Can someone tell me if there is a rule of thumb as to how far above the full pool water line the bottom of the girders should be?

My girders will be set on 6 by 6 posts and I will have a spillway drain for excess water runoff. As a result, I would expect that my water level would not rise very much higher than the full pool mark because I would think that the water could run out of the pond as fast as new water is running in in the case of a storm, etc. Thus, how far above the water line should the bottom of the girders be placed on the pole?

Thanks.


Also, if you use the hidden fastners to attach the decking boards to the joists, in the event that you have to replace a board at some point in the future, would you have to take up all the boards from one edge of the deck to get to the board that needs replacing? By the way these hidden fastners look, it looks to me like you would have to take them all up to reach the board that needs replacing. Is this correct?

thanks all