AB 646 Explained: California's Rental Property Flood Disclosure Law

What AB 646 requires

AB 646 is codified at California Government Code § 8589.45. It requires landlords of residential rental property to give a written flood hazard disclosure before signing or renewing a lease when the landlord has actual knowledge that the dwelling is in a FEMA Special Flood Hazard Area (SFHA) or an area of potential flooding from a dam failure inundation zone.

The disclosure must be in writing, delivered before lease signature, and it must inform the tenant that the landlord's insurance does not cover the tenant's personal belongings.

Who must comply

The statute reaches virtually all residential rentals in California:

• Single-family home rentals
• Multi-unit residential buildings
• Condo and townhome rentals
• Mixed-use buildings with residential units
• ADU and JADU rentals

A handful of narrow exceptions apply (certain public housing and short-term rentals under specific circumstances), but the default assumption should be: if you're renting residential space in California, AB 646 applies.

What triggers the disclosure

The statute is triggered when the landlord has actual knowledge of flood exposure. The law defines "actual knowledge" broadly — you're deemed to know if any of these are true:

• You received notice from a public agency that the property is in a special flood hazard area or dam inundation zone.
• Your mortgage lender requires you to carry flood insurance on the property.
• You currently carry flood insurance on the property.
• The property has previously received federal disaster assistance for flood damage that required flood insurance as a condition of aid.

In practice, most landlords will have actual knowledge if their mortgage requires flood insurance — and most SFHA properties' mortgages do.

What tenants need to know

The disclosure isn't just a checkbox — it exists so tenants can make informed decisions about their exposure. Key points to communicate:

• The landlord's property insurance does not cover tenant possessions.
• Standard renter's insurance policies typically exclude flood damage — a separate NFIP flood policy is required.
• NFIP renter policies are widely available and generally affordable relative to residential coverage.
• Flood insurance normally has a 30-day waiting period, so it should be arranged before move-in.

How to comply

The simplest compliance path is to order a Verity NHD Lease Hazard Disclosure report at lease signing. The lease report bundles the AB 646 flood disclosure with all six statutory hazard determinations and a Verity AI™ plain-English summary — in a single document tenants can sign and landlords can file.

For a full pricing breakdown across residential, lease, commercial, and developer products, see the pricing page.

Penalties for non-compliance

AB 646 doesn't spell out a statutory fine for non-disclosure — but that doesn't mean it's toothless. A landlord who fails to disclose known flood exposure creates civil liability if the tenant later suffers flood damage. The tenant can sue for uncovered losses, and the landlord's insurer may deny defense coverage on the theory that the loss was foreseeable and undisclosed.

The cost of compliance is small; the cost of skipping it can be the difference between a covered claim and a personal-liability judgment.

Bottom line

If you rent residential property in California and any of the "actual knowledge" triggers apply, AB 646 requires a written flood disclosure before lease signing. Ordering a lease-tier NHD is the cleanest way to satisfy the statute and put a defensible disclosure in the tenant file. For a broader tour of every statutory hazard the report covers, see the six California natural hazard zones.