The Hawaii office of Earthjustice, the environmental law organization, has been in the middle of some of the most contentious environmental issues in recent years — water rights, renewable energy, endangered species protection, sustainable agriculture — making a name for itself through aggressive advocacy and some significant legal victories along the way.

Just last month, Earthjustice won a court ruling to strengthen the state solar water heater mandate for new homes, closing a loophole that “developers had abused for years” to install tankless gas heaters, said Managing Attorney Isaac Moriwake.

“Now, the state energy office can no longer rubberstamp variances and give a free pass for gas at a time when Hawaii needs to get off the dirty stuff,” he said.

Moriwake, 47, grew up in Makiki and Hawaii Kai, and now lives in Kaneohe with his wife and two children. He graduated from the University of Hawaii’s law school in 1998, and clerked for Hawaii Supreme Court Justice Paula Nakayama, who would write the court’s 2000 decision on Waiahole Ditch affirming the public trust doctrine for water use.

He joined Earthjustice in 2002 and recently succeeded Paul Achitoff, who led Earthjustice’s Mid-Pacific outpost for much of its 30 years in the islands. Moriwake now leads a 5-1/2-member legal team (including himself).

He’s proud of Earthjustice’s successes, but notes it hasn’t all been smooth sailing.

“My very first case for Earthjustice 16 years ago was a loss,” he said. “We sued to stop cruise ship visits to Molokai. The lawsuit landed with a thud, but the cruise ship ended up canceling its visits in the face of community opposition. That’s an example of how you can lose the legal battle, but win the war.”

The biggest challenge?

“I think climate change eclipses everything else, not only in the long-term, but also in the near-term because it’s already happening, and we all needed to get serious on this yesterday,” he said. “The threats to Hawaii of rising seas, dying reefs and habitat chaos are starting to hit home. We’re no longer talking about stopping climate change, just hoping to avoid the worst catastrophes. But I believe we can — and must — do this, which is why I can still show up at the office.”

Question: Now that the big-plantation days are over, what are the biggest challenges to water rights and access to water as a public resource?

Answer: The plantations started phasing out decades ago, and the last big one shut down on Maui at the end of 2016. But I’m not sure the plantation days are “over,” because plantation politics and mindsets on water are still alive and well today.

Almost 50 years ago, the Hawaii Supreme Court ruled that water was not the plantations’ property, but rather a public trust that belonged to all, including future generations. This public trust law is enshrined in our state Constitution, and it’s now a leading-edge model for the nation and even the world.

But the successor companies to the old plantations are still trying to hoard water as their own. For example, in our Na Wai ‘Eha (“The Four Waters”) case on Maui, the former C. Brewer plantation sold off all its agricultural lands, then turned into a “water company” trying to sell diverted stream flows to developers. We’ve spent 15 years battling that company and Alexander & Baldwin’s former HC&S plantation. And while we now have all four streams flowing to the ocean, believe it or not, that case isn’t over yet.

On Kauai, we’re dealing with diversions of two streams flowing from Mount Waialeale, which is revered in Native Hawaiian culture and the hula tradition for its sacred water. The former plantation there drained the streams dry for sugar, but when it closed down it handed the diversion ditch, along with a couple of small plantation hydro plants, to the local electric utility. Kauai Island Utility Cooperative (KIUC) wants to keep those 19th-century diversions going and calls it “renewable” energy, but that just renews the cultural insult and injury for a whole new century. This is Hawaii, and you have to be environmentally and culturally pono.

And now, the Legislature is going off the rails, pushing a bill (House Bill 1326) that would give diverters of water from state-owned lands — including the new buyer of A&B’s plantation lands and KIUC — a blank check to keep taking the water with zero accountability.

That’s what I mean by the plantation days are over, but they’re not over.

Q: What are the possible consequences of a U.S. Supreme Court decision on whether Maui County violated the Clean Water Act?

A: We’re confident that the court will affirm the prior rulings in this case, which concluded it would make a mockery of the Clean Water Act to let Maui County use the groundwater under its Lahaina plant as a sewer to convey millions of gallons of wastewater each day to the ocean. Peer-reviewed studies by government and university scientists have conclusively established that the wastewater discharges are destroying the formerly pristine reef at Kahekili Beach, violating the Clean Water Act’s mandate to protect the nation’s water quality.

A decision from the court reaffirming that the county cannot freely pollute the ocean would have far-reaching consequences across the U.S.

A who’s who of the nation’s worst polluters has lined up in support of the county’s attempts to convince the court to blow a hole into the Clean Water Act. Earthjustice will do everything in our power to prevent that from happening.

Q: What are some top priorities for Earthjustice’s Hawaii office?

A: We hope to bring the Na Wai ‘Eha case to a pono conclusion that establishes a model for 21st-century ahupua‘a-based water stewardship. The current phase of the case is the biggest top-to-bottom adjudication of water rights in Hawaii history. It will decide not only the restoration of more stream flows because of HC&S’s closure, but also the rights and permits for every stream water user in the region, including individual ohana who have been farming kalo for generations.

In the Lahaina sewage treatment plant case, we want a pono resolution that stops the degradation of the beaches and reefs and upholds our nation’s bedrock legal protections of clean water.

We’re engaged in a landmark case before the state Public Utilities Commission to reform the incentives of the Hawaiian Electric utilities to a performance-based system. The traditional utility business is “build more to profit more,” but the wave of the future is to tie utility financial incentives to its performance in serving customers and the public.

Q: What would you consider to be Earthjustice’s most important legal victories over the past 30 years?

A: When we recently celebrated our 30th anniversary, the moment really opened our eyes to how far we’ve come. Some of our most important victories:

>> Established landmark precedent that water is a public trust in the Waiahole Ditch case on Oahu, and built on that precedent on Maui and Kauai.

>> Ended military live-fire training in Makua Valley on Oahu.

>> Protected endangered sea turtles from bad practices in the Hawaii-based longline fishery, marine mammals from the use of Navy sonar and explosives, and seabirds from power lines and light attraction, and more.

>> Helped build Hawaii into a world leader in rooftop solar, and defeat the proposed takeover of Hawaiian Electric Co. by NextEra and the plan to switch the utility to imported gas.

Q: How would you rate Hawaii’s progress in adopting renewable energy?

A: I like how a friend described it: Hawaii gets an “A” on mandates, but so far, maybe a “C+” on implementation. Renewable energy is already cheaper than imported oil and gas, but we’ve been grinding a bit trying to get it in full gear. HECO has stopped trying to sidetrack us to importing gas and is better focused on increasing renewables.

The transportation and building sectors are the next frontiers where we need tons of progress ASAP. We can make the state’s 2045 100 percent renewable energy goal, but don’t take my word for it: HECO has already said we can do it, before 2045.

Q: Are our land-use laws and policies generally sound?

A: Like our water law, I think our land use laws and policies are sound, but again, implementation and enforcement is the problem. Big landowners and big dollars always seem to trump planning vision. I see Oahu moving on urban infill like in Kakaako, but for whom? Meanwhile, prime ag land is still being lost to suburban sprawl on Oahu, and to luxury mansions and fake farms on the neighbor islands. We can do better.