Established lawns only need an inch of water a week, including rainfall to stay healthy. Longer infrequent watering will help develop deeper, healthier roots. Rather than frequent shallow watering, water your lawn deeply once or twice a week. Avoid watering during the hot sun and while it’s windy to prevent losing water to evaporation!
Mowing the grass around 3 inches high, provides more shade for your lawn’s root system. By doing so, the soil is able to retain moisture, weed growth is prevented, and evaporation from the sun and wind is reduced. Mulching is also a great tool, the mulch moderates soil temperature, holds moisture, slows erosion, and suppresses weeds which would compete with your plants for soil and water.
If water is not being absorbed optimally by your lawn, dethatching and aerating might be necessary. Thatch is a layer of organic material between the grass and soil, thatch over half an inch thick can prevent oxygen and water from reaching the grass roots. Aerating promotes grass roots to absorb all the natural moisture available, and allows oxygen to flow to the grass roots.