Cans or a rain gauge can be used to determine how much water is being delivered in a certain period of time. It takes 640 gallons of water to apply 1 inch of water per 1,000 square feet. Because clay soils accept water slowly, water should be measured to prevent wasteful runoff. Water clay soils until runoff is about to occur, wait 30 minutes for the water to be absorbed, and rewater until the desired moisture depth is achieved. This same technique can be used on slopes and compacted soils.
Sandy soils require more frequent watering.
Adjust any automatic irrigation system to supplement rainfall so that the lawn is not overwatered. Position sprinklers so that the water falls on the lawn and not on impervious surfaces. Watering schedules should be consistent. Unless watering can be maintained throughout the summer, do not water fescue, bluegrass, or ryegrass lawns. Suspension of watering in midsummer is a major cause of lawn failure.