How did King County earn a Class 2 rating?
Participating communities receive points for their local floodplain management activities. Floodplain management activities fall into four categories:
- Public information
- Mapping and regulations
- Flood damage reduction
- Flood warning and response
Public information credits
King County receives credit for its wide range of public information services:
- Maintaining information on FEMA elevation certificates and making them available to the public;
- Maintaining and providing information on floodplain maps;
- Providing information on flood insurance purchase requirements;
- Conducting outreach to floodplain property owners through the mailing of a flood warning brochure and through a public outreach strategy developed with incorporated cities;
- Disclosing flood hazards through notices on title, permanent signage, floodplains delineated on plat maps and real estate transactions;
- Making floodplain information available online and at public libraries; and
- Providing flood protection assistance to property owners through walk-in inquiries at the Department of Local Services - Permits and outreach bulletins.
Mapping and regulation credits
King County has completed floodplain mapping studies on hundreds of miles of river and coastal shorelines. Flood hazard mapping activities contribute to King County’s overall CRS credit. King County also maps channel migration hazard areas.
King County has preserved several thousand acres of open space within the regulatory floodplain and receives additional credit for maintaining those properties in a natural state (i.e., no development) to provide beneficial floodplain functions.
King County has adopted several regulations that exceed the minimum NFIP standards, including, but not limited to:
- A three-foot freeboard (height above the base flood elevation) standard for most structures and three-foot standard for critical facilities;
- Requirement to provide compensatory storage at the same elevation for fill placed in the floodplain;
- A zero-rise standard throughout the zero-rise floodway to preserve flood conveyance;
- Restriction on development in areas where depths exceed three feet and velocity exceeds three feet per second;
- Requirement for new lots to have at least 5,000 square feet outside the zero-rise floodway;
- Restriction on non-residential structures in the FEMA floodway, with some exceptions for agricultural buildings;
- Standards for manufactured home parks located in the floodplain;
- Requirement to remove temporary structures and hazardous materials from the floodplain during the flood season;
- Restriction on critical facilities in the zero-rise floodway and FEMA floodway, with some exceptions;
- Density restrictions in portions of the floodplain under land use and critical areas protection measures; and
- Regulating development within channel migration.
King County also receives credit for maintaining surveyed benchmarks, geographical information systems flood data layers and copies of all flood insurance rate maps issued for the community. View an interactive map with flood and channel migration areas (requires a popup window).
King County’s Surface Water Design Manual earns the county CRS credits for water quality and quantity standards.
Flood damage reduction credits
King County conducts a wide range of outreach projects each year to mitigate FEMA repetitive loss properties within unincorporated King County.
Since forming in 2007, the King County Flood Control District has provided funding and technical support for the following flood risk reduction accomplishments (as of Oct. 2013):
- 70 construction projects completed to reduce flood risks in King County;
- 50 homes (as of 1993) and three agricultural structures elevated above 100-year flood levels (King County Home Elevation Program and Buyout Program); and
- 101 properties and 287 acres in the floodplain acquired to move people out of harm’s way and reduce repetitive loss.
Credit is also provided for King County’s drainage system annual inspection and maintenance program, along with a capital improvement program to repair problems areas.
Flood warning and response credits
King County receives credit for its Flood Warning System operations and the National Weather Service's StormReady designation. In addition, King County received credit for the Washington State Dam Safety program for dam operations on several of the major rivers in King County.
A robust flood warning communications program provides advance warning to nearly 8,000 subscribers (as of October 2022) to the automated King County Flood Alert.