Open the water slowly, and this is why
Charging a dry system quickly sends a pressure surge through pipe that has been sitting empty all winter. That surge is what turns a hairline crack from the last freeze into a split line, and it can damage fittings that were otherwise fine.
Open the isolation valve slowly, roughly a quarter turn at a time, and let the system fill gradually. It takes a few minutes and it is the single easiest way to avoid causing the damage you are checking for.
Listen while it fills. Water running continuously after the system should be pressurised means you already have a leak somewhere.
Check the backflow assembly first
The backflow preventer is above ground, holds water, and takes the worst of any freeze. It is the most likely thing to have failed over winter and the most expensive small component to replace.
Look for cracks in the brass, weeping at the test cocks, and any sign of water where it should be dry. If the assembly is cracked, do not keep running the system, because you are pushing water through a broken backflow protection device.
In Texas this work sits under an irrigation license for a reason. Backflow protection is what keeps irrigation water out of your drinking supply.
Run every zone and watch it
This is the part people skip. Run each zone one at a time and physically watch it, rather than trusting that the controller ran it.
You are looking for heads that do not pop up, heads that pop up and stay stuck, spray patterns blocked by growth that happened over winter, misting that signals high pressure, and weak throw that signals low pressure or a leak upstream.
Also look at where the water lands. Winter settling and mulch topping can leave heads buried or aimed at a fence, and neither shows up on the controller.
Look for the wet spots that were not there before
After the system has run through all its zones, walk the property again twenty minutes later. Areas that are soggy when the rest of the yard is not are where a lateral line is leaking underground.
That symptom is easy to dismiss in spring because everything is greening up anyway. It is also the difference between a repair now and a water bill you notice in July.
Bubbling at a head, water surfacing along a straight line, and a persistently soft area all point the same direction.
Reset the schedule for spring, not summer
A controller left on the previous August schedule will badly overwater in spring, which wastes money and invites disease in turf that is just coming out of dormancy.
Spring needs less frequency and shorter run times than peak summer. If you have a smart controller, confirm it actually reconnected and is pulling weather data rather than falling back to a default program.
If you would rather have this done properly and on a schedule, spring start-up is part of what our WaterWise annual service covers.