Douglas Park Causeway is temporarily closed due to a road hazard this afternoon.
A tree has fallen across the causeway, leading to the road being blocked in both directions.
A Wollondilly Council spokeswoman said a council crew is on the way to the scene.
The incident was caused by strong winds this afternoon.
Weatherzone has reported that winds have reached up to 45km/h across some parts of Macarthur.
Advertiser reader Carina Perry said she had tried to drive across the causeway in the past hour, but was forced to do a U-turn.
Ms Perry said motorists could use either the Menangle or Picton roads as diversions.