ALAMEDA — City officials joined the developer that will transform the former Del Monte warehouse into housing and retail on Monday for a groundbreaking at the landmark site.

Mayor Trish Spencer and others sank shovels into the earth to mark the beginning of the project’s first phase — the construction of 31 affordable units.

The units, which will include senior housing, will be built on what was once a parking lot for the warehouse at Sherman Street and Buena Vista Avenue. They are expected to be available next year.

“Today is a great day for the city of Alameda,” said Mike O’Hara of Tim Lewis Communities, which will build up to 380 apartments, lofts and townhouses and at least 30,000 square feet of commercial and retail space on the Del Monte site. A total of 55 units will be affordable.

The start of construction of the first phase on what’s now called Star Harbor within the next few weeks will mark the culmination of an eight- year effort to redevelop the 240,000 square foot warehouse, O’Hara said.

“We still have lots of work to do,” he added.

Monday’s groundbreaking comes in the wake of Alameda County voters passing Measure A1, which will raise up to $580 million in general obligation bonds to provide for up to 8,500 units of affordable rental housing and supportive housing for homeless people, as well as for helping low- and middle-income households buy homes.

“That’s good news for projects like this,” Vanessa Cooper, executive director of Alameda’s Housing Authority, said about the county measure.

Cooper called the project at the former Del Monte site “the best practice of private and public collaboration.”

Built in 1927 for California Packing, the warehouse stretches 1,000 feet long. The red brick exterior of the building, one of the city’s 30 designated landmarks, will be maintained under the developer’s plan, while a new walkway will be cut through it to allow public access to the Oakland Estuary.

The Roseville-based developer has renamed the building, “Warehouse 48.”

“This is why we are lucky to have historic landmarks,” Spencer said. “And it really does take a community to bring them back to life.”

Similar projects will take place as Alameda Point, or the former Alameda Naval Air Station, gets redeveloped, she said.

The project at the former Del Monte site will include changes to some nearby streets to make them more bike- and pedestrian-friendly.

Work on the warehouse is set to start in spring 2017, with the units available for occupancy about the middle of 2018, O’Hara said. There will be 415 parking spaces for future residents.

Until recently the warehouse was used as a distribution facility.

The Alameda City Council approved the master plan and development agreement for the project with Tim Lewis Communities in December 2014.