Skip Links

USGS - science for a changing world

Open-File Report 2012–1256

Prepared in cooperation with the U.S. Army Corps of Engineers

Total Dissolved Gas and Water Temperature in the Lower Columbia River, Oregon and Washington, Water Year 2012: Quality-Assurance Data and Comparison to Water-Quality Standards

By Dwight Q. Tanner, Heather M. Bragg, and Matthew W. Johnston

Thumbnail of and link to report PDF (2.6 MB)Significant Findings

Air is entrained in water as it is flows through the spillways of dams, which causes an increase in the concentration of total dissolved gas in the water downstream from the dams. The elevated concentrations of total dissolved gas can adversely affect fish and other freshwater aquatic life. An analysis of total-dissolved-gas and water-temperature data collected at eight monitoring stations on the lower Columbia River in Oregon and Washington in 2012 indicated the following:

  • During parts of the spill season of April–August 2012, hourly values of total dissolved gas (TDG) were larger than 115-percent saturation for the forebay stations (John Day navigation lock, The Dalles forebay, and Bonneville forebay) and the Camas station. Hourly values of total dissolved gas were larger than 120-percent saturation for the tailwater stations (John Day Dam tailwater, The Dalles tailwater, Cascade Island, and Warrendale).
  • During parts of August and September 2012, hourly water temperatures were greater than 20°C (degrees Celsius) at the eight stations on the lower Columbia River. According to the State of Oregon water-temperature standard, the 7-day average of the daily maximum temperature of the lower Columbia River should not exceed 20°C; Washington regulations state that the 1-day maximum should not exceed 20°C as a result of human activities.
  • Of the 98 laboratory TDG checks that were performed on instruments after field deployment, all were within ± 0.7-percent saturation.
  • All but 1 of the 83 field checks of TDG sensors with a secondary standard were within ± 1.0-percent saturation after 3–4 weeks of deployment in the river. All 88 of the field checks of baro-metric pressure were within ±1 millimeter of mercury of a primary standard, and all 85 water-temperature field checks were within ±0.2°C of a secondary standard.
  • For the eight monitoring stations in water year 2012, a total of 97.0 percent of the TDG data were received in real time and were within 1-percent saturation of the expected value on the ba-sis of calibration data, replicate quality-control measurements in the river, and comparison to ambient river conditions at adjacent sites. Data received from the Cascade Island site were only 77.8 percent complete because the equipment was destroyed by high water. The other stations ranged from 98.9 to 100.0 percent complete.

First posted May 14, 2013

For additional information contact:
Director, Oregon Water Science Center
U.S. Geological Survey
2130 SW 5th Avenue
Portland, Oregon 97201

Part or all of this report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.

Suggested citation:

Tanner, D.Q., Bragg, H.M., and Johnston, M.W., 2013, Total dissolved gas and water temperature in the lower Columbia River, Oregon and Washington, water year 2012—Quality-assurance data and comparison to water-quality standards: U.S. Geological Survey Open-File Report 2012–1256, 26 p.


Significant Findings


Methods of Data Collection

Completeness and Quality of Data for Total Dissolved Gas

Quality-Assurance Data

Effects of Spill on Concentration of Total Dissolved Gas

Comparison of Total-Dissolved-Gas Concentration and Water Temperature to Water-Quality Standards


References Cited

Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Contact USGS
Page Last Modified: Tuesday, May 14, 2013, 06:32:55 PM