The dam reduced the amount of silt and water coming down from the waterfall into the gorge by 90 percent. This led to the spray toad's microhabitat being compromised, as it reduced the amount of water spray, which the toads were directly reliant on for oxygen.
A significant reduction in silt and water flow into the gorge occurred due to the dam, resulting in a compromised microhabitat for the spray toad. The decrease in water spray, essential for the toads' survival, was a direct consequence of this change.