Floodplain Development Regulations Update - Background


In February 2020, FEMA published a Flood Hazard Determination adopting a new Flood Insurance Rate Map (FIRM) and Flood Insurance Study (FIS) for all jurisdictions in King County, including Seattle. FEMA's adoption of the new FIRM and FIS requires that each jurisdiction update their regulations with this new information in order to comply with the National Flood Insurance Program (NFIP).

In addition to adopting the new FIRM and FIS, the City of Seattle is required to have floodplain regulations that apply to the new maps that did not apply to the existing 1995 FIRM and FIS. These requirements come from the NFIP regulations in Title 44 of the Code of Federal Regulations (CFR). Specifically, 44CFR section 60.3e contains regulations for coastal high hazard flood zones, which were not identified on the 1995 maps. These coastal flood zones are designated as VE zones on the new FIRM.

FEMA finalized the Flood Insurance Rate Map and Flood Insurance Study for King County on February 19, 2020. FEMA requires that all jurisdictions within King County adopt the new Flood Insurance Rate Map and Flood Insurance Study within six months of the February date, which was August 19, 2020. Additionally, local FEMA officials reviewed Seattle's floodplain regulations and this review directed the minimum amendments to the Floodplain Development Regulations (SMC 25.06) to meet 44 CFR Section 60.3 (d and e) for the August 19, 2020 deadline.

We updated the Floodplain Development Regulations through interim regulations as provided in RCW 36.70A.390. New interim Floodplain Development Regulations and floodplain maps took effect on August 23, 2020. These interim regulations will be effective for approximately six months while we work on permanent regulations.

Properties within areas mapped as special flood hazard areas are required to meet standards intended to protect the occupants' lives and mitigate damage to property and buildings. The standards vary by the specific flood zone designations, characteristics of the property, and the nature of the development proposed. Generally, the requirements include:

  1. The elevation that the first floor of a new structure must be built at to keep the first story above anticipated flood levels
  2. Structures must be engineered to withstand wind from anticipated storms
  3. Structures must be engineered to withstand flood waters should anticipated flood levels be exceeded

Additionally, if your property is in a FEMA mapped area, flood insurance may be required by your mortgage lender, if you have one. For additional information from FEMA regarding flood insurance please see FEMA's website.