Diagnose Leak and Prepare for Water Flow

What happens here

The video begins with an observation of the sprinkler system, noting a problematic sprinkler head that is spraying water horizontally, indicating a leak. Before attempting any repairs, the main irrigation water shut-off valve needs to be located. The valve box is found covered by a purple lid. For safety, the individual uses a torch to scare away any potential critters or insects that might be residing in the valve box before reaching in. The main valve is then slowly opened about halfway to gradually repressurize the system and then fully opened once air is bled from the system by opening various hose bibs.

Goal: Identify sprinkler leak and safely open main irrigation valve.