Dam Removal Blog

March 15, 2013
Behind the Scenes of Elwha River Restoration

 

Park Volunteer Aaron Velasquez disperses some of the approximately 1,400 pounds of seed that will be sown in the drained reservoirs during March.

The Elwha revegetation crew is busy this month, sowing approximately 1,400 pounds of native plant seeds in the former reservoirs. They are sowing a special mix of eight different native plant species, all proven to be successful colonizers of fine sediments. Most of the eight species are native grasses, with several wildflower species also included.

March is one of two prime sowing times in the Elwha, with just the right temperature and moisture conditions for good germination. In October 2012, the last seeding period, more than 500 pounds of seed were sown. More will be planted next fall and spring, after the Glines Canyon Dam is completely removed.

This week, we introduce guest blogger Leonie Goebel. Leonie is a native of Munich, Germany who is spending a year volunteering at Olympic National Park. She plans to begin a Master's degree program in plant ecology after she returns home late this summer.

 

Leonie with her first seedling planted in 2013.

Volunteering as an International Volunteer for the Elwha Dam Removal
by Leonie Goebel

My name is Leonie. I am a volunteer from Germany who helps with the revegetation of the drained reservoirs along the Elwha River. After having graduated with a Bachelor of Science in Biology last summer I decided to take a year off, go abroad and do something useful. Having been fascinated with nature in the US for a long time I was given the great opportunity to come to the Olympic National Park through the "International Volunteers in Parks" program offered by the National Park Service.

Coming from a country with no real wilderness, where even in national parks every piece of land has been influenced by humans for hundreds of years, the landscape and wilderness here are just incredible for me. And even more fascinating for me is working to restore some land that is surrounded by natural and pristine forests.

Since my arrival in early September I have been able to see many different stages a plant has to pass to be finally planted in the former reservoirs.

It all starts with the seeds. Depending on the ripening of the different species, seeds from over 60 native species are collected in the watershed of the Elwha from May until November. After collecting, the seeds are taken to the Matt Albright Native Plant Center, the park's own nursery. Following cleaning, some of the seeds are sown right away as they require a cold, moist period before they are able to germinate in spring. Other species are stored over the winter and are sown in February.

In November the planting season starts. Every plant that goes into the reservoir is checked for weeds and some of the soil is taken off. Then every plant is packed and transported to its future planting site. In this planting season, 37,521plants were planted on 29.9 acres. Planting can be quite exhausting, especially when carrying the plants to the planting sites for a mile outside in the cold and rain, the whole day covered in grey mud from all the silt and clay in the dewatered reservoirs. But it is a great feeling to give something back to nature after so many years and that definitely makes up for it.

The reservoirs are not only replanted but also reseeded. Seeding is being done two times a year, in October and March. A total of 123.2 acres will have been reseeded since last October at the end of this March with over 1,849 lbs pounds of seeds from grasses and forbs.

In February the plants for the next planting season are prepared for germination, so far over 80,000 pots have been sown with multiple seeds each! Most of the plants have already germinated in the greenhouse. Over the summer they will grow in the 1-acre nursery can yard before they will be planted in the reservoirs next winter and spring. But before that they have to be transplanted in May and June and as you can guess 80,000 plants make a lot of work, so we will need a lot of hands. If you are interested in volunteering you can contact Jill Zarzeczny at 360-565-3047 or email her at e-mail us.

I am really proud to be part of this big restoration project that has no comparable counterpart anywhere in the world and am looking forward to my remaining exciting five months here with the Elwha Revegetation crew.

 

Supper Sacks ready to be moved into position by crane.

Photo courtesy of Macnak Construction.

March 11, 2013
Repairs to EWTP

 

February 22, 2013
2012 Year in review

 

View of the Elwha Dam during constuction and from approximately the same location in 2012 after the removal was complete.

This year marks one hundred years since Thomas Aldwell completed construction of Elwha Dam. For almost a century, Elwha Dam, and later Glines Canyon Dam, trapped water and sediment in two large reservoirs - Lake Mills and Lake Aldwell, provided power that helped fuel the development of Port Angeles, and blocked anadromous fish passage to over 70 miles of the Elwha River and its tributaries.

