, utilities, staff labor costs tied to negotiated labor agreements, and other expenditures increases described below.

Factors affecting the O&M rate:

O&M Fund
Expenditures
Increase
(Decrease)
in Dollars
Percent
Change Description
Labor $1,074,000 5.06%
Increase is attributable to an increase in labor costs for maintenance projects. Most of this increase is due to negotiated labor rates.

Power $50,000 1.04% Power demand and costs expected to increase roughly 1% from prior year budget.

Chemicals $46,000 3.81% Costs expected to remain stable after several years of large increases.

Testing/Analysis $0 0.00%
Costs expected to align with FY2025/2026 budget. Budget includes sampling and analysis tied to the Santa Rosa Plain Wells Projects as well as microplastics and Perfluoroalkyl/Polyfluoroalkyl Substances (PFAS) testing.

Contract Services $1,979,000 20.68%
Increase primarily attributable to increased budget needs tied to the Tank Recoat Program, partially offset by deferral of tank recoat rate smoothing efforts and a decrease in costs for studies.

Maintenance -
Equipment $166,000 6.22%
Increase is attributable to a general increase in routine maintenance costs and fencing repairs at water tanks and booster stations.

Rents and Leases
- Heavy Eqt $0 0.00% Costs expected to align with FY2025/2026 budget/actuals.

Sonoma Water xiii Draft 2/11/2026
O&M Fund
Expenditures
Increase
(Decrease)
in Dollars
Percent
Change Description
Equipment
Usage Charges $0 0.00% Costs expected to align with FY2025/2026 budget/actuals.

SCADA $7,200 0.28% Increase attributable to water transmission system’s share of SCADA maintenance expenses and capital project costs.

Operating
Transfers $1,961,000 8.00%
Operating Transfers (OT’s) move revenue generated by rates into respective funds (debt service funds, subfunds, aqueduct capital funds and Common Facilities) and maintain an appropriate fund balance.
• Subfunds: (Budget Packet Pages 26-34):
o Subfund rates are calculated by dividing subfund expenditures minus grant revenue by budgeted water deliveries.
o Water Management Planning:
 Expenditures are for Urban Water Management Planning (UWMP) which is required to be updated every five years and the Annual Water Supply & Demand Assessment.

Water
Management
Planning
Increase
(Decrease)
in Dollars
Percent
Change Description
Rate per AF ($1.94) -42.4%
Fiscal Year 2025/2026 rate is $4.57. Fund is for Urban Water Management Plan updates and the Annual Water Supply &
Demand Assessment. Using $50,000 in fund balance. Rate
decrease is due to reduced needs due to 5-year cycle of Urban Water Management Plan partially offset by lower use of fund balance.

Revenue ($90,000) -42.8% Decrease due to subfund rate decrease and decreased interest earnings.

Expenditures ($190,000) -54.3%
Budget decrease is tied to reduced efforts for contract service and staff time related to the Urban Water Management Plan. The next UWMP will be issued in 2030. Sonoma Water attempts to smooth the cost for this 5-year report to avoid rate spikes.

Sonoma Water xiv Draft 2/11/2026
o Watershed Planning and Restoration:
 Expenditures are for planning, design, and implementation of watershed restoration projects and projects required under the Biological Opinion.

Watershed
Planning and
Restoration
Increase
(Decrease) in
Dollars
Percent
Change Description
Rate per AF $49.71 108.7%
Fiscal Year 2025/2026 rate is $45.71. Rate increase is primarily a result of costs associated with the new Biological Opinion, including Estuary Enhancement, Eel Grass & eDNA monitoring, Dry Creek small scale restoration, Hydrologic index work, CEQA petitions, and the upper river steelhead migration study and a decrease in the use of fund balance. Rate of $152.86/AF based on $6.4M in expenditures and 41,776 AF is reduced to $95.41/AF by using $2.4M in fund balance. In Fiscal Year 2025/2026, $3.2M in fund balance was utilized to offset rate increases.

Revenue $2,157,000 99.8%
Increase due to subfund rate increase partially offset by lower interest earnings and use of fund balance to reduce and smooth overall rate increase.

Expenditures $1,248,000 24.3%
Increase is primarily a result of costs associated with the new Biological Opinion, including Estuary Enhancement, Eel Grass & eDNA monitoring, Dry Creek small scale restoration, Hydrologic index work, CEQA petitions, and the upper river steelhead migration study and a decrease in the use of fund balance.

Sonoma Water xv Draft 2/11/2026
o Recycled Water and Local Supply:
 Expenditures are for planning, design, and implementation of recycled water and local supply projects. The fund previously included water contractor projects under the Local Recycled Water Tier 2 (LRT2) Program.

Recycled Water
and Local Supply
Increase
(Decrease)
in Dollars
Percent
Change Description
Rate per AF ($0.14) -100.0% Fiscal Year 2025/2026 rate is $0.14. Dropping to $0.00 by using Fund Balance.

Revenue $2,000 29.2% Using an estimated $6,000 in fund balance. Increase in revenue is associated with anticipated interest earnings.

Expenditures $0 0.0% The only budged expenditure is $6,000 in depreciation. No change from prior year.

Water Conservation:
 Expenditures are for water use efficiency projects, outreach, and education.

