Rounding down, Zoos Vic received $74 million from admission and sales, while it cost them $136 million to run the four zoos (22-23 figures). In other words, they are already running at a substantial deficit. This deficit is funded by Government grants. It is up to the Government to decide how much their subsidy will be, and the Board has to decide how they manage the zoos to make that work. A growing unfunded deficit would not see the zoos close, but it may see a number of senior people in Zoos Vic looking for other work.
The size of the State deficit is about the only election issue the opposition have at the moment, so the Government will not be looking to grow it.