Five years ago, Abi Echevarria, a single father of two, was out of a job and living on public assistance when a caseworker told him about openings at the Buffalo Olmsted Parks Conservancy, which had just taken over supervision of the city’s historic parks and parkways.

Echevarria put his experience in property management to use right away as a welfare-to-work zone gardener for the nonprofit conservancy, picking up leaves and trash on the parkways between his Upper West Side home and Delaware Park and— on his own initiative — the streets and parks in his neighborhood.

The strong work ethic quickly got him promoted to foreman. For the last four years, he has been responsible for keeping the Japanese Gardens on Hoyt Lake, behind the Buffalo & Erie County Historical Society, in pristine condition. Last month, a friends group that supports the gardens sent him to Japan for a two-week horticultural course.

Echevarria’s expertise is “unique to Western New York” and one of many assets that might be lost if the nonprofit conservancy’s stewardship of the landmark system ends when the city retakes control of all urban parks Jan. 1, David J. Colligan, the conservancy’s chairman, said at a news conference Wednesday in Martin Luther King Park.

As many as 30 conservancy workers could be laid off unless Mayor Byron W. Brown agrees to a new contract extending the organization’s stewardship of the high-profile Olmsted system, Colligan warned.

Two members of the control board overseeing city finances took Brown to task Wednesday after the board narrowly approved the mayor’s plan to hire 49 workers now employed by Erie County and add an $85,000-a-year deputy commissioner as part of the overall takeover of the city’s roughly 180 parks.

Five members voted for the plan, which still needs Common Council approval. But Alair Townsend, the board’s acting chairwoman, and Gail E. Johnstone, a board member, abstained, saying the mayor had submitted the resolution at the last minute, giving the board virtually no time to review it,

Townsend argued that key questions have yet to be answered, including what role the conservancy will play. Johnstone claimed the city has been operating “behind-closed doors, in secrecy.”

Brown, who sits on the control board, denied that the parks takeover has been shrouded in secrecy. He said all contracts are negotiated privately.

“It would be inappropriate for me and others in this government to try to negotiate this agreement out in public, as other entities have been trying to do,” Brown said, in a verbal swipe at the conservancy.

Conservancy employees in maroon sweaters and caps bearing the Olmsted logo surrounded Colligan during the King Park news conference, and he called them key to the day-to-day management of the six historic parks and connecting parkways designed by landscape architect Frederick Law Olmsted in the 19th century.

The conservancy leader said another important asset might be lost if the city turns its back on the nonprofit organization — the money, good will and sweat equity of countless volunteers who have pitched in to spruce up the system.

“I don’t think the volunteers will come out the way they have in the last five years,” Colligan said. “They are not replaceable.”

The city’s foot-dragging also might clog a financial pipeline that has delivered millions in private aid to the Olmsted system during the conservancy’s tenure, Colligan suggested.

“There’s a lot at stake here— not just jobs but private funds,” he said.

Colligan singled out the Margaret L. Wendt Foundation’s $500,000 commitment to restore the King Park wading pool as one project that could be jeopardized. Acknowledging the Wendt trustee who has championed the pool restoration, Colligan said Robert J. Kresse “can’t justify” the grant without a contract between the city and conservancy. Kresse nodded in agreement.

Colligan said Olmsted trustees have contributed $1 million, and foundations and other private sources $7 million, to the parks during the conservancy’s tenure.

A public rally for the conservancy is scheduled for noon Sunday in the King Park shelter house on Fillmore Avenue north of Best Street.

tbuckham@buffnews.com and meyer@buffnews.com