We get massive flows on the Columbia in the summer. Makes fishing the Columbia a problem. The
average flow rate is about 37 million Imperial gallons a minute and that ramps up I would guess, to about
30 percent more in May through August with the flows dropping again in September. The high flows don't seam to effect the bugs as there is no dirt or sand to scour the bottom during high water.
Here's a little trivia on the Columbia River. Interesting.
http://en.wikipedia.org/wiki/Columbia_River
Bjay