Current Interisland Cable Activities

A series of six photographs featuring animals and plant life on the ocean floor in Hawaii; three on top and three on bottom. The first photo on the top left reads RCV-440, south of Honolulu Harbor. The first, second, and third photos on the bottom read Solitary bamboo coral, Towcam17; Sponges on rippled sediment, Approaching Ilio Pt. NW Molkai, Towcam 2; Seastars on sand near Ilio Pt. NW Molkai, Towcam 13.

Fish, rays, seastars, urchins, seapens, and sponges were sparsely observed on UHM-SOEST video tows and remotely operated vehicle (ROV) dives along the proposed cable routes. Exceptions to this generally occur in the precious coral beds on the slope east of the Makapu‘u Shelf and along the easterly transect of Penguin Bank. UHM-SOEST recommended against the two routes originally considered to cross these benthic habitats, both of which entail longer stretches in the Humpback Whale Sanctuary.

The state Department of Business, Economic Development and Tourism (DBEDT) is coordinating the engineering and design of the proposed interisland power cable. Having confirmed the technical feasibility of the cable and identified a number of potential routes, the state of Hawai‘i must now determine

  • How to precisely lay the cables around deep-water obstacles (e.g., former reefs, dumped materials, munitions)
  • How to connect the cables to shore under (via micro-tunnels) and/or over (via dredged micro-channels) fringing coral reefs that are up to 2 km across
  • Whether and/or how to bury the cables in areas of hard substrate.

These issues will be addressed through assessments of the undersea cable's environmental impact and will be resolved by the time the cable developer is hired.

Environmental Impact Studies

DBEDT is responsible for securing all required offshore and onshore land rights permits and approvals for the cable, including environmental impact assessments. The following environmental impact documentation is required:

  • An environmental impact statement (EIS) drafted by DBEDT (with input from the wind developers on Lana‘i and Moloka‘i and the utilities on O‘ahu and Maui)
  • Environmental assessments (EAs) and/or EISs for individual wind farms drafted by wind developers on Lana‘i and Moloka‘i
  • EAs and/or EISs for the utility infrastructure upgrades on O‘ahu and Maui drafted by Hawaiian Electric Company (HECO) and Maui Electric Company (MECO).

DBEDT is moving forward with the request for proposals process for the EIS, which will consider

  • Impacts of the cable's installation, operation, maintenance, repair, and long-term development
  • Mitigation strategies
  • Alternatives.
Department of Energy
State of Hawaii