Uniform sprinkler system coverage and duration of water time can be determined with the old fashion, low tech… Tuna cans. Tuna cans work best because they are low in height and uniform in size.
Try this low cost Metering Trick
Works with sprinkler systems and garden hoses.
1) Determine how much water you need to apply for the week.
Kentucky bluegrass requires 1″ to 2″ of water per week depending on temperature and rainfall.
2) How many days can you water?
Twice… three times? If you can water 3 days per week and want to apply 1.5″ total during the week, your sprinkler system needs to apply 1/2″ of water each time you water.
3) Set Tuna cans all around your yard
Place the Tuna cans in dry spots, green spots, and near sprinkler heads… basically just scatter them all over the yard.
4) Let your system run through the various zones.
5) When done measure how much water landed in each can.
6) If 1/2″ of water landed in each can then you have a great sprinkler system. To much water… cut back on time. Not enough water… increase time. Tuna cans unevenly filled indicates that an adjustment needs to be done to the sprinkler heads, or add a new head to cover dry areas.
A Couple of Additional Considerations
A couple of other thing to consider are… the slope of the land, sun and shade exposure. For slopes, you may have to cut the watering time in half and water twice in order to prevent runoff. Shady areas will require less water than lawns exposed to full sun.
The Tuna can trick is a low cost… yet effective way to determine how efficient your sprinkler system is at applying water.