8. Sprinklers
In April, in Portola Valley, its usually time to turn on the sprinklers. You may be able to selectively water just a few plants by hand before the end of April and save gallons of water. Consider planting native plants that require no watering.
The cost could be zero if you reduce watering, or you may want to invest by replanting with native plants. You may also invest in drip irrigation to replace sprinklers. If you really need to use your sprinklers, adjust them so they don’t water the road or driveway.
Purchase a soil moisture sensor to decide whether you really need to water or check soil moisture for a lawn with a long screwdriver—it should go easily into the ground seven inches. If not, it’s time to water.
For a lawn one inch of water per week is needed at the beginning of spring, rising to 2” per week in the summer (Source: Cal Water).