In Hawaii, beaches are a public trust, and the state is constitutionally obligated to preserve and protect them. But across the islands, officials have routinely favored landowners over shorelines, granting exemptions from environmental laws as the state loses its beaches.

Over the past two decades, officials have awarded seawall easements to more than 120 property owners, who have sometimes paid hundreds of thousands of dollars to bypass rules designed to protect the public shoreline, according to an investigation by the Honolulu Star-Advertiser and ProPublica. Among those owners are business and real estate executives from Hawaii, the mainland U.S. and Japan; a former Honolulu City Council chair; and a former managing director of a large hedge fund.

Intended to protect homeowners’ existing properties, easements have also helped fuel building along portions of Hawaii’s most treasured coastlines, such as Lanikai on Oahu and west side beaches on Maui. Scores of property owners have renovated homes and condos on the coast while investors have redeveloped waterfront lots into luxury estates. Meanwhile, the seawalls protecting these properties have diminished the shorelines. With nowhere to go, beaches effectively drown as sea levels rise against the walls and waves claw away the sand fronting them, moving it out to sea.

Researchers estimate that roughly a quarter of the beaches on Oahu, Maui and Kauai have already been lost or substantially narrowed because of seawalls over the past century. That has left less coastal habitat for endangered monk seals to haul up and rest and sea turtles to lay eggs. By midcentury, experts predict, the state will be down to just a handful of healthy beaches as climate change causes sea levels to rise at unprecedented rates.