King County redraws Vashon flood zones

Thanks to a new county study, Islanders who own property along Vashon’s 45 miles of shoreline will soon have access to better information about flood hazards.

Next week, officials from King County’s Department of Natural Resources and Parks and the Federal Emergency Management Agency will visit Vashon to present a draft flood zone map that they say is more detailed and accurate than the current map, and will answer questions about specific properties. 

Jeanne Stypula, a supervising engineer in the River and Floodplain Management section, said the county recently performed a thorough study of Vashon’s shoreline flooding risks as part of a larger effort to update flood maps across King County. Using satellite imagery and information about land elevations, high tides and wind speed, the county was able to map flood hazard zones on the approximately 1,500 parcels that line the shores of Vashon and Maury islands, Stypula said.

“Its very complicated, but the end product is to be able to provide a map to the public to let people know where there is a flood hazard and to be prepared for that,” she said.

Stypula said that in the past some Islanders have paid to have officials determine, for insurance or construction purposes, whether their property lies on a flood zone.

“It’s costly to the landowner,” Stypula said. “By doing this in a comprehensive way all around the Island, one study … produces all this information that landowners can use directly.”

She added that the new map places more shoreline structures outside flood zones than the previous map did, meaning some residents who have flood insurance now will no longer require it.

“People will probably view the map pretty positively because of that,” she said.

Stypula said the county is interested in hearing comments on the draft flood map, as Islanders may have information about property that has flooded in the past but isn’t reflected as being in a flood zone.

“We use a lot of data and sophisticated modeling … but we want that feedback,” Stypula said. “We’ll take those comments and make revisions where we need to.”

At the meeting the county will also hear feedback on a new set of regulations being sent to the King County Council concerning homes built on the shoreline.

Priscilla Kaufmann, a project program manager with the River and Floodplain Management section, said existing regulations for shoreline homes only consider river flooding, while new ones would take into account the type of flooding that occurs on coastal shorelines.

“The design of house has to be somewhat different,” she said.

Kaufmann said the regulations would only apply to new homes or significant remodels.

“A person that has an existing house that doesn’t plan on making major changes would not be affected by these new regulations,” she said. 


King County will hold a public meeting to present a draft flood map of Vashon from 6 to 8 p.m. Thursday, April 28, at Vashon High School. 

The map is available at

We encourage an open exchange of ideas on this story's topic, but we ask you to follow our guidelines for respecting community standards. Personal attacks, inappropriate language, and off-topic comments may be removed, and comment privileges revoked, per our Terms of Use. Please see our FAQ if you have questions or concerns about using Facebook to comment.
blog comments powered by Disqus

Read the Oct 26
Green Edition

Browse the print edition page by page, including stories and ads.

Browse the archives.

Friends to Follow

View All Updates