It’s more about the interaction of warmer temperatures, wildfire, and subsequent debris flow into water supply:

The periods of heavy rain that followed the fires assisted vegetation recovery but also triggered soil erosion and landslips, the report says. There was an “increased likelihood of compounding effects of extreme rainfall following significant fire seasons due to climate change”, the report concluded.

“Climate change is predicted to drive more frequent and extreme natural disasters in coming years.

“This will threaten the resilience or capacity of the catchment to maintain essential ecosystem services such as the provision of adequate, good quality source water.”