Backfilling would not make sense, the amount of aggregate which is extracted from pits for the construction industry and roads gets used up, where would the material come from on a general pit/quarry basis.
EVG would have leech heaps, but they are a designed creature, best to not disturb it, but to cover it at the end of the day.
Re-vegetation with local flora is normally what is done for rehab.
The kicker for the state would be the royalty fees they would receive from a large development. I don't think any State would say not to royalty monies and the taxes that a primary industry (and its suppliers, contractors and workers) would bring.
greater value to the state then a couple of cattle.
JMHO
remain positive.
g.d.