North Shore seasonal erosion becoming more severe

HONOLULU (KHON2) — Some North Shore homeowners are relieved because their homes survived another summer. However, the winter surf is not coming fast enough for homeowners at Pūpūkea beach.

In February 2021, Richard Sterman counted how many steps it took for him to get from his lanai’s steps at the Pūpūkea beach to the shoreline. He said it was the equivalent of a football field and the bleachers.

On Saturday, Sept. 18, that distance was down to about three feet.

“We’ve diminished to three feet from 360 feet,” he said.

Scientists and experts have studied the trend for years. Powerful swells from the west or northwest hit the beach during winter. In the summer, small northeast trade wind swells push sand back west toward Waimea Bay.

A series of hurricane swells in late August and early September of 2018 put Sterman and his neighbors’ homes on the edge. It was the worst erosion they had ever seen.

Some homeowners worked with the Department of Land and Natural Resources (DLNR) and added temporary measures to save their property. The following summer, the DLNR authorized sand pushing in order to provide a buffer before winter. The homes were fine throughout 2019 and 2020.

The summer of 2021 was the first time the sand retreated and the ocean had gotten as close to homes as it did in 2018.  Homeowners monitored the surf forecast and said there is an upcoming northwest swell. However, on some days, one foot or more of sand could be removed from the front of their homes per day.

Sterman’s neighbor has lived in Pūpūkea since 1957 and said, prior to 2018, the last time the erosion was that bad was the late 50s.

About half a mile down the road at Kammie’s, next to Sunset Beach, the situation is critical. Randy Moore bought his property at Kammie’s in 1969. He said there was an additional 45 feet of sand in front of his home in 1969 than there currently is in 2021.

“Then, four or five years ago, there started being a significantly greater erosion, and in a single episode you could lose 15 to 20 feet in a matter of a day,” Moore explained.

Experts said the erosion is getting worse, and the sand is not recovering.

“It chews a little bit more landward than it did the year before,” explained Dolan Eversole from the University of Hawaii Sea Grant College Program.

He said sand pushing and burrito bags were like putting a Band-Aid on a bigger issue, and foot traffic also played a role in the issue.

“Decadal scale events that might occur every 20 or 30 years now appear to be occurring every five years,” Eversole explained. “It feels like in certain places, like Kammie’s and Laniakea, in particular, that it happens on a seasonal basis now where it’s getting very close to the homes.”

Thousands of people stop at Laniakea every week, and the sand there and at Papa‘Iloa has also begun to disappear.

“Unfortunately, we have such a high volume of people walking down the beach, the waves don’t have time to put the sand back up where it would naturally exist,” he said.

Some homeowners believe their homes should be saved and are willing to do whatever it takes to protect them. They also believe their structures are the last lines of defense before the ocean reaches the highway.

Others argued the beach should not be threatened by sea walls or other measures and should be around for the public to enjoy in the future.

“I think it is fair to say that we should expect these types of extreme events to occur more frequently,” Eversole said. “We don’t know how often they’re going to occur, but at some point, they’re going to occur so frequently, that we’re going to have to come up with alternative measures to what we’re doing now.”

Moore said he has enjoyed the last 50 years in his home at Kammie’s.

“If I have to go, I have to go, but I feel badly for those who don’t have a choice to retreat and recently bought their property,” he said. “Some of us can say at least we’ve been here a long time and enjoy it and leave.”

The North Shore Sustainable Communities Plan is currently being updated. Eversole and others are continuing to study the shoreline issue, and there may be preliminary results as early as the beginning of 2022.