Lahaina, the former capital of the Hawaiian Kingdom, was once a thriving, ecologically diverse landscape full of fish ponds and diverse crops that included sweet potatoes, kalo (taro), and ‘ulu (breadfruit). But colonization, and the extractive agricultural systems that came with it, had a devastating impact on reshaping the landscape ecologically, culturally, and economically—not only depleting soils of fertility but making much of the island more fire-prone.

As these maps of historic sugarcane lands and pineapple lands illustrate, the two crops covered vast portions of West Maui.

The sugarcane and pineapple industries reigned for nearly two centuries, with monocropping farming methods made exceptionally profitable with indentured servitude. This process transformed natural ecosystems, as the companies diverted water from wet areas of the island to irrigate the fields in the drier parts.

As workers slowly gained rights, profits plummeted, and Brazil and India became competitors of cheap sugar production. Maui’s last sugar mill, the 36,000-acre Hawaiian Commercial & Sugar, Co. (HC&S), shut down in 2016, and the land was left in the hands of management company Alexander & Baldwin.

Now, tens of thousands of acres that had been used for sugarcane and pineapple production sit untended, much lying fallow, some overrun with non-native grass species, or in the hands of development companies who aim to offset the economic loss of agricultural production with tourism. Meanwhile, local communities are engaged in an ongoing battle for water rights as the residents of Hawaii look toward rebuilding.

Civil Eats spoke with Noa Lincoln, an assistant professor of Indigenous crops and cropping systems at the University of Hawaii, Manoa, about water diversion, deforestation, and Big Ag’s impact on Maui.

Will you briefly describe the history of sugarcane? When did it get to Hawaii and what were some of its benefits?

Sugarcane was introduced to Hawaii probably about a millennia ago by Polynesians. It played a pivotal role in a broad range of traditional cropping systems before Europeans’ arrival.

We have very recent work that shows that it has high nitrogen fixation potential, and it was probably critical in the long-term sustainability of our dryland systems for nitrogen dynamics. It plays really important hydrologic functions in certain systems, acting as a windbreak. It’s one of the world’s highest biomass producers, so it was critical for mulching and labor maintenance in terms of weeds and covering the soil.

And sugarcane itself is actually a tremendously powerful tool, when applied properly, and it enhances soil health and ecosystem function within agricultural systems. Which then, of course, becomes very ironic in terms of how the plantations then [put] a horrible, detrimental end to our soil quality.

What conditions did the sugarcane thrive in originally?

Pretty diverse conditions. [Many] varieties of sugarcane tend to be much more grass-like, much more acclimated to dry habitats. When you look at the wild occurrence of these sugarcane ancestors, they occupy everything from inundated bogs, all the way to pretty dry mesic habitats. Polynesians, as they traveled across the islands, occupied a broad range of habitats, and selected varieties that performed across a broad spectrum of habitats.

While everyone always thinks of sugarcane as a very thirsty crop [that] can take up a lot of water, it is also actually drought adapted. It’s coated in wax to reduce water loss. It has amazing stomatal control, so it can really close itself up and reduce its water loss. So, yes, if you pump them full of water, you are going to get more production. But, actually, sugarcane can perform and produce across a range of habitats, including pretty dry habitats.

Can you describe the diversion of water for sugarcane?

You could grow sugarcane without irrigation in the wet areas of Hawaii, but you had lower sunlight, so you got lower yields. A lot of the plantations wanted to exploit the drier, mesic areas of Hawaii, which have better sunlight and significantly better soil. A lot of the big water diversions are to move water from these wet areas out into the mesic areas that don’t have flowing surface streams. It’s not that they needed irrigation everywhere, but they did need irrigation to establish these plantations in areas that probably shouldn’t have been supporting plantations.

On Maui, most of the sugarcane cultivation is in the Central Valley, which is largely a mesic habitat. Alexander & Baldwin, one of the early, large sugar plantations, created a really extensive irrigation ditch that cut across 27 windward valleys; they completely de-watered those streams and took all 27 and diverted them into this canal that went into the Central Valley so they could irrigate an area that was not wet enough for sugarcane cultivation.

Where do those water diversions stand today?

It’s fascinating and unprecedented in our country, because [at the time the plantations were planted] Hawaii was an independent monarchy. The monarchy eventually got overthrown, and Hawaii became a territory, and eventually a state. There’s really not a parallel in U.S. law or U.S. history. It’s a unique case study.

There have been very long fights over the water in East Maui, because obviously when they took all the water from the stream, that displaced the ability for the downstream Native communities to cultivate, for instance, the flooded irrigated Kalo, which was their main production and food staple. This has gone through a lot of legal fights.

One of the big culminating cases that went to the Hawaii Supreme Court and is actually taught in a lot of water law courses today is the Waiahole Ditch case, in which the Supreme Court affirmed that cultural applications of water are protected under the public trust doctrine for governing water law.

