Authorities in Townsville, Australia, have warned residents to beware of crocodiles and snakes spotted in floodwaters in residential areas.
More than 1,100 people have been evacuated from the town amid a "once-in-a-century" flood.
Up to 20,000 homes are at risk of being inundated.
Much of the city of Townsville in Queensland state is flooded, with residents left without power and some compelled to seek safety on the roofs of their homes, according to CNN affiliate 7 News.
Intense rain on Sunday forced authorities to open the floodgates on the Ross River Dam to relieve pressure and prevent a collapse, releasing around 1,900 cubic meters of water per second downriver. The dam was holding 224 percent of its capacity Monday afternoon, according to CNN affiliate 9 News, after peaking Sunday night at 247 percent.
The Queensland Bureau of Meteorology has warned of "dangerous and high-velocity flows" in the Ross River over Sunday night and Monday and of "unprecedented areas of flooding" in Townsville." Access routes may be cut off, it added.
The massive downpours hitting Townsville come as Australia is reeling from a record-breaking heat wave that affected all eight of the country's states and territories.