Run time
How long to water a lawn
A spray puts down about 1.5 inches an hour. A rotor is closer to 0.4. Same weekly inch, different minutes. Split clay so the water can soak.
Four tools
Irrigation calculators
How long to water, how much it costs, how many zones, and whether the pressure fits the heads.
Water use
How much water a sprinkler system uses
Read the zone at the valve, not the hose bib. Gallons per minute times minutes times days is the month. Edit the rate to match the water line on your bill.
Default $3.80 / m³ is a GTA starting point. Change it to your combined water charge.
Design
How many irrigation zones you need
A spray zone covers a smaller patch than a rotor zone. Beds, banks, and shade usually want their own valve. Do not mix sprays and rotors on one station.
PSI
Sprinkler water pressure vs head type
Sprays want 20–30 PSI. Rotors want 30–50. Drip wants less. Measure at the farthest head. Extra minutes will not fix the wrong pressure.