BOARD AGENDA MEMORANDUM
Government Code § 84308 Applies: Yes ☐ No ☒
(If “YES” Complete Attachment A - Gov. Code § 84308)
SUBJECT: Title
Receive the Winter Preparedness Briefing.
End
RECOMMENDATION: Recommendation
Receive information on the Santa Clara Valley Water District’s preparedness for winter operations.
Body
SUMMARY:
Santa Clara Valley Water District (Valley Water) provides local flood protection on district-owned property. Valley Water staff work diligently to protect Santa Clara County residents and businesses from the devastating effects of flooding within our authority. This report provides information regarding various measures Valley Water has taken to prepare for the Winter season. Specifically, it includes information on the following:
• Weather Forecast
• Board Natural Flood Protection Ends Policies
• Flood Awareness Campaign and Community Outreach, including to known Hot Spots
• Emergency Action Planning
• Monitoring and Flood Forecasting
• Reservoir Management
• Real-time Information, Alerts and Warnings
• Valley Water, Countywide and Regional Emergency Management Systems
• Valley Water Field Response Actions and Capabilities
• Storm Ready Recognition with National Weather Service
Background
Winter Hazards
Winter brings an additional set of seasonal hazards that threaten both watersheds and water utility operations. Severe and/or extended precipitation can overwhelm engineered and natural channels and has the potential to damage Valley Water's flood protection infrastructure. The resulting flooding can prompt municipalities to initiate evacuations and sheltering and disrupt transportation. Severe storms can also bring high winds and cause land movement that have the potential to impact power, communication, water, and wastewater utility infrastructure.
Weather Forecast
National Weather Service (NWS) seasonal weather models predict a greater than 90% chance of El Niño during the Northern Hemisphere fall/winter 2026-27. El Niño results in warmer equatorial sea-surface temperatures that bring wetter weather to the southwest quadrant of the United States. While the El Niño seasonal forecast is certain, levels of precipitation impacting Valley Water’s service area are uncertain and will need to be watched closely. Total seasonal precipitation remains an open question.
Medium range forecast capabilities will help to distinguish storm events with as much lead time as 10-14 days, though the details may not be worked out until within a few days of any given event. Keep in mind that a season with below-normal rainfall can still produce flooding, especially if much of the rainfall occurs over a short period of time.
Near-term weather forecasts enable Valley Water to anticipate the location and intensity of rainfall to better mobilize response efforts. Valley Water receives weather forecasts from multiple sources, including meteorology consultants and the NWS. Using this data, Valley Water staff make decisions for flood response and reservoir operations.
Board Natural Flood Protection Ends Policies
Valley Water’s Board of Directors has established Natural Flood Protection (NFP) Goals 3.1, 3.2, and 3.3 to provide flood mitigation within Valley Water’s authority that benefits residents, businesses, and visitors; and to reduce the potential for flood damages. These NFP Goals establish the following nine objectives:
1. Prioritize maintenance of existing facilities over construction of new capital projects (Objective 3.1.1)
2. Inspect and maintain facilities on a regular basis (Objective 3.1.2)
3. Perform maintenance using maintenance guidelines updated on a regular basis (Objective 3.1.3)
4. Develop, maintain, and communicate emergency action plans (Objective 3.2.1)
5. Develop, maintain, and communicate flood information to the community (Objective 3.2.2)
6. Provide expertise in flood forecasting and flood warning systems to municipalities (Objective 3.2.3)
7. Provide expertise to encourage public agencies to reduce flood risk and protect floodplain benefits (Objective 3.2.4)
8. Provide equitable, timely, and achievable flood protection for health and safety (Objective 3.3.1)
9. Protect people and property from flooding by applying a comprehensive, integrated watershed management approach that balances environmental quality, sustainability, and cost (Objective 3.3.2)
This memorandum describes how Valley Water staff is working to achieve each of these objectives.
