Downpour doesn’t begin to describe it. Biblical deluge might be more accurate. Between August 22 and 26, 2018, Hurricane Lane dumped more than fifty inches of rain on the east side of Hawai‘i Island. It was the wettest four-day period ever recorded in Hilo, which says a lot, considering Hilo is one of the wettest places in the country.
For Jason Fox, the founder of Vetiver Farms Hawai‘i, the extreme rainfall provided a chance to see his handiwork in action. Vetiver is a grass native to the Indian subcontinent (Sri Lanka, Pakistan, India) and used around the world for erosion control, water diversion and slope stabilization. Its roots penetrate fifteen feet deep, absorbing water and retaining soil.
Fox estimates he’s put half a million vetiver plants in the ground over the last eleven years for clients trying to keep their land intact. Major projects include Waiehu Golf Course on Maui and the Pacific Missile Range Facility on Kaua‘i, but most customers are Hawai‘i Island residents who want to stop their cliffside properties from collapsing into the sea.
So how did vetiver hold up? Very well, says Fox. “We didn’t have any slides during the hurricane,” he says. “It was a really good opportunity to show how vetiver works, but it was a bummer for a lot of people. I can’t count how many landslides there were from that storm.” Like the cliffside neighborhood in Hilo where Fox planted vetiver on one property; there the soil held. Neighbors, however, watched their saturated land give way, and the damage is jarring: A sidewalk on one property nearly leads off the cliff, and a corner of the house is now only a few feet from the edge.
It’s time vetiver got more attention, Fox says. Adherents see it as a miracle plant: In addition to mitigating erosion, it can absorb heavy metals, treat wastewater and even be used for medicine, insect repellent and essential oil. It’s considered low risk on the invasive species scale. It is used widely in places like Thailand and the Philippines, says Fox, and it could be more widely used in Hawai‘i as a cheaper, more resilient and environmentally friendly alternative to concrete. “It’s a great tool,” said Fox, “that’s not on a lot of people’s radar.”