Yeah, setting up a small tank near the orchard is probably a good idea. We do have the house, irrigation, and animal tanks all separate, so we still have water in the other tanks, it was the irrigation tank that drained. But, if I put a smaller tank, or even a barrel on that line and fill it once a week for irrigation, that would reduce the risk, somewhat.
I do use globe valves on everything, I just turned on the irrigation line and completely forgot about it until this morning. It's an honest mistake, but one I hope to never do again!
I don't know that I could completely trust a timer to shut off. Electrical components fail, but I'm not sure if they fail more than humans.
The flexible hose is a good idea. My irrigation tank is gravity fed, so no problem with the pump. I check the level of the tank once every week or 2, so it would be trivial to lower the flexible hose.
Another idea I thought about was a flashing red
LED that turns one when a valve is open. I would have noticed that, because I water in the evening, and then shut the animals up in the barn at night, so it would have been easy to see something like that.