Our Waikīkī: King Tides, Beach Erosion and Water Pollution—Can Waikīkī Be Saved?

How the state is dealing with king tides, eroding beaches and trash in the Ala Wai.
Waikiki King Tide
Last year’s king tides hit record levels, rising 9 inches above predicted tide levels.
Photo: Aaron K. Yoshino


Walking down bustling Kalākaua Avenue, lined with hotels, surf shops and convenience stores, it’s hard to believe this area was once a wetland teeming with taro that fed much of Honolulu. More than a century ago, Waikīkī was the center of government and culture for Hawaiians, where streams met the ocean and fishponds provided food for chiefs. By the late 1800s, this stunning shoreline started to lure visitors, creating a demand for accommodations on the beach. This development, which included the construction of seawalls, groins and piers, prompted the eroding of the very beach that had been attracting tourists. Today, the fishponds are gone, the lo‘i have been replaced with hotels and condos. The neighborhood now has classic urban problems: crime, homelessness, litter and more concrete than coconut trees.


Can the natural beauty of Waikīkī be saved?



Ask the workers at any surfboard rental stand on Kūhiō Beach and they’ll tell you that king tides are no joke.


“You couldn’t even get to our stand,” says one surf instructor. “We had to close up.”


King tide is the buzziest environmental phenomenon in Hawai‘i, so trendy Maui Brewing Co. released a King Tides IPA last year. It’s a term used to describe the highest tides of the year that usually occur during the summer and winter months. And last year’s tides hit record levels: In April, the high tide surpassed the state’s 112-year-old record, rising 9 inches above predicted tide levels, according to the National Oceanic and Atmospheric Administration.


“The water level got higher than anything that has ever been seen before,” says Chip Fletcher, a University of Hawai‘i at Mānoa professor and expert in coastal geology. “It shut down three catamarans, it shut down all the beachboys, it shut down the makai access to restaurants. It had a pretty dramatic economic impact.”


Last year, the Hilton Hawaiian Village had to cancel its Friday night fireworks show over Memorial Day weekend because of these abnormally high tides.


The phenomenon is partly related to long-term sea level rise, a result of global warming, Fletcher says. And conditions can worsen with common ocean anomalies, swells and even heavy rainfall.


“We’ll probably see more and more of this as we move forward,” he says.



Waikiki beach
Photo: Thinkstock


Waikīkī generates about 42 percent of the state’s visitor industry revenue. The beach alone accounts for more than $2 billion in annual income for the local economy, according to the Waikīkī Improvement Association. So saving it is economically important.


“Waikīkī without a beach is not Waikīkī,” Fletcher says. “This is a billion-dollar beach and people come here for that beach. If it’s not a pleasant experience, they’ll stop coming.”


The beaches in Waikīkī have been steadily eroding for decades, shrinking by about 1 foot a year, and, if they’re not properly replenished or maintained, they could all but disappear.


Beach erosion is common around the world, with the solution often being to truck in sand from elsewhere. Back in the ’60s and ’70s, sand was mined from Pāpōhaku Beach on Moloka‘i and from a sandbar offshore from Kahuku to fill the beaches in Waikīkī. More recently, in 2012, the state dredged sand from about half a mile offshore and pumped it underwater back to the beach. That seemed to work.


But problems arose. The suction from the dredging of the sand broke the grains into a smaller size and created silt, which clouded the water. The trucks that moved the sand from one part of the beach to another drove over the new beach, crushing and compacting the sand. Some parts are as hard as concrete.


In 2015, the Waikīkī Beach Special Improvement District was created by city ordinance to preserve and restore the beach. Commercial businesses from the Ala Wai Small Boat Harbor to the Kapahulu Groin and from the Ala Wai Canal to the ocean are assessed a special improvement fee to fund long-term beach management and replenishment projects, including one to repair or replace the groin fronting the Royal Hawaiian Hotel sometime this year. Last December, scientists started mapping the beaches in Waikīkī, noting how they erode and where the sand goes.


“What we currently have is a 100 percent artificially engineered [beach],” Fletcher says. “And like all engineering projects, such as highways and buildings, you need maintenance. The beach needs to be maintained.”



Waikiki ala wai canal
photo: kahi pacarro


Removing the trash and debris from the Ala Wai Canal and nearby boat harbor is no simple—or cheap—task.


In 2016, the nonprofit Sustainable Coastlines Hawai‘i proposed installing a Mark Twain-esque water wheel in the canal, outfitted with a conveyor belt powered by either the tradewinds or solar energy that scoops trash out of the canal and into a dumpster. The goal was to get this up and running by 2018, but permitting costs started to balloon and the nonprofit is now rethinking the project, says Kahi Pacarro, executive director.


He estimates that it may cost $100,000 just to secure the permit. The wheel itself is expected to cost about $900,000, and the city has already allocated $350,000 to help. The project isn’t dead, Pacarro says, just on hold until financing can be figured out.