Drought conditions across the islands of Hawaii have sparked concerns about fire in the Aloha State. In the latest Drought Monitor update, southern portions of Kauai, Oahu, Maui, and Hawaii islands are all experiencing abnormally dry conditions; the same is true for the eastern half of the Big Island and Maui. But for the western two thirds of Maui and the northernmost portions of Hawaii Island, moderate drought conditions exist. On Maui, for the first time this summer, there are also portions under severe drought conditions. With dry and drought conditions spreading, the risk for fire also increases.
Hawaii Division of Land and Natural Resources (DLNR) Division of Forestry and Wildlife State Protection (DOFAW) Forester Mike Walker said, “It’s no surprise we’re seeing wildland fires ignite in areas that are seeing worsening drought conditions. Forecasters continue to predict things will get worse before they get better, with an expectation that more severe drought conditions will plague larger areas of the state into late summer, early fall, and even through next winter.”
Beyond the larger major islands of the Hawaiian Island chain, some of the smaller islands are also experiencing dry conditions. The entire island of Kaho‘olawe is abnormally dry, as is western Lana‘i and west Moloka‘i, with a thin strip of southwestern Moloka‘i experiencing severe drought.
A week ago, the southern tip of Hawai‘i Island was not seeing drought conditions, but is now considered abnormally dry, and firefighters fought a fire there this week. The North Kohala district continues to have moderate drought conditions and all east Hawai‘i Island is termed as abnormally dry.
The Saddle Road area, the site of the 17,000-acre Leilani fire last year, appears to be green and lush now. However, DOFAW Hawai‘i Island Branch Manager Steve Bergfeld commented after a recent aerial survey, “Even after rain, within a couple of days and the wind kicks in, the fuel dries out quickly. Though it looks green, invasive grasses can still carry fire.” Non-native grasses like fountain grass cover 25% acres of Hawai‘i’s land mass.
Virtually all wildfires in Hawai‘i are started by people, mostly by accident. The chief causes are fireworks, heat from vehicle exhaust that can ignite dry grass, sparks from machinery like weed whackers, chain saws, grinders, and welding equipment, and unattended campfires or barbecues.
According to Hawaii Volcanoes National Park, yesterday afternoon, National Park firefighters were called to help County firefighters put out a brushfire off Old Volcano Road near the park. The County was able to control the fire and used a helicopter and water bucket drops to help stop the spread. They’re concerned the arrival of Calvin, currently a Major Hurricane in the Eastern Pacific, may create more problems.
According to the Hawaii Wildfire Management Organization, each year, about 0.5% of Hawaii’s total land area burns each year, equal to or greater than the proportion burned of any other US state. Over 98% of wildfires are human caused. Human ignitions coupled with an increasing amount of nonnative, fire-prone grasses and shrubs have increased the wildfire problem.
In May, Kevin Kodama, Hydrologist at the NWS Honolulu office, shared their 2022-2023 Wet Season Rainfall Summary. According to Kodama, the October-April wet season in Hawaii was an unusual one, starting off with severe or extreme drought in portions of all four of Hawaii’s counties. La Nina was in place during all of 2022 and into early 2023, which made an impact on the weather pattern and the overall wet season. As La Nina faded, the drought faded too, with rain returning in earnest; overall, Hawaii saw the 9th wettest wet season over the last 30 years based on data collected from 8 sites across the state. The Big Island saw the most rain, with rainfall amounts recorded at 130-170% of average. Hilo Airport alone recorded their 11th wettest wet season, with 87.29″ of rain falling over the October-April period.
ENSO, short for El Nino Southern Oscillation, is a recurring climate pattern involving changes in the temperature of waters in the central and eastern tropical Pacific Ocean. On periods ranging from about three to seven years, the surface waters across a large swath of the tropical Pacific Ocean warm or cool by anywhere from 1°C to 3°C, compared to normal. This oscillating warming and cooling pattern, referred to as the ENSO cycle, directly affects rainfall distribution in the tropics and can have a strong influence on weather across the United States and other parts of the world. El Niño and La Niña are the extreme phases of the ENSO cycle; between these two phases is a third phase called ENSO-neutral. While this phenomena impacts the entire United States, Hawaii may find itself particularly vulnerable this year to bad weather conditions.
Meteorologists with the National Weather Service in Honolulu explained that El Nino will impact hurricane season, which is why an above-average season is expected. And while there’s an elevated risk of being impacted by hurricanes, Hawaii could see severe drought unfold. Severe drought and possibly extreme drought is expected to develop by the end of the dry season, with the highest likelihood in the leeward areas, especially in Maui County and the Big Island.
The Honolulu NWS office warns, “Impacts are expected to be the worst for non-irrigated agriculture, water systems dependent on surface water diversions, and residents relying on rainfall catchment.” Due to late wet season rainfall, a significant wildfire risk is expected to develop later than the normal late-July to early-August time frame. Fuels from recent wet season growth will be abundant, setting the stage for fire problems later in the year.
Hawaii County Civil Defense Administrator Talmadge Magno is concerned about the forecast for dry conditions in the coming weeks. He attended a presentation by the National Weather Service which talked about both the upcoming hurricane season and the seasonal dry/wet periods on the islands.
“We know, through dry periods in January, people were suffering with the lack of water. People need to build capacity,” Magno said. “With this forecast, knowing there’s going to be less rainfall, people need to build capacity. Get larger tanks, catch that water, make sure you don’t have leaks in your system. Remember: water isn’t only for your consumption, but it’s also for fighting fires.”
Water catchment, also known as water harvesting, is the process of collecting and storing rainwater. Water catchment systems collect water from rain gutters and use pipes to direct it to a storage tank. Once collected, pumps move the water from storage into the home in place of typical municipal water systems. On the Big Island of Hawaii, there is limited public water service and an abundance of residential catchment systems.