1. Protect Parcels from Flooding (3.3.1 and 3.3.2)
Valley Water’s Watersheds Design and Construction Division plans, manages and implements capital improvements to comply with the Board’s Ends Policy to mitigate flooding. A total of 13 flood mitigation projects are underway in Fiscal Year 2026-2027 with a total FY27 budget of $169.1 million. This amount total is comprised of the Watershed Stream Stewardship Fund and the Safe, Clean Water and Natural Flood Protection Fund. Eight of these projects are Safe, Clean Water projects, and five are funded by property taxes. All have the primary objective of providing natural flood mitigation for residents, businesses, and visitors.
2. Preserve Flood Conveyance Capacity (3.1.1, 3.1.2 and 3.1.3)
Valley Water’s Watersheds Operations and Maintenance Division (Watersheds O&M) performs sediment removal, levee inspection and maintenance, debris removal, vegetation management, and erosion protection and repairs on Valley Water property to comply with the Board’s Ends Policy to preserve flood conveyance capacity. Watersheds O&M work that has been accomplished in 2026 through Valley Water’s Stream Maintenance Program includes the following.
• Removal of approximately 20,200 cubic yards of sediment (estimated)*
• Stabilization of approximately 1,830 linear feet of riverbank (estimated)*
• Completion of 1,146 acres of in-stream vegetation control over 139 miles of streams*
*Work continues. Quantities estimated through September 30, 2026.
Valley Water staff continues to respond to calls from throughout the county regarding vegetation concerns. Field crews continue to monitor Valley Water creek conditions to selectively reposition or remove fallen trees that could potentially block flows in local creeks or cause other hazards.
3. Integrated Watershed Management to preserve floodplain functions (3.3.2)
Valley Water preserves floodplain functionality and other watershed assets and interests from external land-use activities by reviewing and commenting on development proposals for consistency with the Guidelines and Standards for Land Use Near Streams, and by participating in the review of municipal General Plan updates.
Valley Water’s Community Projects Review Unit issues encroachment permits that regulate the third-party use or modification of Valley Water lands along local waterways and provides ordinance enforcement consistent with the Board adopted encroachment remediation program and Board governance policies. Additionally, Valley Water reviews and comments on environmental documents and plans for projects outside Valley Water right-of-way to promote Valley Water’s water resource interests. Through these processes, Valley Water advocates for development setbacks and site layouts that strive to maximize protection of stream and riparian corridors and floodplain function.
4. Reduce flood risks through engagement with other agencies and the public (3.2.4)
Flood Awareness Campaign and Community Outreach
A strong El Niño this winter may bring heavy, prolonged rainfall, increasing the risk of flooding along streets, low-lying areas, and local waterways. Valley Water tracks conditions year-round and maintains flood protection infrastructure, but intense storms can stress even well-maintained systems. When creeks or reservoirs overflow, timely action is critical. While Valley Water takes on these efforts as a good neighbor to the community, the party responsible for conditions and mitigation on any property is the property owner.
Valley Water’s 2026-2027 multilingual flood preparedness campaign launched on October 15, 2026, and will continue through the rainy season. This year’s slogan “El Niño can bring big problems. Be Flood Ready” reinforces community awareness of elevated El Niño-related flood risks and encourages personal preparedness.
Campaign outreach focuses on three property groups:
• FEMA SFHA: ~45,000 homes and businesses in FEMA’s Special Flood Hazard Area
• Hot Spots: ~17,000 homes and businesses located in historically flood-prone areas
• Creekside Properties: ~90,000 parcels adjacent to creeks
Valley Water website, newsletter, and social media channels
Valley Water’s flood preparedness hub, valleywater.org/floodready, provides emergency registration instructions, safety tips, sandbag site information, and real-time stream and reservoir gauge data. The site prominently features the Flood Watch Tool.
Flood awareness content is shared via Valley Water’s news blog, social media channels, and monthly newsletter. We also post a Nextdoor message from each Board Director with flood preparedness messages.
Flood Awareness media/digital campaign
The annual advertising campaign launched October 15, 2026, and runs through February 2027. Geotargeted audio, digital, and social media ads reach devices associated with addresses in FEMA SFHA and Hot Spot areas.
Multilingual flood preparedness messaging appears in community newspapers across Santa Clara County. Billboards and creek banners will be placed in flood-prone neighborhoods starting in October.
