Lower Columbia River Dissolved Gas Monitoring Network

Science Center Objects

USGS total dissolved gas (TDG) data help guide spill and discharge management from dams operated along the lower Columbia River.

The U.S. Army Corps of Engineers operates several dams along the Columbia River that fulfill regional needs for flood control, navigation, irrigation, recreation, hydropower production, fish and wildlife habitat, water-quality maintenance, and municipal and industrial water supply. When water is released through the spillways of these dams ambient air becomes entrained in the water, resulting in an increase in the concentration of dissolved gases in the water downstream of the dams. Concentrations of dissolved gases greater than 110 percent saturation can cause gas-bubble trauma in fish and adversely affect other aquatic organisms. The U.S. Army Corps of Engineers uses real-time USGS data to regulate streamflow and spill from its dams to minimize the production of excess dissolved gases, while providing fish passage through the spillways.

Eight monitoring stations are operated on the lower Columbia River, from the navigation lock of the John Day Dam to Camas, Washington. Five of the stations (John Day navigation lock, The Dalles forebay, Bonneville forebay, Cascade Island, and Camas) are operated from March to September, encompassing the usual period for dam spill operations. The stations John Day tailwater, The Dalles tailwater, and Warrendale are operated year-round.