How to Find Your Water Pressure

If there's one thing I've learned in 35 years of irrigation work, it's this: every great sprinkler system starts with knowing your water pressure. Skip this step, and you'll end up with heads that barely dribble or pipes that blow apart.

What You'll Need

• A pressure gauge (you can pick one up at any hardware store for about $10)
• Access to an outdoor hose bib (spigot)

How to Measure

1. Turn off all water inside and outside your home. That means dishwashers, washing machines, showers — everything.
2. Screw the pressure gauge onto your outdoor hose bib. Hand-tight is fine.
3. Turn the spigot on all the way and read the gauge.
4. Write down the number. This is your static water pressure.

What the Numbers Mean

• Under 30 PSI: You've got low pressure. You'll likely need a booster pump, or you'll need to design zones with very few heads.
• 30–50 PSI: This is workable, but you'll need to plan carefully. Stick with matched precipitation rate nozzles and don't overload zones.
• 50–80 PSI: The sweet spot. Most residential systems work beautifully in this range.
• Over 80 PSI: Too high! You'll need a pressure regulator. High pressure wears out valves and fittings fast.

Pro Tip

Test your pressure at different times of day. Morning pressure when nobody's watering is usually your peak. Evening during neighborhood watering is your low point. Design your system for the low number — that's reality.

Water pressure is the foundation of every design decision you'll make. Get this right, and everything else falls into place.