More than 140 people attended a forum in Sydney last week opposing the construction of a dam at Cranky Rock.
Headlined by environmental activist Professor Tim Flannery, Save Cliefden Caves Association's Harry Burkitt said the forum sent a strong message that the flooding of the caves by the proposed dams were unacceptable.
"We were very pleased to see a large number of locals attending the event, including those who hail from the central west but reside in Sydney," he said.
"It was also great to see local Country Labor and Greens candidates Bernard Fitzsimons and Janelle Bicknell who came all the way to Sydney to show their support, plus Joe Maric from the Central West Community Union Alliance."
Professor Flannery talked about the importance of preserving caves and geoheritage sites such as Cliefden in researching Australia's past environments.
"I haven't been to Cliefden Caves, but the one thing I know about them is they're under-researched, so we don't know enough about them and the kinds of things they may have in them to really make an informed choice about whether we should flood them or not," Professor Flannery said.
"Nothing ever changes unless good people give up a little bit of their time to do things that are important, like preserving these caves."
Also speaking was University of Sydney cave scientist Associate Professor Armstrong Osborne.
He stressed the international scientific significance of the ordovician fossils on the site.
"This is one of Australia's most important invertebrate fossil localities of international significance. Cliefden is a very complicated site and its important for a whole range of reasons to do with its non-living environments," he said.
Associate Professor Osborne said the only reason the sites are not listed for statutory protection is that no such list for non-living environments exists anymore.
He said the caves are the first place in the world where there's a record of animals like brachiopods building themselves above the tide level. He said the site also has a link to China.
"460 million years ago we shared an ocean with China. There are beasts that lived here that only live here and China," Associate Professor Osborne said.
While he conceded many of the higher fossil sites would be saved from the waters due to the shift of the site of the proposed dam from Needles Gap to Cranky Rock, Associate Professor Osborne said the "best dam will still flood at least one cave and the lower parts of most of them".
"One of the caves at Cliefden is a really complicated maze cave. These are quite significant features, they're of international scientific interest at this very moment because there's a huge argument about how they form. This is also one of the lowest level caves at Cliefden, the entrance to the cave is at about 410 metres, and the cave is about 24 metres deep. This means the lowest level of Cranky Rock dam, which would be at about 400 metres, would flood the lower part of the cave by at least 16 metres," Associate Professor Osborne said.
Mr Burkitt said one of the main themes that came out of the forum was that building dams is simply not the answer to the region's need for water.
"The Save Cliefden Caves Association is now focused on opposing the Cranky Rock dams and building a strong local supporter base to oppose these proposals which would flood this national treasure," Mr Burkitt said.
"The Water NSW report published in February shows that if either of the proposed Cranky Rock dams are built they will inundate caves, fossils and the thermal spring at Cliefden. The report also does not rule out the Needles Gap dam."
Mr Burkitt said the group plans on holding another forum in Cowra in the coming months.
"Local support from central west towns plays a key role in our campaign and we could not be where we are today without it," Mr Burkitt said.