Waterland was now looking for a new place to set up but pointed out that was difficult for her and the 28 volunteers to helped run the store, which has been in Greenmeadows for six years.
"The idea to set up an op-shop was born six years ago because I am passionate about the cause. They don't get government funding these rescue centres, so I decided to start an op-shop.
"Fortunately we found a very generous landlord and it took off straight away. The trust couldn't afford to buy new fixtures to set up the shop, so I begged and borrowed and we got the shop going.
"We are the only op-shop in New Zealand that generates funds for New Zealand wild bird rehabilitation, trying to raise funds to help injured native bird species."
In 2014, her work garnered her a nomination in the inaugural Pride of New Zealand Awards, to celebrate New Zealanders who make the most positive, uplifting and inspiring contributions to their community.
The shop was an immediate success with the public until the building premises were sold to an Auckland resident last year.
"It all ticked along for a while until this.
"The response from the public has been huge. There was a huge uproar, one family wanted to start a Givealittle page to help raise the difference. There's been other suggestions too, it has been overwhelming. People love our shop."
The op-shop is administered under the auspices of the Taupo Bird Rescue Charitable Trust.
Trust secretary Judi Smith said over the past six years the op-shop had generated huge grants for institutions and individual "rehabers" nationwide, including a $10,000 to a rehabilitation ward at Massey University.
Groups supporting kiwi in Whangarei and Yellow-eyed penguins in Otago had also received grants or incubation equipment from the group.
"What we do is we ring people who are working, sometimes on their own, rehabilitating native species, and didn't even realise that they could get financial support, and we ask them to apply by way of a grant."
Trust chairman Frank Weeks said it would be a "great pity" if the op-shop had to close.
The building's owners had only been contactable through an Auckland law firm, and had been very hard to deal with, he said.
"We've tried communicating in the past over various things and had no reply."
However, speaking to Hawke's Bay Today a spokeswoman for the law firm urged the trust to contact the building owner directly, hopeful that a deal could struck between parties.