The Rohnert Park City Council acted quickly Tuesday to approve an agreement under which the Federated Indians of Graton Rancheria will pay the full cost of widening Wilfred Avenue.

"We will be moving to expedite this project, it's in the community's best interest," Mayor Jake Mackenzie said following the 4-0 vote. Vice-Mayor Pam Stafford was absent.

Under the terms of a 2005 revenue-sharing contract, the tribe was to pay for half of the widening work, which is estimated to cost $10 million. Wilfred Avenue, now a narrow street bordered by ditches, is the main access to the 3,000-slot-machine casino the tribe is now building.

City Engineer Darrin Jenkins said Tuesday that about 11,000 additional vehicle trips a day will be made on the street once the casino opens just south of Home Depot.

No explanation was given for why the Graton Rancheria has agreed to pay more than the original agreement; the tribe has declined comment. City Manager Gabe Gonzalez has said only that it wants to be a "good neighbor."

The agreement comes after the council and the tribe in June came to terms under which the casino would be connected to the city's sewer system.

Along with that agreement, "This allows us to continue to control and mitigate the (casino's) impacts on the city," said Gonzalez.

No one spoke against the agreement Tuesday, although opponents of the casino have said that the city is enabling it by approving such contracts. The state gave final authorization to the casino in May, a step the federal government signed off on in July.

A Dowdell Lane resident, Tom Roberts, said he supports both the casino and the widening "100 percent," but asked that measures be taken to ensure access to his street once the work begins.

The Stop the Casino 101 group submitted a letter arguing that the city had erroneously concluded that the Wilfred Avenue project was exempt from state laws requiring new environmental studies.

The project could harm the endangered California tiger salamander, the group said. In 2011, federal officials designated 47,383 acres of the Santa Rosa Plain as "critical habitat" for the salamander, which can trigger additional environmental reviews in the case of certain developments. But that ruling exempted virtually all the tribe's reservation.

In a Stop the Casino 101 statement, Rohnert Park Pastor Chip Worthington suggested the group may take legal action. It has already filed a state lawsuit challenging the Graton Rancheria's sovereignty over its reservation.

You can reach Staff Writer Jeremy Hay at 521-5212 or