AURORA - Tony Zang says he has tried to do all the right things when it comes to conserving water. He limits his sprinklers to 20 minutes three times a week, he waters only at night, he put mulch around his shrubs and tries to cut the grass tall.

His efforts have paid off. Zang said he was able to cut his total water consumption by about 14,000 gallons a month between this summer and last summer.

But that only made his shock worse when he opened his July water bill and found he owed $445, up from about $300 for the same month last year.

That makes his water bill bigger than other monthly bills for utilities, property tax or insurance payments, Zang said.

"It's not only me. The neighbors in the area have seen their water bills go out of sight," Zang said. "It's really just outrageous."

When Zang called Aurora officials to complain about his water bill hike, he learned it was no fluke.

Residents in the city are seeing the outcome of a new rate structure that went into effect in January. On average, residents are midway through shouldering three consecutive years of 12 percent rate hikes.

Melissa Elliott, spokeswoman for Aurora Water, said the rate hikes help foot the bill for the Prairie Water Project, an effort to increase Aurora's overall water supply about 20 percent by late 2010.

The $754 million project will bring about 10,000 acre-feet of water that the city owns from wells along the South Platte River near Brighton via a 34-mile-long pipeline with three pumping stations.

The project was conceived after a drought in 2002 drained 26 percent of the city's water supply capacity.

Zang is also among those in the top tier of the new water rate structure, in which residents with the largest area of property to water are being charged at a higher rate. Zang said the portion of his property that gets watered covers about 12,000 square feet. Elliott said the citywide average is about 2,200 square feet.

Zang contends the city is paying for the bulk of the new water projects by putting the burden on long-time residents such as himself, while it uses the additional water to fuel new housing.

Elliott countered that new residents also have to shoulder the burden, noting that the city raised its new tap fee to $18,000.

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