I am turning on my sprinkler system for the year and I am very unfamiliar with this setup. The system was winterized by a professional last year and I am not sure what all was turned off, opened, etc.
So far I have: closed the backflow valve (as to not spew water everywhere), attached my pump (no leakage and turns on), and turned on the sprinkler system at the control panel computer and verified each zone works and each sprinkler works.
However, I noticed that after the sprinkler system is turned off, one of the green access panels in the ground was flooding with water. After further investigation, it appears that there are several "valves" and each is spraying water - even when the system is turned off. I have turned off the water to the sprinkler to avoid a costly water bill. I am not sure if these valves (included in the photos) are "opened" to bleed water and allow air or if there is another component that is faulty. This mostly stems from me not knowing what these valves are.
tl;dr: What are these valves and how can I keep them from spraying water?