ÌìÃÀÊÓƵ

The Honolulu Board of Water Supply could raise its rates soon. Even so, Oahu residents will still pay less than for their water than residents in other cities.

The city water agency recently announced its proposal to raise water prices by through 2015. By then, the average single-family household’s monthly bill could be 70 percent more expensive, up from about $39 per month to about $67 per month.

To get an idea of how Honolulu residents’ water bills stack up, we called municipal water agencies in three west coast cities: San Francisco, Seattle and Portland.

Civil Beat calculated the cost per 1,000 gallons for basic residential use. And even with its proposed increases, Honolulu’s water board will still charge less for water than other cities.

Currently, the Honolulu board charges of water for the first 13,000 gallons. According to the United States Environmental Protection Agency, an average family of four can use of water per month.

By comparison, single-family households in Portland typically pay about $4.13 for every 1,000 gallons, according to a spokeswoman for the . In , families pay about $4.68 per 1,000 gallons.

In , water costs even more: about $5.32 per 1,000 gallons, or almost twice as much as in Honolulu.

On the whole, neighbor island residents pay less for water than their Honolulu counterparts. Maui’s Department of Water Supply $1.75 per 1,000 gallons for the first 5,000 gallons used and $3.20 for the next 10,000 gallons used. In Kauai, 1,000 gallons of water generally $3.20. And on the Big Island, general-use water 89 cents per 1,000 gallons for the first 5,000 gallons used and $1.80 for the following 10,000 gallons used.

By 2015, assuming Honolulu’s rate increases go through as planned, Honolulu residents would pay .

But all three mainland cities we contacted said their rates are going up — making Honolulu water look even cheaper in the long run.

In San Francisco, residents by 2013 will be charged about $5.36 per 1,000 gallons (Honolulu residents will pay $3.68 for the same amount that year).

And Seattle wants to set the 2013 rate at $6.44 per 1,000 gallons. In 2014, their rate will be even higher: $7.09 for every 1,000 gallons.

Future water rates for Portland are not yet available. But the city’s water bureau has proposed increases of over the next five years, meaning that water would almost certainly cost more in Portland than in Honolulu in 2015.

Estimated monthly bills typically include water rates and base service charges. In San Francisco, Seattle and Portland, those service charges are based on the size of a household’s meter.