Boulder looks to satellites to help guide water usage

Residents who conserve will be rewarded on bill

Bill Scanlon, Rocky Mountain News

Published December 9, 2006 at midnight

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The Boulder water department knows every patio, walkway, gazebo and square foot of grass in its customers' front and backyards thanks to satellite photos.

Starting next month, it will use that information to give each customer a water budget - rewarding them for using no more water than should sustain a Kentucky blue grass lawn, charging them extra for every gallon of excess water use.

Customers can go online, to boulderwater.net, to make sure the photos really are of their own yards, and that the utility, say, is up to date on that flagstone sidewalk the family removed last summer.

When all the calculations are done - the concrete area subtracted from the grass area - each resident gets a water budget based on the total square footage of his or her irrigable land.

"The intent is to provide water at a reduced amount to encourage conservation and to discourage a really large lot from being 100 percent blue grass," said Ned Williams, director of Boulder's Public Works Utilities.

"Customers still have a choice, but they'll begin to likely see some impact on their bills," he added.

Boulder may be the first city in the state to go to such a detailed water budget, although Highlands Ranch has a modified version.

Boulder got the idea of using satellite photos and the gallons-per-square-foot formula from Irvine Ranch, Calif.

Already, hundreds of people have called with complaints or worries about the plan.

The most common worry is misplaced, Williams said.

"They say, 'I don't want to be billed on my budget. I want to be billed on my actual use.' "

And they will be, he said.

The budget doesn't specify a minimum cost, so aggressive conservation will be rewarded, Williams said. The budget merely divides watering rates into five thresholds based on gallons used per square foot, he said. Those who use small amounts will see that reflected in smaller monthly water bills.

People with large lots are worried that they'll pay more - and they will, if they don't find alternatives to Kentucky blue grass and insist on greening up the entire lot, he said.

The objective isn't to make money or save it, but to be "revenue neutral," while encouraging a little extra conservation, he said.

Boulder water customers already have caught the conservation bug, using 10 percent less water this summer than they did in 2000 or 2001.

Utilities throughout the state struggle with a balancing act - encouraging conservation while trying to make up for that loss in revenue that comes from customers using less water.

Denver Water, which has 1.2 million customers in the city and suburbs, is projecting a 7 percent, or $12.2 million shortfall, blamed largely on customers doing a good job of using less water.

Like a lot of water districts, Denver Water pumps a lot of its revenue back into the system, to encourage conservation, pay for increases in water treatment costs and to expand a water recycling plant.

The typical residential water customer in Denver pays about $256 a year, and would see his or her bimonthly water bill go up by about $3 next year to help pay for the shortfall.

A typical suburban customer of Denver Water pays about $529 a year, and could see a $6 increase in the bimonthly bill.

How it works

A family living in a single-family ranch-style home may have 5,000 square feet of irrigable land.

The water department figures that every square foot of grass, shrubs or flower beds needs no more than 15 gallons of water per year. None is needed in December, January or February.

About 1 percent of that water budget should be used in March, another 1 percent in November.

By the time June and July roll around though, each of those months probably need about 20 percent of the water budget for the entire year.

So, in June, they can put three gallons on every square foot of grass - a total of 15,000 gallons.

If the family stays within that limit, it pays only $1.88 per 1,000 gallons for the first 9,000 gallons in June, and $2.50 per gallon for the next 6,000 gallons.

But what if there's a heat wave in July and the family uses 20,000 gallons?

The family pays the same as it did in June for those first 15,000 gallons, but $5 for each extra 1,000 gallons - or a $25 surcharge for July.

$6 Amount of increase that a typical suburban customer of Denver Water who pays about $529 a year can expect in the bimonthly bill.

scanlon@RockyMountainNews.com or 303-442-8729

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