The amount of water used by people across the state every day is dropping, driven by an increasing concern about the environment and nudges from the government — even as the price of water continues to climb rapidly.
Water usage by residents dropped by 10 gallons per day on average between 2006 and 2011, according to state figures. That is enough to fill two standard office water dispensers.
“That’s good news,” said Kate Bowditch, director of projects of the Weston-based Charles River Watershed Association, which is heavily involved in water management issues. “If we can use less water and still have a good quality of life, that’s a good outcome for everyone.”
Nonetheless, water usage is high in some communities south of Boston, topping 80 gallons per person per day in two communities in the Globe South area, Freetown and Plymouth.
Around the region, the average cost of water in cities and towns is climbing rapidly, sparked by costly repairs to crumbling infrastructure, which in some communities is more than a century old, and increased regulation.
The state’s most expensive community was Cohasset, with average annual water bills of more than $1,500, according to Tighe & Bond, a Westfield-based company that collects the statistics. The estimated average annual cost of water for a household statewide hit $498 last year, up more than 35 percent from 2006, according to Tighe & Bond.
Tighe & Bond conducts a survey of water rates in Massachusetts communities nearly every year, and uses an average annual use of 90,000 gallons per household per year. Some observers complain that the company’s numbers are inflated, because usage has dropped steadily over the years. But the company says it has stayed with 90,000, rather than adjust it downward, to make year-to-year comparisons easier.
To be sure, water use and cost can vary tremendously from town to town or even from home to home — obvious to anyone who has watched lawn sprinklers firing away on rainy days or who has teenagers immersed in marathon shower sessions.
“They all add up,” said Jennifer Pederson, executive director of the Acton-based Massachusetts Water Works Association, an industry group made up of 1,100 water suppliers, consulting engineers, equipment manufacturers, and others.
She pointed out that prices are also up, oddly enough, because water suppliers are pumping less water, which cuts into revenue, but suppliers still must cover their fixed costs, so they raise prices.
Statewide, annual household costs in different communities ranged from the high in Cohasset to less than $200 in places such as Burlington, Pittsfield, and Lynnfield, according to Tighe & Bond.
As for usage, the amount of water consumed in a given community varies because of a number of factors.
“Lawn watering is a big variable,” said Duane LeVangie, a program director with the state Department of Environmental Protection. “Some communities don’t have lawns. My backyard ia a half acre. The land-use patterns and demographics of each community vary widely.”
Local communities are understandably sensitive about water rates, and Cohasset is no exception. The Tighe & Bond survey said the coastal community has the state’s highest estimated average annual bill, at about $1,566.
But Peter J. DeCaprio, who is chairman of the town’s Board of Water Commissioners, said he thought the survey’s number was too high, saying average household consumption is about 85,000 gallons, while the survey uses 90,000 as a base.
The good news is that water rates were reduced this year, he said.
Costs have been high because the town has spent $36 million revamping the water system, including the treatment plant and pipes, he said.
“We literally touched every aspect of our water treatment system,” said DeCaprio. About $21 million was spent on pipes alone, he said.
Water costs a household about $940 a year in Hingham, Hull, a few hundred homes in the northern section of Cohasset, and a handful of houses in Norwell, according to the survey.
That is considerably higher than many other communities, acknowledged John Walsh, the vice president for operations for Massachusetts and New Hampshire for Aquarion Water Co., the Connecticut-based private company that supplies water to the communities.
The reason is simple, he said: costly infrastructure. A $37 million water plant, serving its local communities and built in 1996, makes up 36 percent of costs, he said.
He said water costs have increased less than 2 percent a year since 2002.
Water use is also an issue in Sharon. The town is considering changes to how it bills for water, which has angered supporters of the current system.
The change is necessary because not enough money is coming in to pay for needed infrastructure repairs, said David Crosby, chairman of Sharon’s Water Management Advisory Committee.
The department needs to do about $1.2 million in annual infrastructure repairs, according to Crosby and others.
The town currently has a four-tier water rate system. The lowest tier of usage costs $3 per 1,000 gallons in winter, while heavy users pay four times as much, $12 per $1,000 gallons.
The advisory committee is considering options to present to selectmen. One plan would take into account how many people live in each household.
But the plan with the most committee support would create a three-tier system. Costs would be increased at the lowest tier to about $7 per 1,000 gallons, and at the top would be reduced to $9.32.
Crosby said the current price at the lowest tier does not cover the cost of delivery —- meaning the cost of pumping the water to homes — so that cost is actually subsidized for the lower-tier users. Raising the price would make costs more equitable for all users, he said.
Paul Lauenstein, another member of the Sharon advisory committee and the water conservation coordinator in Georgetown, said the current system does not need to be changed because the low rates at the bottom and high at the top encourage conservation.
“It ain’t broke so why are you trying to fix it?” said Lauenstein, who feels the changes would benefit people who use the most water.
“I’m pretty sure it is because people are paying $2,000 and $3,000, slathering it on their lawns,” he said. “[Rates] should be higher because people continue to water in the rain.”
Water use in Sharon has slowly declined, even as the population rose, he said, noting that water use topped 600 million gallons three times in the 1990s, and this year it should be about 460 million gallons.
He credits higher rates for heavy users, rebates for water-saving toilets, and consumer education.
According to state numbers, the town used about 56 gallons per person per day in 2011, and has been under 60 since 2009, partly due to an irrigation ban that went into effect that year.
The state has been pushing communities and water suppliers to lower the average number of gallons used per person per day to 65 gallons or less.
The work is paying off. In 2011, about 220 water suppliers met or exceeded the goal, compared with about 140 in 2006.
Repairs to infrastructure, which reduce leakage, and tighter plumbing codes, which require more efficient toilets and faucets, have helped, said LeVangie of the DEP, who is the state’s point person in charge of making sure communities reach the mandated goal.
If towns fail to get to 65 gallons, the state can require additional conservation measures, such as restrictions on lawn watering, more aggressive leak detection in pipes, and stepped-up public education. Aquarion issued voluntary water restrictions to customers in Hull, Hingham, and North Cohasset earlier this month, for example.Matt Carroll can be reached at email@example.com. Follow him on Twitter @globemattc.