IMPACTS AND RESILIENCE IN THE SPOKANE RIVER, WA, USA
The Spokane River is a central feature of the Spokane metropolitan area, and a major recharger of the Spokane Valley - Rathdrum Prairie Aquifer, the sole source of drinking water for over 500,000 people. The river has a history of human impact, including discharge of untreated sewage for 50+ years, hydroelectric dams, and metals from historic mining. Portions are listed as impaired by the US EPA for metals, PCBs, temperature, and DO. We observed significantly higher macroinvertebrate diversity downstream of the City of Spokane, and community composition indicating widespread impacts of toxic metals. We are investigating effects of sediment from Hangman Creek, a major agricultural tributary. We monitored phosphorus loading during spring 2017. Loads consistently exceeded the TMDL allocation, with highest loads over 400x the allocation. We observed strong relationships between TP and discharge (R² = 0.83, p < 0.0001) and turbidity (R² = 0.997, p < 0.0001). We are also investigating the effects of these sediments on invertebrates in the Spokane River. Through ongoing research, we hope to better understand interactions among diverse sources of impact and resilience affecting the Spokane River.
Carolyn Connelly (Co-Presenter/Co-Author), Eastern Washington University, firstname.lastname@example.org;
Larissa Delahunt (Co-Presenter/Co-Author), Eastern Washington University, email@example.com;
Anwar Bushnaq (Co-Presenter/Co-Author), Eastern Washington University , firstname.lastname@example.org;
Camille McNeely (Primary Presenter/Author), Eastern Washington University, email@example.com;