It was a friendly beginner surf and spin wave yesterday, but wouldn't allow for any big moves. Still fun, but on it's way out until...
Gates affect the flows as well as water. If you had 2000cfs there would be a little tiny feature where Big Sur normally is if they opened the gates (trust me, I've surfed it). Thus, if they close all the gates at 30,000, you would likely have nothing to surf. Assuming gates are open, it appears that the higher the better for flows.