Chinook Observer, July 11, 2001
LONG BEACH--Dog-eared postcards show the ocean rolling up to the Long Beach arch, tossing drift logs to within a stone's throw of the main drag. A five-year study of coastal erosion concludes those times are likely to return.
Likewise, the Seaview dunes that have been the center of so many knock-down, drag-out political fights in the past 10 years will be gone by 2050 unless there is a huge increase in the amount of sand flowing from the Columbia River, according to the U.S. Geological Survey and the Washington State Department of Ecology.
And what about Beards Hollow, where Washington State Parks and community organizers envision installing floating walkways as part of the Discovery Trail? A few hard winters will reunite it with the ocean, again making it a wave-tossed cove, as it was a century ago.
By mid-century, these changes on the southern half of the Peninsula may consume all or most of the area of beach that accreted in the first half of the 20th century, according to findings by the Southwest Washington Coastal Erosion Study.
The only hope of slowing this erosion lies in convincing the U.S. Army Corps of Engineers to undertake massive reform in how it and its contractors dispose of millions of cubic yards of dredge spoils removed from the river each year, and even that may not be enough in the long run, according to one of the erosion study's lead researchers.
Officials surprised by pace of erosion
In December 1993, a typical winter storm swiftly breached the narrow isthmus between the ocean and bay at Westport in Grays Harbor County. This was followed the next year by a similar event at Ocean Shores. At the same time, erosion at Cape Shoalwater in Pacific County--going on for decades--reached a critical juncture at which it threatened to destroy State Route 105 between Raymond and Tokeland.
''The amount of erosion that happened over a short period of time really surprised people, how rapidly it can just really take off when we had an event like that [the 1993 storm at Westport],'' said George Kaminsky, coastal engineer with DOE's Coastal Monitoring & Analysis Program in an interview last week. Kaminsky and Guy Gelfenbaum of USGS are principal authors of the erosion study.
''The questions came up--well, where is this going, when will it end, where will it stop, what should we do? We didn't really have any kind of knowledge base for decision making,'' Kaminsky said. ''We could apply Band-aid fixes on each of these little spots, but what's happening overall?''
All this puzzled state and federal officials, leading to a five-year study that recently concluded. The results have not been shared with the general public until now.
Historic offshore sand supplies used up
Scientists didn't find what they hoped on the sea floor off the Washington and northern Oregon coasts: Enormous banks of sand that once protected and nourished beaches near the mouth of the Columbia, Willapa Bay and Grays Harbor.
''Those offshore shoal areas that were outside the entrances, north and south of the jetties ... those areas were acting basically as sand sources to feed the beaches and a lot of the beach accretion we've seen over this century has been due to that loss of sand. Basically, there was a source area and that material was being pushed onshore by waves over decades of time and then the dominant drift pushed that sand northward,'' Kaminsky said.
Here north of the mouth of the Columbia, studies of the sea floor discovered the huge sand bank known as Peacock Spit has largely disappeared. The sea floor off the southern Peninsula is getting steeper as sand erodes away in the current.
A bigger surprise awaited when scientists looked across the river at the broad arc of beach from Tillamook Head to the South Jetty in Fort Stevens State Park.
There, a detailed look underwater found ''a very large area of erosion, which is larger than anything on the Washington coast,'' Kaminsky said. ''So we think of that area essentially serving as a sacrificial loss area that's acting to help supply beaches to the north.''
''This could lead to a long-term chronic, but probably moderate, amount of erosion off the Oregon side,'' he said. The angle of the shoreline and longer-term stability of the beach there should somewhat protect Seaside, Gearhart and other Oregon towns from truly disastrous erosion, he said.
But, in effect, Oregon sand has acted as a reservoir for the Peninsula, and that reservoir is running low. ''It's why we actually haven't seen higher rates of erosion off of southern Long Beach than we have. But that will have its limit and when it comes to an end, the erosion rates might even become higher,'' Kaminsky said.
''We have a shoreline that had historically built out that is no longer in equilibrium with the amount of sand being supplied to it, so we get a shoreline retreating now because the supply of sand at historical levels is not being continued.
''It's kind of difficult to predict exactly what's going to happen, how much the beach will retreat, but when you put it all together, what we see is a large net loss of sand that's not being resupplied,'' Kaminsky said. ''Eventually, the offshore losses will give us more beach retreat on the uplands.''
Losses working north from North Head
Old-timers on the Peninsula scoffed at the very idea of beach erosion until a 1997-98 El Niño event began to shave off the end of Fort Canby State Park.
