I used to think it would be easy to adjust my automatic sprinkler system to account for rain. When the forecast calls for rain, shut the system down, and a few days after the storm is over, turn it back on. After all, rainfall is so infrequent in our parched climate, how hard could it be?

Unfortunately, although we had plenty of warning for last week’s storm, predicting rain is usually difficult. Remembering to turn a switch off and on can also be a problem. Hardest of all is adjusting an irrigation system to water more on sunny days and less on foggy days.

People buy automatic sprinkler systems not just to save time, but also to prevent accidental over-watering. Both goals are best accomplished with a system that is not just automatic but also smart. Smart systems sense moisture or receive weather information through wireless networks and adjust on a daily basis.

Functioning correctly, smart automatic sprinkler systems are impressive water saving devices. Water agency studies show that smart irrigation controllers alone can reduce your water bill up to 40 percent.

Weather-based “smart controllers” are available for residential or commercial use from local landscape and irrigation companies. Simple controllers, costing less than $300, use moisture sensors. More sophisticated devices, capable of adjusting to “June gloom” in the morning and bright sunlight in the afternoon, and sensitive to the particular types of landscape needing water in each zone of your garden, can cost over $700. For a monthly fee, you can even get automatic sprinkler controllers linked to a satellite with weather data from a station near your home.

Some water providers subsidize customers’ purchases of smart irrigation controllers. For example, the Casitas Municipal Water District is offering up to $250 rebates for qualifying irrigation controllers. Camrosa Water District offers rebates up to $100. Ventura Water has complete subsidies for a limited range of controller products.

Even with subsidies from water providers, smart irrigation systems can be expensive. But besides the financial cost of wasting water with other watering methods, the environmental cost of over-watering is also a justification for a smart system. Wasting water also wastes the energy it takes to pump water to our homes, creates waste from excessive plant growth, and causes run-off into storm drains.

“Weather based” irrigation systems are just one of the tools people can use to reduce water waste. Some water providers also offer free shower heads, faucet aerators and replacement toilet flappers, along with dye to put in your tank so you can determine if you need a replacement flapper. Casitas even offers subsidies for turf removal and for low-water-using commercial and residential washers and toilets. Camrosa offers classes on irrigation design, landscape planning and other topics.

With all this promotion of technologies to conserve water, let’s not forget the most basic technological “fixes.” Check for leaks, repair broken sprinkler heads and manually reset controllers after a power outage. After outages, many sprinkler systems default to factory settings, watering 10 minutes per day every day, even when it’s raining.

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