High on the list of concerns is the threat of long wall and open cut mining causing catastrophic damage to vital groundwater aquifers.
Landholders reiterated their long-standing call for an independent study into the impact mining would have on the catchment and wider Murray-Darling Basin.
Caroona Coal Action Group president, Spring Ridge farmer, Doug Ranken, led the call for an independent inquiry.
Adding their support were federal Independent Member for New England, Tony Windsor, Greens MLC, Lee Rhiannon, Nationals MLC, Trevor Khan, and Constitutional Property Rights Association member, Bevan Oâ€™Regan, of Narrabri.
Mr Windsor told the rally the mining industry didnâ€™t want an independent study into the impact of mining on groundwater systems because it knew there was no guarantee there would be no long-term damage.
â€œIf you have a hydrological system and you cut across it, what impact does that have hundreds of kilometres away? We donâ€™t know; there is nowhere in the world where that information is available.â€
Mr Windsor said the ground-swell of support for the landholdersâ€™ cause and the large turnout at the rally were a turning point in the debate.
â€œI have absolutely no doubt you will win this based on the sustainability issue, the stupidity of trying to mine in these sorts of systems and the impact it will have on the whole Murray-Darling Basin,â€ he said.