Good question Rooster!
This time of year all kinds of rip rap can and will hold fish. If I was going to come down and fish your pool, first thing I would look for is rip rap on the outside bends of the river. With the lower flows we have right now these areas would hold a bit more current giving me more confidence. The outside bends usually have deeper water really close by which is another big plus when the water temps fall in to the 40’s. Once you find an area like this you will find that the area you catch most of your fish will have something a bit different about it. Example would be a small rock slide creating a high spot, or point, giving the fish faster access to deeper water.
With high water, the current dictates the areas I will concentrate on when fishing rip rap but with the low water he have in the river right now the above areas should be prime areas to target.
The more time you spend on rip rap you will find that some shorelines have no rhyme or reason to why the fish hold there. I have rip rap areas on pool 4 that are about 1 mile long, I will get fish along the whole stretch. The key to areas like this is the whole 1 mile has 20’+ depths really close by.
Hope this helps!