Hawaii is famous for its spectacular beaches. But over the past century, three of the state’s major islands, Oahu, Maui and Kauai, have lost roughly one-quarter of their sandy shores.

With rising seas, the losses are projected to grow much worse. Why is this happening?

Seawalls like these are erasing beaches.

Hawaii’s Beaches Are Disappearing

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This article was produced in partnership with the Honolulu Star-Advertiser, which is a member of the ProPublica Local Reporting Network.

Hawaii’s beaches are owned by the public, and the government is required to preserve them. So years ago, officials adopted a “no tolerance” policy toward new seawalls, which scientists say are the primary cause of coastal erosion.

But over the past two decades, oceanfront property owners across the state have used an array of loopholes in state and county laws to get around that policy, armoring their own properties at the expense of the environment and public shoreline access.

Government officials have granted more than 230 environmental exemptions to owners of homes, hotels and condos, according to records compiled by the Honolulu Star-Advertiser and ProPublica. Those exemptions have allowed property owners to keep old seawalls in place, build new ones and install mounds of emergency sandbags along the beaches.

Explore the last 20 years of shoreline exemptions in Hawaii →

Officials defend their actions, saying that forcing property owners to comply with anti-armoring laws would cause them too much hardship, particularly along coastlines that already have lots of seawalls.

Over time, though, waves hitting the barriers pull the sand away from the shore and carry it out to sea. As a result, the government approvals have fueled beach loss and perpetuated the redevelopment of private properties along treasured and environmentally sensitive coastlines — all at a time when scientists have been warning of the dire need to push development inland.

Oahu’s Lanikai Beach has suffered some of the most rapid beach loss, almost entirely due to seawalls. This is what the beach looked like in 1968, following a surge of home development along its shore in the earlier half of the century. The beach was so wide, residents remember being able to play volleyball and walk the full length of coastline.

Here is the same beach in 2020. Today, the south half is gone.

In the 1980s, homeowners increasingly built seawalls to protect their properties from the ocean, setting off a domino effect of erosion. That armoring has continued, despite the “no tolerance” policy set in 1999. Officials have continually allowed people to build new seawalls and reconstruct older, crumbling ones, while approving illegally built structures after the fact.

While seawalls have destroyed much of the public beach, the homes along this stretch of coastline continue to sell for millions of dollars as real estate agents boast of their private, oceanfront locations. Luxury homes listed for sale this year ranged in price from $4.9 million to $15.6 million.

This wall of boulders at 1562 Mokulua Drive was built without approval. Despite the violation, officials with the City and County of Honolulu issued building permits in 2009 to the owner, allowing her to redevelop the property into a sprawling, luxury estate, which in 2015 sold for $9.35 million — more than double its 2006 sales price.

If a seawall is significantly damaged or destroyed, state and county laws limit what property owners can do to repair it. But officials have been lenient in their approach to enforcement, ensuring shorelines like Lanikai remain fixed in place and armored for decades to come. This wall at 1368 Mokulua Drive was largely destroyed during a storm in 2003, but the owner was allowed to rebuild it.

Owners have also found a loophole by getting approvals for temporary sandbags but then keeping the structures indefinitely. The sandbags at 1326 Mokulua Drive have been sitting on the beach since the 1990s, after the previous owner was required to tear out an illegal seawall. This year, the City and County of Honolulu approved a new seawall.

Old seawalls like this one at 1240 Mokulua Drive were built before Hawaii established coastal protection laws in the 1960s. In 2003, the property was purchased for $6 million and the new owner sought an easement to keep the wall in place for an additional 55 years. State officials gave their approval, which allowed the owner to redevelop the estate. Earlier this year, it was listed for sale for $21 million.

After the stretch of seawalled coastline, the beach reemerges. While this part of the shore has undergone a period of natural growth, scientists warn that erosion from the southern seawalls could eat away at this part of the beach too. Owners of the profiled properties declined or did not respond to requests for comment.

On Oahu, where the majority of the state’s population lives, the ocean is threatening to damage or wash away hundreds of structures, including roads, hotels and homes. Owners looking to protect their properties have obtained seawall easements extending the life of walls, permits for emergency sandbags and county seawall approvals.

In one case, officials allowed owners of an estate tied to former President Barack Obama to exploit loopholes in Hawaii's environmental laws to revamp its aging seawall. The owners said they needed exemptions to protect the compound from the ocean and pursued them lawfully.

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Obama and the Beachouse Loopholes

The North Shore, in particular, has become a hot spot in the battle between private property owners and the public. The state has approved emergency sandbag structures for 30 homeowners here, from Sunset Beach to Laniakea Beach, alarming coastal scientists and beach advocates.

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How Famous Surfers and Wealthy Homeowners Are Endangering Hawaii’s Beaches

Along this stretch of coastline in Mokuleia, private property owners have been able to obtain approvals from the City and County of Honolulu to build new seawalls or keep illegal seawalls in place. Officials have granted many of these permissions in the past two decades, following the state’s “no tolerance” policy against shoreline armoring.

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Officials Let Hawaii’s Waterfront Homeowners Damage Public Beaches Again and Again

The loss of Hawaii’s beaches threatens the way of life in the islands and imperils the state’s tourist-driven economy.

But the environmental damage of coastal armoring is already clear. Endangered species, like monk seals, have lost critical shoreline habitat.

Particulate pollution and turbulence caused by waves slamming into seawalls has harmed already-stressed coral reefs and threatens to disrupt the islands’ famous surf breaks.

If Hawaii doesn’t step up enforcement of its “no tolerance” policy toward shoreline structures, scientists warn that, by midcentury, the state could be down to just a handful of healthy beaches.

About the Data

The data was compiled from public records requests filed with Hawaii’s Department of Land and Natural Resources and the City and County of Honolulu’s Department of Planning and Permitting. The records include state approvals for seawall easements and emergency sandbags, as well as county approvals for new or illegally constructed seawalls. The documents cover approvals issued between 2000 and 2020.

Records on seawall easements were compiled from individual paper files archived at the DLNR, as well as annual government reports filed with the Hawaii Legislature. The data for emergency permits was derived from paper files at the DLNR. The City and County of Honolulu, as well as the counties of Maui and Kauai, provided files for shoreline setback variances requested by private property owners seeking approvals for shoreline hardening structures.

A handful of properties with a known exemption in the past two decades could not be linked up to an address from source documents and were not marked on the map.

The data is available on the ProPublica Data Store.


Archival photos from City and County of Honolulu, 2020, historical Lanikai shorelines from The Coastal Geology Group at the University of Hawai‘i, building footprints, lidar and street data from the Hawaii Office of Planning.

Drone imagery by Darryl Oumi for Honolulu Star-Advertiser

Ash Ngu is a journalist, designer and developer with ProPublica's news apps team.

Sophie Cocke is a reporter with the Honolulu Star-Advertiser. She has covered government and politics in Hawaii for the past decade. Please get in touch at [email protected] if you have information you want to share about seawalls or other shoreline hardening structures.

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