Myall Broadwater is located on the mid-north coast of New South Wales. It is classed as a lake which has an entrance permanently connecting it to the sea via the Myall River and Port Stephens.
Myall Broadwater receives water flowing downstream from the Myall River. A separate channel that connects it to the larger Myall Lake. Tidal influence extends up the Myall River from Port Stephens in the south.