The monthly bill for a typical single-family home that uses 13,000 gallons of water would increase by $27.53, or 70 percent, by mid-2015 if the Ho­nolulu Board of Water Supply gets its way.

On Wednesday, the city’s water agency announced its proposal to raise rates by 9.65 percent in each of the next five fiscal years. The first increase would occur in January, when residents would pay an additional 27 cents for every 1,000 gallons of water used.

"Deferring a rate increase will only result in higher costs down the road," said Kurt Tsue, spokesman for the board. "Our current water rate will not allow us to keep pace with the needed infrastructure improvements. Without a rate increase, our water system and facilities will continue to age, resulting in additional water disruptions."

The Board of Water Supply is a semi-autonomous, self-supporting city agency that has to raise its own operating revenue.

Duane Medeiros, who lives with his family in Aina Haina, said the increase along with the mounting costs of living will hurt his pocketbook further.

"It’s hard to really determine who’s at fault, but it’s just poor management," he said. "They knew (the system) was aging."

The proposed increase will be up for a public hearing next month. The Board of Water Supply’s board of directors will then decide on whether to approve the plan.

The board last raised rates in 2006, after approving a similar five-year rate schedule that ended last month. Before the 2006 increase, the last water rate increase had been in 1995.

With the new proposed rates, officials hope to gain an additional $203 million over five years for capital improvements. The agency has about $345 million worth of capital improvement projects in its queue, said acting board manager Dean Nakano.

Nakano said there has been a 40 percent increase in water main breaks in the past three years.

Out of almost 2,100 miles of pipeline across the island, about 47 percent are more than 40 years old, the board said.

"We have roughly 21,000 hydrants, 38,000 valves … all of which need to be repaired and maintained," Nakano said.

Aiea resident Reece Fuse said the financial burden of upgrading infrastructure should not be borne entirely by consumers.

"All I can say is, I better not hear of any more water main breaks or sewage spills four years from now" if the rates increase, Fuse said in an email to the Star-Advertiser.

"I am in awe of the Board of Water Supply’s audacity to propose such a large rate increase over just 4 years during this tough times," Fuse wrote. "Daily expenses for Hawaii residents keep going up and wages are not. How is one to make ends meet when there seems to be no end to these rising costs?"

The board said its fixed operating costs, which include electricity, fuel and construction materials, have increased over the years while revenue has remained flat.

"Any rate increase we’re facing is going to affect all of us. We’re all consumers," Nakano said.

The current rate for 13,000 gallons of water per month is $39.19, including billing charges, a sum that would rise to $66.72 under the five-year rate schedule, an increase of 70 percent.

The agency’s board of directors has the final say on the increase. City Councilwoman Ann Kobayashi said she has talked to the board about the increase.

"They said they’re going to be very open and transparent, going to the various neighborhood boards," Kobayashi said. "When you look at it, it doesn’t amount to that much. People spend more on bottled water I think."

But Kobayashi said what is more frightening is the water increases coupled with other hikes, including gas, sewage fees and electricity.

She suggested that to curb the water rate increases, the Board of Water Supply move out of its aging Beretania Street location and lease the land for other uses. The parking area could be used for the Queen’s Medical Center, she said.

"They don’t have to keep going to the ratepayer," Kobayashi said.