Close the town down. 
This will not end. 
The shortsighted people who founded the town, built on a flood plain
Offer to relocate everyone.
Want to stay.
🤷‍♀️  

Grok
Yes, the city of Lismore, located in the Northern Rivers region of New South Wales, Australia, is indeed built on a floodplain. 
Lismore sits at the confluence of the Wilsons River and Leycester Creek, both tributaries of the Richmond River, in a low-lying area prone to flooding. 
This geographical position has historically made it one of the most flood-prone urban centers in Australia outside of tropical zones.