When the water is high and dirty, hatch fishing can be a bit inconsistent. One thing about these conditions is that it can often provide great streamer fishing. Fish are sometimes a bit hungry with the lack of steady insect activity, and thus I think this also brings out some extra aggressive behavior. Here are a couple things I like to keep in mind for streamer fishing.
Look for fast water. I think mature fish especially learn over time that by holding in and around fast water they have the opportunity to see more potential food pass by. I like to find small bits of “pocket water” where a fish can sit in a seam or small break in the current and wait in ambush for passing prey. Another great advantage of fishing fast water is the fish is presented with a very short amount of time to make its decision of attacking your fly or letting a big meal pass. More times than not the fish will make a move, and if you are able to get your line tight hang on.
Watch the bank. In high water especially fish will stay close to the bank. This is not only to get out of the fastest water, but also because of the great cover it provides. The bank is also a great food source, as worms, terrestrials, rodents, you name it end up close to the bank as well. As summer heat sets in, a shaded pocket of knee deep pocket water next to the bank is high-rent zone for big fish.
Fish up. Time and time again I find casting a streamer up stream and stripping it back down so much more effective than any other presentation. There are several reasons this may or may not be the best approach, but for me its consistently more productive. Erratic action is easy to produce with this retrieve, and I think the fish see it coming at them and just like dragging a mouse through a room full of cats, the fish just can’t resist making a quick pounce.