NSW SES crews saw the animal jump across the Lachlan River in Forbes earlier today.
9Reporter Hayley Francis said the wallaby took more than 40 minutes to swim across the river.
She said the SES crews had done routine checks and a reconnaissance mission on the river.
It comes when Forbes was hit by slow flood waters with the peak yet to come.
The SES patrolled the flooded Lachlan River, but while floodwaters crept into a number of houses in Forbes, damage to city property has so far been minor.