Irrigation Shutdown Checklist Middle Tennessee

Fall Irrigation Shutdown Checklist for Middle Tennessee

Half of a good winterization happens before the truck arrives. Here is what to handle yourself, and what to leave to compressed air.

Published 2026-09-04 · About 745 words

Aqueduct at a glance

  • Serving Nashville and Middle Tennessee since 1988
  • Licensed, bonded and insured, locally owned and operated
  • Irrigation design, installation, activation, repair, winterization, backflow testing, coverage audits and pump service
  • Landscape lighting design, installation, repair and Christmas light installation
  • Service area covers Davidson, Williamson, Sumner and Cheatham counties

Why a mild winter is not an argument for skipping

Middle Tennessee winters are forgiving in aggregate and unforgiving in the specific. Long stretches of 50-degree December weather convince homeowners to skip winterization, and then one multi-day Arctic outbreak drops overnight lows into the teens and freezes the water standing in the backflow assembly above grade.

Water expands about nine percent when it freezes, and a brass assembly or a PVC lateral has nowhere to put that expansion. The split does not announce itself in January. It shows up in March when the system is pressurized and water pours out of the relief port, at exactly the moment every irrigation contractor in the region is booked for spring activations.

The components at risk are the ones you can see: backflow preventers, exposed valve manifolds, anything in an unheated garage wall or crawl space, and water trapped inside pop-up bodies. Buried laterals sit below regional frost depth and are rarely the problem.

What to do yourself, before the crew arrives

None of this replaces a blowout, but all of it makes the visit faster and the result more complete:

  1. Locate and label the irrigation shutoff. On many properties, finding it takes longer than the blowout. Label it once and never repeat the search.
  2. Write down the zone count. Check the controller program against the physical valve boxes. Split-controller properties routinely have zones that appear on only one controller, and those are the zones that get skipped.
  3. Flag anything that misbehaved this season. A zone that would not shut off, a head that weeps, a dry patch that never resolved. The shutdown visit is when every zone runs under observation, so a list makes it a diagnostic pass rather than a guess.
  4. Clear access. Cut back plantings hiding the backflow assembly and valve boxes.
  5. Note pumps and secondary sources. Booster pumps, wells, ponds and cisterns each hold water that a standard zone blowout does not clear.

Then stop. The next step involves a compressor, and that is where do-it-yourself shutdowns cause the damage they were meant to prevent.

What the blowout itself covers

A blowout is a controlled evacuation of every drop of water from the mainline, laterals and heads using compressed air, run zone by zone: supply isolated, air connected downstream of the backflow assembly, zones run individually starting farthest from the compressor, each in short bursts until the heads discharge mist rather than water, then the assembly drained with its test cocks left partly open and the controller shut down for the season.

Pressure is the part homeowners get wrong. Manufacturer guidance caps rigid PVC at roughly 80 PSI and flexible polyethylene at roughly 50 PSI. High air volume clears a line; high pressure blows seals and cracks fittings. The compressor that safely clears a twelve-zone system is a towable unit, not a pancake compressor from a hardware store.

City-specific scheduling and service detail sits on the local pages: sprinkler winterization in Nashville, sprinkler winterization in Brentwood and sprinkler winterization in Franklin.

What winterization does not include

Three services are commonly assumed to be part of a shutdown and are not:

  • Certified backflow testing. Draining an assembly protects it; it is not a certification test, which carries its own procedure and paperwork. Backflow testing and service is booked separately.
  • Repairs. Air does not fix a failing valve. Problems found in the fall are best documented now and corrected in spring, since irrigation repair work on a drained, depressurised system is neither cheaper nor easier.
  • Spring activation. The other half of the seasonal cycle is a separate visit. Spring sprinkler startup includes zone-by-zone inspection, controller programming, a pressure check, head adjustment and a written audit report.

Homeowners who would rather not manage the calendar at all can bundle the lot: annual irrigation maintenance agreements combine spring activation, seasonal audits, winterization, a limited backflow freeze warranty and priority scheduling.

When to book, and the November collision

The window is after the last meaningful watering of the season and before the first hard freeze, which in Middle Tennessee generally means mid-October through November. Booking after a freeze appears in the forecast is the standard mistake, because everyone does it in the same week and the regional schedule closes.

Worth planning around: the same November weeks are peak holiday lighting installation weeks. If you want both handled by one company, arrange them in a single call rather than phoning back in December, when Christmas light installation in Franklin and Christmas light installation in Hendersonville are already booking out.

Aqueduct Irrigation / Southern Light has serviced Middle Tennessee irrigation systems since 1988 across Davidson, Williamson, Sumner and Cheatham counties, and is licensed, bonded and insured.

Frequently Asked Questions

When should I shut my sprinkler system down in Middle Tennessee?

After the last meaningful watering of the season and before the first hard freeze, generally mid-October through November. Book before a freeze appears in the forecast, because regional schedules fill within about a week once one does.

What should I do myself before the winterization visit?

Locate and label the irrigation shutoff, confirm the zone count against the controller and the valve boxes, note anything that misbehaved this season, clear access to the backflow assembly and valve boxes, and flag any pump, well or pond feeding the system.

Is draining the system enough without a blowout?

No. Manual and automatic drains do not clear the backflow assembly, the valve manifold or water trapped inside pop-up bodies, and those above-grade components are what a Tennessee freeze actually cracks.

What air pressure is safe?

Manufacturer guidance is roughly 80 PSI for rigid PVC and 50 PSI for flexible polyethylene. Clearing a line depends on air volume rather than pressure, which is why small high-pressure compressors damage systems instead of protecting them.

Does the shutdown include backflow testing or repairs?

Neither. Certified backflow testing is a separate service with its own documentation, and repairs are better done at spring activation when the system can be pressurized and tested properly.

Talk to Aqueduct

Aqueduct Irrigation / Southern Light has winterized Middle Tennessee irrigation systems since 1988 and is licensed, bonded and insured. Book a fall shutdown, or call (615) 256-5293.