Flood Zones in Burlingame and Hillsborough, CA

Burlingame's Bayfront: No Natural Buffer, Real Mapped Risk

The majority of Burlingame's land area falls within FEMA and California Department of Water Resources-mapped flood hazard zones, and the city has participated in the National Flood Insurance Program since 1981. Two distinct flood mechanisms threaten the area, per the city's own planning materials: shoreline flooding from San Francisco Bay driven by storm surge and high tides (worsening with sea-level rise), and separate inland flooding during major rainfall events that overwhelm local creeks and storm drains, compounded when it coincides with high tide. Unlike some neighboring Peninsula and Bay Area communities, Burlingame's own materials state that its shoreline is not protected by natural defenses such as beaches or wetlands -- a genuinely candid admission worth taking seriously rather than assuming the risk is overstated.

BCDC sea-level-rise projections cited in the city's own planning documents indicate that most of the Bayfront Area and parts of Rollins Road could face permanent inundation by 2070 absent intervention. This is a regional, long-horizon planning projection, not a specific-property prediction for any given year -- but it's the reason the city began actively studying Bayfront adaptation strategies starting in 2019, and it should factor into any long-term ownership horizon for a bayfront-adjacent Burlingame parcel.

The Millbrae and Burlingame Shoreline Resilience Project

The real, current response to that risk is the Millbrae and Burlingame Shoreline Resilience Project, led by OneShoreline (formally the San Mateo County Flood and Sea Level Rise Resiliency District), which is planning long-term protection for slightly more than three miles of this heavily urbanized shoreline. The area covers an estimated $2.4 billion in property at risk, including two water treatment plants, electrical distribution infrastructure, a rail corridor, and a section of Highway 101. Design work has explored several alternatives, including an offshore barrier creating a lagoon extending from SFO to northern San Mateo, and a shoreline barrier with or without tide gates -- each constrained by limited space from existing development, regulatory preferences for nature-based approaches that limit new Bay fill, the need to meet FEMA accreditation standards (so landward areas aren't automatically mandated to carry flood insurance once complete), and a genuinely unusual requirement specific to this shoreline: avoiding any increase in wildlife hazards to aircraft operating at SFO immediately to the north.

The project received $8 million in state budget funding, with half directed specifically to the Burlingame-Millbrae effort. This page does not have a confirmed current construction timeline or completion date and recommends checking OneShoreline's own project materials directly for current status before assuming any specific level of protection is already in place.

FEMA Zones and What a Buyer Should Actually Ask

This page does not state a specific FEMA flood zone designation for any individual Burlingame parcel, since that depends on the exact address, elevation, and current map revision. What a buyer evaluating a bayfront-adjacent property should ask directly: the property's current FEMA flood zone designation, whether flood insurance is a lender-mandated requirement for that specific parcel, and whether the property falls within the Millbrae and Burlingame Shoreline Resilience Project's planned protection area. Confirm all three directly with the City of Burlingame Public Works Department and a FEMA flood map lookup for the specific address before making an offer.

Liquefaction Overlaps With Flood Risk on the Bayfront

A related but distinct hazard worth understanding alongside flood risk: much of Burlingame's bayfront corridor sits on fill placed over former tidal marsh and bay mud, and eastern sections of the city -- including tower sites near the Burlingame Lagoon and San Francisco Bay -- are flagged in state hazard mapping as highly susceptible to liquefaction during a major earthquake. This is a separate mechanism from flooding (ground-shaking-induced soil failure versus water intrusion), but both hazards concentrate in the same general bayfront geography, and both are covered in more structural depth on the Coastal Insurance and Storm Prep Costs pages. A buyer should treat the two as related but separate due-diligence questions for the same bayfront-adjacent property, not a single combined risk.

Hillsborough: A Genuinely Different, Much Smaller Flood Picture

Hillsborough is landlocked -- 6.2 square miles, all of it land, zero square miles of water per the U.S. Census -- and it does not face the Bay-driven shoreline flooding, mandatory NFIP flood insurance, or sea-level-rise inundation risk that applies to Burlingame's bayfront. That does not mean zero flood risk in an absolute sense: like any hillside community, Hillsborough can see localized inland flooding from creek overflow or storm-drain capacity during unusually heavy rainfall events, the same general atmospheric-river-driven winter storm pattern covered on the Storm Prep Costs page. But the FEMA Special Flood Hazard Area designation, the shoreline-band BCDC jurisdiction, and the sea-level-rise planning horizon that shape Burlingame's flood conversation simply do not apply to Hillsborough in the same way, given its landlocked geography.

What This Page Does Not Know

This page does not have a confirmed specific FEMA flood zone for any individual Burlingame parcel, a confirmed current completion timeline for the Millbrae and Burlingame Shoreline Resilience Project, or confirmed data on Hillsborough's specific inland flood history. Confirm current flood zone status and any mandatory insurance requirement directly with the City of Burlingame Public Works Department and FEMA's own flood map service before making a purchase decision.