Estimate of Greenhouse Gas Emissions for the Lower Snake River Dams and Reservoirs using the All-Res Modeling Tool

The four Lower Snake River dams, reservoirs, and their hydropower systems (“LSR dams”) – Lower Granite, Little Goose, Lower Monumental, and Ice Harbor – in the state of Washington have been at the center of national controversy in recent months. Because the dams block the passage of native salmon, a decades-long interest has come to a head to promote removing the dams to restore salmon. At the same time, some advocates for keeping the dams in place continue to argue that the dams create “clean energy” and are “carbon-free” sources of electricity. This report seeks to address those claims by shedding light on the greenhouse gas (GHG) emissions caused by the LSR dams and the reservoirs the dams impound.