That opened the door for a lot of other traditional users to fight for these water returns. And so on that East Maui irrigation ditch, there have been some victories over the last decade in terms of reestablishing inflow streams standards and guaranteeing a certain amount of water for downstream users.

How much land in Maui is currently fallow?

It’s pretty high. Maui has probably one of the lower percentages [when compared to other islands across the state], but more than 50 percent of our agriculturally zoned lands are fallow. It’s estimated that only something like 15 percent of our ag lands are actually used to grow active crops.

How are farmers working to regenerate the soil on former sugarcane land?

Unfortunately, it’s hardly on the radar, because there are so many larger struggles just to operate in agriculture in Hawaii today. The biggest is that our state does nothing to protect or value land for agriculture. And therefore, the land value of ag land is tied to its development potential.

On the north shore of Oahu, if you want to get an acre of land, you’re talking like half a million dollars. And the costs of land, water, and labor in Hawaii are so high, it’s very, very challenging to just exist as a farmer. Because of that, if you’re thinking about regenerative agricultural practices, that is a further investment on the farmers’ behalf; it’s taking a longer time horizon. [Organic] amendments are more expensive than industrial fertilizers. If you’re doing tree crops, that takes longer [than annual] crops. All these things amount to additional economic investment on the farmer’s behalf in an already extremely challenging economic landscape.

Because of that, the vast majority of people who are engaging in regenerative agricultural practices are not strictly farmers. There’s a lot of nonprofit education or social enterprises that subsidize farming through youth engagement or cultural education, and that allows them to engage in more regenerative practices without being beholden to the bottom line.

You have a lot of retirees or people who work other jobs to support themselves. That farming is more of a passion and, in some cases, a hobby. And they have the luxury, I would say, of engaging in regenerative practices. But in terms of where the food production is coming from in Hawaii, there are very few food-producing farmers who can do that. It’s just economically restricted.

How much of the former sugar ag land is going toward development?

Since the 1950s, we’ve lost about 1 percent of our farmlands annually. That’s being rezoned for residential or other development purposes. There are no restrictions, really, of what you can do with agricultural lands in Hawaii.  There’s a tremendous amount of ag lands that are supporting gentleman’s farms where people come in and buy 20 acres. They put up a mansion; they have a horse.

How did the history of the sugarcane industry lead to this month’s wildfire?

In some of the old Hawaiian language newspapers, Lahaina used to have significant wetlands and lowland flats. They would say, “Lahaina sits in the house of the Ulu trees,” or the ancient breadfruit grove Mala Ulu o Lele.

People just describe almost the entirety of Lahaina town as this forested area filled with breadfruit. And as the plantations came in, they were cutting down a lot of these trees. It got to the point where they passed a law that made it illegal to cut down an ulu tree. And so plantation owners started to pile their bagasse, their spent sugarcane pressings, around the base of the tree and burn it.

After three or four burnings, it would kill the tree. They weren’t breaking the law. They weren’t cutting it down, but they were very systematically and deliberately eliminating the trees from this region.

Those trees probably had a very significant effect in terms of the region’s moisture. Deep-rooted trees are able to tap into the water table. If you look at the rainfall, Lahaina was always way too dry to grow breadfruit. But the fact that you had this huge breadfruit growth and all these wetlands essentially speaks to the fact that the trees were tapping into this subterranean water table, lifting moisture up to the surface, redepositing some of that moisture through leaf litter, allowing for additional rain capture, for reduced evaporation, increased carbon in the soil, and holding additional moisture.

You basically just had an entirely different ecology of that region for two reasons: the undisturbed flow of the river, which allowed the recharge of the subterranean water sources; and these extensive treed landscapes in that area. The plantations removed both of those. They diverted the river in its entirety and eliminated the tree cover. I think the long-term ecological implications of those changes were a huge factor in [the conditions that led to] the fire.

Is there anything you’d like to add?

It’s not a new concept, but it’s important to recognize that agriculture provides a lot of different services, most of which are not valued. Our country has, over the last century, become increasingly aware of the negative externalities of agriculture, in terms of soil loss, groundwater poisoning, and eutrophication and dead zones in the Gulf of Mexico. As a country, we’ve started to acknowledge and at least begin to address the negative externalities of agriculture.

I would like to see the conversation shift to focus on agriculture’s positive impacts. Basically everything that can be done negatively, agriculture can also do it positively. Agriculture can contribute to soil remediation, improved water quality, and biodiversity. How do we encourage those activities? That work really needs to be accelerated and expanded. In Hawaiian culture, really any Indigenous culture, agriculture is the fundamental way that people interact with their environment. To me, it really sets the tone for our entire society.

This interview has been edited for length and clarity.