I was wondering what fish do when you have a river that you would kayak/canoe (not big enough for boats) that is about 6ft depth max. But when it rains and the water levels go up to 18ft. Do the fish stay in the same spot or move up closer to shore. And when the water is moving pretty fast is the whole water moving that fast or just the top 2-3 feet of 15-18ft depth area? Is it calm near the bottom or are the fish trying to find a side creek to hide from the main river channel. And are they going to be at the edge of the main channel and creek meet or will they go has far as they can up the creek that they can? I'm new to river fishing. Usually a lake fishing man but rivers are fun to camp on. I wasn't sure what I should look for or focus on during the high water times.

I'm wondering the exact same thing as we just got a lot of rain and it's moving big time at my local river. 

A river that is 12 feet over normal is in flood stage. I hope you aren't in a kayak at that stage. Any time a river is running higher and faster than normal the fish will be holding in any slack water they can find, usually right up close to the bank in cuts or behind trees and rocks. They have to get out of the fast water.

I'm not going in my kayak at that time but near my jobsite looks like a good bank fishing area but didn't know if the fish are trying to get out of the way of the fast current and not really in eatting mood. I didn't know if you could still catch a fish or if that is a waist of time until the water gets back closer to normal level.

I talked to a guide on the Upper Delaware that claims to do pretty well on the smallmouth with a spinnerbait along the banks when the water is high. I don't think high water affects their mood the way a cold front will. It must make it harder for them to eat though with the decreased visibility.

Fishing a blowin out river from time to time makes fishing a challenge but I always seem to catch more fish and bigger fish during those times..I also lose a lot of lures haha. I'm stuck on the bank so I always thought that higher faster water brought the fish to slack or slower moving water closer to the bank to get out of the ripping river current. Good luck