Koalas don’t drink water
Historically koalas got much if not all the water they needed from gum leaves however the loss of higher quality habitat and lower water content in the ground (and thus leaves) has led to koalas needing to supplement this (hence koalas drinking from pools, dams, creeks, gutters etc).
IMPORTANT fact: PLEASE DO NOT GIVE KOALAS WATER FROM A BOTTLE. The safest way to provide a thirsty koala with drinking water is via a bowl, cup, helmet or hat from which they can lap. We’ve all seen videos of well-meaning people giving koalas water from a bottle however they risk forcing water into their lungs and developing aspiration pneumonia!