We had the dam on my new pond 99% done when a 6" rain nearly filled it overnight - before I got my dock piers in. I drained about 8' out of the 1.6 acre lake over a month to get the dock built. I used treated utility powerline poles set in holes dug by PTO auger. Interestingly, the top ~6" of clay was wet, but dry below that! I drove spikes into the sides of the poles near the bottom, then poured a "plug" of concrete in the bottom to engage the spikes - mainly to help resist any liftup.

So I would look seriously at lowering your pond, and also build a bigger dock than you think you need! They shrink fast with tables/chairs/coolers/tackle boxes/kids, etc.