A new business improvement district will contribute $1.5 million a year to maintenance of the Rose Fitzgerald Kennedy Greenway, providing new stability to the financial future of the downtown parks.

The Boston City Council Wednesday approved the new district, which will be paid by an assessment on properties bordering the park. 82 percent of the 61 property owners representing 50 buildings in the BID district area voted to support its creation. Assessments will take effect beginning in July.

The Greenway’s annual budget totals $5.5 million, including a $1.4-million contribution from Massachusetts Department of Transportation. The Greenway Conservancy will contribute another $640,000 from donations and earned income from its endowment, and the city of Boston agreed to contribute $500,000 beginning Jan. 1, Conservancy Executive Director Jesse Brackenbury said.

The state’s contribution is earmarked for maintenance and horticulture. Costs related to administration, park rangers, and public art and programming are paid by private sources.

The Conservancy will continue to need up to $1.5 million a year from fundraising and income from vendors such as two summer beer gardens for its share of the budget, Brackenbury said.

“It creates stability in the long term,” he said of the BID’s creation. “But it’s important that donors don’t mistake the BID for the idea that (financial sources) are all taken care of.”

The Conservancy will host a second beer garden sponsored by Downeast Cider this summer at the Dewey Square Park running from every Monday, Wednesday and Friday from late May to October, along with more than 400 free events this summer and new light-based artworks, Brackenbury said.

This story has been updated since publication with comments from The Greenway Conservancy.