Saturday 14 March 2015

No quick fixes with history of erosion at jetty


OCEAN SHORES — More than 80 people packed a City Council study session last week that proved to be a history lesson on the jetty’s development and the impact of beach erosion on the southern tip of the Ocean Shores peninsula.


While the session brought together the major agencies with jurisdiction over issues at the jetty — the U.S.Army Corp of Engineers, the Port of Grays Harbor, the state Department of Ecology and the city — little overall progress was made on what many residents and local officials believe is an immediate problem: the failing and torn geotube sand structure battered by recent storms.


Mayor Crystal Dingler noted that Ocean Shores and Ecology are beginning to study the problem, and that the Port “has been very supportive,” but there were no promises of long- or short-term solutions.


“We got a lot of information out of it,” Dingler said in summing up the results. One suggestion is to put together a committee of advisers and experts to “help us make a decision in where we go from here.”


Many of the people in the audience were residents of the jetty area, including some of the ocean-view condominiums and homes in most danger should the beach continue to erode.


“This is the summer that we need to do something,” Dingler told the full City Council after the study session.


David Michalsen, Army Corps coastal engineer, started the session with an overview of the jetty, which was built in 1916. Most recently, the Corps repaired the jetty interior portion in 2000 to an elevation of 23 feet. The outer portion of the jetty was last repaired in 1976 to plus-20 feet.


“Before jetty construction, the shoreline was pretty far landward or eastward where it is right now,” he said. “What happened after we put the jetty in, there has been massive pushing of sediment out into the near-shore area. As the current scours those sediments out of the inlet, they basically accreted on both the north side of the north jetty and the south side of the south jetty.”


In 1942, when the jetty was lengthened and raised, it had already accreted, or built up, on either side, widening the peninsula in effect, slides shown by the Corps showed. It also is what caused Damon Point to grow and curl into the south of the Harbor.


“That feature is important because it shows how sediment is coming into the Harbor over the north jetty or through the north jetty, and that sediment has fed the growth of Damon Point as you know it now,” he said. With dune erosion and sediment moving north to south, the coastline has been further damaged by storms, and property owners as well as the city have tried separate efforts to mitigate the damage; the geotubes, which are like large heavy fabric tubes filled with sand meant to bolster the hillside and build up more sand; and the so-called wave bumpers, which essentially are rocks placed to lessen the impact of the sea.


Storms, however, create another problem. Michalsen noted that a channel forms between the dunes and the jetty itself during high storm events.


“As a result of the most recent storm in 2007 that caused significant over-topping of the jetty, we saw that channel to be cleared out again and it left a big void,” he explained of the area at the very south end of Ocean Shores Boulevard. “A lot of the sediments that are accreting there now are actually coming from the north from that area near the geotube and the wave bumper structures.”


Most of the residents and city officials wanted to know what could be done in the short term, especially with recent exposure and tears in the geotube.


The Corps discussed some potential help, Michalsen said, through its emergency management authority or in offering technical assistance.


“There is the repairing or the replacement of the geotube structure itself, refilling the tubes or patching the tubes,” he suggested as possible short-term solutions.


Other possible solutions include “dune nourishment” using local sand or trucks of material brought in to stabilize the dunes; “sand fences” to promote dune growth in the non-storm season, and dune plantings with native dune grass.


Ocean Shores would have to be responsible for being the lead agency for permitting those efforts, but Michalsen indicated the Corps would be supportive.


Engineer Vladimir Shepsis from Coast &Harbor Engineering has been hired by the Port of Grays Harbor to look at a history of the jetty project and provide that information and experience to the Corps and the city as well.


“It’s important — the history of the north jetty — to the history of Ocean Shores,” he said.


In 1996, he was brought on specifically to look at the erosion problems at the jetty for Ocean Shores. The last time he was back was about a decade later, until just recently.


“I was quite surprised to see what has happened since the years I was there,” he said of seeing the area first-hand on Monday.


In 1996, Shepsis was called in when the Ocean Shores shoreline started eroding from the past winter’s storms.


“It was a big surprise for everybody,” he noted. By then, it was already June and the distance between some properties and the shore was 15-to-30 feet.


It was obvious, Shepsis added, that if nothing was done, the properties “would go into the water” the next winter. That led to the wave bumpers, paid for by the residents, which were supposed to be a maximum of two years worth of solution.


Shepsis said the wave bumpers were two tiers of rock and filled with a “red rock” local material.


“We need to separate wave energy and break it into pieces,” he said of how the process worked as waves hit the tires of rock, lessening the impact of erosion. The cost at the time was $450,000.


Likewise, Shepsis said, the geotube plan was only meant to be a temporary fix.


Giving what he said was his personal opinion, Shepsis said the area now faces a “major problem.”


Port Director Gary Nelson suggested forming an ongoing coastal committee to review and examine long-term solutions to the jetty and erosion issues, both at the Ocean Shores and Westport structures.


Joe Taller of Olympia, president of the Pacific Avenue Condo Association and a former state Parks and Recreation commissioner, asked what responsibilities the owners of the land in front of the geotubes had in paying for potential repairs. He noted the wave bumper rocks that protect his property were paid for by the owners themselves.


“Shouldn’t they be required to pay part of the the cost to protect their building?” he asked.


“I think something has to be done immediately to repair the geotubes,” Taller said. “If you wait another year, you’re going to have a much larger problem. Right now, the wave bumpers work around our property, but the waves take the sand away from the geotubes.”


Resident Jerry Mergler asked what the outcome would be if the city and other agencies “let it erode. Is there something worse that could happen from this erosion?”


Some have suggested letting the area “go back to nature,” Dingler noted, in discussions with emergency management officials. “The difficulty is that we are dealing with an artificial thing here, like a jetty. The jetty giveth and the jetty taketh away,” she said.



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