In Augusta, Max Hicks has documented that -- even with this year's searing August heat and drought -- the city's peak daily consumption totaled just 54.3 million gallons per day.
By comparison, during a similar dry year in 1999, peak usage shot up to 58.6 million gallons per day, and there are about 5,000 more households using city water now than in 1999.
In fast-growing Columbia County, where as many as 1,500 new taps are added each year, Billy Clayton has a different sort of evidence to prove there is water conservation under way: it's called "super sewage."
In the Euchee Creek Basin, which accounts for most of the new homes and growth, the proliferation of low-flow taps, toilets and other water-saving technology has created "super sewage" that is 33 percent stronger than similar content from older areas of the county.
"We are seeing a stronger strength sewage come back to us than we do in the Reed Creek basin and it's directly tied to low-flow fixtures," Mr. Clayton said. "It means there is not as much water to dilute sewage because all the fixtures use less water when you flush or shower."
Concentrations of oxygen-demanding materials and solids, he added, have increased from an average of 200 parts per million to more than 300 parts per million in fast growing areas with newer fixtures, he said.
Columbia County also had peak demand during this year's drought that was comparable to 1999 and 2000 -- despite a huge increase in population and new taps, Mr. Clayton said.
"We saw, this year, our peak day was about the same as the year 2000," he said.
With peak demand staying the same, and the addition of 1,000 to 1,500 new households per year over seven years, the only conclusion is that people are conserving water, he said.
"When we look at domestic use, we've seen a decrease in the average," he said. "The only way that can happen is with conservation."
Although some conservation is driven by technology and conscience, there is another powerful factor at work: economics.
"Part of the thing that is helping drive conservation in our area is the rate structure we have -- a four-tiered increasing block rate," he said. "The more you use, the more you pay for what you use."
For example, he said, homes that use zero to 10,000 gallons pay just $1.79 per thousand gallons. Homes that use 50,000 gallons or more pay $4.88 per thousand gallons for anything over the 50,000 mark.
"So that's a significant jump," he said. "It makes your bill, shall we say, blossom. It was done for the main purpose of conservation."