Direct mail to homes and businesses in flood-prone areas
October 2026
Postcard: A multilingual flood-readiness postcard sent to 45,000 FEMA SFHA properties encouraging flood risk awareness, insurance information, emergency planning, alert sign-ups, and safe driving behavior during flooding.
Door hanger: Flood safety tips delivered to ~17,000 homes in Hot Spots.
Creekside mailer: Guidance for creekside landowners on maintaining private creek segments.
November 2026
Floodplain mailer: A multilingual mailer with nine preparedness messages, local floodplain manager contacts, and a QR code to valleywater.org/floodready, sent to 45,000 FEMA SFHA properties. This year’s version includes a step-by-step guide to proper sandbag use.
December 2026
Trifold: A multilingual brochure on what to do before, during, and after a flood, distributed at peak storm season to 45,000 FEMA SFHA properties.
Outdoor advertising
Billboards, creek banners, and other outdoor alerts will be displayed in high-risk areas throughout the rainy season.
Community outreach, multi-agency news conference, and Winter Preparedness Workshop
Valley Water will host a multi-agency press conference highlighting coordinated flood preparedness efforts. The event will showcase Valley Water’s primary sandbag distribution center and include an interactive sandbag demonstration.
Staff will present campaign details at the Valley Water Winter Preparedness Workshop for external agencies. A partner toolkit has been distributed to retailers, Public Information Officers, Community Rating System partners, community associations, and elected officials. Additional flyers and a social media toolkit were mailed to community associations in flood-prone areas.
Event outreach
Beginning in October, the Office of Government Relations resumed sharing flood-preparedness materials at local community events across Santa Clara County.
Education outreach
Flood awareness education includes winter-season messaging and virtual or in-person visits to schools, libraries, and youth organizations.
Emergency alerts
Valley Water continues encouraging residents to sign up for Santa Clara County’s official emergency notification system, AlertSCC. This free, confidential service delivers real-time emergency warnings by text, email, mobile device, or landline. Since AlertSCC requires residents to opt in, outreach emphasizes its importance for receiving flood hazard updates and evacuation instructions. Residents are also encouraged to download the American Red Cross Emergency App.
5. Prepare and Respond Effectively to Flood Emergencies (3.2.1, 3.2.2 and 3.2.3)
Despite all the proactive efforts to remove parcels from flood hazard zones, maintain channel conveyance capacities and floodplain function, and engage the public with flood awareness and safety messages, floods still can and do occur.
Flood emergency preparedness entails the combined efforts of many units at Valley Water, notably the Office of Emergency Services, Watersheds Operations and Maintenance, Raw Water Operations, Water Supply Operations and Planning, Hydrology, Hydraulics and Geomorphology, Communications, Government Relations, and the Clerk of the Board, among others. Valley Water staff perform field emergency response and recovery activities, while others fulfill positions in the Departmental Operation Centers (DOCs) and Emergency Operations Center (EOC). Other staff are key to the preparedness planning for flood emergencies.
To ensure the best possible state of readiness to address flooding when it does occur, Valley Water maintains tools, processes, trained staff, and interagency relationships that enable coordinated field response and public information.
Emergency Action Planning
Emergency Action Plans (EAPs) are documents that identify potential emergency conditions at facilities, such as creeks or dams, and specify actions to minimize loss of life and property damage. These documents include the following:
• Actions, in coordination with emergency management authorities, to respond to incidents or emergencies
• Warning and notification messages for responsible downstream emergency management authorities
• Inundation maps to help emergency management authorities identify critical infrastructure and population-at-risk sites
• Roles and responsibilities between responding agencies
The EAPs for dams are created following the Federal Emergency Management Agency guidelines for emergency action planning (FEMA Publication No. P-64). The Anderson Dam EAP also incorporates the guidance of the Federal Energy Regulatory Commission (Chapter 6 Emergency Action Plans of the Engineering Guidelines for the Evaluation of Hydropower Projects), due to Anderson’s small hydropower facility.
The EAPs for creeks have been developed in coordination with the affected jurisdictions where flooding may occur. The Joint EAP with the City of San Jose includes Coyote Creek, Guadalupe River, Ross Creek, Canoas Creek, Lower Silver Creek, and Lake Cunningham. Staff recently updated the Joint EAP to incorporate new flood mitigation measures completed as part of the Anderson Dam Seismic Retrofit Project as well as expand its coverage to include Berryessa Creek. This update has been signed by the Valley Water CEO and the San José City Manager.
