The removal of the Elwha and Glines Canyon dams on the Elwha River has not only resulted in astounding changes to the environment, it has also provided great opportunities for scientists to better understand how the ecosystem functions. Researchers have studied delta erosion and development and how fish, mammals, invertebrates, and birds respond to a return to more natural processes. And, in new data, they are seeing what can happen with the removal of shoreline armoring. “It’s like watching a highlight reel, sped up,” says Jamie Michel, a nearshore biologist with the Coastal Watershed Institute.
Over the past several years, Michel has been involved in a nearshore restoration project about a mile east of the Elwha River delta. The project began in 2015 when Michel and CWI began to study the effects of a ¾-mile long armored wall built of large rip rap and concrete slabs sometime in the 1950s. The seawall had been constructed to protect an artificial lake, Beach Lake, which had formed from a lagoon that existed prior to construction of the dams. Because the dams drastically reduced the supply of sediment to the beach, the lagoon had morphed into a lake.
The wall, however, did not stop erosion from taking place and over the subsequent decades, the beach and armoring suffered. By 2006, the lake and the beach could no longer withstand the decades of degradation, and sometime during the year most of the lake drained out, probably because much of the seawall was littered across two acres of beach. Little changed until 2014, when sediment that had been trapped by the Elwha River dams began to reach the delta.
“When we started looking at this area around the armoring, we noticed a chronic pattern of continued erosion. It was the one area near the delta that was behaving differently,” says Michel. He and other researchers wondered if the erosion was due to a delay in beach sediment traveling this far east of the delta or whether there was something about this location that prevented sediment accumulation. The ability to address this question came in 2016 when an opportunity arose to buy a portion of the armored section of shoreline and the land behind it. Working with U.S. Fish and Wildlife Service (USFWS), Washington State Department of Ecology, Washington State Recreation and Conservation Office (RCO), and the Puget Sound Partnership, CWI purchased the property.
Within days, the group took advantage of extremely low tides and collaborated with the Lower Elwha Klallam Tribe to take out approximately 1/2 mile of armoring. A week later, they had removed 3,000 cubic yards of the seawall and another 100 cubic yards of concrete from the beach. The results were immediate: By the next tidal cycle the beach had risen ten feet and grown twenty feet seaward in places. “It really showed what can happen when sediment is available and ready," says Michel.
The new beach also influenced the landowners to the east, who had decided not to participate in the armoring removal in 2016. When they saw what happened, the decision became easy for them, says Michel. At great expense, including moving their house 500 feet back from the shoreline, they hired CWI to remove their armoring.
CWI has continued to return to the site and remove additional armoring. It wasn’t that they left the boulders and slabs during the initial work. The material only became visible as storms and tides shaped and reshaped the landscape, bringing in sediment and woody debris, washing it away, and returning it again, in the natural cycle that had prevailed prior to building of the dams. And, with the physical changes came biotic ones. Beach wrack accumulated. Surf smelt began to spawn again. Insect diversity increased. Mammals arrived. With the full removal of the ¾ mile of wall, the ecological and physical effects have continued to spread. They now extend east three miles along the shoreline—up to a permanent riprap wall at the Port Angeles Landfill—creating what Michel describes as a textbook example of shoreline process restoration.
“We know that not every armored shoreline has a century of sediment available, but the project speaks volumes about the need for considering the entire ecological and physical processes during armoring removal” says Michel. “It’s a template for learning about the possibilities and what can be accomplished.”
[Editor's note: Additional funders for the restoration project included the Estuary and Salmon Restoration Program. Additional scientific monitoring was funded by Patagonia.]