KIUC to study hydro diversions

LIHUE — Kauai Island Utility Cooperative announced Friday that the board has put money toward environmental studies for the Blue Hole and Waikoko diversions, which support the cooperative’s request for a long-term lease for the two diversions.

The Blue Hole and Waikoko diversions supply water to KIUC’s upper and lower Waiahi hydroelectric plants.

“KIUC remains committed to responsible operation of all of our facilities in pursuit of the state’s mandate to achieve 100 percent renewable generation,” said KIUC’s President and Chief Executive Officer David Bissell. “We will continue to collaborate with all state and federal agencies with jurisdiction over these waters to ensure our natural resources are appropriately protected.”

Both diversions are operated and maintained via a revocable permit pending completion of tasks in support of the lease application process.

The hydro plants have been in operation for nearly a century, and are an important component of KIUC’s renewable energy mix, according to KIUC representatives. The energy generated by the plants displace the use of roughly 500,000 gallons of diesel annually, and is KIUC’s lowest-cost source of power.

Diverted water also provides irrigation for agriculture, supports recreational activities, and provides a source of drinking water.

Stream and habitat surveys are included in the additional studies, which will support the environmental review process as required under Hawaii law.

Department of Hawaiian Homeland officials were contacted to ensure their water needs are considered under the lease approval process.

The decision ultimately will be subject to approval by the state of Hawaii’s Board of Land and Natural Resources.

At its December meeting, the KIUC Board approved authorization for short-term modifications to diversions at Blue Hole, Waikoko Stream and Iliiliula Stream, which will immediately return some water to these tributaries and reduce flow to the hydro plants. Work on the short-term modifications is already under way, along with improvements to flow gauging infrastructure.

Work on design and implementation of long-term modifications that will ensure mauka to makai flows in both the North Fork of the Wailua River and Waikoko Stream has also been authorized by the KIUC Board. Those designs will be finalized once the State Commission on Water Resources Management has established interim instream flow standards for the North Fork of the Wailua River.