![\"\"](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/03\/IMG_6611-edited.jpeg\")
Hui O Ka Wai Ola volunteers collect water samples off Waipu\u2018ilani in March 2025. Volunteers go out every three weeks to each of the hui\u2019s 46 sites in West and South Maui. Photo: Liz Yannell<\/p>\n\nHui O Ka Wai Ola volunteers collect water samples off Waipu\u2018ilani in March 2025. Volunteers go out every three weeks to each of the hui\u2019s 46 sites in West and South Maui. Photo: Liz Yannell<\/p>\n
Liz Yannell remembers when the waters off North K\u012bhei were calmer, clearer and lined with vibrant coral reefs just a few years ago.\u00a0<\/p>\n
Now \u201cit\u2019s chronically brown,\u201d and judging from recent test results, saltier than usual, too.<\/p>\n
HJI Weekly Newsletter<\/p>\n
Get more stories like these delivered straight to your inbox. Sign up for the Hawai\u2018i Journalism Initiative’s weekly newsletter:<\/p>\n
ADDING YOU TO THE LIST…<\/p>\n
\u201cWhat we think we\u2019re seeing is just that the drought is showing up in our coastal waters,\u201d said Yannell, the program manager of Hui O Ka Wai Ola<\/a>, a group of citizen scientists who monitor ocean quality in West and South Maui.\u00a0<\/p>\n Yannell and her team are trying to understand more about what\u2019s causing the recent increase in salinity, \u201ca very curious new thing,\u201d she told a crowd earlier this month at the Kula Community Association meeting.\u00a0<\/p>\n Yannell spoke to Kula residents because she suspects the changes in South Maui could reflect a \u201ctrifecta\u201d of factors Upcountry: worsening drought, large fires in 2023 and 2024 that left the landscape scorched and bare, and an \u201cexplosion\u201d in the population of deer who trample the soil and make it harder for rain to filter through the earth.\u00a0<\/p>\n The hui, which has collected more than 6,000 samples since it was formed in 2016, measures the basics of water quality: pH levels, oxygen, temperature, salinity and turbidity. They\u2019re like the first screening checkpoint for water quality. If they notice something alarming, they\u2019ll work with their partners to investigate it more.\u00a0<\/p>\n From 2018 to 2020, they found the waters off Sugar Beach had salinity levels of 34 to 35 parts per thousand, which is normal for seawater<\/a>. Now, they\u2019re consistently seeing levels of 36 to 37 ppt \u2014 still normal, but enough of a change from a decade of data that they\u2019re curious to see whether it\u2019s a trend.<\/p>\n For the hui that goes out to collect samples every three weeks, every little change in the ocean offers a clue, raising early red flags about how the wider environment could be taking a toll on Maui\u2019s critical reefs and nearshore waters.\u00a0<\/p>\n \u201cOur ecosystems can be really fragile, and any changes in the ocean water quality can affect them,\u201d Yannell told the Hawai\u2018i Journalism Initiative. \u201cWe\u2019re trying to figure out what this means, and what it means for the connection between our land, our weather systems and our ocean waters.\u201d<\/p>\n A lack of funding paused salinity testing at Sugar Beach for a few years, but recognizing its importance, the hui worked to bring it back in 2024.\u00a0<\/p>\n Turbidity levels, which measure water clarity, also are up across North K\u012bhei. In the waters off the K\u012bhei Canoe Club, turbidity rose from less than 10 nephelometric turbidity units, or NTUs, in early 2018 to over 20 NTUs in early 2026.\u00a0<\/p>\n At sites the hui has observed with turbidity levels over 5 NTU, \u201cyou can pretty much guarantee that the coral out from the coastline is either already dead or it\u2019s challenged or degraded,\u201d Yannell said. <\/p>\n Too much sediment in the water can cover the reef and block out the sunlight they need to live.\u00a0<\/p>\n The areas where salinity and turbidity have increased are downslope from recent burn scars in P\u016blehu and Kula, and at the base of the Waiakoa and Hapap\u0101 watersheds that contain some major gulches, Yannell said.\u00a0<\/p>\n This includes places like K\u012bhei Canoe Club, Mai Poina Park, Kalepolepo Park and Waipu\u2018ilani Park, which all tend to be hotspots for turbidity and nutrients compared to the more than 50 sites in West and South Maui that the hui monitors. <\/p>\n Cove Park, called one of the best places to learn to surf on Maui, is one of the worst sites for turbidity and nutrients. Yannell noted it\u2019s located in the vicinity of the K\u012bhei Wastewater Reclamation Center as well as nearly 100 cesspools.\u00a0\u00a0<\/p>\n Nutrients such as nitrogen and phosphorus<\/a> can run off into the ocean from areas where fertilizers are used or where there\u2019s pet and wildlife waste. Yannell said hui members have spotted lots of clumps of deer poop washing up onto the shore. Too many nutrients can cause excessive algae growth that blocks sunlight and leads to lower levels of oxygen that can kill aquatic life.