On June 10, 2026, FEMA's updated Flood Insurance Rate Maps take effect for the City and County of Honolulu.
These are not minor boundary adjustments. FEMA has redrawn flood zones along nearly 100 miles of Oahu streams. The result is that approximately 3,492 parcels are being placed into a Special Flood Hazard Area for the first time. Some of these are properties that owners have never considered to be at flood risk. That changes on June 10.
Whether you own a home, are actively selling, or are in the middle of a purchase, this remapping affects you. This guide covers what a Zone A designation means in practical terms, what it will cost, and the specific steps you should take before the maps go official.
The Basics · What Is a Special Flood Hazard Area
Zone A: The Designation That Changes Everything
A Special Flood Hazard Area is a zone with a 1 percent or greater chance of flooding in any given year, commonly referred to as the 100-year flood zone.
Once a property lands in Zone A, a series of obligations are triggered. Federally backed mortgages require flood insurance. Renovation projects face stricter permitting requirements under ROH 21A. Sellers carry a new disclosure obligation. And buyers need to factor a new line item into their monthly carrying costs. The good news is that acting before June 10 gives you options, and one of them is worth up to 70 percent off your first-year premium.
3,492 Oahu parcels newly designated · Nearly 100 miles of stream corridors remapped · Effective June 10, 2026
1. Mandatory Flood Insurance
What lenders will require, what it costs, and why timing is everything
Federally Backed Mortgages
Coverage Will Be Required
If you carry a federally backed mortgage, whether FHA, VA, USDA, or conventional, your lender will require you to carry flood insurance once the new maps go official on June 10, 2026. This is not optional and not a soft recommendation. It is a loan condition, and lenders will enforce it.
The 45-Day Window
Act Before Force-Placement
Lenders will send a notice giving you 45 days to provide proof of insurance. If you do not respond in time, they will force-place a policy on your behalf. Force-placed insurance is significantly more expensive and provides less coverage than a policy you purchase yourself. Do not wait for that letter.
The Newly Mapped Discount · Time-Sensitive
Save Up to 70% on Your First-Year Premium
FEMA's National Flood Insurance Program offers a Newly Mapped discount for property owners entering a Special Flood Hazard Area for the first time. Zone X policies are often under $600 per year, while Zone A policies run higher. However, purchasing a policy within the first 12 months of the map change qualifies you for preferred rates that reduce your initial premium by up to 70 percent.
There is one critical catch. The NFIP standard waiting period is 30 days. Policies purchased after mid-May may not be active by June 10. If your property is in a newly mapped zone, the time to secure coverage is now, not next month.
Contact a licensed Hawaii insurance agent who works with NFIP policies to lock in your rate before the deadline.
2. Stricter Building and Renovation Rules
What ROH 21A means for your improvement plans
The 50% Rule
Renovations Over Half of Value
If you plan a renovation costing more than 50 percent of your structure's market value, not the land, you may be required to bring the entire home up to current flood codes. Because the threshold applies to structure value only, it can be reached more quickly than most homeowners expect.
Elevation Requirements
New Builds and Substantial Improvements
For new construction or substantial improvements in Zone A, the lowest floor, including utilities like water heaters and electrical panels, must generally be elevated to at least one foot above Base Flood Elevation. This requirement meaningfully affects both project scope and cost.
Permit Delays
A New Layer of Permitting
Once your property is in a Special Flood Hazard Area, even minor exterior work may require a Flood Development Permit in addition to the standard DPP permitting process. Plan for additional lead time on any projects currently in the pipeline.
3. Property Value and Disclosure Requirements
What sellers must disclose, and what buyers need to understand
For Sellers · Disclosure Timing and Strategy
Zone A Is a Material Fact. Early Disclosure Protects the Transaction.
Sellers of newly mapped properties are not required to disclose the new flood zone designation until June 10, when the updated maps officially take effect. However, disclosing early is the strategically smarter move. Buyers doing due diligence will discover the designation on their own. A proactive seller who discloses upfront, prices accordingly, and helps the buyer navigate the insurance process is in a far stronger position than one who lets a disclosure surface mid-escrow and derail the transaction.
A well-priced, well-disclosed listing in a newly mapped zone will still sell. An undisclosed one creates legal exposure.
Early disclosure builds trust. Surprises in escrow erode it.
Appraisals
Appraisers Will Note the Zone
Appraisers are required to note high-risk flood designations in their reports. For homes that have not been elevated or mitigated, this may slightly affect valuation. For homes with documented elevation certificates, the impact is generally reduced. If your property is newly mapped into Zone A, obtaining an elevation certificate from a licensed surveyor is a practical first step.
For Buyers
Factor Flood Insurance Into Your Numbers
If you are purchasing a home that is entering or already in a Special Flood Hazard Area, flood insurance is not optional. It needs to be factored into your monthly carrying costs before you make an offer, the same way you account for property taxes or HOA dues. Get a quote during due diligence, not after closing.
4. How to Check Your Zone
Two tools. Two minutes. Start here.
