Alice Springs, Northern Territory, Australia

Alice Springs is considered Australia's definitive outback town, but when it comes to irrigation efficiency it's the epitome of progress. Located in the Northern Territory's arid inland, this popular tourist destination struggled to conserve water and maintain green landscapes with a manually controlled irrigation system. Then the town's parks department turned to Rain Bird's MAXICOM Central Control System. With MAXICOM, not only was the department assured cutting-edge control and excellent water savings, but it would receive the unmatched support of an established Rain Bird sales representative and distributor right in its own
backyard.

Water Supply, Evapotranspiration Rate (ET) Widely Discrepant

Alice Springs is the destination for tens of thousands of visitors who come every year to the vast and scenic area of Australia known as the Red Center. Using "the Alice" as base, visitors explore nearby natural attractions like aboriginal rock carvings, meteorite craters and the famed monolith Uluru (formerly "Ayers Rock").

One natural phenomenon seldom encountered in this desert region is rainfall, which totals only about 22.5 centimeters (nine inches) per year. The dry climate, and the fact that the isolated town depends on an artesian well for its water, has made conservation a priority. "Water is a finite, unreplenishable resource here," said David Perry, manager of Parks and Gardens for the Alice Springs Council. "When it comes to our landscapes, we've got an obligation to irrigate as efficiently as we can."

The town's 173 hectares (70 acres) of irrigated landscape include nine multi-use sports fields, formal gardens in the town center and parklands. To maintain the turf and plants at their optimum requirements would mean irrigating for an evapotranspiration (ET) rate as high as three meters (about 10 feet) per year.

"We can't afford to water at that requirement, so grass is in some degree of stress during the hottest months," said Perry.

From Manual to MAXICOM

Alice Springs's irrigation system was operated by 70 stand-alone controllers, all of which were manually programmed and located as much as eight kilometers (about five miles) apart. The system's limitations were tangible when rain did fall. "It would take a lot of manpower and expense to turn off all the controllers, and we still couldn't get to them all in time," said Perry.

Finally, it was time to research central control systems. MAXICOM was chosen for three big reasons: its proven track record of tackling tough site challenges; a nearby authorized Rain Bird distributor, Southern Cross Alice Springs; and a Rain Bird representative in southern Australia. Rain Bird International supports customers in more than 120 countries with representatives close at hand to offer technical knowledge and after-sale support. For Alice Springs, Rain Bird's MAXICOM specialist, Nick Moschis, provided both technical support and training. Southern Cross's Simon Worssam helped with the layout and Southern Cross
supplied the equipment.

Sophisticated Features Enhance Efficiency

The system uses 65 ESP-Sat-Link satellite controllers which are spread throughout the city to control 500 valves. Moschis specified the radio-direct MAXICOM model and four 28-station Cluster Control interfaces (CCU-28) to communicate via radio with the field satellites. Key to the system is the Rain Bird weather station (WS-200), which monitors and stores daily ET parametersincluding air temperature, solar radiation, relative humidity, wind speed and rainfalland transmits the data via telephone link to the MAXICOM computer. This information allows MAXICOM to efficiently adjust the irrigation schedule according to each day's ET values.

Before selecting Rain Bird and MAXICOM, the department examined a number of central control systems, according to Perry. "Some manufacturers didn't have a local agent while others needed to custom design software for the system," he said. "Rain Bird has a local agent and good support. Their software is the same no matter where you are in the world." Furthermore, because the system affords savings on labor, Perry estimates that it will pay for itself in seven years.