Dam Removal: Before and After Emily Cavaliere PhD Candidate - PowerPoint PPT Presentation

Elwha River Dam Removal: Before and After Emily Cavaliere PhD Candidate University of Saskatchewan

Acknowledgements  Co-Author: Dr. Peter Homann  Sampling Support:  Funding  Olympic National Park  Shawn Hinz and Gravity  Fund for the Enhancement of Environmental Ltd. Graduate Research  James Michel  Huxley College Small Grants for  Sarah Steely Graduate Research  Biogeochemical Initiative  Technical Support:  Nancy Bonnickson  Sally Elmore  Erin Macri  Clint Burgess  Joan Vandersypen  George Mustoe  Zachary Keesey

Dams and Dam Removal  The US: 2000 dams – high risk or needing repair in 2015  By 2020 - 50% of US dams will be 50 years old  Canada: 933 large dams – many thousands more smaller dams  Dams have a limited lifetime...  Risks... https://www.nytimes.com/interactive/2017/02/23/us/americas-aging-dams-are-in-need-of-repair.html https://www.ec.gc.ca/eau-water/default.asp?lang=En&n=9D404A01-1&wbdisable=true#intorduction

Dams https://www.hydroworld.com/articles/print/volume-25/issue-1/features/dealing-with-sediment-effects-on-dams-and-hydropower- generation.html

Elwha River Glines Canyon Dam Elwha Dam

Elwha River • Olympic Peninsula, WA • Flows North to Strait of Juan de Fuca • In Olympic National Park https://www.usgs.gov/news/moving-mountains-elwha-river-still-changing-five-years-after-world-s-largest-dam-removal

Olympic National Park https://www.nps.gov/olym/learn/photosmultimedia/photogallery.htm

Elwha River  Supported salmon populations  Two dams built in the early part of the 1900s  2 dams were removed  Aging structure (sediments)  Fish Habitat  Lower Elwha Klallam Tribe

Fish in front of the dams http://www.michw.com/2013/04/when-the-wall-comes-tumbling-down-elwha-river-sediment-transport/

Dams on the Elwha River http://www.michw.com/2013/04/when-the-wall-comes-tumbling-down-elwha-river-sediment-transport/

Sediments behind the dams http://www.michw.com/2013/04/when-the-wall-comes-tumbling-down-elwha-river-sediment-transport/

Removal and Restoration  In 1992, Congress passed the Elwha River Ecosystem and Fisheries Restoration Act  $325 million USD

Collaboration in the Elwha  Lower Elwha Klallam tribe  US National Parks Service  Olympic National Park  US Department of Interior  Working together to restore and understand fish returns to the Elwha

Elwha Sediment  30 megatons of sediment  Why do we care?  What happens to the sediments after the dams are removed?

Elwha Sediment & Bank Stabilization  Predict sediment deposited in the river or on the flood plain  Stabilization – hold sediment & maintain good salmon breeding habitat  Plants – need nutrients for growth  Sediment nutrients  Cavaliere, E.; Homann, P. Elwha River Sediments: Phosphorus Characterization and Dynamics Under Diverse Environmental Conditions. Northwest Sci. 2012, 86 , 95 – 107.

Sediment characterization: Particle Size and Nutrient Availability  Nitrogen and phosphorus limited  Low concentrations – likely hard for plants to colonize  Large P binding, 99.99% P bound  Ferric oxyhydroxide and calcium

P Availability: Sorption

P Availability: Fine Sediment P Release Microbial Cell Lysis P Released ( μg P kg -1 ) Fe~P Equilibrium Porewater Displacement 4 300 Incubation Period (hr)

Different Processes Before Dam Removal After Dam Removal

Post-Dam Removal

Dam Removal https://www.usgs.gov/news/moving-mountains-elwha-river-still-changing-five-years-after-world-s-largest-dam-removal

Sediments https://www.usgs.gov/news/moving-mountains-elwha-river-still-changing-five-years-after-world-s-largest-dam-removal

Sediment Fate  Unpredictable sediment pulses, despite deconstruction techniques to control release…  Large quantities (>86%) moved in second year following removal – larger than average discharge  A fraction deposited in the river  Of the 30 mega tonne of sediment, 65% was eroded  Increased delta by 60 ha  Ritchie et al. 2018; Magirl et al. 2014

Sediment https://www.usgs.gov/news/moving-mountains-elwha-river-still-changing-five-years-after-world-s-largest-dam-removal

Plant Community Nutrient Limitations  Remaining reservoir sediments  Plant growth  Mycorrhizal inoculation  Difficult further away from established plant communities  Cortese & Bunn 2017 https://www.mdpi.com/2073-4395/7/4/75

