St Mary's Inlet

	St Mary's Inlet at a glance
	Inlet length:		One kilometre
	Inlet width:		250 metres
	Data selection

      


Saint Mary Inlet is the smallest of the four estuaries of the Fitzgerald National Park with lagoon barley one kilometre long and 250 metres wide. The riverine part and the inlet channel are each about 700 metres long. The estuary lies east - west in a valley between the spongolite on the south and quartzite and coastal limestone on the northern shore. The mouth opens onto the beach at the southern end of the seven kilometres long Point Charles Bay.

Saint Mary River flows to the inlet in a steep rocky valley with several pools, the last nearly one kilometre long, and discharge to the inlet through a densely vegetated swamp. Small tributary creeks also flow direct to the northern rocky shore of the inlet. The southern shore of the lagoon has narrow sand flats with samphire and other marsh plants backed by paperbark tree against the hill slope.

The sand bar is part of the beach and is only about 1.5 metres above sea level. Waves wash over it and carry sand into the channel shallowing it for about 200 metres from the dune line. The estuary is shallow throughout with the lagoon floor being around sea level. Consequently the lagoon often dries out in the summer months, leaving only a small amount of water in the channel.

Further Information:

South Coast Regional Land and Water Care Strategy: The Fitzgerald-Biosphere Sub-region. Prepared by the South Coast Regional Assessment Panel and the South Coast Regional Initiative Planning Team March 1997.