Alaska Risk MAP Program

Community Risk MAP Studies

Ketchikan Gateway Borough


FEMA and the State of Alaska are conducting a coastal Risk MAP Study in the Ketchikan Gateway Borough that began in 2013.

Ketchikan Gateway Borough Risk MAP Discovery Documents

Ketchikan Gateway Borough Risk MAP Coastal Study Documents

The scope of work of the Ketchikan Gateway Borough Risk MAP Study includes (see also the map below):

  • A detailed coastal flood hazard analysis including the collection of storm surge (coastal hydrology) and overland wave height analysis (coastal hydraulics), as well as floodplain boundaries for 1-percent and 0.2-percent-annual-chance (100- and 500-year) flood events. Updated detailed modeling will be completed for 0.99 miles on Hoadley Creek, 1.2 miles of Ketchikan Creek, and 1 mile on Schoenbar Creek. Redelineation using new LiDAR will be completed for 0.08 miles of Carlanna Creek. The draft maps will be completed in Fall 2015.
  • Preparation of a regulatory Flood Insurance Study (FIS) Report document to the Community. A FIS is a book that contains information regarding flooding in a community and is developed in conjunction with the FIRM. The FIS, also known as a flood elevation study, frequently contains a narrative of the flood history of a community and discusses the engineering methods used to develop the FIRM. The study also contains flood profiles for studied flooding sources and can be used to determine Base Flood Elevations for some areas.
  • Preparation of a regulatory Flood Insurance Rate Map (FIRM) map for all panels within the Community which identifies the Community's flood zones, base flood elevations, and floodplain boundaries. This map is used to determine where the purchase of flood insurance is required for properties with federally-backed mortgages. The preliminary FIS and DFIRM’s are scheduled to be released in Winter/Spring 2016.
  • Collection of LiDAR data in Summer of 2014. This data will be delivered to the community in the Fall 2014.
  • All of the above datasets will be in the in the North American Vertical Datum of 1988.
  • The State and FEMA will provide guidance, feedback, coordination and technical support throughout the Risk MAP Project Life Cycle.

Status of Project

The project is currently in the Field Survey and Topographic Data collection stages. The following table illustrates project status and includes major milestones with dates:

Activity Actual or Projected End Date
Discovery Interview June 17, 2013
Discovery Meeting August 7, 2012
Base Map Acquisition February 2, 2014
Discovery Report Summer 2014
Perform Field Survey August 31, 2014
Develop Topographic Data November 30, 2014
Hydrologic Analysis December 31, 2014
Perform Coastal Analysis July 17, 2015
Hydraulic Analysis July 17, 2015
Perform Floodplain Mapping July 17, 2015
Develop DFIRM Database September 25, 2015
Draft Work Maps September 25, 2015
Produce Flood Risk Products November 30, 2015
Mitigation & Community Outreach March 30, 2016

The red line indicates denotes the extent of the Ketchikan Gateway Borough coastal mapping study
Ketchikan Study Scope Map

 

Ketchikan Discovery
(FEMA Region X Workspace)
  Ketchikan Gateway Borough
PIN Website
  FEMA Region X
Risk MAP Newsletters

For more information contact:

Sally Russell Cox

State of Alaska Risk MAP Coordinator
Division of Community and Regional Affairs
Department of Commerce, Community, and Economic Development
550 West 7th Avenue, Suite 1640, Anchorage, AK 99501-3569
Phone (907) 269-4588 Fax (907)269-4539
Email: sally.cox@alaska.gov