Get a phone and the number of your sprinkler system's installation company.
The company will tell you the location of the water valve that controls the sprinkler system in your home or business.
Find that valve and turn it clockwise until it the sprinkler system turns off.
Go outside your house, where you would hook up a hose.
On or near the same location where you would hook up your hose, there should be another valve. It is circular, usually red, and has holes in the knob.
Turn this valve clockwise to shut off the main water supply in the house until you can reach your sprinkler system manufacturer to learn the location of the sprinkler system valve.
Once you can find and turn off the sprinkler system valve, turn the water supply to your home back on.