Wait until the risk of damaging freezes is acceptably low for your property, then bring the irrigation system online slowly and inspect every zone. Castle Rock can still have cold spring nights, so there is no single guaranteed safe calendar date.
Choose timing based on conditions—not just the calendar
Castle Rock’s elevation and spring weather make late freezes possible. Some homeowners wait until May to complete full startup, but conditions change year to year.
If freezing nights are still forecast, keep exposed equipment protected and consider postponing full operation. Avoid running an irrigation schedule just because a sunny afternoon feels warm.
Before you turn on the water
Locate the irrigation shutoff, inspect visible piping and the backflow preventer, and review any notes from last fall’s winterization.
If a fitting is cracked or a valve appears damaged, do not pressurize the system until repaired.
Bring the system online gradually
Open supply valves slowly to reduce water hammer. Follow the startup instructions for your particular backflow assembly and controller.
Check for visible leaks immediately. If the system cannot hold pressure or water sprays near the backflow device, shut it down and call a professional.
Run and observe every zone
Manually test each zone and watch for heads that do not rise, misting caused by high pressure, blocked spray patterns, soggy patches, and runoff.
Adjust head direction away from sidewalks and check the amount of water applied. Note repairs needed rather than compensating for bad coverage with longer runtimes.
Set your Castle Rock watering schedule
Castle Rock’s normal watering season begins May 1, with assigned residential days and limits on irrigation hours. Current drought notices may impose stricter rules.
Verify your address group and the latest Town guidance before turning on automatic scheduling. Smart controllers should still be checked for compliance.
Sources & verification
These links support the local rules, published prices, or technical guidance discussed above. Service fees and regulations may change.