Grants Administration

Community Development Block Grant – Disaster Recover (CDBG-DR) – 2024 Juneau Flooding (Zip Code: 99801)

FEMA Disaster #4836

Juneau 99801 area map

The Department of Commerce, Community, and Economic Development works to rebuild Alaskan communities by putting Alaskans back in their homes, restoring critical infrastructure and mitigating future damage through resilient community planning.

The Division of Community and Regional Affairs is the lead agency for administering the U.S. Department of Housing and Urban Development (HUD) Community Development Block Grant Disaster Recovery for the 2024 Juneau Flooding (CDBG-DR 2024 Juneau Flooding) funds on behalf of the State of Alaska.

Glacial Dam Outburst Flooding

A glacial dam outburst flood (GLOF) occurred in the Mendenhall Valley, approximately 10 miles northwest of downtown Juneau, on August 5-6, 2024. The flood originated from Suicide Basin; a side basin located less than one mile from the terminus of the Mendenhall Glacier. Suicide Basin was once filled with ice from Suicide Glacier, but as the glacier has receded, ice is no longer deposited into the basin. Now, water from annual snowmelt, ice melt, and rainfall fills the basin. In addition to a calving face of the glacier that holds back water in the basin, floating icebergs from ice calving off the main trunk of the Mendenhall Glacier further complicate the understanding of this dynamic system, along with other factors. Suicide Basin fills up annually and has drained multiple times per year, with some events producing minor or moderate flooding impacts and others producing no impacts along Mendenhall Lake and River. The U.S. Geological Survey (USGS) stream gauge was installed in 1965. There were no documented impactful glacier outburst events recorded by the stream gauge until July 2011. The Mendenhall Glacier and River system has experienced approximately 39 glacial-dammed lake release events since July 2011. Release volumes of GLOFs vary considerably. Many releases are relatively small, less than 10,000 AC-FT. Three releases, occurring in 2016, 2020, and 2022, were between 24,500 and 29,000 AC-FT. On August 5, 2023, Suicide Basin nearly fully drained, releasing approximately 44,500 AC-FT and causing the Mendenhall River to reach a new record crest of 14.97 FT (gauge datum). In August 2024, the basin fully drained again, releasing a preliminary amount of approximately 49,000 AC-FT and causing the Mendenhall River to set yet another preliminary record crest of 15.99 FT (gauge datum), almost a foot higher than 2023. The 2023 and 2024 releases were so much larger than the previous releases because the basin drained nearly completely in these two cases; prior releases only accounted for a portion of the basin’s dammed volume. In 2024, Suicide Basin filled to the top of the Mendenhall Glacier on August 1st, reaching a maximum pool height of approximately 1,381 FT (gauge datum) and began to flow over the side drainage channel. On the morning of Sunday, August 4th, 2024, Suicide Basin began dropping quickly as the drainage started subglacially, and Mendenhall Lake slowly began to respond, causing a Flood Warning to be issued by the National Weather Service’s Juneau Weather Forecast Office (WFO). The pre-GLOF release stage at the Mendenhall Lake gauge was approximately 5 FT (gauge datum), rising to minor flood stage of 9 FT by August 5th, 2024 at 9:15 AM, moderate flood stage of 10 FT by August 5 at 12 PM, major flood stage of 14 ft by August 5th at 9 PM, cresting at 15.99 FT on August 6, 2024 at 3:15 AM, and falling back to a baseflow of 5.7 FT by the afternoon of August 7th, 2024. The Mendenhall River remained above flood stage for approximately 28 hours.