Water
Conservation
Increase
(Decrease)
in Dollars
Percent
Change Description
Rate per AF $8.30 13.0%
Fiscal Year 2025/2026 rate is $63.83. Rate of $77.49/AF based on $3.2M of net expenditures and 41,776 AF is reduced to $73.66/AF by using $160,000 in fund balance. In Fiscal Year 2025/2026, net expenditures were 2.9M and $210,000 in fund balance was utilized to offset rate increases.

Revenue $298,000 9.1%
Increase due to subfund rate increase to cover budgeted expenditures and lower anticipated grant funding than prior year budget, partially offset by increased revenue from Town of Windsor diverted water charges.

Expenditures $229,000 6.9%
Increase is primarily associated with negotiated labor rates and outreach programs. Expenditures are used to implement water use efficiency, outreach and education projects, and address ongoing water conservation needs.

Sonoma Water xvi Draft 2/11/2026
• Storage, Common, and Sonoma Bond/Loan Charges: (Budget Packet Pages 41-55):
o The rates are calculated by dividing the annual debt service and reserve requirements (2015A, 2019A, 2022A, and anticipated 2026A Water Revenue Bonds) by water deliveries.

Storage and
Common
Bond/Loan
Charges
Increase
(Decrease)
in Dollars
Percent
Change Description
Storage
Bond/Loan
Charge
($4.29) -8.6%
Fiscal Year 2025/2026 rate is $50.09. Rate is based on revenue requirement for debt service divided by water deliveries. Total Debt service lower than previous year as issuance costs tied to the 2026 Bonds for capital projects in the Storage Fund were paid in FY2025/2026. Decrease partially offset by a decrease in budgeted water deliveries.

Common
Bond/Loan
Charge
($13.51) -6.9%
Fiscal Year 2025/2026 rate is $196.36. Rate is based on revenue requirement for debt service divided by water deliveries. Total Debt service lower than previous year as issuance costs tied to the 2026 Bonds for capital projects in the Common Fund were paid in FY2025/2026. Decrease partially offset by a decrease in budgeted water deliveries.

Petaluma
Aqueduct
Bond/Loan
Charge
$11.89 75.9%
Fiscal Year 2025/2026 rate is $15.66. Petaluma Aqueduct pays an additional revenue bond charge for the bonds associated with Ely BPS Flood Control and Electrical Upgrade and Wilfred Booster Station Projects. Rate is based on revenue requirement for debt service divided by water deliveries.

Sonoma
Aqueduct
Bond/Loan
Charge
$21.91 15.2%
Fiscal Year 2025/2026 rate is $144.56. Sonoma Aqueduct pays an additional revenue bond charge for the bonds associated with Sonoma Booster Station Electrical Upgrade and Pumping Reliability Project, Bennett Valley Fault Crossing Project, and other Creek Crossing Projects on the Aqueduct. Rate is based on revenue requirement for debt service divided by water deliveries. Total Debt service higher than previous year due to structure of the bond payments on existing debt.

Aqueduct Capital Charge: (Budget Packet Page 1):
o A discretionary charge is added by the water contractors to build fund balance for future aqueduct capital projects and to provide rate stabilization capacity. o The FY 2025-2026 budget included an $11 per Acre-Foot charge for the Santa Rosa Aqueduct, a $10 per Acre-Foot charge for the Petaluma Aqueduct, and a $34.90 per Acre-Foot charge for the Sonoma Aqueduct.
o The FY 2026-2027 draft budget includes a $11 per Acre-Foot charge for the Santa Rosa Aqueduct, a $10 per Acre-Foot charge for the Petaluma Aqueduct, and a $34.90 per Acre-Foot charge for the Sonoma Aqueduct pending input from the water contractors
• Overall Draft Proposed Rate Increases: (Budget Packet Pages 1-8):
o 8.21% (Santa Rosa Aqueduct); 8.97% (Petaluma Aqueduct); 8.72 % (Sonoma Aqueduct) o FY2026/2027 budgeted deliveries are based on 12-month actual water deliveries (41,776 AF).

FY2026/2027 budgeted deliveries are 1.5% less than FY 2025/2026 budgeted deliveries.

Sonoma Water xvii Draft 2/11/2026
FY 2026-2027 Capital Projects (Budget Packet Pages 35-40):

Water Transmission Budget FY26-27
Capital Projects Summary
Project Category Amount Status
Wilfred Booster Station Petaluma AQ 548,910 Equipment prepurchase and fabrication underway; construction contract awarded Dec 2025.

Bennett Valley Fault Crossing
Sonoma AQ 50,220 90% design in progress; final design and construction on hold pending possible FEMA funding.

Kawana-Ralphine SBS Pipeline
Storage 267,136
Design agreement for Ph 1 (Ralphine to SBS) approved June 2025; multi-year design effort underway.

Seismic Retrofit of Storage Tanks-Sonoma 1 Storage 648,360 Design in progress; include with Sonoma 1 recoat project scheduled to advertise March 2026.

Seismic Retrofit of Storage Tanks-Sonoma 2 Storage 480,600 Finalizing geotech report; assessing seismic design needs for larger recoat project (design to begin Spring 2026).

Seismic Retrofit of Storage Tanks-Ralphine 1 Storage 13,100 Design in progress; include with Ralphine 1 recoat project scheduled to advertise Jan 2026.

