See area 10 on Aerial Photo Map. This is a fenced-off area which at the time the park was formed contained two basalt quarries dating from the 1950s and 60s, both of which contained water. The water level in the quarries was at the level of the groundwater, and rose and fell only slightly. It was not allowed to be pumped into the creek due to it's salinity.
Parks Victoria had long wanted the quarries filled in, due to the risk of getting sued by people injured while swimming in them and the impossibility of keeping people out. A contract to dispose of clean fill in the quarries was finally announced in July 2006, after protracted difficulty in arranging truck access without excessive impact on the park. This contract resulted in considerable revenue to Parks Victoria, some of which was used to replace most of the Park's boundary fences, something not possible under the normal Parks Victoria budget. (Neighbours to a National Park are completely responsible for fencing, but when the park borders a road there is nobody else to foot the bill.)
Unfortunately after a few years the Environment Protection Authority detected some building waste in the fill, and prosecuted the contractor, which was fined $200,000. However the contractor, EnviroFill Greenvale Pty Ltd, had no assets and immediately went into liquidation.
The eastern quarry had been filled, and the other partially filled. The EPA will not allow any more work on the site until the offending material is removed, which Parks Victoria will never be in a position to do. There is actually no reason why inert building waste such as concrete and bricks should not have been dumped in the quarries, except that there was no permit to do so. The impasse will probably never be resolved without an Act of Parliament.
While this fiasco illustrates the danger of signing a contract with a shell company, there was an even bigger problem with the contract, because it was signed before making any plan for landscaping or re-vegetating the site. There is an embankment along the creek which expands into a considerable overburden dump at the eastern end, and most of this material needs to be pushed into the quarries. (The exception is at the point closest to the creek where the embankment has been built on top of a natural basalt outcrop.) It seems likely that if the contract had been completed, the site would have been overfilled.
Currently the fence is derelict, and the quarry area is used as a thoroughfare by horse riders wishing to make an unauthorized circuit of the park.