The Seattle City Council on Monday approved three city-state tunnel agreements giving notice to the state to proceed on the Alaskan Way Viaduct replacement project, bringing to a anti-climactic close a decade of debate over how best to replace the Alaskan Way Viaduct.

In a nearly empty council chamber, with two representatives from the state transportation department looking on, the council unanimously passed the agreements that became the subject of the August referendum to gauge support for the state's tunnel project.

With 59 58 percent of voters giving approval to the referendum, Monday's vote carried little practical or political significance. The council adopted the measure as a resolution, not an ordinance, so there cannot be another referendum challenge.

At Monday's meeting, Councilmember Tom Rasmussen reminded colleagues that the agreements spell out protections for the city over design, right-of-way and relocation of utilities as the state begins tunnel construction.

City Council President Richard Conlin, who became the subject of a recall attempt for his official acts in support of the tunnel, thanked the voters, the state and his colleagues.

"It's great to be at this place at this time," Conlin said with a big smile.

Councilmember Mike O'Brien, the lone tunnel opponent, said after the meeting that he hoped the past year of debate over the agreements clarified the state's responsibilities and the need to protect the city's interests.

He also voted in support of the agreements. "The city has decided this is the direction it's heading in and I'm supporting that," O'Brien said.

The council also approved creation of a 15-member tolling advisory group to review tolling options for the tunnel, how to meet state funding goals and to minimize traffic diversion.