Washington State Ferries — faced with a mandate to shave $17 million from its budget — has proposed service reductions on both the north and south ends of Vashon that will likely mean longer lines for Island commuters.

The ferry division has suggested taking the 124-car Issaquah off of the north-end triangle route, replacing it with the 87-car Evergreen State, the second-oldest ferry in the fleet. The Issaquah would go to the Bremerton route.

It has also suggested lengthening the wintertime schedule — when only two boats serve Vashon’s north end on the weekends — from 12 to 20 weeks. During the other three seasons, Vashon has three boats on the north end.

And on the Tahlequah-Point Defiance route, the ferry division has proposed an elimination of the last run of the night, a service extension that was provided in fall 2009.

David Moseley, who heads the ferry division, a part of the state Department of Transportation, said the cuts are painful but necessary.

“We do not have the resources to sustain our current level of service,” he said. “The system is not financially sustainable.”

The reductions, should they go into effect, reflect some of the most significant cuts in service to Vashon in years, said Ray Deardorf, planning director for the ferry division.

“This is probably the biggest reduction … that will affect us year-round,” he said.

Asked what the impact will be, he added, “Longer waits and longer lines.”

Moseley and Deardorf are planning to visit Vashon on Thursday, Dec. 9, when they’ll discuss the ferry division’s financial situation and answer questions.

Kari Ulatoski and Greg Beardsley, Islanders on Vashon’s Ferry Advisory Committee, said they’re hoping for a strong turnout.

“We need a lot of people there,” said Beardsley. “That’s the key to it. … This is going to go through the roof.”

The ferry service has proposed cuts on most of its routes; only the Bainbridge and Edmonds/Kingston routes were spared. But Beardsley said he believes Vashon has been particularly hard hit — losing, for instance, more car-carrying capacity than any of the other routes.

Currently, the Issaquah’s morning and afternoon sailings are completely full, he noted. Replacing it with a boat that holds 37 fewer vehicles will have a measurable impact, he said.

“It’s really going to be devastating for the Island,” he said.

Like Beardsley, Ulatoski said she hopes Vashon residents will come out in force to protest the cuts, similar to a proposal that was floated two years ago but did not go into effect. “We have time to try to fight this,” she said.

The budget cuts were made public days after voters defeated two initiatives that would have helped the state address its ongoing financial woes. But even without those measures, the state’s financial situation was grim. According to the state’s Office of Financial Management, state officials are looking at a $4.5 billion shortfall — a budget hole that comes after two years of significant statewide cuts to address previous shortfalls.

The ferries division was asked to trim $17 million from its 2011-2013 budget, delivering up a $212 million spending plan to the governor, who is the process of creating her two-year budget proposal for the state Legislature. The cuts are tough, both Moseley and Deardorf said, coming as they do after shaving more than $25 million from the ferry division’s budget over the past two years.

“We’ve already gotten all the low-hanging fruit,” Deardorf said.

Moseley said he believes the budget cuts are fair; he and his staff, he said, tried to ensure that the pain was shared by many routes. At the same time, he said, the cuts reflect a painful, statewide reality.

“These are very tough economic times,” he said.