You can save a lot of irrigation water by employing simple water conservation measures. If you buy water from a water company, water conservation will save money on your water bill. If you use a well, water conservation will reduce your electrical costs for pumping.
Plant a tree. The shade of a large, well-placed tree can greatly reduce the moisture needs of your other landscaping by blocking the direct sunlight of mid-day.
Water when it is cool. Watering in the heat of the day is hard on plants, and much of the water evaporates and never reaches the plant roots. It is also most expensive for water companies to provide water during the daytime peak-electricity periods. Use timers to confine watering to cool morning and evening off-peak periods if you have an irrigation system.
Water only as necessary. Every few days is sufficient for most grasses. Once a week is enough for shrubs. Trees especially should be watered several times a year, so that deep root development is encouraged.
Take care in adjusting your sprinklers. Water that lands on the sidewalk or driveway doesn’t keep your yard green. If you have underground sprinklers, observe their watering patterns and adjust them away from areas that don’t need water and around the foundation where watering causes moisture problems such as rot and termites.
Use concentrated watering methods. Soaker hoses or hose-end bubblers direct water where it’s needed. Better yet, install a drip irrigation system. They are calibrated for each plant or area in your yard so that the optimum amount of water is delivered. They can be installed above ground or buried, and they are often controlled by automatic timers.
See The Homeowners Handbook to Energy Efficiency for simple practical energy-efficiency ideas.