And the river kept rising ...

Floodwaters are rising so rapidly at Rockhampton that emergency services are having trouble filling sandbags fast enough.

Rockhampton Mayor Brad Carter told reporters that able-bodied volunteers were urgently needed to fill 2000 sandbags.

The Fitzroy River is at 8.8m and expected to hit 9m today.

When the river reaches 9m, 200 homes will be inundated and 4000 parcels of land affected by flooding.

Authorities estimate 40 per cent of the city could be affected by a 9.4m peak and 400 homes waterlogged.

Carter said the city was now cut off from the south and east and water had started lapping the highway to Mackay to the north at Yaamba.

The Rockhampton Airport was closed to domestic flights at noon on Saturday and could be out of action for up to three weeks.

Emergency helicopters are still able to land at the airport.

- AAP