Is Your Stockton Home in a Flood Zone? Levees, Maps and Flood Insurance

Published November 6, 2026 · Last updated November 2026

Stockton sits where the San Joaquin River, the Calaveras River and a web of sloughs and canals meet the Delta. Levees protect most neighborhoods. This guide explains how to check your flood zone, what changed in 2026, where levee work stands and how flood insurance fits in. It is written for homeowners and renters in Stockton, Lathrop and Manteca.

How do I check if my Stockton home is in a flood zone?

Look up your address on FEMA's Flood Map Service Center. The Flood Map Service Center lets you search by address, place or coordinates to find your official flood map.

The map shows whether your property is inside FEMA's high-risk "Special Flood Hazard Area." If you're not sure what your result means, ask your insurance agent or your city's building department to read it with you.

What changed near Smith Canal in 2026?

About 8,000 property owners were removed from the high-risk zone in February 2026. The San Joaquin Area Flood Control Agency (SJAFCA) said a FEMA map revision took effect after the Smith Canal gate was finished in 2024. The gate cost $96 million.

The area had been mapped as high-risk in 2009, and some owners paid flood premiums near $3,000 a year, SJAFCA said. Construction began in July 2020, according to the project page. The Smith Canal area includes Stockton's Country Club neighborhood.

Should I drop my flood policy now?

Think before you cancel. Lower risk is not zero risk. The City's own Safety Element background report says the Country Club area would flood if the Smith Canal levees failed. San Joaquin County's SJReady flood page notes that 20% of flood claims are filed in low-to-moderate risk areas. Policies in lower-risk zones usually cost less, so ask your agent for a new quote before deciding.

Which waterways and levees protect Stockton?

Several. The City's Safety Element background report (December 2023) lists the Calaveras River, the Stockton Diverting Canal and Mormon Slough as part of a locally built flood control project. It also lists Bear Creek, Little Bear Creek and Pixley Slough. The same report says no levees there meet the state's 200-year protection standard.

Flooding has happened before. The report notes a voluntary evacuation of Weston Ranch during 1997 flooding, and about 1,500 acres of Stockton flooding in 1955–56. It also says most City storm drains are built for a 100-year storm.

What is the 200-year flood protection rule?

It is a California standard set by a 2007 law, SB 5. The law requires urban areas in the Central Valley to have protection from a flood with a 1-in-200 chance of happening in any year, with a 2025 deadline. That is how the City of Lathrop summarizes it on its flood protection page.

The standard is stricter than FEMA's 100-year line used for flood insurance maps. A home can be outside FEMA's high-risk zone and still be in an area that hasn't met the state's 200-year goal.

Lathrop and River Islands

Lathrop says its levees are certified for 100-year protection and that the Dell'Osso Farms area (Reclamation District 2107) does not have 100-year protection (City of Lathrop). River Islands is protected by Reclamation District 2062. In June 2024, the Lathrop City Council adopted a finding that RD 2062 was making adequate progress toward 200-year protection, valid through the end of 2025 (Council item). See our Lathrop page.

Manteca

A 2016 report to the City of Manteca said the Reclamation District 17 levees were not yet certified for 200-year protection. Those levees protected about 10,698 homes and 46,000 residents at the time. See our Manteca page.

What is the Lower San Joaquin River Project?

It is a large levee project for the Stockton area that broke ground April 18, 2025. According to SJAFCA, it includes 23 miles of levee improvements and two closure structures, at Fourteenmile Slough and Smith Canal. The agency estimates it will protect about 264,000 residents and roughly $21 billion in property, at a total cost of $1.39 billion. The project was authorized on October 23, 2018.

How recent storms affected Stockton

• Late December 2022 to January 2023: San Joaquin County proclaimed a local emergency effective January 1, 2023, citing local flooding from a storm that began December 28. Stocktonia reported the City declared its own emergency after Stockton's wettest December in nearly 70 years.
• March 2023: The County declared another local emergency for storms starting March 1, with isolated flooding.
• February 2025: Stocktonia reported a flood advisory during the fourth atmospheric river storm in two weeks.

Does homeowners insurance cover flooding?

No. Homeowners policies typically exclude flood, says the California Department of Insurance. Flood coverage comes from the National Flood Insurance Program, run by FEMA, or from private flood insurers.

The 30-day wait

A new flood policy usually takes effect 30 days after you buy it, with some exceptions such as a new mortgage (CDI; FloodSmart). Buying one when a storm is in the forecast is usually too late.

What about sewer backups?

Federal flood policies cover a sewer backup only when a flood causes it, not a backup caused by clogged pipes (FloodSmart). For a clog, see our sewage backup page.

A storm-season checklist

• Look up your flood zone and save a screenshot.
• Know where your water main shutoff and electrical panel are.
• Save the City's 24-hour line, (209) 937-8341, for street flooding and downed trees (City storm page).
• Know the City's free sandbag sites: Stockton Soccer Complex, Weber Point and Van Buskirk Park, when activated. Bring a shovel and proof of address (City storm page).
• Sign up for County emergency alerts through SJReady.
• Photograph your rooms and belongings now, so you have "before" pictures for a claim.
• Never drive or walk through moving water. Six inches can knock you down, the County warns.

Renters and flood risk

Renters can buy flood coverage for their belongings, called contents coverage. Building and contents coverage are usually bought separately, according to FloodSmart, so a landlord's policy on the building doesn't protect your furniture or clothes. If you rent near a levee or canal, ask an agent before the wet season.

Who's who

• San Joaquin Area Flood Control Agency (SJAFCA): runs the Smith Canal gate and Lower San Joaquin River projects.
• FEMA: publishes flood maps and runs the National Flood Insurance Program.
• City of Stockton: storm drains, street flooding reports and sandbag sites.
• San Joaquin County Office of Emergency Services: emergency declarations and SJReady alerts.
• City of Lathrop and local reclamation districts: levees around Lathrop and River Islands.

If storm water does get in, see storm and flood water damage for what to do next, and our insurance claims guide.