In former mining community Cwmtillery, Blaenau Gwent, an apparent landslip left buildings deep in sludge and mud as water poured down what appeared to be a street.
Some homes were evacuated as a result, with resident Wayne Green saying he was looked after in a leisure centre until accommodation was found at about 01:30 GMT.
Firefighters had to evacuate a family from their home near Wrexham after a tree crashed through the wall of the house due to floodwater.
Trevor Baters from Llansantffraid Glyn Ceiriog Community Council said it was “devastating to see”.
First Minister Eluned Morgan said talks were under way for possible emergency funding.
“The severity and frequency of these events is something we all need to be aware of,” she said, adding “hundreds of millions of pounds have been put into flood defences in Wales over the past few years,” she said.
Bryant said people in his constituency, which includes Pontypridd, were “utterly miserable” and added he did not understand why a more significant alert was not put in place on Saturday evening.
It came after council leader Morgan said he was “surprised” a red warning was not in place for Storm Bert.
“During Storm Dennis we did see an amber warning well in advance, and a red warning issued in the early hours,” he said.
He also said between 200 and 300 properties were affected, with the rainfall surpassing some records set by Storm Dennis in 2020.
He added one bridge that was under construction, and which was replaced after Storm Dennis, was completely washed away.
