In the swamps we do.Need to flood irrigate in the far north?
Leave the dams in for 2 to 4 weeks depending on weather.Are you able to put in dams and just leave them? I spend an hour or two every morning moving dams.
No where near that up town! We have a few spots where we have placed a 16 to 20 foot length of 24 inch culvert. A piece of plywood makes for a quick dam. Some of these ended up being lifted by frost and have never been replaced.I put a dam in the main ditch and open a tap to flood the field ditches. Those main ditch dams get left for about a week. It is the dams in the field ditches that I move every day.
The first picture is a dam in the field ditch which spreads to water out on to the field. The second picture is the dam in one of the main ditches. You can't really see the dam as it is under water. In this case it is 4 2x6's place across the ditch at a concrete structure to raise the water level. Just to the right of center is a piece of sheet metal which is used to closes off the tap (a pipe). You can see the water leading out into the field ditch. I assume that Dave those something similar.
I assume that your fields are a lot bigger and flatter too. Also mine are all old river bed with no shortage of rock . They drink water pretty quick. If I just put in a dam one the big ditch it would be pretty wet right there and dry as a bone several hundred feet away.No where near that up town! We have a few spots where we have placed a 16 to 20 foot length of 24 inch culvert. A piece of plywood makes for a quick dam. Some of these ended up being lifted by frost and have never been replaced.