Live near a stream on Oahu? See changes to flood insurance maps

Owners of thousands of properties along Oahu streams may be required to purchase flood insurance due to changes in the flood maps that show evolving risks.

The city and state are assisting the Federal Emergency Management Agency in alerting property owners and communities that it has updated its flood maps once again. The latest update is for stream areas only, not coastal areas, and becomes effective June 10.

Since 2019, FEMA has studied flood risks along numerous Oahu streams, some which have not been examined before.

“The update studied nearly 100 miles of stream across Oahu, resulting in a total of 3, 492 parcels being added to the Special Flood Hazard Area, ” Sarah Harris, Hazard Mitigation and Long-term Disaster Recovery Program manager for the city’s Office of Climate Change, Sustainability and Resiliency, said in response to a Honolulu Star-Advertiser inquiry.

Based on its studies, FEMA released preliminary updates to the Flood Insurance Rate Maps. Property owners are encouraged to review the final maps to determine whether there have been any changes in their property’s designation.

Property owners with a federally backed loan or mortgage who are newly mapped in the Special Flood Hazard Area may be required by their lender to obtain flood insurance.

FEMA issued a letter of final determination for the city’s preliminary Flood Insurance Rate Maps, starting a six-month compliance period ending June 10 that gives property owners and the city time to prepare, the city said.

The preliminary maps underwent a 90-day public appeal and comment period this year from March 13 to June 10.

Harris said the city, with support from the state Department of Land and Natural Resources and FEMA, has been proactively notifying Oahu residents about the flood maps update since last year.

In October 2024, the city sent postcard mailers to property owners with properties newly mapped into the Special Flood Hazard Area. They were invited to attend open houses in November 2024 and to visit the website.

Another round of postcard mailers will go out in January to those same property owners, inviting them to three open houses and to check the same website for more information.

Oahu residents who purchase a new National Flood Insurance Program-backed flood insurance policy or renew an existing policy will automatically receive a 10 % discount on their annual premiums. That’s because the City and County of Honolulu participates in the FEMA-administered voluntary Community Rating System program that encourages flood plain management activities beyond the minimum NFIP requirements.

The city also is advising owners to consider obtaining flood insurance even if their properties are not located in a designated flood hazard area. Additionally, all residents are being encouraged to check whether their homes are in or near a flood zone.

Oahu property owners who want to see whether their properties fall within the flood hazard area or if there has been any change to flood hazards may visit.

To use the map viewer, use the slider and move to the extreme left to see “Preliminary Flood Zones, ” which shows the new mapping for any changes in risk. Move the slider to the right to see the “current ” or previous flood zones.

“If you have a few (different ) zones (on one parcel ), it matters where the structure is on your property, ” Harris said.—Oahu flood map updates Here are the dates and times of future GetFloodReady open house meetings Virtual open house—Jan. 15, 6 to 7 :30 p.m.

Register online for meeting link and more information at.

In-person open houses—Kaneohe Community & Senior Center multipurpose room, 45-613 Puohala St., Jan. 21, 9 :30 a.m. to noon—Aiea Public Library public meeting room, 99-143 Moanalua Road, Jan. 21, 5 :30 to 8 p.m.

For more information on updated maps and to download Flood Insurance Rate Maps, visit FEMA’s Flood Map Service Center at.

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