Landscape view of traditional farm in Hawaii, with mountain in background.
He'eia Valley In partnership with Kāko‘o ʻŌiwi, TNC is reintroducing traditional farming to minimize flood damage and reduce sediments and nutrients flowing into Kāneʻohe Bay. © John DeMello

We’re helping to restore wetlands for healthy and resilient coral reefs and coastal communities.

Aerial black-and-white photo from 1928 with He‘eia nearshore reefs and fishpond at the top, wetlands covered in taro fields in the center, and edges of lowlands below.
'Āina Momona The rich, fertile and abundant wetlands at He‘eia nourished wildlife and the local population through the early 20th century. © Courtesy Kākoʻo ʻŌiwi

Why Here

Historically, Heʻeia nourished Hawaiian people and native wildlife while being one of the most productive places on the island of Oʻahu. Here, eight streams provided habitat for larval and juvenile reef fish, invertebrates and stream species, such as oʻopu (goby) and hihiwai (snails), and converged into a wetland estuary cultivated with hundreds of acres of loʻi kalo (taro fields) since 1200 AD, before flowing through an 800-year-old fishpond and into Kāne‘ohe Bay. While the wetlands served as a haven for native waterbirds, the bay’s coral reefs, sand flats and seagrass beds provided refuge for green sea turtles, migrating whales, birthing sharks, foraging manta rays and resting spinner dolphins.

Circa 2000 color satellite image of urban development bordering uplands, wetlands and a fishpond and invasive mangroves covering acres of the wetlands and surrounding the fishpond.
Decades of Disruption Water flows, native species and cultural traditions were displaced by agriculture, grazing and urbanization at He‘eia. © Eagle View Technologies

But land-use changes and ranching introduced in the 1950s and subsequent urbanization of the area disrupted the natural flow of water, displaced native plants and animals, and led to a proliferation of invasive species and sediment runoff that took a severe toll on the bay’s reefs and fish populations.

Illustration of He‘eia ahupua‘a with eight streams flowing from the mountains and converging into one before flowing through the wetlands, taro fields and fishpond and into the sea.
Oahu Watershed He'eia Traditional ahupua'a management © Nirupa Rao

With an exceptional understanding of the natural world, Native Hawaiians developed a stewardship system that maintained healthy, productive mauka-makai (mountain-ocean) habitats and abundant resources for generations—a system where wetlands and fishponds provided food for people and habitat for native species and absorbed the sediments and nutrients that would otherwise reach and imperil the health of coastal waters, coral reefs and marine life. Today, there is an ambitious and coordinated effort to revive these practices at He‘eia.

Restoring natural water flows and mauka-makai (mountain-ocean) habitats is essential to building community and coastal resilience and ensuring that Hawaiian culture and species thrive.

Project and Partners

The Koʻolaupoko Hawaiian Civic Club initiated the effort to restore Heʻeia ahupuaʻa (land division), which spans an entire watershed. Multiple groups, including some led by a new generation of native Hawaiian leaders, have joined forces to restore health and abundance to Heʻeia’s upland forests, wetlands and coastal fishpond through the perpetuation of traditional practices. In 2017, Heʻeia was designated the 29th site in the National Estuarine Research Reserve (NERR) System.

Click Points to Learn More RETURN
GOING WITH THE FLOW (4:37) Heʻeia leaders share their perspectives on the project in a 4-minute video.

Since 2008, TNC has been working in partnership with Kākoʻo ‘Ōiwi to restore He‘eia’s wetlands. We also contribute to NERR research to help demonstrate the socio-cultural and ecological benefits of traditional management.

How TNC Helps

After working with the Division of Aquatic Resources to remove invasive algae smothering Kaneʻohe Bay reefs, TNC joined forces with Kākoʻo ‘Ōiwi to restore the wetlands and loʻi kalo as a way to reduce sediments that flow into the bay and propel algae growth.

Rocky and dome-shaped coral of varying pastel colors.
Olive green algae covering large areas of coral.
Algae Removal Using customized underwater vacuums, crews and volunteers removed 160 tons of algae from 40 acres of reef, then reintroduced native sea urchins to prevent regrowth.

