West Maui’s Coral Reefs

West Maui’s coral reefs are important sources of coral larvae that replenish reefs across Maui, Lana‘i, Moloka‘i, and Kaho‘olawe. Because of this, the area has been designated a priority conservation site by the U.S. Coral Reef Task Force and the Hawai‘i Department of Land and Natural Resources.

But West Maui is laden with historic sugarcane and pineapple plantations that are now out-of-use. During heavy rain events, the soil from these degraded landscapes travels down old dirt roads, enters stream gulches, and ultimately reaches the ocean where it smothers coral reefs.

Stormwater runoff is considered a major source of water pollution and has led to a 25-50% decline in Maui’s coral cover in the last fifteen years. It also regularly causes the Hawaiʻi Department of Health to issue “Brown Water Advisories”, which are warnings to the public to avoid swimming or fishing because of risks to human health.

Our Work

Our mauka to makai (ridge-to-reef) approach restores the natural function of an ahupua’a (watershed), so that chemicals, nutrients, and sediment are naturally removed from stormwater before they reach the ocean.

Toward the top of the mountain and in the midslope region, we use native plants—and over 100 supportive volunteers—to restore the degraded landscapes and trap the sediment before it has a chance to runoff into the ocean. We’re restoring the mauka (mountainside) with native plants like pili grass and natural materials like coconut coirs to slow the runoff, trap the sediment, and absorb the nutrients. 

On the coast, we work with resort property owners, the tourism industry, and Maui County to implement reef-friendly Low Impact Design (LID) landscaping that serves as a last-ditch effort to filter stormwater before it reaches the ocean. Looking for more details?

Get Involved


We’re always looking for local volunteers to help us grow native plants and reforest the mountainside. Volunteers grow native plants from seed at their homes. And once a month, we have a volunteer planting day where volunteers transplant native plants into the ground at our restoration site. Interested? Sign up by completing our volunteer interest form, and a member of our team will contact you shortly. Before volunteering at our field site, you will also need to complete the volunteer waiver.

Become a Citizen Scientist

Through our partner organization, Hui O Ka Wai Ola, volunteers collect water quality samples around the island to improve our understanding of Maui’s coastal areas and threats to coral reefs. Visit the Hui O Ka Wai Ola website to become a water quality sampler. 

Recent News

2023 Year in Review, Ocean-Style

As we welcome in 2024 and anticipate the exciting developments ahead, let’s pause to reflect on the impact we made together in 2023. It was a year filled with significant achievements, insightful articles, and some fantastic new faces joining our team. We invite you to join us in revisiting the standout moments that made 2023… Continue Reading →

Protecting Molokai’s Coral Reefs with the Restoration of Ancient Hawaiian Fish Ponds

A Vital Mission for a Sustainable Future In the crystal clear waters surrounding Molokai, the legacy of Ka Honua Momona (KHM) spans generations, rooted in the island’s rich heritage. Coral Reef Alliance (CORAL) and Ka Honua Momona have recently joined hands in a shared commitment to preserving Hawaii’s precious coastal ecosystems. Their partnership aims to… Continue Reading →

“Climate REEFS” Initiative Launched to Advance Equitable Pathways to Climate Adaptation in Asia Pacific

(OAKLAND, CA – November 10, 2023) Today, a consortium of universities, development agencies, and NGOs announced the launch of Climate REEFS, a collaborative project to advance socially equitable climate change adaptation for coastal communities that depend on coral reef resources in Indonesia and the Philippines. Climate REEFS is a project under the UK-Canada Climate Adaptation… Continue Reading →

CORAL Receives Transformational Funding for the Reefs of Maui Nui

CORAL and our partners in Maui Nui have been selected to receive a $3.1 million federal grant from the National Oceanic and Atmospheric Administration (NOAA)’s National Coastal Zone Management Program. The grant recognizes our alliance’s dedication to protecting and restoring coral reefs around the world and its successful track record in implementing conservation projects. Our… Continue Reading →

CORAL is Selected as a Grantee of the Hawai‘i Community Foundation’s Marine 30×30 Pooled Fund

In recent weeks, CORAL was selected as a grantee for the Marine 30×30 Pooled Fund by the Hawai‘i Community Foundation, alongside five other community groups and nonprofit organizations in Maui, Hawai‘i. Together, we are working with the state, partners, and community members to restore Hawai‘i’s marine environments and contribute to the protection of 30 percent… Continue Reading →


How to Build a Rain Garden to Filter Stormwater

Building a rain garden can be an effective, low-cost tool to reduce stormwater pollution reaching our streams and the ocean. This guide outlines how to build a new rain garden, but you can also use these guidelines to improve water filtration within your current landscape by retrofitting existing flower beds or gardens.

Case Study

Installing a Curb-out Raingarden

A rain garden is a landscaped depression in the ground that is designed to collect stormwater runoff from rooftops and other impervious surfaces. This case study documents the process of building a rain garden along a heavily trafficked road—the Kā‘anapali Parkway—used to access a popular resort in West Maui, Hawai’i.

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