On the morning of January 3, 2026, Colette Tanaka was working her sump pumps and stacking sandbags around her home in the Larkspur Marina neighborhood. She described her routine to CBS News San Francisco in four words: "Every sump pump, every sandbag." By noon that day, roughly half the neighborhood's streets sat under water, the result of a king tide colliding with heavy rain and pushing Corte Madera Creek back over its banks. Larkspur Mayor Stephanie Andre, surveying the damage, told KQED, "The streets looked like a lagoon."
Six weeks later, Marin County paused the one infrastructure project built to lower Corte Madera Creek's flood risk for Larkspur, Kentfield, and Ross. If you're buying or selling a home anywhere near that creek this year, the pause is worth understanding. But it doesn't mean what most people assume, because the project halted in February was never designed to fix the kind of flooding that hit the Marina neighborhood in January.
Two Creeks, Not One
Corte Madera Creek carries two very different kinds of flood risk depending on where a property sits along its length, and treating them as a single problem is where confusion starts.
Upstream, near Baltimore Canyon Preserve, where a footbridge crosses Larkspur Creek on its way down from the slopes of Mount Tamalpais, the risk is rainfall-driven. Storm runoff moves faster than the channel below can carry it. That's the mechanism behind the January 1982 flood, still the largest on record for the watershed, which caused serious damage in Fairfax, San Anselmo, Ross, Kentfield, and Larkspur.
Downstream, where the creek widens and slows on its way to San Francisco Bay near the Larkspur Marina neighborhood and the ferry terminal, the physics change. King tides, which occur each winter when the sun, moon, and earth align to produce unusually strong gravitational pull, raise the water level in the bay itself. When that happens during a rainstorm, the creek has nowhere to drain, so it backs up into the closest streets. That's what happened in January 2026.
One is a capacity problem upstream. The other is a drainage problem at the mouth. They don't share a fix.
What the Paused Project Actually Touches
The Corte Madera Creek Flood Risk Management Project, paused by the county on February 19, 2026, was built to address the upstream, rainfall-driven version of the risk. Its footprint runs from Lagunitas Road in Ross downstream to an earthen channel in Kentfield, replacing sections of the concrete channel the Army Corps of Engineers installed through Ross and Kentfield in the 1960s and 70s. Completed work includes a new stormwater pump station at Granton Park and a restoration project along the creek behind College of Marin. Still pending before the pause: removing a fish ladder in the channel's Unit 4 and building taller floodwalls in Units 2 and 3.
The pause followed a FEMA determination that removing that fish ladder could actually increase flood risk downstream rather than reduce it. Public Works Director Christopher Blunk called it a "strategic reset," saying the county needed to "step back, reassess our approach, and ensure we are making responsible decisions on behalf of the community." Sandra Guldman, president of the Friends of Corte Madera Creek Watershed, pushed back in a published opinion piece, arguing that only the fish ladder removal carried real flood risk and that the project's other components, including larger fish resting pools, "would not change water levels downstream." County Supervisor Brian Colbert framed the stakes for the review: the county needs to "understand where this process veered off course" before resuming work. As of the county's most recent public update this spring, no resumption date had been set.
None of that changes the tidal flooding at the creek's mouth. The paused project's footprint stops at Kentfield's earthen channel. It never extended into the Larkspur Marina neighborhood, and upstream channel work does little to change how high the bay itself rises during a king tide.
| Upstream (Baltimore Canyon through the Ross-Kentfield channel) | Downstream (Larkspur Marina, near the bay) | |
|---|---|---|
| Trigger | Heavy rainfall exceeding channel capacity | King tides raising bay water level and blocking drainage |
| Historic example | January 1982, the largest flood on record for the watershed | January 2026 king tide flooding |
| Addressed by the paused project | Yes, this is its design purpose | No, outside the project's footprint |
| What it means for a nearby home | Risk tied to storm intensity and channel condition upstream | Risk tied to tide charts and sea level, independent of the paused project |
The Disclosure Rule Hiding in Civil Code 1103.2
Any Larkspur seller already knows they need to complete a Natural Hazard Disclosure Statement, the report required under California Civil Code section 1103 that flags whether a property sits inside a Special Flood Hazard Area along with five other hazard categories. Buyers get three days to review it once they receive it. That much is standard across the state.
