Check existing sprinkler systems for efficiency. Adjust heads to spray onto planted areas only. For new systems and old ones, make sure that you have uniform coverage so that you don't have to drown one spot to get enough water on another. If areas with different requirements, such as lawn and shrubs, are on the same valve, install separate valves.
Check your valves, pipes, sprinkler risers and drip connections for leaks. Leaks are likely to occur outdoors, where they are apt to go undetected. Even a small leak can waste hundreds of gallons of water in a single day.
Separate irrigation zones based on landscaping needs and requirements with each. Turf, shrubs and groundcover should be in different irrigation zones
Install a drip system with a fertilizer injector to feed your plant roots. Drip systems minimize run-off, encourage root growth and are excellent for watering and fertilizing shrubs and trees. Coil the drip hose around the tree and insert a few drippers for good coverage.
If you have high pressure, use a pressure regulator with your valve zone to lower the pressure to the recommended pressure suggested for drip irrigation or sprays heads.
Install a drip irrigation system. Water is applied at a slow rate directly to the root zone, evaporation is less, and weed growth is minimized because water is applied where it's needed.
Convert your manual valves to automatic operation by using an AC or DC controller and solenoid valve, or a battery-operated controller. Automating the irrigation system will allow you to water in the early morning when evaporation and wind are lowest. Be sure to check the irrigation frequently to see that the right amount of water is being applied and make adjustment as needed.
Install a rain shut-off device with your automatic controller to avoid watering during a rainfall.