I have no experience with these systems but does anyone here know about those sprinkler systems that you don't blow out at the end of fall. There are holes or something in the pipes that allow the water to flow out of them so they are always ready to be used.
Do they work? How do they work? Do they get damaged without blowing them out?
Have you checked with Ewing irrigation in you area?? (assuming you have one)
I know here they are really cool to deal with and can help you with things like this.
If they don't know they can get you in touch with the rep for the product in most cases.