Berryessa Creek is also included in a Lower Penitencia Creek Watershed EAP that was developed in coordination with the City of Milpitas and covers both Berryessa Creek and Lower Penitencia Creek.
Existing EAPs for West Little Llagas Creek and Uvas Creek has been updated and incorporated into a new Upper Pajaro River Watershed EAP along with Llagas Creek.
The EAP for West Valley Watershed was originally developed in coordination with the City of Santa Clara and includes a response procedure for San Tomas Aquino Creek.
The Lower Peninsula Watershed EAP that includes San Francisquito Creek, the Palo Alto Flood Basin and the Permanente & Hale Creeks was updated and now includes Stevens Creek.
In addition, Valley Water staff have developed EAP Quick Guides for all existing EAPs. These concise reference documents are updated alongside the EAPs and provide Emergency Operations Center staff with rapid access to key response information. All public versions of the final documents are available for access to the public and other agencies on the Valley Water website.
Monitoring and Flood Forecasting
Valley Water evaluates forecasts of incoming weather systems based on weather reports received from multiple partners, including the National Weather Service (NWS), paid weather consultants, and partnerships with the University of California San Diego and Colorado State University. In addition to standard weather reports, detailed quantitative precipitation forecasts (QPFs) are obtained from these sources to get a picture of a storm event. These QPFs include details such as the amount, duration, location, and timing of storm patterns.
For real-time monitoring, as the rain and flood events unfold, Valley Water operates more than 100 precipitation, reservoir level, and stream gauges. All of Valley Water’s stream and rain gauges are regularly maintained and calibrated. Valley Water also hosts an “X-band” radar unit on the rooftop of the Penitencia Water Treatment Plant. The unit is part of the Bay Area AQPI (Advanced Quantitative Precipitation Information) system. This short range and lower elevation radar supplements our existing rainfall gauge system, and more importantly, provides more precise radar data. During storm events, this X-band radar augments the existing radar operated by the NWS to provide Valley Water with a clearer picture of the storm system.
Under Valley Water’s Safe, Clean Water Program Priority F7 Project, Emergency Response Upgrades Project, Valley Water runs an experimental flood forecast and warning system, using automated hydrologic and hydraulic models to determine creek runoff and expected reservoir levels. The models process data from both the QPFs and monitoring sensors mentioned earlier. Valley Water also partners with the California-Nevada River Forecast Center (CNRFC), who forecasts several creeks and reservoirs in our jurisdiction. In addition, Valley Water is leveraging innovative tools that use machine learning to model hydrologic processes. Combined, these flood forecasting resources provide intelligence to decision-makers, emergency responders, and the general public.
Reservoir Management
Valley Water owns and manages ten surface water reservoirs throughout the county. The reservoirs are operated primarily as water supply facilities for conjunctive use to capture local runoff and store imported water for groundwater recharge or in-lieu groundwater recharge activities. Releases from the reservoirs are made based on water right provisions, recharge operations, dam safety requirements, incidental flood risk reduction, and environmental compliance.
Currently, all of the reservoirs, with the exception of Vasona, Uvas, and Calero reservoirs, have rule curves that were developed from historic hydrology and provide an incidental benefit of flood risk reduction. These rule curves balance reservoir capacity for water supply with flood risk reduction and allow for a high probability that water storage will be recovered by the end of the season. Vasona is a small reservoir and has no rule curves. Because Uvas Reservoir does not have an incidental flood-risk-reduction rule curve, it may consequently experience more frequent, longer-duration, and higher-magnitude modest spills intended to improve downstream channel habitat. Instead, the reservoir’s natural resource permitting requires pulse flow releases for fish migration, which can decrease reservoir storage. Calero Reservoir’s flood risk reduction rule curve is not presently in effect because the seismic restriction -imposed by the California Department of Water Resources’ Division of Safety of Dams (DSOD)- limits storage below the rule curve.
