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Can hydropower leave its plantation legacy behind on Kauaʻi?

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On a cool March evening almost 135 years ago, residents of Honolulu drew back their curtains and found themselves blinking.

A bright, new kind of light flooded the streets. The street lamps of the kingdom's capital city had come awake with electricity for the first time.

And what 19th-century energy source powered the sudden illumination? Not coal or gas, but a small hydroelectric power plant tucked into Nuʻuanu Valley.

Hydropower has been powering Hawaiʻi for decades, and the way it works hasn’t changed all that much.

"It's just basically transferring the potential energy of water falling at higher elevations into usable or kinetic energy by spinning turbines," said Matt Rosener, a hydrologist and water resource engineer.

History of hydropower on Kauaʻi

Rosener has spent 15 years as a stream restoration consultant on Kauaʻi, which has its own long history with hydropower.

"The primary driver behind hydropower development in the islands was the need for electricity and water for the plantation systems," Rosener said.

The McBryde Sugar Company built the first hydropower plant on Kauaʻi in 1906. By the 1950s, half of the island's energy came from hydropower. The plantations diverted millions of gallons of water out of natural stream beds for irrigation and power — and some of those diversions continued long after the sugar era ended.

Now, Rosener said, the community on Kauaʻi is reckoning with that legacy, and trying to figure out the best way to balance the demands of agriculture and power production with stream restoration efforts.

"With no more need to divert water for sugar production, there is this discourse that's happening about what happens with the water," Rosener said.

Stream diversion can degrade habitat for native species, as well as lead to detrimental sediment build-ups downstream, Rosener said. "There's a lot of debate going on about how much water should be left in the stream versus how much should continue to be diverted, if any, at all."

Waimea River runs through Waimea Canyon in this photo from the 1920s.
Hawaiʻi State Archives
Waimea River runs through Waimea Canyon in this photo from the 1920s.

Kauaʻi Island Utility Cooperative pursues a modern hydropower plant

Amid these discussions, the Kauaʻi Island Utility Cooperative is pursuing a multi-year lease for a new hydropower plant on the Waimea River, called the West Kauaʻi Energy Project. The project would divert a rolling average of 11 million gallons of water a day.

WKEP seeks to combine solar PV + Battery Energy Storage with a pumped storage hydro project. KIUC estimates that once operational, the project could meet roughly 25% of Kaua‘i’s electricity needs.

It would also add several hours of energy storage capacity, which "will allow the island to run on 100% renewable energy for prolonged periods without sunlight," KIUC said in a statement.

KIUC also said WKEP would provide grid stability "by balancing intermittent solar with firm hydropower."

Although solar power is the darling of the renewable energy movement, many officials maintain that some kind of firm power, or power that can be produced 24/7, is critical to a resilient grid.

"That's why KIUC is very interested in hydropower, because the water can be stored and released at times when solar panels aren't producing energy," Rosener said. "So it's a nice balance for solar power in a lot of ways."

Hydropower plant proposal hits legal and cultural roadblocks

KIUC published a first draft environmental assessment for public comment in August 2021. Last September, a 3,300-page revised DEA was published for comment, and the utility submitted a final EA to the state Department of Land and Natural Resources in early December 2022.

DLNR issued a Finding of No Significant Impact in response, giving the project the green light to move ahead.

But the project hit a roadblock early this year when community organizations Pōʻai Wai Ola and Nā Kia‘i Kai filed a lawsuit against DLNR alleging the state agency failed to require an environmental impact statement for the proposed hydro-project.

Elena Bryant, an associate attorney with Earthjustice, is representing the plaintiff organizations in the lawsuit. Bryant said the DLNR is side-stepping its responsibility if they do not reverse the decision.

"An EA or environmental assessment is for a project that is not going to have a significant impact on the environment," Bryant said. "An EIS would require KIUC to fully look at alternatives and mitigation measures."

"The type of legacy project KIUC and AES are proposing is exactly the type of action that should be subject to full environmental review through the preparation of an EIS," she added.

John Aʻana is a kalo farmer on Kauaʻi and vice president of Pōʻai Wai Ola. He said the legacy of the plantations is part of why he wants to leave no stone unturned when it comes to the possibility of a new hydro-project.

"[The plantations] took away the water without anybody having any say about it," Aʻana said. "It really alienated a lot of Hawaiians from their lands...That's a real deep hurt."

Aʻana said that transparency is the key to winning the community's trust.

"For them to ask for the water to be taken away for another 65 years, that's our grandkids' time and whatnot. You know, that's not taken lightly," Aʻana said. "Maybe KIUC doesn't realize how important it is to Hawaiian and local people."

Calls for an environmental impact statement

In a statement, KIUC said, “The EIS process would not be expected to result in a different outcome or identify new information about the project. What is certain, is delaying the project would result in burning more fossil fuel, increased carbon emissions, and higher costs to our members.”

"A legal challenge to the extensive environmental due diligence that has been completed could delay the project for years," KIUC said. "In the meantime, every month the project is delayed an additional 6,600 tons of CO2 emissions — which could have been avoided — is released."

Bryant points out that the utility had originally considered completing an EIS before changing course.

In 2019, a draft Environmental Impact Statement Public Notice was prepared but not published, according to page 784 in Volume 5 of KIUC's environmental assessment.

"The community has been asking KIUC to do this for years now," Bryant said. "So had they had done it like they originally planned to back in January of 2019, this would be done already."

The hydrologist Matt Rosener sees the promise of WKEP, but still hopes KIUC completes an environmental impact statement.

"A lot of times we use the terms renewable and green energy interchangeably. That's not always true," Rosener said. "There are some hydropower projects out there that actually have pretty significant environmental impacts."

Savannah Harriman-Pote is the energy and climate change reporter.
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