Time to rethink the sprinkler system

AS you dutifully water your parched garden this summer, here’s something to think about: Outdoor water use can account for half or more of all residential water use, depending on the area.

This is especially true in hotter inland areas where population growth is now the fastest, according to the new report “Lawns and Water Demand.”

It’s not exactly light summer reading unless you’re a policy wonk, but the report is the latest to raise concerns about water-guzzling lawns and wasting precious H2O around the home.

As gardeners prepare for fall planting, it’s a good time to consider downsizing the lawn and giving more space to drought-tolerant native plants. For an irrigation system that doesn’t squander water, consider drip lines and “smart” sprinkler controllers, which automatically adjust water times based on plant cover and weather conditions.

Using such sprinkler controls for a lawn area and drip irrigation for native plants could yield at least 15% to 20% annual savings in home water bills, says Ellen Hanak, a research fellow and lead author of the report, released in July by the Public Policy Institute of California in San Francisco.

Statewide water conservation efforts, which had focused mainly on indoor use in the 1990s, are now expanding to outdoor use.

Many local water agencies are offering a rebate program to customers who replace their old sprinkler controllers with the new “smart” ones, which have on-site sensors or communication links to a weather monitoring system.

With a conventional irrigation controller, you set a program and often leave it unchanged. In the summer, for example, you may set the controls for a high level of watering and keep it that way even though the weather cools with the seasons.

With a “smart” controller, once you’ve punched in answers to questions about soil, sun and other conditions, the device automatically regulates irrigation on its own.

But this new technology is not cheap; prices start at about $250. To encourage residential use of these sprinkler controllers, the following water agencies offer rebate programs and other useful conservation tips: