I am in the planning/budgeting stage of my 1 acre pond to be built next year.

My small pond will freeze with ice sometimes being 6" or more. Will treated 6X6s stand up to ice or should I go with concrete pillars. I am not against spending a little more in the beginning so I don't have to spend a lot more later.

I used old telephone poles and placed a half bag on dry concrete at the bottom of each hole, and then another half bag after setting each post and then backfilled with soil and packed. My holes were 3.5' deep to get below the frost line. It has held up very well.

I assume you are taking about the damage ice can do by lifting?
If you get lift from the dock being frozen to the ice mass/sheet and then the water level rising after that, not much will help you except having a floating dock, or a removable one.

Thank you

I built mine using concrete pads (about 50lbs each) with 4x4 preformed concrete holders like used for decks with 4x4 treated posts attached. It has been in-place for 5 years now, and the pond regularly freezes deeper than 6" in winter. Absolutely no problems, and it does not lift. I believe the weight is enough that it stays pinned down. No chew marks on the posts from ice, just skate marks on the top of the dock!

Since pond ice < 4 acres is not subjected to too much of a wind load like a lake or river, ice pressure is minimal. You will be fine with 4x4s and up. Just make sure to purchase lumber treated for 100% soil contact and complete water immersion. The Home Depot variety is not suitable.

Dock In Winter

Oh, HEP Sales is a great place to get well-treated square and properly kiln-ed lumber. I have had great luck with them lately.