Valley Water operates five water supply facilities that are subject to seismic safety restrictions including Calero, Almaden, Guadalupe, Coyote, and Anderson dams. DSOD imposed a seismic safety restriction limiting storage in Calero Reservoir to 46 percent (%) of its capacity. DSOD also imposed dam safety restrictions on Almaden, Guadalupe, and Coyote reservoirs limiting their capacities to 93%, 65%, and 53%, respectively.
For Anderson Reservoir’s operation, the Federal Energy Regulatory Commission (FERC) issued a directive on February 20, 2020, to draw down Anderson Reservoir to water surface elevation 488 feet (in NAVD 88 datum). The FERC directive was amended on April 4, 2024, by revising the deadpool elevation to 490 feet and allowing for an additional two feet of storage above deadpool as a buffer to benefit the fish in Coyote Creek. The storage limit of 3,485 acre-feet constitutes about 4% of the reservoir’s full capacity. Valley Water has complied with the FERC directive that substantially reduced the risk of spilling the reservoir. In addition, Valley Water is anticipating completion of the Anderson Dam Tunnel Project in 2026. The new tunnel will increase the operator’s ability to draw down the reservoir by fivefold ahead of and after storms while Anderson Dam is undergoing a seismic retrofit construction project beginning in 2027.
Since February 2019, Lexington Reservoir has been re-operated with a temporary flood-risk-reduction rule curve (between December 1 and April 1) to significantly reduce the flood risk to the community along Guadalupe River from Tasman Drive to Interstate 880. Since this temporary flood-risk-reduction rule curve could impact water supply, a methodology was developed to comply with the District Act and State Law regarding the use of a facility funded by groundwater charges. In the winters of 2023 through 2026, staff used Forecast Informed Reservoir Operations (FIRO) on Lexington Reservoir. FIRO allows for storing more water in Lexington Reservoir above the flood-risk-reduction rule curve or drawing down the reservoir below the rule curve depending on the weather forecast. Unless the Board directs otherwise, staff will continue to implement the temporary flood-risk-reduction rule curve and FIRO on Lexington Reservoir during the 2026-2027 winter season.
Real-time Information, Alerts, and Warnings
Valley Water provides precipitation and stream gauge data to the public via multiple websites, such as the surface water monitoring website <https://alert.valleywater.org/>, which utilizes a user-friendly interactive map to allow residents to monitor levels in their own neighborhoods. We also regularly coordinate with the National Weather Service and local jurisdictions during storm events to share information about potential floods.
Valley Water’s website provides access to reservoir levels, precipitation data, stream flow, and flood-safety measures. Valley Water also promotes the County’s emergency alert system AlertSCC <https://emergencymanagement.sccgov.org/AlertSCC>.
Valley Water, Countywide, and Regional Emergency Management Systems
Valley Water maintains facilities, technology, equipment, procedures, trained staff, and inter-agency relationships that enable it to respond to floods and other emergencies. Valley Water emergency management facilities include its district-wide Emergency Operations Center (EOC) and Water Utility/Watersheds Departmental Operations Centers (DOCs). Valley Water maintains a dedicated, primary EOC that is equipped with both high and low-tech communication information storage and display technologies to allow the EOC functions to perform under all hazard scenarios. Valley Water has also incorporated virtual hybrid EOC environments where remote and onsite staff may operate effectively during emergency activations. EOC equipment is regularly inventoried, maintained, and tested to ensure readiness. Valley Water DOC facilities are equipped for emergencies that can be handled within departmental operational resources and capabilities. EOC position-specific checklists are available to help guide EOC staff in the performance of their Standardized Emergency Management System (SEMS) response functions.
