The Jefferson County Commission on Thursday approved allocating $30 million for the construction of a stadium to be built on Birmingham-Jefferson Convention Complex-owned property downtown.

The commission voted unanimously to allocate $1 million a year from the county's economic development fund for 30 years to the debt service on the multi-purpose facility, according to the resolution.

Commission President Jimmie Stephens said the stadium will be an economic engine for Birmingham and Jefferson County. He said the commission wanted to make its financial commitment official to push other entities to do the same.

The county's funding, though, is contingent on construction starting before the end of the year.

"We are on a very limited time frame," Stephens said. "The ground must be broken if we want it to be there for the (2021) World Games."

Officials also want to have the stadium available to be used by Birmingham's new professional soccer team which will debut in spring 2019.

The city of Birmingham has yet to commit financially to the project.

The proposed $174 million open air stadium was designed by Kansas City, Mo.-based design and architecture firm Populous. It was included in the BJCC's master plan released in 2016.

The proposed stadium will include 45,000 permanent seats and space for 10,000 more temporary seats. The facility would also have 90,000 square feet of meeting and exhibition space.

BJCC's 20-year master plan also includes a Legacy Arena makeover and an outside piazza renovation with a total price tag of $300 million.

"We are going to have a state of the art facility," Stephens said. "Downtown Birmingham is going to be easy to get to. It is going to have wonderful parks around it. It is going to have retail there. We are adding retail to the BJCC complex. We are renovating the BJCC arena - $123 million. It is going to look brand new."

BJCC didn't immediately respond to a request for information on the timeline for the projects.

Stephens said he hopes the Legacy Arena renovations and stadium construction could take place over the next two years while the Alabama Department of Transportation is rebuilding the Central Business District bridges.

Because of the road construction access to the BJCC will be limited, he said.

Besides Jefferson County and Birmingham, the project is going to need corporate sponsors and other partners.

"This is the first piece of the financial puzzle," Jefferson County Commissioner David Carrington said. "Hopefully, we will have that puzzle complete in 60 to 90 days and have construction start before the end of the year."

Birmingham has been asked to contribute as much as $3 million a year for 30 years on the project, but the funding hasn't gone before the city council for a vote.

"Mayor Randall L. Woodfin is committed to continuing to have a conversation with the Jefferson County Commission and the Birmingham City Council to make sure everyone is on the same page when it comes supporting a downtown stadium," the mayor's office said in a statement. "It is too early to provide additional details, as the mayor wants to have those conversations first."

University of Alabama at Birmingham is expected to lease the stadium for its six home football games, but it doesn't plan to contribute to the building of the venue.

"UAB has been an active leader in conversations with the corporate community, county and city about the proposed new stadium at the BJCC, and I have been in substantial talks with BJCC leadership regarding the terms of a proposed long-term lease agreement," UAB Director of Athletics Mark Ingram said in a statement to AL.com. "To accommodate the Blazers six home football games per year, UAB would be a major tenant of the proposed stadium, and our lease terms would reflect that.

"In addition, UAB - like many corporate members of the community - are considering sponsorship opportunities at the facility that would be determined at a later date," he added.

Updated at 11:23 a.m. with additional information from Jefferson County Commission.