Te Puna Quarry Park Society Inc president Shona Purves said he had been a volunteer, friend and stalwart supporter of the park for many years.
"It's an absolute tragedy for [his] family, all our volunteers and everyone else concerned with the park. Yesterday was a very hard day for everyone involved.
"Trying to sleep last night was very difficult, and our heartfelt condolences go out to the man's family."
Purves said in the 12 years she had been involved with the park, he had always done the excavating work inside the park.
Until the police, WorkSafe and Western Bay of Plenty officials had completed their inquiries, she would not comment further about the crash itself.
Western Bay of Plenty District Council said on its Facebook page on Wednesday afternoon the park would be closed until further notice.
Council chief executive John Holyoake said he was deeply saddened by the incident.
"While the details of the accident remain unclear council will co-operate with all investigations.
"Our deepest sympathies are with the operator's family at this terrible time."
Local kaumatua blessed the site late Wednesday and Te Puna Quarry Park would remain closed until the digger had been removed from the Park, Holyoake said.
Support had also been offered to Te Puna Quarry Park Society members who were on-site at the time, he said.
The Te Puna Quarry Park land is owned by the Department of Conservation with control and management vested to the council.
The council has a management agreement with the Te Puna Quarry Park Society for the day-to-day operations and management.
The park, founded in 1995, was opened to the public in 1997 after being transformed from an old quarry into a major horticulture and floriculture tourism destination in the Western Bay of Plenty.
Covering about 32 hectares, it has many walking tracks through a variety of garden scapes. The park was a quarry in operation from 1911 to 1970 but is now run by a group of volunteers.