Valley Water EOC staff have participated in multiple trainings as well as internal and multi-agency exercises. Training and exercises are designed and utilized to develop, learn, and test response capabilities under various hazard scenarios. Whenever possible, Valley Water is a good neighbor and offer training and exercise opportunities to partner jurisdictions when appropriate and applicable. The table below shows some examples of past trainings/exercises for Valley Water staff:
The training opportunities allow for staff to become more familiar with their roles and build comfort in the tools and processes they will be expected to utilize during emergencies. This has proved true during emergencies such as flooding, the COVID-19 Pandemic, wildfires, earthquakes, extended power outages, and PG&E Public Safety Power Shutoff (PSPS) events, as well as drought. The real-life experiences, as well as the exercise opportunities, enabled staff to practice and identify areas of improvement for operational coordination, operational communication, situational awareness, public information and warning, and infrastructure system core capabilities as defined by the National Response Framework. Joint exercises with our response partners help to foster mutual understanding and improve our collective response capabilities
Each Fall, Valley Water’s Office of Emergency Services hosts a multi-jurisdictional Winter Preparedness Workshop. The purpose of the event is to educate partner jurisdictions on Valley Water’s year-round flood preparedness activities. This year’s event will be held on October 29, 2026, and conducted as a hybrid (both in person and through Zoom Webinar). Attendees will include emergency managers and public works representatives from local cities, the County, and other local and state agencies. Valley Water staff will present the following topics during the workshop:
• Reservoir Operations
• Emergency Services
• Flood Forecast & Warning System
• Public Information
• Sandbag Operations
• Watershed Field Operations
• Drone Operations
External presentations will also be provided:
• The National Weather Service - winter season outlook regarding the probability of seasonal precipitation, temperatures, and other environmental aspects
• Santa Clara County Office of Emergency Management - Regional coordination during inclement weather events
In addition to the Winter Preparedness Workshop, Valley Water emergency management staff, senior executives, and elected officials foster strong interagency emergency preparedness relationships by participating in several important groups, including the Santa Clara County Emergency Managers Association, the Santa Clara County Operational Area Signatories, and the Santa Clara County Emergency Operational Area Council.
Valley Water Field Response Actions and Capabilities
In preparation for a possible flood event, Valley Water can mobilize a field response that:
• maintains a Watersheds 24/7 Hotline;
• deploys Field Information Teams (FIT); and
• maintains a list of known flooding hotspots to expedite on-site arrival of resources and crews that can remove blockages when safe to do so, deploy sandbags, and perform other functions to maximize flood conveyance capacity during a storm.
Valley Water provides filled sandbags at five sites across Santa Clara County: Valley Water’s Winfield site, Palo Alto Airport site, City of San Jose Central Yard, Alviso site, and Morgan Hill site. Typically for winter seasons with average rainfall forecasts, Valley Water stocks 18,200 filled sandbags at these locations by mid-October, restocking those sites as needed. In the event that the availability of filled sandbags cannot meet demand, Valley Water will supply empty bags and sand at those locations.
Additionally, Valley Water provides a limited number of empty sandbags to municipal and county public works departments to help stock an additional 20 sites around the County. Empty sandbags are offered to county public works agencies beginning October 1.
Maps of sandbag locations have been prepared in conjunction with other entities. The site locations are provided through the following link:
<https://www.valleywater.org/floodready/sandbags>
Valley Water currently has an additional 230,000 empty sandbags and 300 cubic yards of sand in storage to support distribution sites.
StormReady Recognition with National Weather Service
Valley Water was recertified as StormReady by the National Weather Service in October 2025. Under NWS policy, StormReady recognition remains valid for four years, with current recognition effective through 2029.
StormReady recognizes jurisdictions and organizations that maintain robust hazardous-weather operations-24/7 warning/EOC capability, multiple redundant ways to receive and disseminate NWS alerts, local monitoring, formal plans, training/exercises, and public outreach. Valley Water meets these standards through EOC readiness and emergency action planning, multi-channel warning and monitoring, and public preparedness resources (e.g., Surface Water Data Portal and flood-safety guidance).
ENVIRONMENTAL JUSTICE IMPACT:
There are no Environmental Justice impacts associated with this item. The Winter Preparedness Briefing provides information to the Board of Directors regarding work throughout the year, emergency preparedness and response, and community communications and outreach during Winter and Pre-Winter periods.
FINANCIAL IMPACT:
There is no financial impact associated with receiving a briefing on winter preparedness.
CEQA:
The recommended action does not constitute a project under CEQA because it does not have the potential for resulting in direct or reasonably foreseeable indirect physical change in the environment.
ATTACHMENTS:
Attachment 1: PowerPoint
UNCLASSIFIED MANAGER: Manager
Alexander Gordon, 408-630-2637