Berryessa Highlands’ water and sewer rates will increase on Oct. 1 — unless a majority of residents opposes the proposed hikes once again.

In June, property owners in the Napa Berryessa Resort Improvement District defeated a rate hike, saying the fees — which would have permanently increased rates by more than 103 percent, according to the residents — were too high.

A citizens’ committee came up with the latest proposal to help fund operations and maintenance of the district’s aging water and sewer systems.

It calls for a hike of:

• 82 percent between Oct. 1 and June 30, 2010;

• 61 percent between July 1, 2010 and June 30, 2011.

Then the rates will start to decrease to their current levels beginning July 1, 2011.

People now pay on average $1,182 a year for water and sewer services, according to Napa County officials who manage the district.

“Nobody is happy with the rate increases, but they all understand this has to be done,” Bart Barthelemy, a committee member, said Thursday.

Under Proposition 218, a state law that allows citizens to weigh in on water and sewer hikes, residents have until Sept. 29 to protest the latest proposal.

The Napa County Board of Supervisors serves as the resort district board, and board chairman Mark Luce said the district will make do with the rates the residents support. The district’s priority is to operate safely, he said.

“We’ll stretch it as we can,” Luce said.

Projected expenses for upgrades are $900,000.

After the June vote, according to Barthelemy, residents spent more than 300 hours reviewing the water and sewer rates in order to come up with the two-year plan.

The latest proposal should bring in enough money to run the district, Barthelemy said — if district officials agree to make operational changes, including hiring an outside firm to manage the systems more effectively.

To come up with the newest proposal, the citizens’ committee took into consideration that the district’s biggest single user, Steele Park Resort, is shutting down later this year. Steele Park’s contributions totaled about 40 percent of the small district’s annual income.

The park, which remains open on a limited basis for boat launching and RV users, is scheduled to close in October while the U.S. Bureau of Reclamation, the federal agency that manages Lake Berryessa, selects a new concessionaire. It is still unknown who will operate Steele Park Resort.

Pete Lucero, a spokesman for the U.S. Bureau of Reclamation, said on Thursday the Bureau will accept bids through Sept. 30.