Maraekakaho Sports Club president Kate Renton said by the time the offending came to light the funds had already been repaid by Arnott, but the club felt socially obliged to report it.
"We don't want it to happen to anybody else and we know that she's involved in an awful lot of other clubs."
Arnott had been involved with the club for many years but had access to its funds for the past three years in her role as secretary.
Ms Renton said the theft was particularly upsetting as Arnott had been a personal friend for about 15 years and there was a lot of trust in small communities.
"It's disappointing as we've been personal friends for quite a long time as well. For a close -knit community it has been quite bad and very disappointing."
The sports club handled modest funds through fundraising, business sponsorship and entry fees at local sports meetings, she said.
"We don't make an awful amount of money but we had accumulated a bit which we're hoping to spend on facilities. We've just painted the pavilion down there and we were planning on spending it on other equipment that we need."
In light of the theft, the club had introduced better money-handling procedures, she said.
"We've been advised by police that we need to not use cheque books and they're advising a lot of clubs not to use cheques any more.
"We're also in the process of looking at getting a club card so you can trace everything."
At the time of Arnott's arrest, police said they wanted to take the opportunity to remind clubs that they should have strict practices in place to help prevent such offending.
Each of the charges laid against Arnott carried a maximum penalty of seven years' jail.
