"BenignVanilla" wrote:

Do the pipes buried in the ground need to be emptied for the winter to
prevent bursting? I am contemplating a series of valves in my design that
will allow me to close the pond off, and use the pump to suck the water out
of the pipes. I figured this would be good for cleaning and for winterizing.

I'd say at least partially, which is to say so they have some air space,
so that the water can expand. (cold water is larger than ice, so
freezing isn't the problem)

If you had a section of pipe, that for example, had a closed valve at
each end, the pipe would burst when the water expanded close to
freezing, like it does in plumbing.

So I'd suggest opening the valves, and letting as much water out as
possible.