OAKLAND -- Customers in the East Bay's largest water district will pay 9.5 percent more for water starting next month, the second large rate increase in two years.

The East Bay Municipal Utility District Board voted 7-0 Tuesday to approve the increase that district managers say is needed to step up pipe and equipment maintenance that had been deferred during the lean economic years from 2008 to 2012.

"We are having to replumb our older service areas," said Abby Figueroa, a district spokeswoman. "Half of our pipes are more than 50 years old. We are shoring up our water system and its finances."

The increase goes into effect July 1.

A neighbor of  Val Mojica, a resident in Bay Point, Calif. waters his lawn on Wednesday,  Sept. 14, 2011. Mojica  along with other members of this
A neighbor of Val Mojica, a resident in Bay Point, Calif. waters his lawn on Wednesday, Sept. 14, 2011. Mojica along with other members of this community, may be receiving yet another rate increase from Golden State Water Co. Mojica has compared his rates with relatives in Concord who have Contra Costa Water District Water and the rates are much lower. (Susan Tripp Pollard/Staff)

The district supplies water to 1.3 million people in areas stretching from Richmond and Crockett in the north, Oakland and Berkeley in the west, Danville and San Ramon in the east and San Leandro to the south.

In a related move Tuesday, the EBMUD board approved 8.5 percent higher sewage rates for 650,000 people living in western Contra Costa and Alameda counties.

The higher sewer rates also go into effect July 1.

This latest increase boosts the district's average residential water bill by about $4.50 a month, from $46.70 to $52.20 for about 270 gallons a day, officials estimate.

The average is higher in warmer suburban areas with bigger lawns in Central Contra Costa County and the San Ramon Valley and less in cooler areas like Oakland, Berkeley, Richmond and San Leandro.

A similar water rate increase of 9.75 percent went into effect in July 2013 -- the first of what district officials said will be several years of increases.

The higher rates, officials said, also are needed to help the district refinance and pay off its $2 billion in debt from projects that include EBMUD's $460 million share of a project that delivered Sacramento River water to the East Bay for the first time this year. Arrival of that water helped the district avoid water rationing and drought rates this summer and instead continue with voluntary conservation.

As a result, the water rate increase approved Tuesday is not aimed specifically at nudging customers to use less water -- although the district has permanent tiered rates that charge higher rates for larger amounts used.

Still, EBMUD's twin rate increases in two years are making some customers think about using less.

"Two substantial increases probably does make people think more about ways to use less water," said Charles Brydon, a Danville resident who has closely monitored district rates for years. "This will affect people more in the warmer parts of the district."

Kathy Wheadon, an Oakland townhouse owner, said escalating water cost is one of several reasons her homeowners group is looking into the possibility of installing individual meters on housing units instead of sharing a single meter for the complex.

The individual meters would let residents in each unit know how much they use and base bills on that.

"For me personally, it's not about the money," Wheadon said. "It's about living in a drought and being careful with the water we use."

Contact Denis Cuff at 925-943-8267. Follow him at Twitter.com/deniscuff.