Seismic Retrofit of Storage Tanks-Ralphine 2 Storage 453,100 Finalizing geotech report; assessing seismic design needs for larger recoat project (design to begin Spring 2026).

Seismic Retrofit of Storage Tanks Design - Other Tanks Storage 752,940 Comprehensive tank program geotech; seismic design for Eldridge 2 and Kawana 1 to commence FY26/27.

Wohler Road Storage Facility
Common 4,600,995
Public Draft CEQA March 2026 with Board adoption in June 2026; advertisement anticipated December 2026.

River Diversion Structure (RDS) Upgrade Project Common 598,625 Design at 99%; anticipated to advertise Feb 2026.

Warm Springs Dam Hydropower Retrofit Common 178,054 90% design; construction advertisement expected June 2026.

Water Treatment System Modernization - Shone Farm & FBS Common 1,273,640
ROW ongoing and geotech completed; 50% design submitted in Dec 2025 with advertise target of Dec 2026.

Water Treatment System Modernization - Wohler Facility Common 1,037,700 Design agreement to be executed in FY26/27.

TOTAL 10,903,380
Santa Rosa AQ -
Petaluma AQ 548,910
Sonoma AQ 50,220
Storage 2,615,236
Common 7,689,014
10,903,380
Budget Packet Page
Rates
Prime Contractor Rates Summary 1-2
Water Charges Per Acre-Foot 3
Revenue Summary 4
Water Rates 5
O&M Rate 6
Line Item Rate Comparison 7
Russian River Projects and Conservation Charges 8
Deliveries
Deliveries (36 Mo) 9
Deliveries (12 Mo) 10
Deliveries and Revenue - All Aqueducts 11
Deliveries and Revenue - Santa Rosa Aqueduct 12
Deliveries and Revenue - Petaluma Aqueduct 13
Deliveries and Revenue - Sonoma Aqueduct 14
Agency O&M Fund
Agency Fund Cash Summary 15-17
Major Services and Supplies Expenditure Items 18
Equipment Maintenance, Contracts, Consulting Services 19-20 Contract Services & Contributions Project Information 21-25 Subfunds
Water Management Subfund 26
Watershed Planning and Restoration Subfund 27-28
Recycled Water and Local Supply Subfund 29
Water Conservation Subfund 30-31
Subfund Contract Services 32-34
Facilities and Other Funds
Santa Rosa Aqueduct Capital Fund 35
Petaluma Aqueduct Capital Fund 36
Sonoma Aqueduct Capital Fund 37
Storage Facilities Cash Summary 38
Common Facilities Cash Summary 39
North Marin Water Deposit Fund 40
Bonds and Loans
State Revolving Loan Debt Service Fund 41
State Revolving Loan Reserve Fund 42
Storage Bonds 2015 Cash Summary 43
Common Bonds 2015 Cash Summary 44
Sonoma Bonds 2015 Cash Summary 45
Common Bonds 2019 Cash Summary 46
Sonoma Bonds 2019 Cash Summary 47
Storage Bonds 2022 Cash Summary 48
Common Bonds 2022 Cash Summary 49
Sonoma Bonds 2022 Cash Summary 50
Petaluma Bonds 2026 Cash Summary 51
Storage Bonds 2026 Cash Summary 52
Common Bonds 2026 Cash Summary 53
Bond & Loan Charges 54-55
Fund Balances and Operating Transfers 56
Sonoma County Water Agency
Fiscal Year 2026/2027 Draft Water Transmission Budget and Rates Fiscal Year 2026/2027 Prime Contractor Rates Summary
Santa Rosa Petaluma Sonoma
Aqueduct Aqueduct Aqueduct FY25-26
Percent
Change
SR Pet Son
O&M Charge [4.2] $1,106.05 $1,106.05 $1,106.05 $1,029.16 $1,029.16 $1,029.16 7.47% Water Management Planning Sub-charge [4.13] 2.63 2.63 2.63 $4.57 $4.57 $4.57 -42.44% Watershed Planning/Restoration Sub-charge [4.14] 95.41 95.41 95.41 $45.71 $45.71 $45.71 108.74% Recycled Water & Local Supply Sub-charge [4.15] 0.00 0.00 0.00 $0.14 $0.14 $0.14 -100.00% Water Conservation Sub-charge [4.16] 72.13 72.13 72.13 $63.83 $63.83 $63.83 13.00% O&M Charge $1,276.22 $1,276.22 $1,276.22 $1,143.42 $1,143.42 $1,143.42 11.61% Storage and Common Bond & Loan Charges 228.65 228.65 228.65 $246.45 $246.45 $246.45 -7.22% Petaluma Aqueduct Bond Charge 27.55 $15.66 75.92%
Sonoma Aqueduct Bond Charge 166.46 $144.56 15.16%
PRIME CONTRACTORS $1,504.87 $1,532.42 $1,671.33 $1,389.86 $1,405.52 $1,534.42 8.27% Capital Charges - to build fund balance
for future projects 11.00 10.00 34.90 $11.00 $10.00 $34.90 0.00% PRIME CONTRACTORS 11.00 10.00 34.90 $11.00 $10.00 $34.90 0.00% TOTAL PRIME CONTRACTORS $1,515.87 $1,542.42 $1,706.23 $1,400.86 $1,415.52 $1,569.32 8.21% Increase from Fiscal Year 2025/2026 8.21% 8.97% 8.72% 8.68% 10.76% 7.60% With No Capital Charge 7.42% 8.26% 6.50%
Deliveries:
12-month 36-month
FY16-17 40,524
FY17-18 41,446
FY18-19 41,768
FY19-20 43,870
FY20-21 43,707
FY21-22 46,095
FY22-23 45,748
FY23-24 41,847
FY24-25 42,826
FY25-26 42,407
FY26-27 41,776
CHARGE PER ACRE FOOT:
2/11/2026
1 Fiscal Year 2026/2027 Prime Contractor Rates Summary
CHARGE PER ACRE FOOT:

