Question
When I turn my water on to the outside of my house, the sprinklers automatically come on.  They won't go off until I shut the water off.  Is there an easy fix to this?

Answer
First I would unplug the controller. This is just to make sure your not having a controller problem.
Sometimes when valves are drained for a long period of time they require a few minutes to readjust themselves and shut-off. You may want to find a valve or 2 and make sure the manual activation is not on.
Other than these few things I will need to know what manufacturer of system you have and any model # would be helpful.

Matt