It has been twenty-one years since the Elwha River Ecosystem and Fisheries Restoration Act passed, and almost a year and a half since dam removal began. We have many years of restoration work to go, and at least another century before the Elwha Valley resembles its former self, but we've already come a long way since the turbines stopped. As we begin a new year of Elwha River Restoration, this blog post looks back at the project milestones in 2012 and where we are today.

 

View of the Glines Canyon Dam during constuction and from approximately the same location eighty-six years later.

January 2012 started off with a bang. After removing the top forty feet of Glines Canyon Dam with a hydraulic hammer positioned on a barge anchored upstream of the dam, Barnard Construction began using a series of controlled blasts to safely remove the remaining 150 feet of dam. At the same time, Barnard continued removal of the Elwha Dam, eight miles downstream. In March, the removal was complete and, by October, only about fifty feet of Glines Canyon dam remained. The final remaining fifty feet of the dam are scheduled to be removed later this year.

This month project managers made the decision to delay removal of the remaining portion of the dam in order to make needed improvements to the Elwha Water Treatment Plant (EWTP). Problems associated with the water intake structure at the EWTP began last fall, when fish screens and pumps became clogged by high concentrations of organic material (leaves, twigs and branches) and sediment. These issues decreased the amount of water the treatment plant was able to process and increased the time and effort required to clean and maintain the plant's pumps, filters and clarifiers. Work to continue lowering Glines Canyon Dam has been put on hold until March 31 to allow the contractor and plant operator Veolia Water time to complete upgrades and repairs to the water treatment plant. A new work schedule for dam removal has not yet been finalized, but the project is scheduled for completion well before the contract ends in September 2014. You can read more about the upgrades to the water treatment plant here.

 

View of Lake Mills from the northwest shore in 2009 and the same view in 2013 after the last of the lake drained. 

Photo Courtesy of John Gussman

Although there are still fifty feet of Glines Canyon Dam remaining, 2012 was a year of great change for the Elwha Valley. Since construction of the dams, two large reservoirs, Lake Aldwell and Lake Mills have impounded two sections of the river. In March, with the Elwha Dam gone, Lake Aldwell became a river once again, and by October the last of Lake Mills was also gone, restoring the Elwha to a free flowing river for the first time in over one hundred years .

Layers of sand, silt, and gravel up to sixty feet thick still remain where the reservoirs once were. The revegetation team has been hard at work planting and seeding these dewatered reservoirs, helping to stabilize to the new shoreline and restore the former riparian forest. Last year the revegetation crew seeded or planted more than six acres in the dewatered reservoirs, including planting over 30,000 seedlings. This year, they have already seeded fifty-seven acres and planted over thirty acres with 36,000 seedlings. By the end of last month, park staff and volunteers had planted over 13,000 native plants where Lake Aldwell once was, including over 600 western red cedars planted in the shade of their predecessors.

 

A newly planted cedar seedling grows in the shadow of Lake Aldwell's ghost forest.

Photo courtesy of John Gussman

Additional acres are naturally revegetating. Unfortunately, some of the naturally colonizing vegetation growing in the newly exposed sediment includes many species of invasive plants. The Lower Elwha Klallam Tribe's invasive plant management crew has had to treat for invasive species at over 500 locations within the dewatered areas.

There are still many years and many acres of planting to go, but the former reservoirs are already full of new life. With the help of volunteers and the Washington Conservation Corps, the revegetation crew plans to plant 340,000 seedlings over the next four years.

 

"Voices of the Elwha" exhibit at Klondike Gold Rush National Historical Park in Seattle.  The exhibition runs through the end of April.

Revegetation crews haven't been the only people hiking along the banks of the Elwha this year. Tens of thousands of visitors, students, film makers and reporters have visited the Elwha River to film, study, and see the project first hand. Newspapers, magazines, and television throughout the world have reported on the project and a few documentary films are in production. One of these films has been made into a series of webisodes and are available to view here. Last month Channel One News featured the Elwha River Restoration project in a news piece shown in thousands of middle and high schools around the country. You can see the piece on their website here.

