Alaska Risk MAP Program

Community Risk MAP Studies: City of Valdez

FEMA and the State of Alaska are conducting a coastal and riverine Risk MAP Study in the City of Valdez that began in 2011.

Study Scope

The scope of work of the City of Valdez 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.
• A riverine analysis will also be performed to include:
  • hydrology and hydraulic modeling for 3.8 miles of detailed riverine study on Mineral Creek
  • 11.7 miles of detailed riverine study on Lowe River
  • 4.6 miles of detailed riverine study on Valdez Glacier Stream
  • 2.2 miles of detailed riverine study on Robe River, and
  • 18.7 miles of approximate riverine modeling on various streams.
• Floodplain delineations and the Flood Insurance Study will be updated for the entire City.
• A draft map for the coastal analysis.
• The draft map for the riverine analysis.

Regulatory Products

• 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.
• 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 were released on August 25, 2014.
• All of the above datasets will be in the in the North American Vertical Datum of 1988.

Non-Regulatory Products and Technical Assistance

• A Changes Since Last FIRM map and dataset that identifies areas where the Special Flood Hazard Area, floodway, and/or flood zone designations have changed since the previous flood study. Engineering factors that may have contributed to the changes such as data used and level of study performed will also be identified. Estimates of structures affected by the changes will be quantified and summarized to capture increases/decreases in known risk areas and enable local officials to better plan for outreach needs.
• 1% annual-chance depth grids for coastal areas and approximate riverine analysis. The detailed riverine work will include 10%, 4%, 2%, 1%, and 0.2% annual chance depth grids. Depth grids depict the depth of flooding at locations throughout a city and when combined with other information, such as first floor elevations, are invaluable in understanding risk.
• Areas of inundation associated with +1, 2, and 3 feet increase to the base flood elevation for coastal areas to be used for planning purposes to represent sea level rise. Elevation increase values can also be adjusted using local sea level rise data as requested by the city.
• A non-regulatory Risk Report which include narratives on multiple hazards and risk exposure, and explains the risk assessment methodology and results for each city. The risk report will provide loss estimations using Hazus for flood, earthquake, and tsunami hazards. Flood depth grids and USGS ShakeMaps will be incorporated into the Hazus analysis. Local data will be added to Hazus for more accurate results. Other natural hazards will include a summary and an exposure analysis.
• The Flood Risk Database which houses data collected, created, and analyzed during the project. This data can be used by the City to recreate maps, develop reports and other products, and to perform additional analysis.
• Highlight areas where risk reduction actions may produce the highest return on investment.
• Provide the City with technical assistance for HAZUS projects.
• Provide the City with Areas of Mitigation Interest findings and recommendations based on best available data.
• The State and FEMA will provide guidance, feedback, coordination and technical support throughout the Risk MAP Project Life Cycle.

Project Status

The Letter of Final Determination (LFD) was issued on July 3, 2018. An LFD is a letter FEMA sends to the Chief Executive Officer of a community stating that a new or updated FIRM or DFIRM will become effective in six months.

Next Steps

The City of Valdez FIRMs became effective on January 3, 2019, six months after the Letter of Final Determination was issued. City officials were mailed the Revalidation Letter that lists previously issued Letters of Map Change (LOMCs) that have been reaffirmed for the new FIRM. The Revalidation Letter becomes effective one day after the publication of Valdez new final FIRM. The Revalidation Letter does not list LOMCs that have been incorporated into the revised panel, LOMCs that are superseded by new or revised mapping, or LOMCs that are no longer valid. While the Summary of Map Actions (SOMA) is a preliminary assessment of which LOMCs may still be valid after the new maps are issued, the Revalidation Letter is the final, effective determination of the LOMCs which remain valid. The SOMA and the Revalidation Letter are meant to assist community officials in the maintenance of the community’s FIRM.

A multi-hazard Risk Report for the Valdez area is being prepared as part of the ongoing Risk MAP study. The Risk Report will include a risk assessment of earthquake, flood, and tsunami hazards. Hazus, FEMA’s loss estimation software, will be used to assess earthquake and flood hazards. Once all risk assessments are completed, they will be compiled into the Risk Report.

The following table illustrates project status and includes major milestones with dates:

*All projected dates are subject to revision as the project progresses

Map of Valdez Study Scope

Click on image to open larger map

Contact for More Information

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 1650
Anchorage, AK 99501-3569
Phone (907) 269-4588
Fax (907)269-4539
Email: sally.cox@alaska.gov

Revised 10/27/2023