Cities and builders in South County find that computers can reap big savings when they are used to oversee landscape irrigation. Labor and water are conserved with devices that are . . . : Making Every Drop Count

The sight of sprinklers adding a fine spray to landscaped hillsides during a rainstorm frequently triggers protests from homeowners who see it as a flagrant misuse of water during a drought.

In response, workmen spend hours in the field adjusting scores of time clocks to turn off automated irrigation valves. Later, when the rain ends, they retrace their steps to turn the valves back on.

But computer technology, coupled with a growing sense of urgency to conserve water and manpower, soon may end this chase to keep pace with the weather.

The drought has helped spur cities and developing communities in the South County to invest in irrigation systems that automatically sense rain, dry Santa Ana winds, coastal fog and other weather changes.

The result: Sprinkler systems are activated more judiciously, and only often enough to give plants, flowers and grass the amount of water they need to survive.

Centralized irrigation systems, first developed in the mid-1970s for golf courses but only recently considered economically feasible for suburban landscaping, allow one person sitting in front of a personal computer to type commands that make adjustments in minutes via telephone lines or radio waves.

Moreover, an increasing number of county systems are carefully attuned to local conditions by means of weather towers.

Wind vanes and other measuring devices in these towers gauge local evaporation conditions that may differ in areas separated by just a few miles. The influence of the ocean and hills form small microclimates that landscape experts say can greatly change water needs.

Within recent years, weather towers have been built for UC Irvine, Coto de Caza and Laguna Niguel; others are planned for San Juan Capistrano’s irrigation system and for Talega, a residential development planned in San Clemente. Other centralized irrigation systems in the county are plugged into information obtained from a state-owned weather station in Irvine.

“The sticking-your-finger-in-the-wind routine doesn’t work any longer,” said Tom Levene, landscape inspector for Mission Viejo, which is installing centralized irrigation systems made by three manufacturers as a test to decide which to buy for 600 landscaped acres that the city maintains.

In Coto de Caza, a central computer automatically tells other computers in the field how to adjust water flow, depending on data that its own weather tower has gathered in the previous 24 hours. The tower measures precipitation, humidity, wind, solar radiation, temperature and barometric pressure.

Arvida/JMB, developer of the community, installed centralized irrigation two years ago and figures that the savings in labor and water has already more than amortized the $150,000 cost of the system.

Last year alone, Coto de Caza homeowners saved $120,000 in water bills for maintaining the 100 acres that the community owns in common, according to Michael A. Green, a principal in a landscape architectural firm that consults with Arvida/JMB in its Coto de Caza and Talega projects.

That is a 40% savings on water consumption, he added.

“I think you will find it is the future for irrigation management,” said Daryl Green, manager of the Coto de Caza system, which he said has been inspected by officials from Orange, Mission Viejo and UCLA.

Green said that besides using weather data, Coto de Caza’s computerized system is programmed to adjust watering relative to the kind of plants and soils found in different parts of the community.

He said if the community had a more conventional irrigation system, it would be impossible to make adjustments as frequently, because there are 73 time clocks controlling more than 1,000 individual valves.

Without central controls, he said, landscape contractors usually adjust irrigation valves seasonally--”and they tend to err on the side of abundance,” he added.

Clark & Green Associates’ Michael Green, Daryl Green’s brother, said Coto de Caza is still an exception because home builders usually decline to invest in a central irrigation system.

Many are not concerned with water bills, he said, because landscape maintenance will become the responsibility of a homeowner association.

But now some of the larger developers in South County are looking at it differently, he said, realizing that centralized systems will help them save on the cost of irrigation during the build-out of their planned communities. Moreover, it will be a selling point to cost-conscious home buyers.

Arvida/JMB plans to use centralized irrigation in Talega, which could cut by more than half its water consumption with conventional irrigation and grading techniques.

In addition, the Mission Viejo Co. has considered installing a centralized system for its new development in Aliso Viejo, and the master homeowner association in Rancho Santa Margarita is shopping for one. Taylor Woodrow Homes is centrally irrigating 312 acres in its Marina Hills project being developed in Laguna Niguel.

While most central irrigation systems--the simplest starts at about $25,000--may not be practical for small homeowner associations, Michael Green said less expensive products tailored for smaller acreages are coming on the market.

“I think there is no question that with the growing scarcity of new water supplies, a developer or homeowner association in the future will have to consider ways to save water, and this system is one of the best water-managing tools out there,” he said.

Cities are also giving central irrigation a try. For several years, Irvine has been installing a system in city-owned parks and greenbelts in new developments.

Also, Mission Viejo intends to centralize irrigation for all 600 landscaped acres that it maintains, which will include retrofitting older neighborhoods. Laguna Niguel is completing the installation of a citywide system, and San Clemente recently began a limited test of a system.

Ron Sievers, director of public lands for San Juan Capistrano, said cities are motivated beyond merely saving money: “It is very difficult to ask people to conserve if we are not. We have to set the example.”

Sievers said San Juan Capistrano has converted 18 of its parks to centralized irrigation since the fall of 1989 and soon will add a 56-acre strawberry farm that the city has bought to preserve open space.

As a result, he said, the city has reduced park water use by about 60% and has saved labor worth about $50,000--or the cost of keeping one more maintenance man on the city payroll for a year.

“We can do all kinds of magic with the system,” said Greg Marguard, a maintenance worker for the city. “It is like having a 24-hour security guard.”

Marguard said if a valve breaks after normal city hours, the city no longer has to hear about it from citizens perturbed about water being wasted. Instead, the system senses the problem, and the computer sends a signal that automatically shuts off the problem valve and leaves a message for maintenance workers.

Virgil Moore, a specialist in irrigation systems maintenance who looks after 198 acres at Saddleback Community College, said for two years he has been trying to persuade college officials to pay the $215,000 cost of centralizing irrigation.

“I spend at least four to five hours almost every day turning sprinklers on to look for broken valves and sprinkler heads,” he said. “Sometimes I find an area that has been leaking for a long time.

“With a centralized system, I wouldn’t have to do that. The system would tell me what was wrong and would prevent a lot of wasted water.”