No it is not normal for boxes to be flooded all the time.

I have several boxes. One big rectangle one and 8 circle ones. and my landscaper was like 'No they are always going to have water in them'. I wonder what they are doing incorrectly...

"Having water in them" is a lot different from "being flooded all the time." It is normal for them to have water in them after a rain or after they've been run. But it drains away at other times.

Thank you for the clarification. Sorry for my hyperbole

Mine has water a lot after a big rain but not flooded. But there are creepy snakes once in a while. I scream like a little kid!

Hi, It's been a long time sense I worked with irrigation system, but I believe the valves have back flow preventer built in. They are supposed to be mounted higher than the sprinkler heads if they are lower the back flow preventer will drain the pipe,

Good Luck Woodbutcher

Backflow preventers simply prevent backflow. They are one-way flow devices that work the same regardless of where they are mounted in relation to the sprinkler heads or drippers. The way sprinkler lines drain is if they are lower than the heads and they do it by gravity. The pipe preceding the backflow preventer does not drain, and a properly functioning backflow preventer and valve assembly should not leak.