Normally dry wash runs through my property and exits near my gate and into the river. When (if?) the rains come it can run fast and furious, maybe up to 3 feet deep and about 25 feet wide at the place I want to fence.
It has been fenced previously but it doesn't take much to blow it out, I don't think it is possible to out muscle the floods. The main things I want to keep from coming in this wash are atv's and trucks, and their drivers who seem to take any non-gated road or drainage as a w* Come on in!!! invitation.
I thought about large boulders spaced narrower than an atv's track but it would be difficult, or expensive. Also I worry about interrupting and potentially diverting the flow.
A high fence might work, or something that could pivot up during high water. Also I am thinking about building it simple and cheap with intent of redoing it 3 or 4 times a year.
Any experiences and ideas appreciated!
Dug I do not think you have all that much of a problem if you can find about thirty foot of cable to span the creek or dry wash. Sink a couple posts in on both sides the location you need to fence off. Stretch the cable across just above the high water mark, then hang a three or four two foot wooden panels across it using some strap iron bent in to a U shape and drilled. The water should lift the panels when it gets high. Then you will have to sort of clean it out and redo once in a while because rubbish will become trapped there. I have seen it done in a couple places. You might want to hang on the cable as well some reflectors to warn the night time trespassers
Up on the east fork of the Jemez they used to run three strands of barb wire across the area that was private. It was usually trampled.
Short of hanging a "Unexploded Ordnance" sign, there is not much to really deter people. A simple "No Trespassing" sign will keep out the honest people.