The Bureau of Meteorology has extended this week's strong wind and a hazardous surf warnings for the Far South Coast into Thursday, with surf and swell conditions expected to be hazardous for coastal activities such as rock fishing, boating, and swimming.

Beach conditions in these areas could be dangerous and people should stay well away from the surf and surf exposed areas, the NSW State Emergency Service said.

Surf conditions are expected to gradually ease from Thursday, they said.

NSW SES volunteers from Bega, Eden and Bermagui have been busy dealing with leaking homes and clearing falling trees.

Water from the Brogo Dam is flowing down the spill way and into the Brogo River due to the week's heavy rain, and according to Water NSW the dam currently sits at 106.5 per cent full.

Flow from the river into the Bega River forced a road closure at the river mouth at Mogareeka on Wednesday.