Petaluma AQ

NMWD NMWD
Percent
Change
FY26-27 FY25-26
O&M Charge [4.2] $1,106.05 $1,029.16 7.47%
Water Management Planning Sub-charge [4.13] 2.63 4.57 -42.44% Watershed Planning/Restoration Sub-charge [4.14] 95.41 45.71 108.74% Recycled Water & Local Supply Sub-charge [4.15] 0.00 0.14 -100.00% Water Conservation Sub-charge [4.16] 72.13 $63.83 13.00% O&M Charge $1,276.22 $1,143.42 11.61%
North Marin Bond & Loan Charge [4.9] 160.87 148.66 8.22% Russian River Conservation Charge [4.18 (a)] 154.06 160.41 -3.96% Russian River Projects Charge [4.18 (b)] 20.00 20.00 0.00% TOTAL NMWD $1,611.15 $1,472.48 9.42%
Rates Rate Increase
Town of Windsor 1,515.87 8.21%
Town of Windsor (Diverted Water) 170.18 48.94%
NMWD 1,611.15 9.42%
MMWD 1,886.15 7.68%
2/11/2026
2 SANTA
ROSA

AQUEDUCT
% INCR.
(DECR.)

PETALUMA

AQUEDUCT
% INCR.
(DECR.)
SONOMA

AQUEDUCT
% INCR.
(DECR.)
2026 - 2027 1515.87 8.21% 1542.42 8.97% 1706.23 8.72%
2025 - 2026 1400.86 8.68% 1415.52 10.76% 1569.32 7.60%
2024 - 2025 1289.02 9.88% 1278.02 9.98% 1458.41 8.14%
2023 - 2024 1173.09 10.56% 1162.09 9.42% 1348.67 10.56% 2022 - 2023 1061.04 6.05% 1062.04 6.15% 1219.90 6.52%
2021 - 2022 1000.46 3.47% 1000.46 3.47% 1145.18 3.43%
2020 - 2021 966.95 5.30% 966.95 5.30% 1107.21 5.57%
2019 - 2020 918.30 4.60% 918.30 4.60% 1048.80 4.77%
2018 - 2019 877.88 3.67% 877.88 3.67% 1001.06 5.98%
2017 - 2018 846.78 4.98% 846.78 4.98% 944.56 5.58%
2016 - 2017 806.59 5.98% 806.59 5.98% 894.62 6.94%
2015 - 2016 761.05 4.16% 761.05 4.16% 836.55 5.46%
2014 - 2015 730.68 3.60% 730.68 3.60% 793.24 3.19%
2013 - 2014 705.30 4.95% 705.30 4.95% 768.75 3.84%
2012 - 2013 672.03 5.98% 672.03 5.98% 740.34 5.26%
2011 - 2012 634.11 5.00% 634.11 5.00% 703.33 4.28%
2010 - 2011 603.92 6.93% 603.92 6.93% 674.47 8.42%
2009 - 2010 564.78 19.88% 564.78 10.50% 622.11 27.95%
2008 - 2009 471.13 6.66% 511.13 10.71% 486.22 7.22%
2007 - 2008 441.70 2.41% 461.70 2.31% 453.49 2.46%

WATER TRANSMISSION SYSTEM
FY26-27 WATER CHARGES PER ACRE-FOOT

FOR PRIME CONTRACTORS
FISCAL
YEAR
A-2 2/11/2026
3 FY26-27 FY25-26 FY26-27
WATER CUSTOMER Budgeted Water
Use (Acre-Feet)
Rate
$/Acre-Foot
Proposed Rate
$/Acre-Foot Dollar Change Percent Change
Santa Rosa Aqueduct 16,027 $1,400.86 $1,515.87 $115.01 8.21% Petaluma Aqueduct 10,125 1,415.52 1,542.42 126.90 8.97% Sonoma Aqueduct 3,090 1,569.32 1,706.23 136.92 8.72%
North Marin Water District 4,708 1,472.48 1,611.15 138.67 9.42% Marin Municipal – Fourth
Off Peak 4,300 1,751.63 1,886.15 134.51 7.68%
Marin Municipal –
Supplemental 1,694 1,751.63 1,886.15 134.51 7.68%
Forestville Aqueduct 351 1,400.86 1,515.87 115.01 8.21% Wholesale/Municipal 902 1,883.18 2,047.48 164.30 8.72%
Surplus 59 1,372.09 1,531.46 159.37 11.62%
Windsor 521 1,400.86 1,515.87 115.01 8.21%
TOTAL 41,776

WATER TRANSMISSION SYSTEM
FY26-27 REVENUE SUMMARY CHART
2/11/2026
4 [x] ESTIMATED [ ] OFFICIAL CHARGE PER ACRE FOOT:

