The city’s brand new Civic Center will throw open its doors with a July 29 grand opening celebration that will include a DJ, food trucks and a flag-raising ceremony to mark the unveiling of the $520 million project.

The event marks the opening of the public side of public/private construction partnership. Residents will be able to tour the lobbies of the new City Hall and Port buildings as well as the Bob Foster Civic Chambers. The new main library will open later, on Sept. 21.

The event will take place from 6 to 8 p.m. on the Long Beach Civic Center Plaza. “The public can see where to come for services and people will get to see the City Council chambers for the first time,” said Jennifer Rice Epstein, public affairs specialist for the city.

Mayor Robert Garcia called the project “the centerpiece of the new Downtown Long Beach, a vibrant, booming and rejuvenated neighborhood” that is seeing almost $5 billion in new construction.

The old city hall and library, built in 1976, will be demolished to make way for retail and high rise apartments and condos along high-value Ocean Boulevard, the “private” part of the deal with Plenary-Edgemoor Civic Partners. The projects also calls for a renovation of the old Lincoln Park site at the Civic Center.

As part of the development, Cedar and Chestnut avenues will reopen again to cars. The streets were closed in the 1970s as part of the original development. Also, the Port of Long Beach, which had been housed in temporary quarters near the Long Beach Airport, now becomes part of the civic plaza.

Under the agreement, Plenary-Edgemoor will design, build and maintain the civic center for 40 years. The city will pay about $14 million annually, about what it costs to maintain and pay off debt from the old structure.

The old library will be demolished this fall, said Rice Epstein, with renovation to Lincoln Park to follow. The old city hall will go down within the year, she said.