I've flood irrigated so I can understand what you're dealing with right there in the moment. But I never irrigated from a source I couldn't shut down or divert to a playa lake in an emergency. It can be nerve-wracking and physically challenging when the water begins gushing in for sure, but in your case it's multiplied. I guess at some point homesteads will be flooded. I'd be lobbying for those main channels to be built up or deepened to take more water back to the main source when the spring runoff reaches uncontrollable conditions. Sounded to me like your property is almost obligated to take the flood if there's too much. Is someone in charge upstream aware of your situation?
Thanks for the comment. Yeah, the irrigation company was able to dig a large ditch just in time to send huge amounts of water past our place down to the river. I couldn't believe how much water was being diverted. It would have spelled disaster had that extremely large track-hoe not have dug the ditch it had.