Santa Rosa Petaluma Sonoma
Aqueduct Aqueduct Aqueduct

PRIME CONTRACTORS
O&M Charge [4.2] $1,106.05 $1,106.05 $1,106.05
Water Management Planning Sub-charge [4.13] $2.63 $2.63 $2.63 Watershed Planning/Restoration Sub-charge [4.14] $95.41 $95.41 $95.41 Recycled Water & Local Supply Sub-charge [4.15] $0.00 $0.00 $0.00 Water Conservation Sub-charge [4.16] $72.13 $72.13 $72.13 O&M Charge $1,276.22 $1,276.22 $1,276.22
Bond & Loan Charges - to pay for existing debt service
Storage Facilities Capital Charge [4.7] 45.80 45.80 45.80 Common Facilities Capital Charge [4.8] 182.85 182.85 182.85 Petaluma Aqueduct Facilities Capital Charges [4.6 b] 27.55 Sonoma Aqueduct Facilities Capital Charges [4.6 b] 166.46 Total Bond & Loan Charges 228.65 $256.20 $395.11
Discretionary:

Aqueduct Capital Charges - to build fund balance for future projects Aqueduct Facilities Capital Charges [4.6 e] 11.00 10.00 34.90 LRT2 - included in Recycled Water & Local Supply Sub-Charge above.

TOTAL PRIME CONTRACTORS $1,515.87 $1,542.42 $1,706.23
Charge without LRT2 and voluntary AQ Capital Charge $1,504.87 $1,532.42 $1,671.33

OTHER AGENCY CUSTOMERS/WHOLESALE CHARGES
(WATER CO’S & PUBLIC AGENCIES)
O&M Charge $1,276.22 $1,276.22 $1,276.22
Capital Charges 228.65 256.20 395.11
Aqueduct Facilities Capital Charge [4.12] $542.61 $515.06 $376.15 TOTAL OTHER AGENCY CUSTOMERS/WHOLESALE CHARGES (4.12) $2,047.48 $2,047.48 $2,047.48 (120% OF HIGHEST PRIME)

FORESTVILLE
O&M Charge [4.2] * $1,106.05
Water Management Planning Sub-charge [4.13] $2.63
Watershed Planning/Restoration Sub-charge [4.14] $95.41 Recycled Water & Local Supply Sub-charge [4.15] $0.00
Water Conservation Sub-charge [4.16] $72.13
O&M Charge $1,276.22
Bond & Loan Charges - to pay for existing debt service
Aqueduct Facilities Capital Charges [4.6] 11.00
Storage Facilities Capital Charge [4.7] 45.80
Common Facilities Capital Charge [4.8] 182.85
Total Capital Charges 239.65
TOTAL FORESTVILLE $1,515.87
* Forestville Water District was exempt from Santa Rosa Aqueduct sub-charge from FY 06/07 to FY 16/17 [4.12].

NORTH MARIN WATER DISTRICT
O&M Charge $1,276.22 Note: N. Marin pays
North Marin Bond & Loan Charge [4.9] 160.87 bond and loan charge Russian River Conservation Charge [4.18 (a)] 154.06 in lieu of Capital Charge.

Russian River Projects Charge [4.18 (b)] 20.00
TOTAL NORTH MARIN WATER DISTRICT 1,611.15

FOURTH OFF-PEAK (MARIN MUNICIPAL)
Highest Prime on SR and PET AQ x 1.11 $1,712.09
Russian River Conservation Charge 154.06
Russian River Projects Charge 20.00
TOTAL FOURTH OFF-PEAK $1,886.15

SUPPLEMENTAL (MARIN MUNICIPAL)
Highest Prime on SR and PET AQ x 1.11 $1,712.09
Russian River Conservation Charge 154.06
Russian River Projects Charge 20.00
TOTAL SUPPLEMENTAL $1,886.15

SURPLUS
Non-Municipal / Municipal [4.11 (a)] $1,531.46 $1,531.46 $1,531.46 (120% of O&M Charge)
Town of Windsor $1,515.87
$1,515.87
The applicable section of the Restructured Agreement has been indicated in brackets.

Beginning in FY22/23 all water delivered to Town of Windsor is charged at the Santa Rosa Aqueduct rate [4.17 (a)]. Town of Windsor pays all subcharges [4.13, 4.14, 4.15, and 4.16] on all water they divert from the Russian River using their equipment [4.17 (b)].

SONOMA COUNTY WATER AGENCY RATES FOR WATER DELIVERIES IN FY26-27 5 FY 2026-27 BUDGET

SONOMA COUNTY WATER AGENCY
Operations and Maintenance Rate Computation

O & M REVENUE REQUIREMENT
ESTIMATED FISCAL YEAR EXPENDITURES $73,265,104
LESS:

Depreciation Amortization 8,082,000
Investment Income, Interest on Pooled Cash, Charges for Services 487,888 Power Sales 300,000
PWRPA Pre-paid Expense - FY 08/09 Rate Reduction-One time only "Mandatory Prudent Reserve" charge
Use of Fund Balance
Recycled Water funds taken from special reserve 0
Transfers Out 16,432,179
REVENUE REQUIREMENT (Net Expenditures) $47,963,037

O & M ACRE FOOT BASE
DELIVERIES: 41,776.4
LESS:

