Potholes every year goes through the same cycle. It is lowest in September and on opening day it is very low, so low that you need a small jet boat, or mud boat to get back there. By early November you can get around back there with a prop if you really know the channels and how to get around back there. When they shut the Irrigation water off and start dropping Moses Lake around the first week of November is when you see the water levels really go up, but it is still shallow in a lot of places back there. They continue to fill it up and it peaks out around Early April before Irrigation is turned back on. So yes it will continue to go up. Potholes is a tricky one to learn and you have to spend a lot of time on it to really know it. I was talking to Aaron Echternkampt about it once and he talked about running his full size bass boat all the back there in September, which you have to know that channel perfectly to do, but he has spent so much time there that he has it down I guess.
If you are really in the main channel it should be deeper than 1-2 feet. My guess is that you are on a side area or not on the channel. I used to have a 16' Jet and I could run it all year and had the channels pretty well memorized.
One trick that you probably know is it is usually deeper on the east side of a dune, and running north and south will get you back there the furthest. If you want to get back into a spot go out towards the main part of the lake and work back in a north or NW direction.