This weekend we were on the South Fork of the American River for a camping/river rafting trip. I went out in the morning and scouted the river looking for deep runs, boulders, submerged logs etc. I went back to have breakfast and eventually went back to actually fish about an hour and a half later. In that 90 minutes or so the river raised up close to 2 feet. The places where I was walking ankle deep was now almost waist deep.

The river changes because they release more water from the dam in the morning for the rafters. By 7pm the river is back down.

I was just wondering how that constant rising and lowering of the water level affects the fishing on a river.