Benefit Assessment
Investing in Community Safety
Benefit Assessment Vote for Flood Control Funding
In spring 2025, property owners in Zones 2, 4, and 9 had the chance to vote on a benefit assessment increase to enable the District to make critical repairs and upgrades. The results of the ballot process are now final: a majority protest was received against the proposed benefit assessment increases in all three zones. As a result, assessment levels, unchanged since 1993, will remain the same for the upcoming fiscal years.
It’s important to emphasize: flood control is not limited to low-lying zones. Stormwater runoff and outdated drainage systems affect everyone, from those in flood-prone areas to residents living on higher ground who use the roads, schools, and stores that are downhill. Protecting our community means recognizing that we are all interconnected when it comes to stormwater management and safety.
Many of the flood control channels in Alameda County do not have enough capacity to carry stormwater from large storms. Most of the floodwalls, pump stations, and other infrastructure is 60 or more years old. It is nearing the end of its service life, leaving people and properties at risk of flooding. The District will continue to pursue state and federal grant opportunities, but funding is limited and grants often require local matching funds that we may not be able to provide.
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Flood Risks in Alameda County
Many homes, schools, roads, and businesses in Alameda County are in a natural flood plain susceptible to flooding. Use FEMA’s flood map tool to learn more about your flood risk.
The critical projects included in the benefit assessment will reduce flood risk. Over time, property owner’s investment in the benefit assessment may lead to savings through reduced maintenance costs, lower or no flood insurance premiums, and fewer expenses for flood-related repairs. However, without an approved increase, projects in the Capitol Improvement Program (CIP) may be delayed, scaled back, or cancelled entirely. Limited resources may need to be redirected to emergency repairs or the most critical safety concerns, leaving routine maintenance and system upgrades unfunded.
Critical Projects Funded by the Benefit Assessment
The Engineer’s Report is a formal required document for each zone and describes the benefit assessment and projects to be funded. The Engineer’s Reports were accepted by the Alameda County Board of Supervisors on April 22, 2025. View them on the page for each zone below.
What is a Benefit Assessment?
Throughout California, benefit assessments are an important source of funding for flood control projects. The existing benefit assessment that property owners pay in Zones 2, 4, and 9 has not increased for over 30 years.
The benefit assessment amount is based on the actual flood protection benefit property owners receive from the projects included in the Engineer’s Report and their contribution to the stormwater system (impervious surface).
Property owners currently pay a flood control related benefit assessment. If the proposed benefit assessment increase is approved, it will replace the existing benefit assessment.
The benefit assessment amount is based on the stormwater and flood protection benefit each property receives from the management of stormwater and the proposed projects. Each property will pay a different amount, based on the amount of runoff each property contributes to the system, estimated from several factors:
Parcel size – Larger properties will typically pay more than smaller properties.
Type of land use – Land use is used to estimate the amount of stormwater expected to run off from the land. Properties with more impervious surface, such as parking lots, industrial facilities, and so forth, will pay more than agricultural or open space properties. This is because more stormwater runs off the impervious surface into creeks.
Location either within or outside of a mapped floodplain – Properties located within a mapped floodplain will pay more than those that are not in a floodplain because they will receive a greater benefit from the flood control projects.
A property owner’s exact proposed assessment amount will be included on their notice and ballot. The benefit assessment may increase every year proportional to the Consumer Price Index (CPI) for this area to accommodate the increase in cost of labor and materials (typically 2% – 7% annually).
Residential property owners in Zones 2, 4, and 9 currently pay approximately $25 each year, an amount that has not increased in 30 years.
In spring 2025, property owners will receive a notice and ballot by mail. The notice will include information on the proposed new benefit assessment and the amount for that property. Property owners will have 45 days to return their ballot to indicate whether they approve or disapprove of the proposed new assessment.
The Alameda County Board of Supervisors will then hold a public hearing on the assessment during one of its regular meetings. Ballots will be tabulated after the close of the hearing.
All mailed in ballots must be received no later than 5:00 PM on June 16, 2025. Personally delivered ballots must be received by the Clerk of the Board before the close of the public hearing which is scheduled to begin on June 17, 2025 at 9:30 AM, at 1221 Oak Street, Room 512, 5th Floor, Oakland, California, 94612.
Votes are weighted based on the amount of each property owner’s benefit assessment. For example, if homeowner Jones is assessed twice as much as homeowner Smith, Jones’s vote will carry twice the weight of Smith’s vote. If a majority of the weighted votes are in favor of the assessment, the Board of Supervisors will have the authority to approve the new assessment at a future meeting.