Marin Municipal 5,993.6
Surplus (Irrigation) 59.4
TOTAL BASE DELIVERIES 35,723.5
O & M RATE COMPUTATION:

Rate = Revenue Requirement - Marin Municipal Deliveries x 1.11 x 0.92568 x (Highest Prime Rate on Petaluma or Santa Rosa Aqueduct - Subfunds Rate)
Total Deliveries - Surplus Deliveries - Marin Muni Deliveries = 47,963,037 - (4,300.00 + 1,693.56) x 1409.99
41,776.4 - 59.4 - 5,993.6
* = 1,106.05
FY26-27
2/11/2026
6 FY25-26 FY26-27
(Actual) (Proposed) % Change
O&M Charge 1029.16 1106.05 7.47%
Water Management Planning Sub-Charge 4.57 2.63 -42.4%
Watershed Planning/Restoration Sub-Charge 45.71 95.41 108.74% Recycled Water Sub-Charge 0.14 0.00 -100.0%
Water Conservation Sub-Charge 63.83 72.13 13.00%
Total O&M Charge 1143.42 1276.23 11.62%
Santa Rosa Aqueduct Rate
O&M Charge 1143.41 1276.22 11.62%
Aqueduct Facilities Capital Charges [4.6 e] 11.00 11.00 0.0% Storage Facilities Capital Charge [4.7] 50.09 45.80 -8.56% Common Facilities Capital Charge [4.8] 196.36 182.85 -6.88% TOTAL 1400.86 1515.87 8.21%
Petaluma Aqueduct Rate
O&M Charge 1143.41 1276.22 11.62%
Aqueduct Facilities Capital Charges [4.6 e] 10.00 10.00 0.0% Storage Facilities Capital Charge [4.7] 50.09 45.80 -8.56% Common Facilities Capital Charge [4.8] 196.36 182.85 -6.88% Petaluma Aqueduct Facilities Capital Charges [4.6 b] 15.66 27.55 75.92% TOTAL 1415.52 1542.42 8.97%
Sonoma Aqueduct Rate
O&M Charge 1143.41 1276.22 11.62%
Aqueduct Facilities Capital Charges [4.6 e] 34.90 34.90 0.0% Storage Facilities Capital Charge [4.7] 50.09 45.80 -8.56% Common Facilities Capital Charge [4.8] 196.36 182.85 -6.88% Sonoma Aqueduct Facilities Capital Charges [4.6 b] 144.56 166.46 15.16% TOTAL 1569.32 1706.24 8.73%
FY26-27
Proposed Water Rates
2/11/2026
7 SONOMA COUNTY WATER AGENCY

RUSSIAN RIVER CONSERVATION CHARGE COMPUTATION
FISCAL YEAR 2026-27
PROPERTY ASSESSMENT VALUES AS OF FY25-26:

TAX CODE ENTITY SECURED UNSECURED TOTAL VALUE
14000 Forestville Co Water District 598,943,439 3,803,881 602,747,320 42800 City of Cotati 1,524,197,657 35,044,711 1,559,242,368 43500 City of Petaluma 13,911,178,062 532,053,317 14,443,231,379 43800 City of Rohnert Park 7,899,916,149 168,879,757 8,068,795,906 44500 City of Santa Rosa 33,561,545,162 1,083,896,031 34,645,441,193 45000 City of Sonoma 3,905,912,134 104,128,722 4,010,040,856 N/A Valley of the Moon Water District 4,965,119,994 22,802,157 4,987,922,151 TOTAL $66,366,812,597 $1,950,608,576 $68,317,421,173
Notes:
1 Total value of secured and unsecured property in service areas of Prime Water Contractors of Sonoma County (see above) $68,317,421,173 2 2016-17 Sonoma County tax rate per $100 of full cash value assessed for payment of Warm Springs Dam Project Obligations 0.007 3 Total tax levied on citizens residing in service areas of Prime Water Contractors of Sonoma County, i.e., (Line 1/100) x Line 2 $4,782,219
4 Total acre feet of water delivered to Prime Water Contractors of Sonoma County (excluding North Marin and Town of Windsor) plus deliveries to Forestville 31,041.00 during the prior 12 month period ending March 31.
5 Total Russian River Conservation Charge per Acre Foot (Line 3 / Line 4) $154.06 Russian River Projects Charge RR Conservation Charge
Historical calculations Historical calculations
For FY Calculated Actual Charge
06-07 17.02 $17.02 $48.33
07-08 21.4 $20.00 $52.70
08-09 25.08 $20.00 $58.44
09-10 24.68 $20.00 $57.70
10-11 24.4 $20.00 $74.62
11-12 23.44 $20.00 $72.27
12-13 20.38 $20.00 $72.08
13-14 14.72 $14.72 $63.30
14-15 8.72 $8.72 $63.90
15-16 12.39 $12.39 $69.38
16-17 12.96 $12.96 $78.73
17-18 13.08 $13.08 $105.78
18-19 9.13 $9.13 $109.75
19-20 8.34 $8.34 $102.09
20-21 8.68 $8.68 $106.12
21-22 10.63 $10.63 $115.94
22-23 13.92 $13.92 $115.36
23-24 15.79 $15.79 $137.33
24-25 20.37 $20.00 $159.28
25-26 26.85 $20.00 $160.41
26-27 30.21 $20.00 $154.06
2/11/2026
8 DELIVERING AQUEDUCT Monthly
Santa Rosa Petaluma Forestville Sonoma Total
36 Jan-23 1111.4 1374.6 24.5 240.3 2,750.7
35 Feb-23 976.6 1058.4 18.4 171.8 2,225.2
34 Mar-23 1055.7 946.1 19.2 147.2 2,168.1
33 Apr-23 872.7 665.8 20.7 166.8 1,726.0
32 May-23 1388.0 1896.0 30.3 328.2 3,642.6
31 Jun-23 1413.1 2301.5 31.4 348.8 4,094.8
30 Jul-23 1853.3 2813.1 42.0 456.0 5,164.4
29 Aug-23 1832.4 2669.5 42.4 452.9 4,997.1
28 Sep-23 1552.3 2229.6 34.3 427.0 4,243.2
27 Oct-23 1600.8 2423.0 33.1 410.8 4,467.7
26 Nov-23 1201.5 1505.0 25.3 225.0 2,956.7
25 Dec-23 1039.9 1196.3 19.2 152.3 2,407.7
24 Jan-24 1173.5 1254.9 22.6 212.5 2,663.4
23 Feb-24 1024.7 975.2 18.9 127.5 2,146.4
22 Mar-24 980.2 936.0 17.6 110.9 2,044.8
21 Apr-24 1091.5 1320.5 24.3 177.1 2,613.3
20 May-24 1395.6 1587.3 28.8 315.9 3,327.6
19 Jun-24 1613.2 2179.8 37.4 454.2 4,284.6
18 Jul-24 2216.4 3252.1 52.3 574.4 6,095.3
17 Aug-24 1855.3 2751.7 41.3 400.2 5,048.5
16 Sep-24 1964.3 2830.7 45.1 427.5 5,267.6
15 Oct-24 1685.8 2692.0 38.3 411.4 4,827.5
14 Nov-24 1033.3 1769.2 21.6 290.7 3,114.7
13 Dec-24 1168.1 1623.6 22.9 281.7 3,096.4
12 Jan-25 1112.0 1142.8 20.5 237.2 2,512.5
11 Feb-25 928.7 910.8 19.2 174.3 2,033.0
10 Mar-25 1014.2 897.8 19.1 157.2 2,088.2
9 Apr-25 1259.8 1324.7 24.9 225.4 2,834.8
8 May-25 1465.2 1662.9 29.2 271.4 3,428.7
7 Jun-25 1842.5 2626.5 40.0 328.1 4,837.1
6 Jul-25 1887.6 2630.9 42.7 400.7 4,961.9
5 Aug-25 1785.6 2443.0 40.0 363.2 4,631.8
4 Sep-25 1902.9 2835.3 44.0 335.9 5,118.0
3 Oct-25 1258.3 1941.8 27.3 223.5 3,450.9
2 Nov-25 876.5 1522.5 20.1 158.2 2,577.3
1 Dec-25 1273.4 1789.8 24.3 214.9 3,302.4
Total Deliveries 49,706.0 65,980.6 1,063.4 10,401.1 127,151.1 3-Year Annual Average 16,568.7 21,993.5 354.5 3,467.0 42,383.7 Past 12 Months 16,606.5 21,728.8 351.3 3,089.9 41,776.4 Total Deliveries 49,706.0 65,980.6 1,063.4 10,401.1 127,151.1 Less: North Marin 15,475.6 15,475.6
Marin Municipal 18,659.5 18,659.5
Sonoma Co. Deliveries 49,706.0 31,845.5 1,063.4 10,401.1 93,016.1 3-Year Annual Average 16,568.7 10,615.2 354.5 3,467.0 31,005.4