Benson Beach and the area shoreward formed after completion of the North Jetty in 1916. The area has become one of the gems of the state park system, attracting tens of thousands of campers and thousands more day-trippers each year.
But now, the park anticipates loss of most of that area to erosion by 2010, and is planning to move its campgrounds.
Erosion has worked its way around North Head and is making rapid inroads on the main Peninsula, spurred not only by a shortage of sand but also by currents and waves that are no longer slowed by now-depleted shoals.
In the Beards Hollow area just north of North Head, the 2000 grassline survey the state undertakes to establish property ownership lines and shorelines law jurisdiction clearly showed the beach is retreating there. ''The grassline has moved significantly landward from where it was in 1990,'' said Kaminsky.
Peninsula's southern beaches are next
Scientists foresee the shoreline on the south end of the Peninsula rotating back to what it was before jetty construction.
''Generally, what we're looking at is a few hundred feet of erosion near the Seaview area and then it tapers off to essentially no change five to eight kilometers [three to five miles] north of North Head, getting into the city of Long Beach,'' Kaminsky said. Bolstad beach approach is about 3.3 miles north of North Head.
These findings ''suggest there will be net loss of beaches that will compromise significant developments in the city,'' he said.
We can ''probably [expect] loss of where the boardwalk is, and this prediction looks at the next 20 years. We might see substantial changes along southern Long Beach. Hopefully, our predictions are wrong, but what we see is a lower sand supply leading to beach erosion on the order of several hundred feet'' near North Head.
Although the main surge of erosion is likely within the next 20 years, without major additions of sand to the system, by 2050 erosion is predicted to extend into long-established areas of Seaview and southern Long Beach, perhaps including loss of one or two rows of houses along the historic shoreline on K Place and Ocean Beach Boulevard, according to preliminary predictive mapping.
''I don't want to predict doom and gloom here, but we have to be honest about what we see,'' Kaminsky said.
Ironically, the sand that is swept away from Seaview and Long Beach is predicted to actually maintain and perhaps expand beaches from the mid-Peninsula and north. ''We may not have to do anything to maintain beaches up by Klipsan but we may have to have a lot of intervention to maintain the beaches along Seaview,'' Kaminsky said.
This process might be slowed, but probably not reversed, if dredging practices are reformed to explicitly place materials where they can reach the beach, Kaminsky and others argue. ''For southern Long Beach, basically unless we have future big pulses of sand coming from the Columbia River, then it will take careful management to minimize the amount of beach retreat in the future. ''
A similar pattern is seen north along the Washington coast, with losses near harbor entrances leading to beach accretion north of them. The sand's ultimate destination is Point Grenville in the Quinault Indian Reservation, where it appears to stop migrating. ''We don't really see those beaches going away, short of a catastrophic event,'' Kaminsky said.
How sure are they and what shall we do?
How good are these predictions and what can we do? The answers depend partly on nature and partly on human intervention.
The pace of erosion depends on the ocean and weather. If the intense ocean conditions of the past seven years were to recur frequently, then damage to the beach will accelerate. If there are few or mild El Niño events, then erosion will be more gradual.
The other chief variable in the equation is sand supply. About 3 million to 5 million cubic yards of sediment once flowed from the Columbia each year, but dam construction and dredge spoils disposal policies have drastically reduced that. Materials dredged to maintain navigation channels are almost entirely lost to the system after being dumped on upland areas or out in deep ocean waters.
The erosion study ''suggests that if we don't use the sand that's dredged from the mouth in a way that resupplies that area of coastline, then ... that sand loss contributes to the ongoing loss,'' Kaminsky said. He said the state and the corps must begin an active discussion about ''What do we do with dredged material and how do we manage navigation projects? What can we do with our decisions to lessen the impact or make a better, more responsible use of material that we have?''
A pilot project was funded by the Legislature this year to test feasibility of pumping some material from Ilwaco channel maintenance over the jetty onto Benson Beach, an experiment that will in itself have no impact on erosion but which on a far grander scale could lead to better sediment management, Kaminsky said.
''It's almost questionable even if we used all of the sand that's dredged from the mouth of the Columbia River if that's even enough,'' he said. ''It would certainly slow the erosion, but is there enough to actually stop it? That's another question.''
No ongoing efforts planned at present
At present, no continuing efforts are planned by the state or federal governments to monitor and plan for erosion. State and federal funding for the USGS-DOE study has run dry, just as monitoring and modeling were getting to the point where they can be useful, Kaminsky said.
He is trying to combine a variety of work projects to secure additional federal funds, trying to keep a minimal effort going, while hoping the Legislature provides additional money in the supplemental budget next year.
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