Nornalup Inlet is an estuarine body of water on the south coast of the South West

Southwest Australia

Southwest Australia is a biodiversity hotspot that includes the Mediterranean forests, woodlands, and scrub ecoregions of Western Australia. The region has a wet-winter, dry-summer Mediterranean climate, one of five such regions in the world...

 of Australia, approximately 450 km (279.6 mi) from Perth

Perth, Western Australia

Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....

.

It is approximately 1300 ha (3,212.4 acre) in extent, and up to 5 m (16.4 ft) deep. It is fed by the Deep

Deep River (Western Australia)

Deep River is a river located in the Great Southern region of Western Australia.The river is under tidal influence for the last of its length.Although generally shallow the Deep River has depths of up to in places....

 and Frankland River

Frankland River

The Frankland River is a river in the great southern region of Western Australia. The Frankland River is the largest river by volume in the region and the eighth largest in the state....

s, and communicates with the Walpole Inlet via a natural channel approximately 1 km (0.621372736649807 mi) long and 2 m (6.6 ft) deep.

The name is Noongar

Noongar

The Noongar are an indigenous Australian people who live in the south-west corner of Western Australia from Geraldton on the west coast to Esperance on the south coast...

 in origin, meaning "the place of the tiger snake (Notechis scutatus)".

The esutary is wave dominated and is mostly not modified but the catchment

Drainage basin

A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 has been substantially cleared. The inlets have a naturally low turbidity

Turbidity

Turbidity is the cloudiness or haziness of a fluid caused by individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality....

 but have a high sediment trapping efficiency. The inlets have a total area of 15.8 km² (6.1 sq mi), most of the area being found in the central basin. The inlet has a mean depth of 2 m (6.6 ft).

The Walpole/Nornalup inlet system is the only permanently open estuarine system in the South West, giving it great biological diversity.
Remains of Aboriginal

Indigenous Australians

Indigenous Australians are the original inhabitants of the Australian continent and nearby islands. The Aboriginal Indigenous Australians migrated from the Indian continent around 75,000 to 100,000 years ago....

 rock fish traps can still be found in the inlets. The main sea grasses found in the inlet are Ruppia megacarpa and Heterozostera tasmanica.

Capt. Thomas Bannister

Thomas Bannister

Thomas Bannister was a soldier and explorer in Western Australia. He was born in Steyning, Sussex in 1799, and arrived in Western Australia in 1829, age 30, with the rank of Captain aboard the Atwick with 3 servants from London, England...

and his party visited the inlet in 1831, although sealers had been based in the area since before 1826.

Both estuaries, with the tidal parts of the tributary rivers, are now the subject of a proposed marine park.