Fewer sellers, and fewer agents, track subsection (d) of Civil Code 1103.2 closely. If FEMA has issued a Letter of Map Revision confirming that a specific property sits inside a Special Flood Hazard Area, the seller must mark "yes" on the disclosure and attach a copy of that letter, even if the public flood map has not been updated yet to show it. The map and the legal disclosure obligation don't have to move together, and the seller is responsible for whichever one is currently accurate.
That gap matters more in Larkspur this year than in a typical one. The city's own floodplain management page notes that FEMA is actively conducting new riverine studies across the Ross Valley watershed, the same watershed that carries both Larkspur Creek and Corte Madera Creek, and that those studies "may include a change in flood risk classification for some property owners." Separately, the FEMA determination that froze the county's flood project was itself a technical finding about flood risk tied to this same creek system. A parcel-specific Letter of Map Revision generated out of either process wouldn't necessarily appear on a standard public map pull the day it's issued. It would surface first in a title company's federal flood determination search, well ahead of most consumer map tools catching up.
Insurance Doesn't Read the Zone Label Anymore
The other place the paper zone and the practical risk have drifted apart is pricing. FEMA's National Flood Insurance Program now uses a system called Risk Rating 2.0, which prices each home individually based on its distance to water, its elevation relative to the base flood elevation, and its rebuilding cost, rather than leaning mainly on the broad zone letter. As of this fall, the average flood insurance premium in California runs near $779 a year according to FEMA data cited by Insurify, but that average hides wide swings. Two homes on the same Larkspur block, carrying the same zone letter, can come back with very different quotes once an insurer runs the actual elevation numbers.
For a buyer comparing a creekside listing near Baltimore Canyon against one two blocks from the water in the Larkspur Marina neighborhood, the zone letter on the NHD report is a starting point, not the number that ends up on a mortgage statement. The only way to know the real premium is to pull a current elevation certificate and get a quote before contingencies come off, not after.
What This Means If You're Near the Water This Fall
- If the home sits upstream near Baltimore Canyon or along the Ross-Kentfield channel corridor, ask whether the seller has any record of water intrusion tied to rainfall events. That's the risk category the paused project was meant to address, and the one most likely to shift once work resumes.
- If the home sits in or near the Larkspur Marina neighborhood, ask directly about the January 2026 event regardless of what the FEMA zone shows. Tidal flooding doesn't always register on a rainfall-based flood map.
- Ask your NHD provider or title company whether their search checks for Letters of Map Revision, not just the currently published flood map, given that FEMA's Ross Valley riverine study is active right now.
- Pull a fresh elevation certificate and get an actual insurance quote before relying on the zone letter alone. Risk Rating 2.0 prices the structure, not just the zone.
FAQ
Does the paused flood control project change my flood insurance requirement? No. Insurance requirements are set by whether your specific parcel sits inside a FEMA Special Flood Hazard Area, not by the status of the county's construction project. The pause affects future risk reduction work, not today's zone determination.
If my home didn't flood in January 2026, does that mean I'm outside the flood zone? Not necessarily. The January event was tidal and concentrated near the creek's mouth. A home outside that immediate area could still sit inside a mapped Special Flood Hazard Area tied to rainfall risk further upstream, and the reverse is also true.
Who do I contact about a Letter of Map Revision on a specific parcel? Your NHD disclosure provider or title company can run a federal flood determination search that checks for LOMRs, and FEMA's Flood Map Service Center allows a direct address lookup as a second check.
Flood risk along Corte Madera Creek isn't one number you look up once and set aside. It's two separate systems, moving on two separate timelines, tied to a disclosure law that doesn't always wait for the public map to catch up. If you're weighing a purchase near the creek or preparing a Larkspur home to list this fall, Holly Welch can walk through what a specific parcel's history and paperwork actually show before you write an offer or sign a disclosure. Let's Connect.