Palo Alto's multiyear effort to build a new downtown garage took an unexpected turn Monday night, when the City Council backed away from its earlier plan to construct the six-story structure on a Hamilton Avenue parking lot.

Spurred by concerns about high costs and environmental impacts, the council declined to approve a design contract that would have allowed the project to advance. Instead, by a unanimous vote, the council directed its Policy and Services Committee to delve deeper into downtown's parking issues before determining whether the structure is really necessary.

The council's decision is a sharp departure for a project that has been on the city's priority list since 2014, when the council put together its infrastructure plan and asked the voters to support a hotel-tax increase to fund these projects. The council followed suit with another hotel-tax increase in 2018, at which point it once again expressed its intention to spend the funding on its infrastructure plan, which includes the downtown garage.

Even so, the project has seen plenty of detractors, both on the council and in the wider community. Vice Mayor Adrian Fine has consistently opposed the new structure, arguing that parking is a valuable asset that the city should not be subsidizing through garage construction. But while he has traditionally been in the minority on this subject, that appeared to change Monday, when one colleague after another joined him in voicing either skepticism or outright opposition to the new garage.

Councilwoman Liz Kniss cited the council's recent adoption of "climate change" as a top priority and stressed the environmental impacts of building a facility that encourages driving. Council members Lydia Kou and Greg Tanaka both talked about the need to better prioritize its infrastructure priority. Councilwoman Alison Cormack said she didn't find enough evidence in the environmental analysis to support the need for the garage.

Fine led the charge Monday by making the motion to pursue a broader parking-management study, rejecting a staff proposal to approve a design contract and to consider a broader parking-management strategy.

"I really haven't seen the studies about existing supply and demand that support a new structure in this area," Fine said. "I really don't think we're going to manage our parking well as long as we give it away for free. And we're giving it away for free on street and off street."

Kniss, who on Feb. 2 led the push to adopt climate change as a 2019 priority, said her biggest concern is not money but environmental impacts. Times have changed, Kniss said, since the council agreed to include the downtown garage on its priority list.

"Money is one thing, but we would find the money. ... But the climate and our commitment now to climate change, to sustainability, is very real," Kniss said.

The six-story structure was being planned for a city-owned lot at 375 Hamilton Ave., near Waverley Street. It would have include 324 spaces, raising the lot's capacity by 238 spaces.

For Mayor Eric Filseth, who supported the downtown garage in the past, the key issue was neighborhood feedback. When the council first embarked on the project, its goal was to address concerns from the Professorville neighborhood about commuter vehicles taking up all the parking spots on residential blocks. Since then, the city had implemented a downtown Residential Preferential Parking program that addressed some of these concerns. On Monday, some of the residents who participated in the creation of that program addressed the council and made the case against the garage.

Downtown resident Neilson Buchanan was among them. Rather than spending the money on a new garage, the council should pursue a "coordinated area plan" for the downtown area and pursue other efforts to reduce traffic.

"The priority you've set years ago is out of date," Buchanan said.

L. David Baron, an advocate for housing, lauded the council for finally considering a dense building downtown. He lamented, however, that the council is dedicating the building to parking.

"I'd like to see zoning allow building of this size since people think a building of this size is reasonable," said L. David Baron. "But I'd like to see buildings of this size built as homes for people and not cars."

Not everyone was thrilled about the change in directions. Judy Kleinberg, CEO of the Palo Alto Chamber of Commerce, urged the council to stay the course. The garage, she said, is badly needed to address downtown's parking problems.

"There is a significant parking deficit downtown," Kleinberg said. "All the studies the city has done prove that's the case. It can only be solved with additional capacity."

Councilman Tom DuBois was the strongest proponent of staying the course. He noted that the council has promised the project to the voters on numerous occasions.

"We voted multiple times on this project and I think we made promises to the community when we raised the transient tax," DuBois said. "And most of us committed to supporting this plan when we supported that tax."

Despite his desire to see the project move forward, DuBois ultimately joined the rest of his colleagues in supporting Fine's motion. Filseth, a downtown resident, also voted with the majority and pointed to both the project's high costs and the neighborhood's changing demands.

"I think we ought to look at if there are other ways to spend $25 million or $29 million or $34 million to reduce car trips by 238 per day," Filseth said. "If we can't find a better way to do it, maybe we ought to come back and do the garage."