River Flooding

The flood on the Mendenhall River from August 5-6, 2024, was caused by the release of a glacial-dammed lake adjacent to the Mendenhall Glacier. The preliminary peak stage was 15.99 FT (gauge datum), measured at the USGS stream gauge. The preliminary estimate of the release volume for this event is approximately 49,000 AC-FT. The previous record peak stage was 14.97 FT (gauge datum) on August 5, 2023. The record major flooding from this event was a result of the volume that came out of the basin at one time and the rate of rise. From Monday morning to the crest early Tuesday morning, the rate of rise on the river was around 0.4 FT per hour. The rate of rise was faster in 2024 than 2023, which could be due to a more efficient subglacial conduit drainage system, primed by a previous atmospheric river. The total water level rise at the USGS Mendenhall Lake gauge from the onset of the glacier-dammed lake release to the peak was around 11 FT and occurred over 36 hours. The rate of rise of Mendenhall Lake and the Mendenhall River, which flows six miles from Mendenhall Lake into Fritz Cove, was similar to the event in 2023; however, the peak stage in 2024 was one foot higher. These two large GLOF events were unprecedented compared to GLOFs before August 2023. The preliminary peak discharge from this event at the Mendenhall Lake gauge was 33,400 cubic FT per second (CFS) versus the 26,000 CFS crest in 2022 and the 16,300 CFS record from July 2016. The outburst event increased discharge into Mendenhall Lake and River by approximately 30,500 CFS. A joint Individual Assistance and Public Assistance Preliminary Damage Assessment was conducted from August 26 to September 03, 2024. A formal request for disaster declaration was submitted on September 19, 2024, and officially declared on October 16, 2024.

Resilience Planning and Practices

Planning is essential to ensure Alaskan communities, residents and businesses are prepared for future disasters. Hazard Mitigation Planning activities help local leadership and the public decide how to allocate funds for housing and infrastructure that is more resilient and reduces the risk of death, property damage, and suffering from natural disasters.

The State of Alaska Department of Commerce, Community, and Economic Development (DCCED) is collecting input on which activities could do the most to decrease risk and benefit the most people.

Resilience Planning: Uses hazard risk assessment to identify where floods, seismic activity, tsunamis, and landslides can cause harm to residents. It determines places where new housing will be safer, but where people will still be connected to transportation, schools, grocery stores and houses of worship. With lots of people looking for temporary and permanent housing, there is a shortage of safe, affordable housing in areas affected by disasters. Resilience planning helps to ensure housing and infrastructure are safe for the next generation and beyond.
Watershed Management: Brings together communities that are connected by a river or stream to balance the effects of disasters and helps people work together to understand and manage flooding, seismic activity, and other risks.
Natural Flood Protection: Includes strategies like creating constructed wetlands for floodwater storage and restoration of vegetated buffers.
Learning Tools of the Trade: Includes training and learning from local government officials, businesses or nonprofit organizations to help communities be more prepared and safer from disasters.
Home Retrofits: Includes updates and fortifications to homes and individual residences that reduce risks during severe weather and flooding. Retrofits can also include improvements to reduce risk of wildfire events.

Public Notices

CDBG-DR Administrative Action Plan

CDBG-DR 2023 and 2024 Floods Administrative Action Plan

CDBG-DR Citiozen Participation Plan

CDBG-DR Language Access Plan

Applicable Plans

Programs

State Administration / Not to exceed 5%
State and Local Planning / Not to exceed 15%
Resilience and Mitigation / Not to exceed 15%
Public Services / Not to exceed 15%
Housing Recovery (New Construction, Reconstruction, Rehabilitation)
Public Infrastructure Recovery
Economic Revitalization

Related Applicable Laws and Regulations

Procurement Policies

Procurement Academy, Office of Procurement and Property Management, State of Alaska

Confidential Citizen Complaints may be filed at:

https://ak-ombuds.i-sight.com/portal

or in writing on a complaint form, mailed to

Alaska Ombudsman
1500 West Benson Blvd.,
Anchorage, AK 99503

or via email to

ombudsman@akleg.gov

or by telephone at

907-269-5290

Report Fraud, Waste, and Abuse in HUD programs to

https://archives.hud.gov/offices/pih/programs/ph/rhiip/uivreporting.cfm

For more information about Alaska CDBG-DR Grants contact

Contact DCRA staff at CDBG-DR-Juneau@alaska.gov

Kevin Bartley
Division of Community and Regional Affairs
Department of Commerce, Community, and Economic Development
Location: Anchorage
Phone: (907) 269-7985
Fax: (907) 269-4563
kevin.bartley@alaska.gov

Revised 03/24/2025

Content Reviewed 04/03/2025

The State of Alaska, Department of Commerce, Community, and Economic Development (DCCED), complies with Title II of the Americans with Disabilities Act of 1990. This publication is available in alternative communication formats upon request. Please contact the DCRA Publication Specialist at 1-907-269-4560

Department of Commerce, Community, and Economic Development Division of Community and Regional Affairs