The great Murray-Darling Basin that feeds the food basket of southeastern Australia. (Linda Davidson/The Washington Post)

Before their prayers were answered, before the rains came back, and before recycled gray water slowly went out of vogue, the citizens of Melbourne had a come-to-church moment — a collective reality check — during the longest stretch of dryness most of them had ever known.

The writing was on the wall. Or, more precisely, on giant electronic boards towering overhead for all of them to see amid the southeast state of Victoria’s so-called Millennium Drought. The reservoir they relied on dropped to 75 percent, then 50 percent, then 30 percent by the middle of a 10-year drought ending in 2010, and everyone got it. The end was near for a city of 4.3 million. The only thing that could save it was water conservation on a major scale with everybody buying in.

[As water runs dry, California dreaming fades to a harsher reality]

That, a new report from the University of California at Irvine’s Water Institute says, is a lesson for the Golden State in its fourth year of the most severe drought in its history. Gov. Jerry Brown ordered the state’s water utilities to cut output by 25 percent in urban areas, asking them to achieve it by providing water efficient appliances and cutting the times of day that residents can water lawns. Farms are exempt from the rule.

A canal runs through farm fields in Los Banos, Calif. on May 5. (Reuters/Lucy Nicholson)

In Australia, public officials didn’t sugarcoat the impact of drought. They communicated to residents in plain terms that essentially asked them to imagine a world without water. And residents responded, cutting use in half. They went from using an average of about 80 gallons per resident per day in every household to about 40. In Los Angeles, 80 gallons per resident is considered to be good stewardship. In Palm Springs, the average per resident use is nearly 350 gallons per day. The state average is nearly 110 gallons, according to the report.

[California’s unquenchable thirst for water was supersized by outdated laws]

The authors argue that California’s government should be more direct about the problem state residents face in a paralyzing drought with no end in sight.

“You can’t just come up with technical innovations and think that’s going to do the trick,” said David Feldman, a professor of planning and politics at UC Irvine and a co-author for the report. “You need education, you need public outreach, and you need all these people working on it.

“During the drought in Australia, if you watered your lawn, you heard about it from your neighbors,” Feldman said.

With citizens engaged in the city’s survival, as water levels in rivers dropped so low that an increase in the level of salt spoiled their quality, officials pushed through regulations that conserved water by the hundreds of acres.

They applied restrictions in water usage similar to California’s, but they also ordered utilities to recycle used water for farm irrigation and various home uses, such as lawn care.

But residents had other lawn care options in drought. One in three households eventually used barrels to capture the little rainwater the city got to use that for lawns and other reasons. They built retention ponds that also captured water for use in gardens. For every barrel and every pond, there was a corresponding rebate on water bills.

[Global warming plagues Australia’s outback]

The study was billed as “the first comprehensive examination of what worked and what didn’t during Australia’s decade-plus dry spell,” documenting when policies were implemented and combining it with data showing how demand decreased.

“Documenting what happened in Melbourne during the Millennium Drought was a real eye-opener,” said Stanley Grant, a UCI professor of civil and environmental engineering who co-authored the report. “It’s like looking into what the future could be for California, if we got our act together.”

Grant said Californians haven’t responded like residents of Melbourne, even in the fourth year of drought, where rivers in the San Joaquin Delta near Sacramento are so low that young salmon die trying to migrate to the San Francisco Bay fewer than 90 miles away.

Some things worked for Melbourne, others didn’t. The rain barrels, retention ponds and dual flush toilets that handle solid and liquid waste differently (we’ll spare you the details) were a hit. The $3 billion Victorian Desalination Plant was not. It was completed well after the drought let up in 2010, and never turned 126 billion gallons of sea water to fresh water as proposed.

[In the drought-stricken West, animals are dying for a drink]

Environmentalists greeted that as a good thing, since 73 billion gallons of salt would be spit back out after the water was converted, altering the ecology from where it came. Even as the plant was being built, water conservation by Melbourne and other southeast Australian residents rendered it unnecessary.

Californians lack that fervor.

“I wish California had the same sense of urgency,” Grant said. “I don’t think the average Joe Blow on the street has any idea what’s coming at them.” The state is sold on conservation through technological advances, he said. “But ultimately it was about people. They could see those reservoir levels, year after year they were dropping. When it dropped below 50 percent, it became clear that things were going south.”