Skagit County, Washington
May 21st, 2007
FEDERAL EMERGENCY MANAGEMENT AGENCY - SKAGIT COUNTY FLOOD INSURANCE STUDY UPDATE
Ryan Ike, Certified Floodplain Manager with FEMA Region 10, recently made a presentation to the Board of County Commissioners on The Skagit County Insurance Study Update. His presentation described the process, schedule and deliverables for the Insurance Study.
Mr. Ike pointed out that a different, more accurate elevation data set, known as NAVD 88, is being used on the new maps. The previous data set used for elevations on the current flood insurance maps, NGVD 29, can be converted to NAVD 88 elevations by adding 3.77 feet. For example, an elevation of 20 feet on the current Flood Insurance Maps = an elevation of 23.77 feet on the new maps that will be issued. So, the first 3.77 feet of increase in elevations shown on the new maps has nothing to do with deeper water or more flooding, it is simply a change in the datum used across the country for elevations represented on flood insurance maps.
Two other important points Mr. Ike made during his presentation are:
- The impact of utilizing different Skagit River Hydrology, which has been subject of much local debate, is a minor factor in the higher elevations that will be shown on the new maps. The primary factor contributing to the higher elevations, beyond the NAVD 88 issue described above, is the policy now used by FEMA when evaluating the impact of levees and failed levees that are subjected to a 100-year flood event.
flood insurance policy holders who can appropriately document they have maintained
a continuous flood insurance policy are eligible for 'grandfathering' at their
current rate, even if the new maps show them to be in new flood zone requiring
a higher rate.