Understand your sprinkler system start times

Updating the start time on your irrigation controller? Remember: You only need one. Any more than that can double or triple your water bill.

New watering hours (for Stage 3 watering rules) are from 5 a.m. to 10 a.m. and from 9 p.m. to midnight, on your watering day. If you’re adjusting the start times on your irrigation controller, remember that you don’t typically need to put in a separate start time for every single zone.

Only one start time is needed to run the entire system.

Here’s why. Start time means the entire program will start running at whatever time you designate, automatically running every single zone on the program in succession. If you enter 5 a.m., for instance, the entire system will begin running at 5 a.m. and run through all the zones until it finishes.

But if you enter a second start time, it will run the entire sprinkler system twice effectively doubling your water bill. Even worse, if you enter third and fourth start times, it’s almost always a very costly mistake because the numbers on the screen don’t exactly mean one, two and three, but rather first, second and third. (If you look closely at the control screen when start times are displayed, you’ll see the tiny ordinal indicator letters.)

For example, with three start times, if you were watching the irrigation system run at night, you’d notice it may not even finish the first sprinkler zone by the time 9:15 rolled around. So it would just continue running through the zones one by one, seemingly ignoring the second start time. But it hasn’t forgotten! It will just “stack” any extra start times and run them when it gets around to it. After running through the first whole cycle — sometimes hours later — it would begin again, running a second cycle and then a third. Like many puzzled irrigation users, you might come out at dawn and find it still running — and not realize it was due to a simple programming error.

Equally frustrating is confusing start times with run times, where you enter how many minutes each zone will run. Just remember that each zone DOES NOT typically need its own unique start time.

So, if you’re updating your sprinkler start times for the new watering times, always remember to run through the first, second, third and fourth start times to see what’s on the screen and watch out for any extras. If you see any, clear them. Otherwise, they will run up your bill in a hurry.

Check the owner’s manual for more information or give us a call. SAWS offers free residential irrigation consultations to customers to help you set those sprinkler settings correctly. Call 210-704-7283 (210-704-SAVE) to schedule.

Picture of Brad Wier
Brad Wier
Brad Wier is a SAWS conservation planner. Years in South Texas landscaping and public horticulture gave him a lasting enthusiasm for native plants that don’t die when sprinklers -- and gardeners -- break down. He’d rather save time and water for kayaking and tubing. He is a former kilt model, and hears hummingbirds.
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