Lake Richmond

Coordinates: 32°17′10″S 115°42′54″E / 32.286°S 115.715°E / -32.286; 115.715 Lake Richmond is a freshwater lake in Rockingham, Western Australia. It is approximately 1,000 m × 600 m (3,300 ft × 2,000 ft), with an area of 40 ha (99 acres), and is 15 m (49 ft) deep in the centre. It is believed to be named after the London borough.[1]

The lake is less than 1 km (0.62 mi) from the coast,[2] having separated from the ocean at Cockburn Sound within the last 4,000 years.[3][1]

The shallow waters within about 15 metres (49 ft)[3][1] of the edges of the lake are home to thrombolites, estimated to be about six million years old.[2][4] The internal structure of the thrombolites is believed to be unique in the world.[3][1]

Before 1960, the lake's salinity was 2000–3500 mg/L.[lower-alpha 1] In the 1960s it was used as part of an urban drainage scheme; the Water Board constructed inlet and outlet drains. Subsequently the salinity level dropped to 300–400 mg/L.[5][1]

A boardwalk extends approximately 115 m (377 ft)[6] into the lake.[2][4]

Water birds that inhabit the area include the Australian pelican, black swan, Australian shelduck, musk duck, white-faced heron and common greenshank.[4] The lake is home to the Swan River goby (Psuedogobius olorum), eastern mosquitofish, sea mullet, goldfish and yabbies.[5][7]

The lake was used as a source of fresh water by the local indigenous Noongar people, as well as the settlers of the Swan River Colony.[2][1]

The 10th Light Horse Regiment had a camp near the lake during the war years.[1]

In 2017, the lake was given a permanent entry on the State Register of Heritage Places.[8] It also listed on the WA Register of Aboriginal Sites, as RAS #15974.[1]

Notes

  1. ↑ less than 10% of seawater, which is typically around 35,000 mg/L

References

  1. 1 2 3 4 5 6 7 8 Register of Heritage Places Assessment Documentation: Lake Richmond, Rockingham, Heritage Council of Western Australia, 2017-06-30, retrieved 2017-08-16
  2. 1 2 3 4 "Lake Richmond's multi-million-year history can be found just beneath the surface". Australian Broadcasting Corporation. 2017-08-15. Retrieved 2017-08-16.
  3. 1 2 3 "Thrombolite (microbial) community of coastal freshwater lakes of the Swan Coastal Plain (Lake Richmond)". Commonwealth of Australia, Department of the Environment and Energy. Retrieved 2017-08-16.
  4. 1 2 3 Lake Richmond, Parks and Wildlife Service, Western Australia, retrieved 2017-08-16
  5. 1 2 Lack Richmond Management Plan 2008 : Final (PDF), Ecoscape (Australia) Pty Ltd, 2008, retrieved 2017-08-20
  6. ↑ Measured on Google Maps' satellite view, 2017-08-16
  7. ↑ Lake Richmond Fish Survey (PDF), Murdoch University, 2004-07-22, retrieved 2017-08-16
  8. ↑ "Lake Richmond". InHerit. Heritage Council of Western Australia. Retrieved 2017-08-16.
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