Step One · Interactive Comparison
Resilient Oahu
Visit resilientoahu.org/getfloodready and use the side-by-side slider to compare your property's current flood zone against the new designation taking effect June 10. This is the fastest way to see at a glance whether your parcel is affected.
resilientoahu.org/getfloodready
Step Two · Official Confirmation
FEMA Flood Map Service Center
Confirm your parcel's official designation at msc.fema.gov, the national repository for all Flood Insurance Rate Maps. Pull the official map panel for your records and for use in disclosures, lender documentation, or insurance applications.
msc.fema.gov
5. What to Do Right Now
A practical checklist before June 10, 2026
Check Your Property on the Resilient Oahu Map
Visit resilientoahu.org/getfloodready and use the side-by-side slider to compare your current flood zone against the new designation. This is the fastest way to know if your parcel is affected.
Confirm the Official Designation at msc.fema.gov
The FEMA Flood Map Service Center is the official national repository for all Flood Insurance Rate Maps. Confirm your parcel's new designation and pull the official map panel for your records, disclosures, and any lender or insurance documentation.
Get a Flood Insurance Quote Before Mid-May
The NFIP standard waiting period is 30 days. To have coverage active by June 10, you need to purchase your policy before mid-May. Contact a Hawaii-licensed insurance agent who works with NFIP policies, ask specifically about the Newly Mapped discount, and lock in your rate before the maps go official.
Sellers: Disclose Early and Price Strategically
You are not required to disclose the new flood zone until June 10, but disclosing it early gives buyers time to factor the insurance cost into their offer and prevents escrow from collapsing over a last-minute discovery. Work with your agent to price the property in a way that reflects the carrying cost reality for the buyer.
Buyers: Know Before You Close
Before making an offer on any Oahu property, check its flood zone status and get a flood insurance quote as part of your due diligence, the same way you would get a home inspection. It is part of understanding the true cost of ownership. A Zone A designation does not mean the home will flood. It means you need to go in with full information.
Official Resources · Use These
Where to Go for Official Information
Interactive Flood Map Comparison
Resilient Oahu: Get Flood Ready
resilientoahu.org/getfloodready
Official FEMA Flood Maps
FEMA Flood Map Service Center
msc.fema.gov
Hawaii Flood Hazard Assessment Tool
Hawaii DLNR Flood Hazard Tool
fhat.hawaii.gov
Hawaii DLNR NFIP Resources
Hawaii DLNR National Flood Insurance Program
dlnreng.hawaii.gov/nfip
The homeowners and buyers who come out of this remapping in the best position are the ones who found out early, got their insurance in place before mid-May, and went into any transaction with full information. The flood zone itself is not the problem. Being caught off guard by it is.
Frequently Asked Questions
Common questions about Oahu's June 10 flood zone remapping
How do I know if my property is in a newly mapped flood zone?
Use the interactive slider at resilientoahu.org/getfloodready to compare your current zone against the new designation. You can also confirm at msc.fema.gov for the official FEMA map panel. The Hawaii DLNR Flood Hazard Assessment Tool at fhat.hawaii.gov is another useful resource for deeper research on your parcel.
What does flood insurance cost for a newly mapped Zone A property?
Zone X policies are often under $600 per year. Zone A policies are generally higher, but if you purchase within the first 12 months of the map change, you are eligible for FEMA's Newly Mapped discount, which can reduce your initial premium by up to 70 percent. Get a quote from a Hawaii-licensed insurance agent before mid-May to take advantage of this window and ensure coverage is active by June 10.
Does a Zone A designation mean my property will flood?
No. A Special Flood Hazard Area designation means the property has a statistical 1 percent or greater chance of flooding in any given year. It is a risk designation, not a certainty. Many properties in Zone A have never flooded. The designation is about actuarial risk assessment, not a prediction about your specific home.
Do I have to disclose the new flood zone if I am selling my home?
Technically, disclosure is not required until June 10 when the maps become official. But disclosing early is the strategically smarter move. Buyers doing due diligence will discover the new designation on their own. Proactive disclosure builds trust, allows buyers to price the insurance cost into their offer, and reduces the risk of a transaction falling apart mid-escrow.
Can I appeal or challenge the new flood zone designation?
Yes. FEMA provides a Letter of Map Amendment or Letter of Map Revision process for property owners who have survey data showing their property sits above the Base Flood Elevation. An elevation certificate from a licensed surveyor is typically required. This process takes time and should be pursued with the help of a qualified professional.
Where can I find deeper guidance on the NFIP and Hawaii flood regulations?
The Hawaii DLNR NFIP page at dlnreng.hawaii.gov/nfip and FEMA's resource page for real estate professionals at fema.gov/flood-maps/know-your-risk/realtor-lending-insurance are the strongest starting points. For parcel-level research, the Hawaii DLNR Flood Hazard Assessment Tool at fhat.hawaii.gov gives detailed property-specific information.
Oahu's flood maps are changing. The homeowners who come out ahead are the ones who find out now, act before mid-May, and go into their next transaction with complete information. If you have questions about how this affects your property or a transaction you are navigating, the conversation starts here.
Ho'okele Homes · Oahu Real Estate · Summer 2026
Privately inquire. No pitch. No pressure. Just strategy.
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