Read more from our Flood and Land Restoration Manager, Artie Valencia
“On May 2nd, 2025, the Trump Administration announced proposed cuts to the Army Corps of Engineers’ construction budget as part of its FY 2026 “skinny budget” that slashes funds for levee upgrades by 53%. The Delta is a system that is held by a thread by aging levee infrastructure. Due to historic disinvestment, this region has fallen decades behind on critical upgrades and rehabilitation measures to ensure its robust holistic protection. Time and time again, Delta levees are being challenged during wet periods, causing erosion and adding pressure to the levee barrier that protects 600,000 residents and 740,000 acres of land in the Delta” (Hanson, Courthouse News Service).
The Looming Threat of Massive Flooding in our Community
Without this significant investment, Delta levees will remain vulnerable to climate extremes like Atmospheric River Storms which are expected to increase by 10-40% across the Sierra Nevada by mid-century (Huang & Swain). These conditions will only increase flood risk in the San Joaquin Valley.
The 2023 Atmospheric River Storms provide a glimpse into the possible future for this region with the current infrastructure in its degrading form. In San Joaquin County alone, there were 15 levee boils due to erosion and pressure from record snow water equivalent levels 300-400% of normal in certain areas of the Sierra Nevada. Eventually, snow melts. Coupled with extreme periods of heat in April and into the summer months, state hydrologists report that snow melt increases flood potential as a result of this rapid melting (Smith, LA Times).
In a 2024 webinar hosted by Sustainable Conservation, UCLA Data Climate Scientist Daniel Swain highlighted that due to climate change, more winter storms will bring more rain than snow. This will lead to the faster filling of rivers and reservoirs in both the Sacramento and San Joaquin areas, thus increasing flood risk.
In practical terms, the Atmospheric River Storms have the potential to overfill these systems, causing river stage levels to increase due to heavy flows coming down and through the 100-year old levee system. Such conditions are the perfect brew for a flood event that could lead to millions in damage to homes, farmland, and infrastructure.
Stockton in particular faces flood risk on all sides, both on the San Joaquin and Calaveras River end due to high tides and sea level rise due to increased rainfall and runoff in the San Joaquin watershed. Localized or otherwise known as street flooding poses another risk due to high water tables that can seep into foundations and outdated street and infrastructure design that is not built to drain or move high volumes or water. As it stands, Insurance Journal Report, claims that Stockton is the second most flood-vulnerable city in the U.S., with 93% of residential properties at risk of flood damages within the next 30 years. Additionally, in the CA Flood Future Report Summary, the Department of Water Resources referred to Stockton as a flood prone area of concern with levees that could pose a catastrophic risk if breached. The Central Valley Flood Protection Board also identifies Stockton’s levees in the high-hazard and deficiencies classifications. Currently, including the Delta and the entire Central Valley region, the Central Valley levee system protects approximately 1.3 million people and $223B in assets yet still they remain vulnerable. Earlier this year, data from the Delta Stewardship Council reports that $10 billion worth of farmland, businesses and infrastructure is at risk. A flood can also affect economics in the Delta since these assets generate $2 billion per year.
Funding for The Lower San Joaquin River Project is Possibly at Risk
The funding cut will target future levee and flood projects including mitigation and restoration in California. Efforts like the Lower San Joaquin River Project may be impacted. In April, the Ten Mile Slough project broke ground in Brookside with a $2 million budget to reduce flood risk for over 120,000 residents. In general, the Lower San Joaquin River Project focuses on North and Central Stockton but includes specific phases of sites and reaches including Smith Canal/Fourteen Mile Slough, Calaveras River Corridor, Shima Tract, Van Buskirk/San Joaquin River-French Camp Slough, and Mosher Slough. The entire project will protect 300,000 residents from flooding in the San Joaquin Basin Project.
Ultimately, the $1.65 billion requested in Trump’s budget is not sufficient to meet flood risk mitigation, ecosystem restoration and community needs. This was emphasized in a letter sent by 12 congressional members to the chairperson and ranking member of the House Appropriations Committee and Energy and Water Subcommittee. Hopefully this will help pressure the administration to reverse the proposed cuts to the US Army Corps of Engineers’ budget. However, if not, the entire Delta and San Joaquin Valley will remain at risk for a Hurricane Katrina level flood that will not only impact homes and livelihoods, but will have irreversible consequences for communities like Stockton. Oftentimes, communities never fully recover from a flood–Pajaro and New Oreleans are examples of that.
Real-Time Flooding Impacts Today
On July 4th, a catastrophic flash flood occurred on the Guadalupe River in Kerr County, Texas. Heavy rainfall from Tropical Storm Barry links the heavy rainfall to warming atmospheres and oceans. Unfortunately, these conditions led to rising floodwaters that overwhelmed infrastructure and caused significant damage to nearby residences and camps. Heartbreakingly, with the damage also came a significant loss of life. In 2023, the community of Pajaro experienced a levee breach that left 3,000 displaced and decades of damage. With the recurrence of atmospheric river storms on the rise, this tragedy is another reminder of what can happen in the San Joaquin portion of the Delta.
The grim connection between these regions is aging levee infrastructure and emergency warning systems that need to adapt to the most current extreme conditions. Just like limited funding from the State for the San Joaquin Valley, Texas lawmakers disregarded the investment for sirens that could alert the public in the event of loss of power or even reach people in rural areas with limited cellular service. Additionally, that disaster was exacerbated by sparse and delayed real-time river-gauge coverage which delayed internal emergency response coordination and mandatory evacuation orders for residents in low-lying areas. Current proposals by the US Bureau of Reclamation to defund Delta gauge tracking will worsen flood warning for the protection of Delta residents.
To prevent future tragedies, local and state governments must invest in adaptive tools like outdoor sirens and weather radios that deliver real-time warnings regardless of connectivity. Regions may share similar histories, but with the right investments in levee infrastructure and emergency response systems, the story of the San Joaquin portion of the Delta can be different.