Topix Underground

Is that like a Texas gate but for water crossings?

Yes, sort of similar.  Many of the small creeks here have steep banks ---u--- The pallets carry the fence across the creek while allowing high water and debris to pass under them as the float up, a regular wire fence would catch much of the debris and then fail.  Cows are big but not overly bright, most times the pallets bluff them. The look like a wall so the cows think they are one.

An old farmer I used to know always said the same about barbed wire fences, that they are just a bluff and a large cow can breach them IF they take a notion. But most times the cattle don't realize it.