PITTSBURG -- Residents and businesses will pay more for water starting in March under a proposal that was unanimously adopted by the City Council.

Council gave approval Tuesday to raising water rates 3.5 percent annually over four years. That is slightly less than the original proposal that called for rates to increase 4 percent annually over four years.

Starting in March, the average residential water bill will go from $63.45 to $66.01 a month based on usage of 350 gallons a day under the 3.5 percent hike. Sewer rates would stay the same, which means the monthly rate for combined water and sanitary service for the average residential customer will rise from $79.24 to $81.31. Qualified low-income seniors who are at least 62 years old, and all disabled residents, would also see a larger discounted rate to offset the increase. That means that the current $7.24 discount applied to the water portion of bills would be increased to $8.69 per month for those who qualify. The annual household income limit required to qualify for a discounted rate is $11,640, a cap that does not include Social Security payments. Currently, 726 residential customers received discounted rates.

The higher rates are needed to help pay for operations, ongoing maintenance and improvements to the city's water treatment and delivery system and to cover higher costs for buying water from the Contra Costa Water District, according to a staff report.

Comparable rates in the region for water service only are $63.88 for the Contra Costa Water District, which serves Concord, Pleasant Hill and Clayton, $75.04 in Martinez, $87.03 in Bay Point and $52.38 in Brentwood, which does not include costs for water softening. (Contra Costa Water District rates are expected to increase by 3.2 percent in April, while Brentwood's are expected to go up 3 percent in July)

Before the vote was taken, Councilwoman Nancy Parent made a motion to vote on the original 4 percent increase that was recommended in the staff report.

"We need to raise the rates. Our rate is reasonable with regard to other cities in the area," she said.

But Vice Mayor Pete Longmire and Councilman Ben Johnson said they would support rates going up 3 percent a year, along with a bigger discount for low-income seniors and disabled residents.

"We need to reduce the rate a little bit more than 4 percent," Johnson said.

"I also think the senior and disabled demographic in the city should be given a further deduction," Longmire said.

"Staff is comfortable if you want to lower rates down to 3.5 percent. We can work with that (along with the larger discounted rate)," City Manager Joe Sbranti said before the vote was taken.

The newly approved rate hike follows a 4 percent yearly increase for combined water and sewer rates that started in January 2010.

Contact Eve Mitchell at 925-779-7189. Follow her at Twitter.com/EastCounty_Girl.