Biological Implications on the Elwha Delta  Community shift – estuary from brine to freshwater  Pioneering vegetation increased on new habitats  Concurrent increases in N and P during removal (estuary)  Foley et al. 2017

Salmon in the Elwha  Mainstem of river – little impact of sediment movement (floodplain)  Landlocked species return to sea (bull trout)  Likely some impact on salmon species – sediment reduced return to Elwha  As of 2018, counts indicate near 20-yr average  Some indication that some salmon species are inhabiting newly open areas  Daily News 2017; Northwest Treaty Tribes 218; Quinn et al. 2017; Peters et al. 2017 http://www.peninsuladailynews.com/news/fish-recolonizing-areas- upriver-of-former-dam-sites-on-elwha-river/

Lessons for Saskatchewan  High costs - $325 million USD for Elwha removal (not necessarily restoration)  Unpredictable sediment release  Targeted restoration likely required  Sediment stabilization  Species at risk  Sediment toxicity?  Restoration to what...  Collaboration!

References  Cavaliere, E.; Homann, P. Elwha River Sediments: Phosphorus Characterization and Dynamics Under Diverse Environmental Conditions. Northwest Sci. 2012, 86 , 95 – 107.  Ritchie, A. C.; Warrick, J. A.; East, A. E.; Magirl, C. S.; Stevens, A. W.; Bountry, J. A.; Randle, T. J.; Curran, C. A.; Hilldale, R. C.; Duda, J. J.; Gelfenbaum, G. R.; Miller, I. M.; Pess, G. R.; Foley, M. M.; McCoy, R.; Ogston, A. S. Morphodynamic evolution following sediment release from the world’s largest dam removal. Sci. Rep. 2018 , 8 , 13279, doi:10.1038/s41598-018-30817-8.  Quinn, T. P.; Bond, M. H.; Brenkman, S. J.; Paradis, R.; Peters, R. J. Re-awakening dormant life history variation: stable isotopes indicate anadromy in bull trout following dam removal on the Elwha River, Washington. Environ. Biol. Fishes 2017 , 100 , 1659 – 1671, doi:10.1007/s10641-017-0676-0.  Peters, R. J.; Liermann, M.; McHenry, M. L.; Bakke, P.; Pess, G. R. Changes in Streambed Composition in Salmonid Spawning Habitat of the Elwha River during Dam Removal. J. Am. Water Resour. Assoc. 2017 , 53 , 871 – 885, doi:10.1111/1752-1688.12536.  Perry, L. G.; Shafroth, P. B.; Perakis, S. S. Riparian Soil Development Linked to Forest Succession Above and Below Dams Along the Elwha River, Washington, USA. Ecosystems 2017 , 20 , 104 – 129, doi:10.1007/s10021-016-0080-1.  Magirl, C. S.; Hilldale, R. C.; Curran, C. A.; Duda, J. J.; Straub, T. D.; Domanski, M.; Foreman, J. R. Large-scale dam removal on the Elwha River, Washington, USA: Fluvial sediment load. Geomorphology 2014 , 246 , 669 – 686, doi:10.1016/j.geomorph.2014.12.032.  Foley, M. M.; Warrick, J. A.; Ritchie, A.; Stevens, A. W.; Shafroth, P. B.; Duda, J. J.; Beirne, M. M.; Paradis, R.; Gelfenbaum, G.; McCoy, R.; Cubley, E. S. Coastal habitat and biological community response to dam removal on the Elwha River. Ecol. Monogr. 2017 , 87 , 552 – 577, doi:10.1002/ecm.1268.  Cortese, A. M.; Bunn, R. A. Availability and function of arbuscular mycorrhizal and ectomycorrhizal fungi during revegetation of dewatered reservoirs left after dam removal. Restor. Ecol. 2017 , 25 , 63 – 71, doi:10.1111/rec.12406.  https://www.usgs.gov/news/moving-mountains-elwha-river-still-changing-five-years-after-world-s-largest-dam-removal  https://nwtreatytribes.org/lower-elwha-partners-studying-chinook-salmon-returning-dam-free-elwha-river/  http://www.peninsuladailynews.com/news/fish-recolonizing-areas-upriver-of-former-dam-sites-on-elwha-river/  http://www.michw.com/2013/04/when-the-wall-comes-tumbling-down-elwha-river-sediment-transport/  https://www.mdpi.com/2073-4395/7/4/75  https://www.nps.gov/olym/learn/photosmultimedia/photogallery.htm