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  Funding

 Fund for the Enhancement of Graduate Research  Huxley College Small Grants for Graduate Research  Biogeochemical Initiative

 Sampling Support:

 Olympic National Park  Shawn Hinz and Gravity Environmental Ltd.  James Michel  Sarah Steely

 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

• r 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

 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

Collaboration in the Elwha

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

Elwha Sediment

 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.

Elwha Sediment & Bank Stabilization

 Nitrogen and phosphorus limited

 Low concentrations – likely hard for plants to colonize

 Large P binding, 99.99% P bound

 Ferric oxyhydroxide and calcium

Sediment characterization: Particle Size and Nutrient Availability

P Availability: Sorption

P Availability: Fine Sediment P Release

Microbial Cell Lysis Fe~P Equilibrium Porewater Displacement

P Released (μg P kg-1) Incubation Period (hr) 4 300

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

 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 Fate

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

 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

Biological Implications on the Elwha Delta

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/

 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!

Lessons for Saskatchewan

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