Investing in the Future

Waiau Transmission Structure Replacements

Waiau Transmission Structure Map

Hawaiian Electric plans to replace lattice structures that carry critical high-voltage transmission lines (shown by the yellow lines in the map above) starting from the Waiau Power Plant through Pearl City and across the island. The structures were installed in the 1960s and are due for replacement. As part of the utility’s modernization efforts and to ensure continued safe, reliable electric service, each existing lattice structure will be replaced with two new steel poles for a smaller footprint.

The map below shows the locations of structures 1-9 in 1968 and today, where residential development has since expanded around these structures.

Site inspections for structures 4-7 (circled in red) were completed in 2023 and the design and construction phase is anticipated to occur in 2026-2028. Affected customers located nearby will be notified in advance of the planned work.

Waiau Historic Map
Waiau Modern Map

The structure replacements will be completed in phases:


The pre-construction phase will involve:

  • Outreach to neighboring customers and the neighborhood board
  • Notifications to affected customers regarding planned work
  • Site inspections to determine clear access and safe work requirements
  • Clearing of vegetation and obstructions in the easement, as needed
  • Certain permitting requirements that require site inspections for biological, archaeological, and cultural surveying.
  • Topographical surveys around the structures


The construction phase will focus on:

  • Notification to affected customers, including any planned outages
  • Installation of foundations
  • Installation of new poles
  • Transfer of power lines from lattice structure to new poles
  • Removal of lattice structures

For updates on the project schedule, please bookmark and refer to this webpage as work progresses.

If you have questions or comments, please email or call (808) 543-4000.

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