Washington Mayor Muriel Bowser speaks after taking the oath of office during her inauguration ceremony at the Convention Center in Washington earlier this year.(AP Photo/Carolyn Kaster)

D.C. Mayor Muriel E. Bowser (D) detailed her plans for a Wizards practice complex and 5,000-seat events venue at the former St. Elizabeths hospital Tuesday, asking taxpayers to foot about 90 percent of the construction costs but pledging to create hundreds of jobs, attract $90 million in new tax revenue and draw hundreds of thousands of visitors to a section of the District starved for economic activity.

The mayor’s staff, working with the parent organizations of the Wizards and Events DC, the District’s quasi-public convention and stadium authority, finalized major terms of the deal late Monday and early Tuesday.

Bowser plans to announce the agreement Wednesday morning alongside Ted Leonsis, majority owner of the Wizards and Mystics, and players from both teams.

[Related: Is sports the cure for St. Elizabeths?]

The mayor expects the 118,000-square-foot center to host 90 events per year, including Mystics home games, concerts and other entertainment, and attract as many as 380,000 people annually to the site.

“Today marks an important day for the District of Columbia and the people of Ward 8,” Bowser said in a press release. “With this new development, we are driving private investment to the St. Elizabeths East campus, boosting the local economy, creating hundreds of jobs, and putting more District residents on their pathways to the middle class.”

In the deal, taxpayers would pay for about 90 percent of the cost of a $55 million entertainment and sports complex. The District would use $23 million from capital improvements already approved for the St. Elizabeths site and combine it with $27 million from Events DC, which is funded with hotel and restaurant taxes.

The parent company of the teams, Monumental Sports & Entertainment, will pay $5 million toward construction. The amount equates to what the company would pay over a 19-year lease. Monumental has also agreed to spend $10 million toward “redevelopment and community philanthropic investments” in the area, according to the statement issued by the mayor’s office.

Leonsis said in the release that he was “extremely appreciative of the Mayor’s and Event DC’s collaboration and partnership with us,” and reiterated his commitment to advancing communities east of the Anacostia River. St. Elizabeths, a mostly vacant former mental hospital, is located between Anacostia and Congress Heights in Southeast D.C.

“We look forward to working together to build a best-in-class Wizards and Mystics training facility and a fantastic new home venue for Mystics games. The facility not only is important to our teams but also the community – it’s much bigger than basketball,” Leonsis said.

The practice and events venue could serve as an anchor on St. Elizabeths along Alabama Ave. SE, near the Congress Heights Metro station. The District has partnered with a team led by Redbrick LMD to develop a mixed-use center including housing, retail and an innovation hub on an adjacent section, including a proposed Microsoft Innovation Center.

Bowser expects the Wizards facility and the Redbrick project to create a combined 600 construction jobs and 300 permanent jobs.

Large construction contracts and long-term leases are required to undergo council review. But officials in the mayor’s office do not expect the plan to need the level of D.C. Council approval required by other large developments like the planned D.C. United stadium. The council has already approved $122.5 million in capital improvements for St. Elizabeths, of which only about $27 million has been spent.

With the approvals in place, construction could start in 2016 with completion in 2018.

The board of Events DC approved its investment and management of the project in a special session Monday evening.

“This new entertainment and sports arena will aid us in attracting a vast amount of new programing that will not only help transform this community but also drive significant economic benefit for the District,” said Greg O’Dell, president and chief executive of Events DC.

Follow Jonathan O’Connell on Twitter: @oconnellpostbiz