Heavy rain has caused river levels to rise sharply in Nelson, with one flash flood sweeping away two cars where a group of people were camping.

Heavy rain has been falling in the region and a police spokesman said they received reports from people camping under the Appleby Bridge along the Appleby Highway.

He said while there were initial reports that one person was missing, he has since been found and is uninjured.

The Nelson City Council said while rain is expected to ease across the region this afternoon, it will be on alert until river levels return to normal.

Heavy rain hitting the area has caused moderate surface flooding in the city, with one road closed so far.

But Council spokesman Shane Davies said the worst of it should now be over.

“We understand that the rain is easing, but often heavy rain in the river catchments can take a while to reach the lower parts of the river.

“We’ll be keeping a close watch on things until the river levels have subsided.”