Just finished digging our 1/2 acre pond and had a couple questions. How far down should the barrier go to keep sand from getting lost? And best material to use to make barrier?

I think the sand in a beach often does not get lost. What I see happening is the sand becomes mixed with years of dead organic materials that accumulate in and among the sand particulates. Thus a beach in a pond often becomes an accumulation of mucky often smelly materials from mostly the dead organics (dead plants, leaves etc) that get mixed on top of and into the sand. It is amazing how much dead plant material that will accumulate after 5-10 years on submerged beach sand. This result often does not happen on beaches on large lakes. This is because beach shorelines on large lakes receive a monthly thrashing from pounding wave action. This has a oxygenation impact upon the upper layers of beach sand which allows or produces fast, clean decomposition of the organic layers that have accumulated since the last pounding wind driven wave action. This does not happen in ponds due to lack of strong wave action.

Best way to create a small pond beach is to build or create a curb of dirt (bull dozer - bobcat) or cement blocks to outline the deep end or outer edge of the beach. This curb helps contain the sand from 'working' its way down the slope toward deep water.

Often I get asked what I think is the best material to use for beach material - sand, small crushed limestone, or pea gravel. Each of these materials has benefits. I often suggest to split the beach 50-50 and use two different materials for a beach bottom variety so when one side goes array the other hopefully remains more usable. The secret to keeping a beach bottom area "clean" is to use Mother Nature's time tested recipe. Frequently (monthly) mix the top layer to keep it well oxygenated so oxygen consuming invertebrates and beneficial bacteria can quickly and cleanly decompose and process the accumulated dead organics. The more physical activity a beach receives the cleaner it stays.

We made a sandy beach for the grandkids. Bluegill decided they needed it more for spawning.

Figured someone should thank you for your excellent direction, Bill. So, thanks!

FWIW The sand beaches only need to last as long as the grandkids are willing to use them. I have a very well built sandbox in the back yard that I have been working on to get rid of. We only used it for abut 3 years. We nailed 4x4s together with those spiral landscape nails, and needed my spud bar and maul to get them apart. So IMHO there isn't a lot of good reason to go overboard on making a long-lasting beach unless you have a much larger family than I do.

Also, we just swim from the dock, and touching the bottom is avoided at all costs. Floats, rafts, diving platforms, small boats, etc. provide plenty of entertainment.

Bill Cody, what you wrote is so true. The local lake has a public access point that is used for swimming. In the Spring the lake bottom in the area is slightly mucky. Away from the public access point the bottom is VERY mucky (up to your knees muck). Once there have been a number of people using the public access point for swimming, the slightly mucky area is now back to being a hard sand bottom.