Norwich — The call came in two weeks ago: An anonymous donor wanted to give Reliance Health $100,000, a few weeks after the nonprofit community mental health center had finished adjusting to state budget cuts and was embarking on a costly but needed expansion into a new building on Cliff Street.

"It's a huge deal, it's fantastic," said Carrie Dyer, the nonprofit organization's chief operating officer.

Dyer said only Reliance Health's CEO, David Burnett, knows who gave the organization its biggest ever individual donation.

"It was this sort of mysterious, trickled-in information," she said.

But the money comes at a time when Reliance Health is trying to balance the needs of its more than 1,000 yearly clients and a move into the building it bought last year at 2-6 Cliff St. in the city's downtown.

In a statement to Burnett, the donor said, "Reliance Health is an organization that has proven to have the community's best interest at heart, and I'm proud to support their mission."

"I will be delighted if my donation gets other people to consider similar large donations," the anonymous donor added.

The donation alone won't make up for cost reductions ordered by the state Department of Mental Health and Addiction Services to the nonprofits it funds, another effect of the chaotic state budget process this year.

Reliance Health cut its budget down by a total of about 5 percent in response, Dyer said, avoiding layoffs but cutting some programs for its clients that were not at capacity and ending one-on-one services for one particularly costly client.

Meanwhile, the organization is expanding into the space at its new building, which will require a new heating and cooling system.

Dyer said the agency's staff also plans to renovate the building to include a kitchen, soundproof office space and room for therapists and education consultants.

"We want the space to be welcoming," she said. "It's sort of this vision (of) an all-in-one place for people to get their needs met. It will all be in that one central location."

Reliance Health used its real estate arm to purchase the Cliff Street building from the Lord Family Nominee Trust in a complex deal this fall.

Two agencies leasing space in the building, the state Department of Correction parole office and the Veterans' Center, have remained there and will continue to pay rent to the Lord trust for the next five years.

Reliance Health already had leased space in the Cliff Street building for its homeless outreach program, outpatient clinic and two community support teams. Those programs will remain and expand at the building, Dyer said.

The donation, while small compared to the costs of the move and the center's approximately $13 million annual budget, will give a boost to Reliance Health during a time of change.

"It sounds like that was the mindset of the person," Dyer said. "'Let me give you a shot in the arm while you're doing this big move."

And the donation could inspire Reliance Health to start soliciting individual donations to shore up the money it raises at an annual road race and other fundraising events throughout the year and protect against future cuts in state dollars.

"In a $13 million agency, it's especially important for us to get dollars that we have control over," Burnett said.

m.shanahan@theday.com