Before Hui o Ko‘olaupoko launched the He‘eia Estuary Restoration Project in 2015, non-native mangrove was choking that 6-acre site in He‘eia State Park and many surrounding acres. The main stream of the estuary was innundated with leaves and other matter that the invasive plant dropped. Sediment accumulated, reducing aeration and water flow, and creating a blanket of anoxic mud, or mud without oxygen.

Because native fish had a difficult time swimming through the mangrove-infested waterway and did not evolve to live in the habitat, it became a nursery for non- native fish.

Fast-forward four years. Volunteers have removed 5 acres of mangrove and other invasive species, and the final acre should be completely cleared by mid-March. Outplanting of native species in that acre will follow, adding to the 4,000-plus native plants that are already improving water quality, helping erosion control, filtering stormwater runoff and increasing habitat for native fish and wetland birds.

“It has been really rewarding to see the transformation,” said Kristen Nalani Kane, executive director of the hui, commonly referred to as HOK. “When we first started working on the project, there were only a few native plants there. Now, outplanted natives are thriving and starting to self-propagate, and native wetland birds and migratory shorebirds are foraging in the newly opened areas.”

Ko‘olaupoko’s 43,598 windward acres extend from Makapuu to Kualoa and include three bays, 11 major watersheds and 11 ahupuaa (land divisions extending from the mountains to the sea). Before Capt. James Cook arrived in Hawaii in 1778, some 10,000 people lived there, making it one of the most heavily populated regions in the islands. At the time, villagers maintained at least 30 fishponds and numerous taro loi, or patches.

“In modern times, overdevelopment, poor agricultural practices and the introduction of nonindigenous flora and fauna have contributed to the degradation of Ko‘olaupoko’s terrestrial and marine ecosystems,” Kane said. “HOK’s goal is to restore the health of the aina (land) and water sources.”

Kane was born, raised and has lived in various communities in Ko‘olaupoko, including Kailua, Kahaluu and Waimanalo, virtually all of her adult life. Her passion for conservation was sparked in the fifth grade by a recycling program at the former Lanikai Elementary School, now Ka‘ohao Public Charter School.

Kane earned a bachelor’s degree in environmental studies, with a focus on Hawaiian resource management and conservation, from the University of Hawaii at Manoa and she said landed her dream job: developing restoration projects, creating volunteer and educational experiences and working shoulder-to-shoulder with people who also have strong ties to Ko‘olaupoko.

Since the hui’s staff is small — just three part-timers, including Kane plus an intern — volunteers are largely responsible for the success of the organization’s restoration efforts. Since 2009, nearly 17,000 people have contributed 47,000 hours of labor in more than 635 workdays at He‘eia Estuary and Kaha Garden, another HOK project that teaches visitors how to grow native plants at their homes. (See sidebar.)

Visitors are welcome to pitch in, learning valuable lessons about native and invasive plants and the importance of establishing a healthy watershed along the way.

Every workday begins with an introduction to the site, then volunteers choose a task. At the estuary, they can pull mangrove seed pods by hand in the mudflats and dig out clumps of invasive grasses with shovels. There’s also tree pruning, weeding, cleaning of trails and planter beds, and spreading of mulch where Hawaiian medicinal plants will someday grow.

“People are often surprised to find out what a big impact restoration of a relatively small area like He‘eia Estuary can have on the health of the entire watershed,” Kane said. “In the same way, every set of hands makes a difference. One person removing an invasive plant and replacing it with a native is a step in the right direction to malama (care for) the Hawaii we love.”

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Kaha Garden

In 2007, Hui o Ko‘olaupoko developed 1.2-acre Kaha Garden to show homeowners how they can incorporate native vegetation in their yards.

The garden’s hardy species can survive on rainwater and with occasional watering during the summer.

Kaha Garden, 750 Kaha St. in Kailua, is open daily from sunrise to sunset. Admission is free. Walk the marked paths and read the accompanying signs to get landscaping ideas.

The garden also has volunteer workdays, 9 a.m. to noon, usually on Thursdays and the second Saturday of every other month. In addition to volunteering, participants learn how to grow native plants and where to plant different species to maximize their ecological benefits. Sign up at huihawaii.org.

About Hui o Ko‘olaupoko

Established in 2007, Hui o Ko‘olaupoko is a nonprofit watershed management group that works with communities to improve water quality through ecosystem restoration and watershed management. Its focus is the Ko‘olaupoko region of Windward Oahu.

The hui provides consulting serv­ices on a variety of topics, including low-impact development, on-the-ground restoration, watershed planning and management and rain gardens, which utilizes vegetation to allow storm water from impervious surfaces to collect and infiltrate the ground. Rain gardens reduce pollution entering streams and the ocean by intercepting stormwater.

Produced by the hui, the Hawai‘i Residential Rain Garden Manual is a do-it-yourself guide to building and planting a rain garden. Download it at huihawaii.org/raingarden.html or contact Hui o Ko‘olaupoko to purchase a hard copy for $5 (add $3 if you want it mailed). Copies are also available at public libraries.

Tax-deductible contributions to the hui are welcome; go to huihawaii.org/donate.

— Adapted from huihawaii.org