November Commercial Irrigation Shutdown Mistakes

An irrigation shutdown seems simple on the surface—blow out the lines, turn off the water, and you’re done. But in commercial landscapes, a rushed or incomplete shutdown is one of the most expensive winter mistakes a property can make. The damage doesn’t show up until spring, when cracked valves, ruptured pipes, dead turf, and failed drip zones reveal the real cost. Avoiding these common errors protects your landscape, reduces repair expenses, and preserves system health heading into the new year

Mistake 1: Incomplete zone blowouts that leave water in lateral lines

The biggest failure in shutdown season is leaving water behind in low points, elbows, and lateral pipes. Even a small amount of trapped water can expand as it freezes and silently split the pipe. When spring startup hits, those cracks cause:

• Subsurface leaks

• Soggy turf areas

• Low pressure across the entire zone

• Unpredictable dry spots

  A thorough blowout requires correct PSI, proper compressor sizing, and zone-by-zone verification—not a single quick pass.

Mistake 2: Ignoring drip irrigation during blowouts

Drip lines are the most overlooked part of a system. While spray heads get attention, drip tubing, emitters, and manifolds often remain pressurized with water that freezes and ruptures. Because drip damage is underground, PMs don’t see the failure until spring planting or mulch installation uncovers it. Proper shutdown requires opening ends, relieving pressure, and ensuring all emitters purge cleanly.

Mistake 3: Failing to isolate and drain backflow preventers

Backflow preventers are one of the most expensive components on any irrigation system—and the most vulnerable to freeze damage. A freeze-cracked backflow can cost thousands to replace. Preventing failure requires:

• Full isolation

• Draining the upper and lower chambers

• Opening test cocks

• Verifying air movement

  If a contractor rushes this step, the system heads into winter exposed.

Mistake 4: Not shutting down controllers correctly

Water is not the only thing that causes winter damage. Controllers that are left active:

• Continue running phantom cycles

• Stress solenoids

• Create moisture risks inside enclosures

• Drain batteries and backup power

  Proper shutdown includes adjusting controller modes, disabling schedules, protecting wiring, and documenting settings for spring.

Mistake 5: Forgetting system documentation for spring startup

A professional shutdown includes a map of what was done. Properties benefit from:

• Notes on weak zones

• Flagged leaks

• Winter risks identified during the blowout

• Photos of exposed issues

• Recommendations for spring repairs

  This allows your spring startup to run efficiently without rediscovering old problems.

Mistake 6: Ignoring newly installed landscaping

New plants, trees, and shrubs have shallow, developing root systems that are extremely vulnerable to winter stress. Shutting down irrigation completely without deep watering beforehand puts new installs at high risk. A proper shutdown includes:

• Final deep watering

• Soil moisture balancing

• Mulch reinforcement

• Protection on south-facing exposures

  These actions dramatically improve survival rates.

Mistake 7: Rushing the process in late November

Once temperatures drop, irrigation contractors get overwhelmed. Rushed shutdowns are the root cause of most spring failures. A careful shutdown:

• Protects the system

• Reduces repair costs

• Prevents water waste

• Ensures consistent spring pressure

• Extends system life

  Properties that schedule early and insist on a thorough process avoid costly downstream surprises.

A proper shutdown protects your entire landscape investment

Irrigation is the backbone of plant health. If it enters winter damaged, everything downstream suffers—soil structure, root systems, evergreens, turf, and even drainage. For property managers, a high-quality shutdown is one of the best ways to control risk, prevent spring emergencies, and safeguard landscape performance year-round.