Then all you have to do is eliminate the sleeping houses and you are left with the homes of the catchable fish. We will start with the fast water. Rapids are the fastest water on any stream. They are deeper than riffles and have larger structure features simply because the smaller features have been moved away by the current flow, or they are buried by the volume of water flowing over them. Boulders, either sticking through the surface or covered by the surface of the water.
Boulders protruding from the waters surface create two pockets of slower water.
They are both feeding lies. The front pocket is formed by the damming effect on the current, this causes the water to stack up and create a bulge of slower water. You will see this bulge and sometimes there is a breaking wave just in front of the bulge. The lee pocket is usually farther from the boulder than you think. The food conveyor belt will show you this point.