Coastal property owners would be required to locate large homes and buildings farther back from the shoreline to protect public beaches and sensitive coastal ecosystems under a bill that unanimously passed the Honolulu City Council in February and is awaiting a decision by Honolulu Mayor Rick Blangiardi.

Bill 41 increases the required coastal setback to 60 feet from 40 feet for new development and adds an additional buffer zone for lots where the shoreline is pushing landward based on erosion rates.

For those structures the added buffer zone would be calculated by multiplying the annual erosion rate for the beach by a factor of 70. The overall setback would be capped at 130 feet.

Properties in the primary urban center, extending from Pearl Harbor to Kahala, would be exempt from the added buffer zone.

The bill also includes an exemption for new homes, including two-story houses, that have a footprint of less than 1,500 square feet, allowing them to continue to comply with the current 40-foot setback. The median home size in Hawaii is 1,164 square feet, according to the Visual Capitalist.

The exemption is one of several concessions included in the bill to placate the concerns of coastal developers and homeowners. The measure would take effect in July 2024.

Blangiardi has until March 9 to make a decision on the bill as well as another measure, Bill 42, which also tightens regulations on coastal development.

Both bills were introduced by Blangiardi’s administration. A spokes­- person for the mayor said Blangiardi is still awaiting official receipt of the final bills and declined to comment further.

Coastal geologists and beach preservation advocates have long urged city officials to increase shoreline setbacks, which have proved woefully inadequate in protecting both private property and public beaches, as evidenced by the proliferation of sea- walls and other shoreline- hardening structures along Oahu’s coastlines. Sea-level rise is poised to make the problem exponentially worse, with Hawaii facing a projected 3.2-foot rise in sea level by 2060.

Scientists have estimated that Oahu could lose 40% of its beaches by midcentury as the shoreline advances mauka at increasing rates along much of the island’s coastline.

The Oahu chapter of the Surfrider Foundation testified in support of both bills, telling City Council members that it was time for Hawaii’s most populous island to join Maui and Kauai in implementing more aggressive setback requirements.

The measure “uses historical erosion data to help make smarter, place-based decisions grounded in science,” wrote Camile Cleveland, Surfrider’s volunteer policy coordinator on Oahu, in testimony on the bill. “This erosion-based shoreline setback policy has already been successfully implemented in Maui and Kaua‘i for decades.”

The measure also received support from Chip Fletcher, interim dean of the School of Ocean and Earth Science and Technology at the University of Hawaii at Manoa, who has spent dec­ades studying Hawaii’s coastlines, and Denise Antolini, a prominent environmental law professor.

But the measure received pushback from beachfront property owners and companies that build and design oceanfront homes, including Eiserloh Architects, JTG LLC and Pyramid Premier Properties.

Ivan Lui-Kwan, an attorney at Starn, O’Toole, Marcus and Fisher, a real estate and business law firm in Honolulu, also raised concerns about the measure, saying in written testimony that Bill 41 could implement a “de facto policy of managed retreat” that he called “premature at this time.”

“Discussions need to explore whether and where retreat should be implemented, or whether other responses, like adaptation and protection, are more appropriate,” he wrote. “Obtaining public consensus is a must because the public is ultimately who will pay the enormous financial and societal costs required to implement managed retreat. Without broad buy-in from the public, forcing retreat will lead to division among and within our communities, litigation, and, ultimately, the failure of the policy.”

In addition to increasing setbacks, Bill 41 limits the amount of repairs that can be done on structures built within the shoreline area before modern-day land use laws were implemented, and increases the potential fines that landowners can face if they violate setback laws. Under the bill, property owners could be hit with an initial fine of $100,000 per violation, up from the current cap of $10,000. Maximum daily fines that can be levied until a violation is corrected would be increased to $10,000 from $1,000.

Bill 42 makes various amendments to the city’s ordinance relating to special management areas — sensitive coastal areas that already have stricter regulations. Many of the changes are designed to align the city’s ordinance with a tougher law passed by the state in 2020. The bill also seeks to make it easier for beachfront property owners to move their homes mauka of the shoreline.

Esther Kia‘aina, chair of the Honolulu City Council’s committee on planning and the economy, said in a statement that both bills would help addresses the threats of sea-level rise to the island’s coastal ecosystems.

“These measures will help mitigate those impacts, build coastal resilience, and protect our irreplaceable public beaches,” Kia‘aina said.