For years, Tom Lucas was charged for about the same quantity of water at his Roseville home, running to 10,000 gallons in a typical quarter.

So his bill for the last three months of 2015 has him positively livid: 112,000 gallons.

"Wouldn't you have assumed they would notice they were sending out more water than they were billing for and addressed this sooner?" he fumed.

Lucas is one of around 1,000 people in Roseville alone who are learning how much water they've been unknowingly getting free for years, due to faulty meters that failed to accurately charge them for the water they used.

And his bill from hell is a symptom of a dramatically heightened effort, in Roseville and across Minnesota, to bore in on the waste and overuse of water.

In an era of unprecedented anxiety over the depletion of underground tables, state and local officials want to shrink an ocean of wasted water by quietly ratcheting up the pressure on water users and suppliers. If people have to pay for all the water they use, officials believe, they may take steps to use less.

Lawns in Woodbury, for instance, are so extravagantly overwatered — with automatic sprinklers fizzing happily away even during rainstorms — that the east metro city alone could save hundreds of millions of gallons a year with the proper controls, a new University of Minnesota study suggests.

Duluth has hundreds of millions of gallons of expensively treated water squirting from its aging pipes and trickling down hillsides into Lake Superior.

And many cities have tackled multimillion-dollar projects to replace aging water meters, described in one national study as subject to "dramatic inaccuracies."

Water shortages looming in places like California are "causing a ripple effect all over the country," said Devan Shields, an Arizona-based civil engineer at Kimley-Horn and Associates Inc., who has studied meter problems. "There's a much greater awareness of how much water is going to waste, and of the need to make sure our supplies are adequate to support our projected growth."

More than a trickle

The extent of wasted water is hard to pinpoint, because measurement and reporting long have been relaxed and imprecise. But the Metropolitan Council points to national research that suggests utilities on average lose 20 percent of the water they pump.

A database at the Minnesota Department of Natural Resources records many cities with rates of unaccounted-for water that are several times as high as the state's goal of 10 percent or less.

Sean Hunt, of the DNR's Water Regulations Unit, warned that the numbers themselves are iffy. City officials sometimes put things in the wrong categories, don't fill in all the blanks or don't send in surveys. The state is pushing for better accountability.

For their part, city officials say that they are learning just how much water is being frittered away.

"We have lots of home irrigation systems in Woodbury," said Public Works Director Klayton Eckles, "and almost everyone around my own home in Stillwater is putting one in. But they are almost always the cheapest thing they can find. And as much as I thought I know, I'm learning that these systems are so poor that 30 percent of the water is coming out as an aerosol mist and never even hits the ground."

With Woodbury pumping up to 3 billion gallons of water a year — perhaps one-third of that sprayed on grass and gardens — the growing city could save 300 million gallons annually with smarter sprinkler controls and up to a billion gallons if other aggressive changes were made, Eckles said.

Faulty meters

Water meters are prone to something called "accuracy degradation," which means that they undercount more and more over time. A wave of swap-outs has been spreading throughout the metro suburbs lately, because those cities have reached the point when lots of things are getting old.

"We had really high growth rates in the '80s and '90s and a lot of our stuff is getting to the same age and needs repair or replacement," said Doran Cote, public works director in Plymouth, which is embarking on a campaign of 17,000 meter replacements.

Emotions are running high in Roseville, which unlike several other suburbs chose to retroactively charge households for water that customers never knew they were using. When word hit, an online message board there lit up with comments like "crazy" and "alarming." One lament: "I can't believe our old meter was that inaccurate."

In a meeting late last year, Roseville Public Works Director Marc Culver spoke of "horror stories" as people awoke to discrepancies between actual use as recorded on their basement meters and the readouts from meters on exterior walls.

With some households possibly on the hook for thousands of dollars, Roseville officials decided to cap back charges at 100,000 gallons, or $245. "We recognize for some folks that's still a lot," Culver said, "so we offer six-month payoffs with no interest."

In Eagan, on the other hand, the city is "just writing it off," said Russ Matthys, chief of public works, whose staff is replacing 800 meters a year.

When Gaylord, Minn., started updating meters, officials discovered that the city had been furnishing free water to a Sibley County-owned building for 21 years because it had never been metered. They sought an $18,000 makeup check before settling for a fraction of that.

Said Gaylord City Administrator Kevin McCann: "We were on the honor system with self-read meters — that was the problem. Other cities were annually checking, but not us. We had people willfully or negligently underreporting."

Taking water for granted

The reasons water is wasted, and the excuses made for it in reports to the DNR, paint a portrait of Minnesota.

During a harsh winter like the one in 2014, many northern cities report freakishly high water usage because residents maintain a steady pencil-sized stream of water running 24/7 to keep pipes from freezing.

Older, hillier cities have a different sort of issue, said Howard Jacobson, Duluth's manager of utility operations.

"We have major problems with … very old pipes," he said. "We have 125 water main breaks and 300 new leaks each year, and we can't get to all of them. And those are just the ones we know about."

DNR water expert Carmelita Nelson said officials in Moorhead have said that some pipes are so corroded that only the ground around them is keeping them intact; touch them and they crumble.

Twin Cities suburbs may have newer pipes and more reliable meters, but they also have their own forms of waste such as overwatered lawns. "It's alarming in my opinion to see the differences between summer usage and winter usage," Cote said. "That's a controllable expense."

State pressure on cities to confront the problem is yielding results. Pushed to find out why so much more water was being pumped out than charged for, Moose Lake fixed leaks that saved 55,000 gallons of water daily, Nelson said.

Such steps could have been taken long ago. But a casual attitude toward water meant that many didn't bother.

"Water here has been cheap and plentiful, and has been really an entitlement we take for granted," said Eckles. "A culture change needs to happen."

David Peterson • 651-925-5039