The amount of irrigation water that falls on a given area can be measured by setting out several shallow, straight-sided containers such as tuna or cat food cans. Mulching with an organic material such as shredded bark minimizes evaporation and weed competition, thereby minimizing the amount water you will need to provide your plants. Avoid sprinklers that put out a fine mist. Too much is lost to evaporation. Avoid watering directly from a hose.
Average soil can only absorb about a half inch an hour.
Native plants usually require less water than non-natives and exotics. Healthy plants need less water than stressed plants. Bluegrass needs to stay evenly moist to do well. But if you have a lower-maintenance lawn with fine fescue and perennial rye, an inch a week will be much more than the lawn needs for health. Frequent, shallow watering encourages poor turf root development and often leads to bare spots and disease prone grass.