The East Bay Municipal Utility District Board of Directors voted 6-1 Tuesday to increase water and wastewater service charges for a two-year period, effective Wednesday.

The change increases water service rates by 9.25 percent starting Wednesday and an additional 9 percent beginning July 1, 2018, while wastewater service charges will increase 5 percent each year, according to the EBMUD website. In total, the service charges for an average single-family customer will increase by about $11 per month.

“As a public not-for-profit agency, we work hard to make smart decisions with the dollars entrusted to us by our customers,” said EBMUD Board President Lesa McIntosh in a press release. “We don’t take the decision to raise rates lightly, but these are challenging times and we have to make difficult decisions in order to support the public health of our East Bay customers.”

The service charge increases are set by the EBMUD board every two years, EBMUD spokesperson Andrea Pook said. She added that over the past decade, water service charges have increased an average of 7.1 percent each year, and the additional 2 percent increase this year amounts to “approximately a dollar more per household.”

Of the total revenue EBMUD will collect from water and wastewater service charges, a third will be used for “critical infrastructure improvement,” Pook said, which includes renewal of the 4,200 miles of East Bay water pipelines and rehabilitation of water treatment plants to improve water taste.

The remaining revenue will be used to cover operations and maintenance, as well as compensate for reduced revenue that resulted from conservation efforts during the recent drought, according to Pook.

“The conservation that customers have done and continue to do is important and imperative to get us ready for the next drought,” Pook said.

More than 100 EBMUD customers attended the public hearing today, many of whom were discontented with the proposed water service charge increase, according to Pook. She added that EBMUD had received more than 400 written protests prior to the hearing, noting that the number was higher than the average 300 written protests in previous rate years.

“The tenor of the protests (indicates) people seem more frustrated,” Pook said. “I think it’s because of that sense of ‘we’ve just finished this drought and now you’re charging us more.’ ”

EBMUD board member Andy Katz said, “There was frustration about the slow pace of (EBMUD’s) work,” but added that moving forward, several EBMUD board members hope to reevaluate the existing rate structure.

“Our vote on the rates was an opportunity to talk about long-term reform of the rate structure to be more environmentally sustainable and equitable,” Katz said. “We’ll be proposing to encourage conservation and not punish customers who conserve and still face a large fixed charge.”

Contact Valerie Hsieh at [email protected] and follow her on Twitter at @valhsieh.