High river levels have caused surface flooding in Southland after heavy rainfall throughout the region on Saturday.
State Highway 90 between Waikoikoi and Tapanui is closed until further notice.
Some roads around Gore are also affected: MacGibbon Road between Millane Road and State Highway One is closed, as is Woolwich Street between Huron Street and Boundary Road.
River Street between Hyde and Salford Streets remains open, but the Automobile Association says extreme care is required.
McGregor Road at Waikaka is also closed, as is Pyramid Waiparu Road at Otama.
They are not expected to reopen until late Sunday night.