Catfish completely hide when they spawn. Then, they sit on their "nest" over the egg mass until hatch. If they can fit between rocks and be totally surrounded, rip-rap is good. So, placement is crucial. Be sure catfish spawning areas are in water less than five feet deep, and it would be best if the opening of each hiding spot opens to the south. I would be tempted to put some type of containers along the area you intend to rip-rap, then surround the container with rocks. Stainless steel beer kegs are good, with the tops cut out.
You are not far from several rock quarries. I would contact local rock and gravel companies and make an inquiry to see what's available at what cost.
