Water may fall from the sky, but it won’t be cheap anymore for some Bainbridge Island residents.

The BI City Council approved an increase on its utility rates at its June 10 meeting that will double the average water user’s current bill over three years, rising 26% annually between 2026-2028, with possible additional increases to follow through 2030. Sewer rates will also rise about 15.5% annually in the same timeframe.

Council also passed an accompanying resolution that amended its financial support program for low-income utility users, expanding the definition to include anyone making between $0-65,000 per year, not just seniors or those with disabilities.

The adjustment is long overdue and necessary to complete several essential infrastructure projects, explained Public Works director Chris Wierzbicki.

A study by consultant FCS found that the city undercharged residents for water, sewer and stormwater management services for over a decade, in some years by as much as $44 per month. Over time, the Public Works department’s income margin narrowed and depleted its on-hand capital funding, which meant when two “once-in-a-lifetime” projects arose in 2022 — the replacement water tank and improvements to the wastewater treatment plant in Winslow — the department had little wiggle room.

Current estimates for the new water tank system price out to $25.6 million, $5 million of which will be covered by rate increases, Wierzbicki said. Improvements to the wastewater treatment plant will cost about $6.1 million, but the city intends to raise $7.6 million through rate increases to cover the plant plus related project costs, like the replacement of the Lower Lovell beach sewer main and about $2.5 million in loans.

“[The water tank] is the most expensive project that utilities has ever funded. It is indeed a once-in-a-lifetime project,” said city manager Blair King at the June 10 meeting. “Other than maintenance, we’re not going to go back to replace it. The reason for that is one, it didn’t meet earthquake standards, and secondly, with the design of the tanks, it had a lot of dead water and a lot of dead space. It was an inefficient way to store and distribute water.”

The city performed “quite a bit of analysis” on the water tank and adjoining system before determining the best course of action, Wierzbicki added. He reminded the council that the cost does not represent just the tank itself, but rather several on-site improvements that are required for the new tank to function properly. The scale of the project meant that no other options proved as cost-efficient in the long term as a total replacement, he said.

“It’s somewhat a function of the size of our system, and the significant elevations of our system, that when you bring a new tank online, that is going to create more pressure… There are regulators and pressure-reducing valves that allow people to turn on their faucet without it exploding and without drips of water coming out. When this new tank comes online, we have to create a third pressure zone, and there’s almost $6.5 million of improvements in that alone,” said Wierzbicki. “The bottom line is that this is a large and expensive project that’s going to serve the system for the next 70 years.”

Councilmembers Clarence Moriwaki and Kirsten Hytopolous both expressed some frustration about past actions from the council regarding utility rates. Hytopolous noted that while no one can predict the future, being fiscally prepared for unexpected expenses is generally a good idea: “the best thing to do is have a rainy day fund,” she said.

Many residents may be frustrated by the hikes, she added, and will likely become more so with further increases that may become necessary down the road.

“Something that gives a lot of context [to this action] is that rates weren’t raised for a decade or more — and that if they had just kept up with inflation, we probably wouldn’t even be talking about this tonight,” Moriwaki said.