This process is in alignment with the requirements of Proposition 218, which regulates local government finance.
Winter Storm Damage in 2023
Explore the pictures below to view just a few areas that were damaged from the December 2022 / January 2023 winter storms. The District is seeking additional funding to protect these and other critical areas during future storms.
Frequently Asked Questions
Flooding in Alameda County
In February 1997 and again in January 2023, we came close to a major flooding disaster within the San Lorenzo Creek watershed. We are facing two challenges at the same time. On one hand, the flood control infrastructure that has protected this area for over 70 years has reached the end of its effective life span, and on the other hand, climate change is introducing more frequent extreme events.
The January 2023 storms alone caused $67 million in damage to Alameda County’s public infrastructure. The District does not have enough funding to continue addressing these ongoing funding challenges. We are at a critical juncture in our flood protection history: restore and upgrade the old infrastructure or face major flooding disasters.
Much of District Zones 2, 4, and 9 are in what is called a “100-year floodplain,” which means there is a 1% chance of a flood occurring each year. Many years can pass with no flooding, however, over time, the chance of flooding increases. Think of it like rolling a 100-sided die – you might not roll a ‘1’ today or tomorrow, but eventually, it’s likely to happen.
Even if your property is not in the official flood zone, your property is not necessarily safe, and local businesses, schools, and roads are all at risk. Severe storm events due to climate change are unpredictable, which could overwhelm the design capacity of the flood control system in accordance with current FEMA design criteria. The projects proposed by the District will substantially reduce or eliminate the risk of flooding. Use FEMA’s flood map tool to learn more about your flood risk.
Benefit Assessments
Benefit assessments are a common and important source of funding for flood control infrastructure. The idea is that property owners pay for the actual benefit that they receive from the management of stormwater and flood control projects. Benefit assessments ensure that funds stay local and are used for a vetted list of priority projects.
With a benefit assessment, only parcel owners who benefit from the planned projects pay. The amount of the assessment is directly related to the amount of benefit their property receives.
In contrast, a tax is a mandatory charge paid by individuals, businesses, and parcel owners for government services that broadly benefit the public.
Much of the flood control infrastructure is more than 70 years old and overdue for repairs and upgrades. The District has not raised the benefit assessment in this area for over 30 years, but maintenance costs have risen substantially. Climate change has increased the frequency and intensity of storms and there is not enough funding to address these challenges.
Replacing the existing benefit assessment with a new, increased assessment amount will fund a prioritized list of critical projects in Zones 2, 4, and 9 that will directly benefit property owners in the area. The increased benefit assessment would also contribute to maintenance and operation costs within each zone and ensure the District has healthy savings in case of emergency.
Property owners in Zones 2, 4, and 9 currently pay a benefit assessment for flood control services. Typical residential property owners currently pay around $25 each year. If approved, the new benefit assessment will replace the existing assessment for flood control paid by property owners in the area.
A notice and ballot will be mailed to property owners. The votes will be weighted based on the amount of each property’s benefit assessment. If 50% or more of the votes approve, the Board of Supervisors can then approve the new benefit assessment.
The District has a duty under District Act 205 to protect people and property from flooding. Without increased funding, the District will only be able to do the bare minimum to maintain system functionality using the limited funding sources currently available.
Proposed Projects
Yes. All funding from the benefit assessment will be allocated in the area it is collected from and can only be used for a carefully selected list of critical projects in that area. For instance, funds collected from Zone 2 can only be used in Zone 2 for approved projects.
As mandated by District Act 205, Alameda County Flood Control District’s primary purpose is to reduce the risk of flooding and protect people and property from the adverse effects of flooding.
Through careful hydrologic and engineering analysis, the District created a list of projects that will protect people and properties from flooding. These projects will repair and upgrade critical infrastructure, such as channel walls, levees, and pump stations to protect properties and people from flooding. They were prioritized in the following ways:
- Projects that will have the highest benefit for the lowest cost to people and property.
- Location to ensure maximum flood protection throughout each neighborhood zone.
- Projects that offer environmental benefits, such as improved habitat for fish.
The proposed new benefit assessment will not be adequate to implement all projects. Therefore, the District has identified certain projects as “critical” to develop a short list of projects that can be funded. If additional revenue is identified – through grants, for example – additional projects could be included.
Yes. Climate change is making storms more intense and frequent, so there is an urgent need to replace and upgrade our aging floodwater infrastructure. If constructed, the projects will incorporate future changes such as sea level rise and climate change into their design.