Hesco Barrier Phase 1

waterside view of flood barriers.

Latest Updates

01/03/2025: CBJ hosted a public meeting on Friday, January 3 to discuss the proposed LID and Phase 1 of the HESCO barrier flood mitigation project which included a presentation (Link to presentation). The recording of this meeting can be found on CBJ’s YouTube page (Link to recording)

12/16/2024: The CBJ Assembly amended and approved for distribution a proposed Local Improvement District (LID) which would distribute the anticipated $7.8 million project cost across the 466 property owners in the project area that would be impacted by a 16-foot flood event (40% of cost), with the rest borne by CBJ (60% of cost).

11/14/2024: CBJ and the U.S. Army Corps of Engineers hosted public events on November 12 and 14 to share knowledge and answer questions about flood preparations for homeowners. An electronic copy of the presentation is available HERE and a recording of the presentation and Q&A is available at https://youtu.be/Ohy0oD4uAU0 .

Project Background

The Mendenhall River Valley in Juneau, Alaska is under imminent threat of unusual flooding from what scientific experts expect will be recurring and likely record-breaking glacier lake outburst flood (GLOF) events. The impact and inundation area of these events have increased each of the last three years; a pattern that puts hundreds of homes and thousands of vulnerable residents, as well as critical infrastructure, public facilities, and community and medical services at risk.

CBJ is working tirelessly with Federal, Tribal, State and local partners to gather the additional information and resources needed to identify and implement a long-term solution. However, a long-term solution will take years before it can be implemented due to the unusual source and nature of the flooding and the complex hydraulics and engineering required.

Therefore, emergency mitigation and immediate flood resilience action is needed to protect the most vulnerable in our community before the 2025 GLOF season.

With extensive consultation and involvement from United States Army Corps of Engineers (USACE) flood fighting experts, CBJ plans to install USACE provided HESCO barriers as a near-term solution to mitigate potential widespread damage from future releases. Based upon factors such as the high-water marks obtained after the 2024 GLOF and the resources available to implement a solution before July 2025, a 2 mile stretch of riverbank was identified which would provide the most protection to the highest number of flood-vulnerable residents and homeowners. This is considered Phase 1 of CBJ’s formal flood mitigation efforts. This interim solution is intended to protect against GLOFs that are up to 20 ft high, or 4 feet higher than the 2024 GLOF event. CBJ will integrate the work of a comprehensive hydrological and hydraulic analysis to implement Phase 1 in a manner to avoid downstream impacts.

Proposed LID

A Local Improvement District, or LID, is a mechanism in CBJ code for a benefited property to pay for an infrastructure improvement (in this case, the installation of the infrastructure to protect properties and homes from flooding). LIDs are governed under CBJ Code.  The Mendenhall GLOF LID has been proposed by the Assembly in Ordinance 2024-40(am).  A copy of the Mendenhall GLOF LID frequently asked questions can be found here.

Project Summary

HESCO Barrier Phase 1 includes additional bank armoring, site preparation (obstruction relocation/removal, soil improvement), barrier placement, drainage installation, and barrier filling.  Additional project and associated information can be found in the Relevant Resources tab.

Project Timeline

  • January, 2025: 95% HESCO alignment published.
  • Jan/Feb, 2025: CBJ to refine alignment with riverfront property owners.
  • Feb/Mar, 2025: CBJ/Property owner MOU negotiation.
  • Mar/Jul, 2025: Bank armoring and barrier installation.

Community Outreach

Engagement with the community regarding the authorization, funding, and execution of this project is critical to successful implementation.  Formal outreach and engagement opportunities will continue to be scheduled (Assembly meetings, Neighborhood meetings, public presentations, and more).  Links to all the public meetings and associated meeting packets and recordings can be found under the “Public Meetings” section of the CBJ Flood Response webpage. Additionally, questions, concerns, and comments can be directed to [email protected].

Relevant Resources

Links to all of the public meetings and associated meeting packets and recordings can be found under the “Public Meetings” section of the CBJ Flood Response webpage.

HESCO Barrier FAQs

Riverfront Property MOU

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