Yes, that’s what I thought too afterwards. It’s the water pressure that lifts the pipe out of the ground. Not being familiar with this type of system, it took me by surprise… as did the stinky water geyser. (Reminded me of all the illnesses one gets from dirty water in some countries, but it is because they drink it too.) I just rescrewed the cleaned nozzle and carefully adjusted the direction, and it seems to be working (for now).

Search YouTube for a video on how to replace a sprinkler head.

Sprinkler
 

Best place for sprinkler parts is Site 1but in Leesburg it's sign says Centralpro on hwy 44