With TNC support, Kākoʻo ‘Ōiwi has:

  • removed mangrove trees and other invasive vegetation that clogged streams and replanted native vegetation,
  • restored a system of loko wai (waterways) and ‘auwai (irrigation channels),
  • replanted loʻi kalo, ulu (breadfruit), mai‘a (banana) and other traditional crops, and
  • worked with partners to develop a Conservation Action Plan to guide their work.
Stream bank carpeted in native groundcover and shrubs in the foreground and mountains in the background.
Nearly barren stream bank with only a few clumps of grass in foreground and a stand of invasive mangrove in the background.
Native Resurgence Once clogged by invasive species, streams now flow along banks brimming with native plants.
Meet Our Partner (5:35) Kākoʻo ‘Ōiwi leaders discuss their inspiration and goals for the wetlands.
Satellite image of He‘eia NERR.
Higher Ground Once invasive trees and plants are removed, an area above the wetland will support agroforestry. © Resource Mapping Hawaii, Maxar. Source: Airbus, USGS, NGA, NASA, CGIAR, NLS, OS, NMA, Geodatastyrelsen, GSA, GSI and the GIS User Community

Now, Kākoʻo ‘Ōiwi is re-establishing māla (gardens, cultivated fields) and food forests where culturally and biologically important plants will be cultivated for harvest and use. They will begin replanting once the invasive trees and vegetation are removed from the fenced and pig-free 20-acre area.

Monitoring station in stream.
Measuring Change TNC monitored changes in the soil surface as the wetland transitioned from an invasive-dominated system to one dominated by native plants. © TNC

TNC also conducts research on watershed hydrology, freshwater fish presence and abundance, nutrient transport through the wetland and soil erosion rates in the surrounding hills.

Impacts and Benefits

Wetlands covered in large areas of stagnant water and invasive mangroves with a couple buildings on the right and edge of fishpond in the distance.
Stagnation Mangrove trees and other invasive vegetation clogged streams, preventing the natural flow of water. © Donald Gentzler
Wetlands carpeted in green, with small streams and a dirt road in the foreground, the poi mill and another building on the right, and the highway and edge of fishpond in the distance.
Free Flow Restored streams flow through the wetlands where native species are thriving after invasive species were removed. © Michelle Mishina
Stagnation Mangrove trees and other invasive vegetation clogged streams, preventing the natural flow of water. © Donald Gentzler
Free Flow Restored streams flow through the wetlands where native species are thriving after invasive species were removed. © Michelle Mishina

Biological and Ecological

As a result of the collaborative efforts, fresh water is once again flowing through the wetlands, nourishing loʻi kalo and providing habitat for freshwater species, including native fish and plants and endangered native waterbirds.

Aerial view of a muddy brown fishpond.
Climate-Friendly He‘eia wetlands and fishpond absorb and filter runoff, ensuring fewer sediments and nutrients flow to Kāne‘ohe Bay reefs. © Kepano Carvalho


Healthy wetlands and fishponds absorb excess sediment-laden runoff during heavy rains, providing vital flood protection for coastal communities and preventing excess sediments and nutrients from reaching ocean waters and reefs.

Three people clear a stream bank of invasive plants.
An Urban Oasis Passing between the wetlands and fishpond and over Heʻeia stream, Kamehameha Highway provides easy access to the area. © Michelle Mishina

Demonstrating wetland effectiveness at Heʻeia—a highly visible and easy to access site—can help build support for adopting the cost-effective natural climate solutions needed to avoid the worst impacts of climate change.

Farm staff wash taro on a conveyor belt.
Farm to Table Kākoʻo ‘Ōiwi built an on-site commercial poi mill, where it processes the taro it grows. © Michelle Mishina


Kākoʻo ‘Ōiwi employs more than a dozen farmers, processes the kalo it grows at its newly constructed poi mill, and supplies local residents and restaurants with poi and fresh produce.

A group of volunteers working in a taro field.
Live and Learn Like the other groups working in Heeia, Kākoʻo ‘Ōiwi offers opportunities for visitors to get wet, dirty and enlightened all at the same time. © Michelle Mishina

The farm also serves as a living classroom, providing hands-on educational programs for youth and families to learn about Hawaiian cultural practices and the traditions that sustained kanaka maoli (Hawaiian people) for centuries.

The traditional and collaborative approach to stewardship in the Heʻeia ahupuaʻa—guided by Native Hawaiian philosophies and values and complemented by NERR research—is creating a robust model for building resilient ecosystems, economies and communities.

Close-up of a young child, knee-deep in water, nurturing a taro plant.
Come One, Come All The farm offers hands-on activities and learning opportunities for visitors of all ages. © Grady Timmons

Get Involved

Thousands of volunteers have contributed to the wetland restoration, helping to weed and maintain loʻi kalo, build ʻauwai and clear invasive vegetation while learning about Hawaiian culture and farming traditions. You can help, too. Kāko‘o ʻŌiwi hosts community workdays open to the public on a regular basis. Visit the Kāko‘o ʻŌiwi website to register and get details.

Learn more about our science, restoration and how we help strengthen conservation management and leadership so Hawaiʻi's reefs can support healthy fisheries and prosperous communities long into the future.

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