\u00a0<\/p>\n One indicator that is decreasing at the North K\u012bhei sites is the amount of nitrates, which are caused by human inputs. From 2018 to 2026, nitrate levels dropped from just over 200 milligrams per liter to around 100. The hui thinks the trend is related to the end of sugar cane production on Maui in 2016.<\/p>\n Robin Knox, lead scientist with the Maui nonprofit Save The Wetlands Hui<\/a> and a longtime water quality researcher, said the wetlands in South Maui followed similar trends as North K\u012bhei\u2019s coastal waters in 2024. The hui was concerned that it was a combination of drought, increasing development and proposals to draw more water from the Kama\u2018ole aquifer.\u00a0<\/p>\n Around that time, the two ponds along Pi\u2018ikea Street dried up, something \u201cnone of us had ever seen\u201d before, including multigenerational families of the area, Knox said.<\/p>\n \u201cWetlands are that dynamic interface between the aquifer and the ocean,\u201d Knox told the Hawai\u2018i Journalism Initiative. \u201cAnd that\u2019s part of why it\u2019s so important that we not destroy the remaining wetlands that we have.\u201d<\/p>\n North K\u012bhei was once covered in wetlands, which help absorb floodwaters so they can filter back into the aquifer. The freshwater pressure in the wetlands near the coast helps prevent saltwater from getting into the aquifer, and the freshwater that mixes with the saltwater creates a nursery for fish.\u00a0<\/p>\n Ke\u0101lia Pond, for example, is \u201ca nice, big bridge\u201d that helps absorb water from the gulches and rivers flowing from the watershed, Yannell said.<\/p>\n But as the wetlands have disappeared, K\u012bhei is less capable of handling the \u201cmud floods\u201d that come barrelling downslope<\/a> during big storms Upcountry, swamping roads and filling wetlands with sediment that keep them from doing their jobs of protecting the ocean, Knox said.<\/p>\n As time goes on and the landscape changes \u2014 houses are built on asphalt, soil is degraded from overgrazing and fires \u2014 there\u2019s less groundwater infiltration and more surface runoff, said John Starmer, chief scientist with the Maui Nui Marine Resource Council<\/a>, one of the members of the Hui O Ka Wai Ola along with The Nature Conservancy of Hawai\u2018i<\/a> and the West Maui Ridge 2 Reef Initiative<\/a>.\u00a0<\/p>\n \u201cAnything that you do, from the ocean all the way up to the top of the mountain, has the potential to run downstream and affect down the line,\u201d Starmer said during the community meeting in Kula.<\/p>\n To emphasize the point, he showed a picture of a Monterey pine cone that rode stormwaters all the way down to K\u012bhei.\u00a0<\/p>\n \u201cEven though it might take months, years, decades, centuries, stuff that goes into the ground eventually comes out to the ocean,\u201d he said.<\/p>\n Starmer said the island fortunately received a few days of slow, steady rain earlier this month, which allowed the water to filter into the ground and didn\u2019t create massive surface runoff. Water levels rose in the muliwai, the salty water estuaries at the end of the gulches, \u201cbut it was all through groundwater.\u201d<\/p>\n In an ideal system, the plants are soaking up the moisture in the air, the soil is treating the water and filtering chemicals, and the rain is infiltrating the ground, which in turn feeds the streams. Water still needs to reach the ocean \u2014 that\u2019s part of the cycle \u2014 but a functioning system cleans it and delivers it in a manageable way, Starmer said.<\/p>\n \u201cIt\u2019s sort of like putting the brakes,\u201d he explained. \u201cYou\u2019re getting the same amount of water, but you\u2019re soaking it into a sponge, and that sponge is slowly releasing it. That means you\u2019re not having torrential flows in the gulches. You\u2019re not seeing as much erosion. And that\u2019s a system we would love to see more prevalent here on the island.\u201d<\/p>\n Planting native species, controlling deer, managing open land and protecting the remaining wetlands are all key parts of improving water quality offshore, the experts said.<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/03\/Kelly-James_Brown-water-Kihei-storm-photo-12_19_22-1.jpg\")
The Kalepolepo Fishpond and North K\u012bhei are seen in December 2022 after a storm and flooding sent massive amounts of sediment into the coastal waters. Photo: Kelly James<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/03\/IMG_1713-edited-scaled.jpeg\")
Hui O Ka Wai Ola Program Manager Liz Yannell (center) joins volunteers in taking water samples from Sugar Beach in February 2025. Photo courtesy: Liz Yannell<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/03\/john-starmer-scaled.jpg\")
At a Kula Community Association meeting on Feb. 11, 2026 Maui Nui Marine Resource Council\u2019s chief scientist John Starmer recalls finding an Upcountry pine cone in South Maui, a reminder of how runoff and flooding higher up the mountain can eventually impact coastal areas. HJI \/ COLLEEN UECHI photo<\/p>\n