SCHEDULE OF WATER DELIVERIES BY AQUEDUCT
PAST 36 MONTHS / 12 MONTHS AVERAGE
2/11/2026
9 SONOMA COUNTY WATER AGENCY SONOMA COUNTY WATER AGENCY SCHEDULE OF ACTUAL PRIOR 12 MONTHS WATER DELIVERIES IN ACRE FEET (BY CUSTOMER TYPE) ACTUAL WATER DELIVERY DISTRIBUTION BY AQUEDUCT (ACRE FEET) JANUARY THROUGH DECEMBER PRIOR 12 MONTHS
Aqueduct * * * * DELIVERING AQUEDUCT * * * *
No. Jan-25 Feb-25 Mar-25 Apr-25 May-25 Jun-25 Jul-25 Aug-25 Sep-25 Oct-25 Nov-25 Dec-25 TOTAL Santa Rosa Petaluma Sonoma TOTAL PRIMES DELIVERED TO:
1 City of Santa Rosa 1,063.2 885.0 964.8 1,192.5 1,402.4 1,756.2 1,798.9 1,688.3 1,817.9 1,198.8 839.1 1,238.8 15,846.0 2 City of Petaluma 453.8 397.4 415.2 575.3 719.3 840.6 807.9 751.4 838.3 597.9 493.4 532.1 7,422.6 CITY OF SANTA ROSA (A) 2 North Marin Water Dist. 413.1 287.5 244.9 400.7 330.6 509.5 474.5 457.2 537.3 328.0 283.6 441.0 4,707.9 Jan 2025 966.8 0.0 96.5 1,063.2 2 City of Rohnert Park 189.4 158.7 170.5 269.0 237.3 264.3 266.6 264.9 323.1 221.9 204.4 344.3 2,914.4 Feb 2025 799.6 0.0 85.4 885.0 2 City of Cotati 29.5 30.3 30.1 42.2 49.0 63.7 62.7 59.9 56.9 34.5 21.5 29.3 509.7 Mar 2025 816.5 0.0 148.3 964.8 1 Town of Windsor 32.6 38.7 48.0 63.9 36.1 36.7 49.2 57.5 50.2 42.8 32.2 32.6 520.5 Apr 2025 960.5 0.0 232.0 1,192.5 4 City of Sonoma 97.3 85.9 89.8 141.9 183.5 226.3 224.8 212.0 205.0 120.3 81.5 116.0 1,784.4 May 2025 1,107.3 0.0 295.2 1,402.4 4 Valley of the Moon Dist. 131.1 80.7 60.0 72.1 64.9 82.7 154.1 132.5 107.4 89.6 62.0 79.0 1,116.0 Jun 2025 1,377.1 0.0 379.1 1,756.2 TOTAL PRIMES 2,410.0 1,964.2 2,023.3 2,757.7 3,023.1 3,780.0 3,838.8 3,623.8 3,935.9 2,633.6 2,017.7 2,813.3 34,821.4 Jul 2025 1,405.5 0.0 393.5 1,798.9 Aug 2025 1,319.1 0.0 369.1 1,688.3
OTHER AGENCY CUSTOMERS Sep 2025 1,433.7 0.0 384.1 1,817.9 1 Cal-American Water 15.2 4.1 0.6 2.2 25.4 46.3 34.4 34.5 31.2 13.2 4.3 0.9 212.4 Oct 2025 939.1 0.0 259.7 1,198.8 2 Penngrove Water Co 11.0 9.3 9.5 12.9 16.7 21.6 21.8 19.5 21.0 13.9 10.1 13.3 180.7 Nov 2025 671.6 0.0 167.5 839.1 4 Lawndale Mutual 1.8 1.4 1.7 3.0 4.5 6.2 8.2 6.1 7.5 3.7 2.1 1.8 47.9 Dec 2025 1,024.1 0.0 214.7 1,238.8 4 Kenwood Village Water Co 0.6 0.5 0.6 0.7 0.6 0.7 0.7 0.7 0.8 0.8 0.6 0.8 8.1 TOTAL SANTA ROSA 12,820.9 0.0 3,025.1 15,846.0 3 Forestville Co Water Dist. 20.5 19.2 19.1 24.9 29.2 40.0 42.7 40.0 44.0 27.3 20.1 24.3 351.3 1 Other Gov-Santa Rosa Aq 0.8 0.7 0.8 0.9 0.9 1.0 1.0 0.9 1.1 0.9 0.8 1.1 11.0 OTHER PRIME CONTRACTORS (B) 2 Other Gov-Petaluma Aq 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 CITY OF PETALUMA 0.0 7,422.6 7,422.6 4 Other Gov-Sonoma Aq 4.9 4.4 3.8 4.9 6.1 7.1 7.5 7.8 10.3 7.7 10.8 15.4 90.7 NORTH MARIN WATER DISTRICT 4,707.9 4,707.9 TOTAL OTHER AGY. CUST 54.7 39.7 36.0 49.6 83.5 122.9 116.3 109.5 115.9 67.6 48.8 57.5 902.1 CITY OF ROHNERT PARK 95.3 2,819.1 2,914.4 CITY OF COTATI 4.7 504.9 509.7
OFF-PEAK CUSTOMERS TOWN OF WINDSOR 520.5 520.5
2 Marin Municipal 46.0 27.6 27.6 24.6 310.0 926.8 997.4 890.0 1,058.8 745.7 509.4 429.6 5,993.5 CITY OF SONOMA 1,784.4 1,784.4 VALLEY OF THE MOON DISTRICT 1,116.0 1,116.0
SURPLUS CUSTOMERS TOTAL OTHER PRIME CONTRACTORS 620.6 15,454.5 2,900.3 18,975.4 1 Irrigation-Santa Rosa Aq 0.2 0.1 0.0 0.2 0.3 2.2 4.0 4.3 2.5 2.5 0.1 0.0 16.6 2 Irrigation-Petaluma Aq 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 TOTAL DELIVERIES TO PRIMES 13,441.5 15,454.5 5,925.4 34,821.4 4 Irrigation-Sonoma Aq 1.6 1.3 1.3 2.8 11.8 5.1 5.4 4.2 4.8 1.4 1.2 1.9 42.8 TOTAL SURPLUS CUST. 1.7 1.5 1.3 3.0 12.1 7.3 9.4 8.5 7.3 4.0 1.3 1.9 59.4 LESS: NORTH MARIN (4,707.9) (4,707.9) TOTAL DELIVERIES 2,512.5 2,033.0 2,088.2 2,834.8 3,428.7 4,837.1 4,961.9 4,631.8 5,118.0 3,450.9 2,577.3 3,302.4 41,776.4 TOTAL SONOMA COUNTY DELIVERIES 13,441.5 10,746.6 5,925.4 30,113.5 2/11/2026
10 FY 2026-27 BUDGET
Water Transmission System Agency Fund
ESTIMATED WATER DELIVERIES AND WATER SALES - O&M plus Surcharges

ESTIMATED