Hesco Barrier Phase 1

Latest Updates

5/12/2025: The CBJ Assembly approved extending the HESCO barrier installation to Phase 1A, as described in this memo. View the Special Assembly COW meeting materials and meeting recording. Work to begin on May 13, 2025.

05/10/2025: Barrier installation work is complete. CBJ continues area cleanup and installation of storm drain improvements.

05/08/2025: New Flood Inundation Maps are now available here. The maps demonstrate the effectiveness of the HESCO barriers for floods similar to those experienced in 2024.

04/30/2025: During the first three weeks of April, technical consultants from USACE inspected and approved the work performed thus far for compliance with USACE and manufacturer standards . The project reached approximately 70% completion as of April 28.

See “Timeline & Status” below for additional updates.

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.

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.

Estimated 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.

Project Status Updates:

5/12/2025: The CBJ Assembly approved extending the HESCO barrier installation to Phase 1A, as described in this memo. View the Special Assembly COW meeting materials and meeting recording. Work to begin on May 13, 2025.

05/08/2025: New Flood Inundation Maps are now available here. The maps demonstrate the effectiveness of the HESCO barriers for floods similar to those experienced in 2024.

04/30/2025: During the first three weeks of April, technical consultants from USACE inspected and approved the work performed thus far for compliance with USACE and manufacturer standards . The project reached approximately 70% completion as of April 28.

04/09/2025: CBJ contractors have installed over 2500 linear feet of HESCO barriers along the project route. Bank armoring and the installation of new one-way storm drain check valves continues. We greatly appreciate the continued cooperation and communication with riverfront homeowners and the wider community.

03/24/2025: CBJ contractors began installing the first HESCO barriers the project route, beginning along Killewich Drive.

03/21/2025: CBJ encourages riverfront property owners in the HESCO barrier project area to research their property’s drainage system to identify the inlet and outlet to all drainpipes. CBJ released an FAQ document with guidance on this topic.

03/19/2025: Contractors began site and access preparation for the HESCO barriers. Please watch for construction equipment and personnel, obey construction traffic control signage.

Four contractors have been selected to perform construction and installation work for Phase 1: Admiralty Construction, Coogan Construction Company, G. R. Cheeseman Construction, North40 Construction Corporation.

Please watch for construction equipment and personnel, obey construction traffic control signage, and stay alert while in and around the work areas to ensure the safety of yourself and others.  We appreciate your understanding and patience.

03/03/2025: The LID ordinance (link) is now in effect. CBJ project managers and contractors are conducting site visits at homes where barriers will be installed. HESCO barriers and flood fighting materials are in transit to Juneau. The Assembly approved the “Notice to Property Owners and MOU” (View Memo and meeting materials).

02/03/2025: The proposed LID passed by at the February 3, 2025 Assembly meeting. View the public hearing meeting materials and objections submitted here.

01/27/2025: CBJ staff presented an a status update and overview of the variety of grants, funding partnerships, funding agencies, and activities being pursued (as of 1/22/25) to support the Phase 1 HESCO and other efforts to meet Juneau’s flood preparedness, response, and/or mitigation needs at the January 27 Assembly PWFC meeting. (Link to memo, funding overview)

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 .

HESCO Barrier Project 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.

HESCO Barrier FAQs

Riverfront Property Memorandum of Understanding (MOU)

At the March 3. 2025 Assembly meeting, the Assembly and the public were provided with a copy of the Notice to Property Owners and Memorandum of Understanding (MOU) being sent to riverfront property owners who will have HESCO barriers installed on their property.

CBJ distributed copies of the Notice to Property Owners and the Memorandum of Understanding to all affected property owners. Project managers in the field will have copies of the MOU and will work with property owners to document their unique circumstances and conditions.

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.

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