Onset Water Commissioners Wednesday voted to raise water rates by 19 percent, effective immediately.

The move comes after three years in which the cost of providing water to Onset Water District residents exceeded the revenue collected from water users.

Onset Water Department Superintendent Paul Bokoski explained the continuing shortfalls as “either the budget was too high, or we were not getting enough revenue.”

The vote by commissioners was unanimous.

Under the new rates, a customer using up to 3,500 cubic feet of water per year will see the semiannual water bill rise from $126 to $150.  A customer using 3,501 to 7,000 cubic feet of water will be charged $4.38 per 100 cubic feet, up from $3.68.

“Basically, everything that we do went up 19 percent,” said Bokoski. “That should give us a little bit of surplus and allow us to meet our commitment” to have water revenues cover water costs.

Bokoski said unpaid water bills and “unforeseen expenses” contributed to the ongoing shortfall. He said an aggressive effort had been made recently to collect delinquent bills, but the proceeds were not sufficient to fill the gap.

“Costs keep going up too,” he said.

“It’s going to be tougher for people that are on a fixed income," he acknowledged, "but it’s something that has to be done.”

Bokoski said Friday that the new rates have been sent to the Massachusetts Department of Telecommunications and Energy. Pending approval, they will be reflected in fall water bills, which will be mailed this month or next.

Looking ahead, Bokoski said a lease agreement with Borrego Solar to put a solar array on Onset Water Department property near Sand Pond is expected to generate new revenue "which will help in the future for rates.”

He said the lease agreement is for 20 years, but noted that the project still needs approval of the Conservation Commission and other town authorities.