An exhibit about Elwha River Restoration is also currently on display in Seattle. "Voices of the Elwha" is at the Klondike Gold Rush National Historical Park in Pioneer Square through the end of April. The exhibit was designed by students in the museology graduate program at the University of Washington. Read more about the exhibition here.

 

A Chinook spawns in a tributary upstream of the site of Elwha Dam in August 2012.

One of the most exciting events of 2012 was the arrival of Chinook salmon above the site of the Elwha Dam in August. It was a realization of many dreams to see these kings of the Pacific naturally spawning above the Elwha Dam for the first time in a hundred years. Anadromous Steelhead, pink, and coho also made their way past the Elwha Dam site in 2012.

It wasn't the easiest year to be a salmon in the Elwha. The dams didn't just capture water; they also held back millions of tons of the sand, silt, gravel, and cobbles that should have been naturally carried downstream by the river. The two dams managed to trap about 34 million cubic yards of sediment - enough to cover a football field with a 5.5 mile deep layer of silt, sand, gravel and cobbles. Now that the dams are mostly gone, the river is able to move some of that sediment downstream. During a wet winter week, the river can erode and move up to half a million cubic yards of sediment out of the former reservoirs.

 

The Elwha River in May 2011 and the same location in December 2012

While all the sediment has made the Elwha look a bit muddy, it is also building critical habitat downstream. Areas of the riverbed where there was once mostly boulders and cobbles is now being mixed with sand and silt, building sand bars, beaches, and the habitat needed by salmon to build the redds where they lay their eggs. Before and after photos taken over the last year reveal dramatic changes resulting from a sediment flow that hasn't been seen in almost a century.

As February draws to a close, spring rains continue to erode and move sediment downstream, the revegetation team is finishing up winter planting and getting ready to begin seeding the two reservoirs, and the park is preparing for the next stage of dam removal.

 

January 2, 2013
Sediment Monitoring Reveals Long-Hidden Secret

 

Glines Canyon just prior to dam construction.

With the new year, there's a newly updated estimated total volume of sediment stored in the former Lake Mills and Lake Aldwell has been updated. Members of the sediment team recently discovered a long-hidden error in the first recorded survey of the Lake Mills area. Completed in 1917, ten years before Lake Mills was flooded, this survey contained mislabeled elevations - the true elevations are actually 20 feet lower than the labels indicate. Over the years, the 1917 survey, including the 20-foot error, served as the basis for all subsequent maps. After 85 years and some careful sleuthing in the Library of Congress, Bureau of Reclamation engineers located and corrected the mistake.

The story doesn't end there, however, as the elevations have long been used to estimate the total volume of sediment contained within Lake Mills. Lowering the elevations by 20 vertical feet means that Lake Mills (and its sediment) are actually 20 feet deeper than previously estimated. The updated estimate of sediment in Lake Mills is approximately 28 (+/- 4) million cubic yards. Pre-dam maps and surveys are not available for Lake Aldwell, making that estimate even more challenging.

The actual sediment volume in Lake Aldwell is becoming more apparent as more of the predam surface is exposed by river erosion. Engineers estimate that the Lake Aldwell sediment volume may be closer to 6 (+/- 2) million cubic yards in that reservoir bed. A total of 34 million cubic yards is difficult to visualize, but is enough to cover a football field with a 5.5 mile deep layer of silt, sand, gravel and cobbles.

Although the change in estimated volume is significant, it is not expected to greatly influence either how long or how heavy the river's sediment loads will be. The rate of dam removal, controlled in response to rainfall, floods, spring melt and other factors influences the rate and amount of sediment erosion. Sediment impacts remain unchanged and well within the parameters of the existing water treatment facilities and other project mitigations. Dam removal is still anticipated to be complete well within the contract period.

This discovery illustrates the challenge of mapping an unseen landscape and estimating the quantity of buried sediments. Even with today's satellite and GPS-linked mapping equipment, the floor of the Elwha Valley in Lake Mills and Lake Aldwell hasn't been seen in decades, a key reason why a team of geologists and engineers continue to monitor and evaluate the amount and rate of erosion in the Elwha.

 

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