April 8, 2009
Sammamish River flood map work gets under way
An effort to improve information about flood hazard areas along the Sammamish River is beginning soon. Consultant survey crews working for King County’s River and Floodplain Management Program will be out along the Sammamish River in April to conduct a river survey that will be used to update federal flood insurance rate maps.
The work is part of a larger collaborative effort between King County and the cities of Redmond, Bothell, Woodinville and Kenmore to prepare a new flood study and update floodplain maps for the Sammamish River, which flows 15 miles from Lake Sammamish to Lake Washington.
The current floodplain maps, called flood insurance rate maps, will be updated using new aerial photographs, topographic maps and river channel surveys. Funding for this project comes from the King County Flood Control District, a special purpose district that provides both funds and funding oversight for a variety of flood-protection projects in King County.
The first part of the work for this study involves collecting ground elevation data and taking aerial photographs along the river corridor. Survey crews will be working in road and trail right-of-ways along the river.
Most of the survey work will involve collecting river channel information by boating or wading in the river. The work is expected to be completed by May.
New survey data and aerial photographs will be used to develop the new flood study that will include estimates of flood elevations and areas of inundation.
This information will be shown on draft maps which will be publicly available in early 2010. The public will have the opportunity to review and comment on the draft maps at that time.
After public comments are reviewed, the maps will be finalized and provided to FEMA for review and approval so that new flood insurance rate maps can be published.
To provide high water mark or other flood information, or for more information about the floodplain study, contact Kyle Comanor, King County project representative, at 206-684-1272.
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The King County Flood Control District is a special purpose government created to provide funding and policy oversight for flood-protection projects and programs in King County. The Flood Control District’s Board is composed of the members of the King County Council. The Water and Land Resources Division of the King County Department of Natural Resources and Parks develops and implements the approved flood protection projects and programs. Information is available at http://www.kingcountyfloodcontrol.org/.
Flooding Services and Information
River and Floodplain Management Section
Water and Land Resources Division