Ice Harbor Example
Ice Harbor Dam is located on the Columbia River immediately upstream of McNary Dam and
immediately downstream of Lower Monumental Dam along the Oregon/Washington border
(Figure 2). Spilling operations conducted for
fish passage, as well as flood control, often
lead to dissolved gas concentrations that are
supersaturated with respect to the atmosphere.
Supersaturation of dissolved gases in water
may have severe detrimental impacts on fish.
As a result, extensive studies to measure
dissolved gas concentrations and dynamics
have been conducted at the U.S. Army Corps
of Engineers projects in the Columbia River
Data gathered during transect studies in
support of the total dissolved gas monitoring
program illustrate how data gathered for other
purposes can be used to plan an automated
monitor installation. The results from these
lateral transects are displayed in Figure 3.
Two monitors were previously installed in the
Ice Harbor tailwater (indicated as the labeled
points in Figure 3); however, they were
neither designed nor intended to reflect the
extent of the variation in total dissolved gas
concentrations in the area.
Figure 2. Columbia River basin
Figure 3. Contour plot of Ice Harbor total dissolved gas transect data
Water Quality Technical Note AM-02 (January 1998)