Aldinga Washpool and Blue Lagoon
A special place
Aldinga Washpool is one of the last remaining coastal freshwater and estuarine lagoon systems along the Adelaide metropolitan coast. It provides environmental open space for the local community and important habitat for waterbirds.
The Kaurna People are the Traditional Owners of the Washpool and surrounds. To the Kaurna community, the Washpool is a place of cultural and spiritual significance and a place where Kaurna, and other Aboriginal groups, have gathered for thousands of years.
The Washpool area is a living landscape that Kaurna people still have a deep connection with despite the effects of colonisation. The Washpool is still visited by the living Kaurna today as a place of spiritual and cultural significance as it was to their ancestors for tens of thousands of years.
The lagoon is a seasonal wetland, meaning it fills up with water during winter and dries up in November/December. It is listed in the Directory of Important Wetlands in Australia as a good example of this wetland type within the bioregion.
The Washpool includes a threatened temperate coastal saltmarsh, nationally listed as a vulnerable, threatened ecological community under the Environmental Protection and Biodiversity Conservation Act 1999.
Plants and animals
There are two main wetland areas, the Blue Lagoon in the north, which supports an area of Lignum shrubland, and the much larger Washpool lagoon, which supports samphire and sedgeland habitats. Along the coast the area is dominated by low coastal shrublands and sand dune habitats, and cobble banks along the upper beach.
Over 80 species of native plant can be found at the Washpool, including 20 plant species listed as rare, vulnerable or endangered at a regional level. These include the regionally vulnerable Salt Angianthus (Angianthus preissianus), Annual Celery (Apium annuum), Lignum (Duma florulenta), Thatching Grass (Gahnia filum) and Rough Raspwort (Haloragis aspera).
As the lagoon fills, aquatic plants and a range of aquatic invertebrates can be found, which in turn attract many waterbirds to feed in the lagoon. The board has undertaken a number of macroinvertebrate surveys to better understand water quality and waterbird prey availability.
When full a number of frog species can be found, but the brackish water limits the amount of frog habitat. There is limited information on reptiles species found in the lagoon, but a number of lizards and snakes species are found in the area.
Fish like the common Galaxias (Galaxias maculates), which is can move between fresh and salt water), can also be found here.
Up 100 species of birds have been recorded in the Washpool area, though their abundance is related to the amount of water in the lagoon.
The site is valuable habitat for many waterbirds species, including migratory shorebirds such as sharp-tailed sandpipers and red-necked stints. Pied Stilt nest in the lagoon area as the water level recedes, the board has established a pied stilt monitoring project with BirdLife Australia and volunteers to learn more about this and other species in the lagoon, and their possible water requirements.
Hooded Plovers may also nest on the beach during spring and summer, so take care to leash dogs especially when these birds are nesting.
Before you go, see what bird species you might find in the Washpool:
Significant threats in the Washpool include:
- the impact of weeds on native vegetation
- historic grazing and cropping practices
- changes to hydrology and flows
- land use change.
A management and action plan for the Washpool was developed by the City of Onkaparinga that included actions to address the above threats.
Know before you go
The Washpool area is of significant spiritual and cultural significance to the Kaurna people and is a reported site under the Aboriginal Heritage Act 1988. Disturbing Aboriginal sites may cause distress and offence to Aboriginal people and damaging, disturbing or interfering with Aboriginal sites and objects, is an offence under the Act.
The Washpool is an important wildlife habitat. Please keep dogs leashed to reduce impacts on native wildlife and other visitors.
Local council by-laws prohibit the use of off-road vehicles in areas such as the Washpool.
The Washpool contains significant native vegetated areas and extensive revegetation is also underway. Under council by-laws, horses are not permitted within 10 metres of dunes or vegetated areas or pebble banks. The City of Onkaparinga has a large network of alternative dedicated horse riding trails, and horse-riding is permitted on a number of beaches subject to conditions.
Managing the Washpool
The Aldinga Washpool consists of land parcels owned by different government bodies including SA Water; Department of Planning, Transport and Infrastructure; Department for Environment and Water; Crown Lands; and the City of Onkaparinga.
Natural Resources Adelaide and Mount Lofty Ranges has been working with the City of Onkaparinga in the Washpool and adjacent coastal habitat areas since 2008, with funding from the Adelaide and Mount Lofty Ranges Natural Resources Management Board’s NRM levy. The Coast Protection Board has also invested in on-ground works, with the Department of Planning, Transport and Infrastructure and SA Water also contributing to conservation work in the Washpool.
To better coordinate revegetation efforts, seasonal vegetation surveys have been conducted, and a five year Aldinga Washpool and Blue Lagoon Revegetation Plan developed. These help guide pest plant control and significant revegetation works that will restore and maintain the health of the site.
Additional consultation and an on-site cultural survey has been undertaken to inform revegetation works and provide Kaurna with updated, consolidated documentation of cultural heritage values of the Aldinga Washpool.
More information on the board’s Aboriginal Partnerships.
Natural Resources AMLR supported local community groups to hold an Aldinga Washpool Community Forum and establish a website to inform and promote the environmental and ecological values of the Aldinga Washpool wetland to the local community.
The Aldinga Washpool and Silver Sands Heritage group, in association with the Friends of Aldinga Scrub and Friends of Willunga Basin website contains many additional resources about the Washpool including this brochure.
Willunga Environment Centre.
Natural Resources AMLR, in partnership with the City of Onkaparinga, is coordinating revegetation efforts across the different land tenures in the Washpool.
SA Water, Department of Planning, Transport and Infrastructure; Department for Environment and Water; Crown Lands; City of Onkaparinga; Aldinga Washpool and Silver Sands Heritage group; Friends of Aldinga Scrub; Friends of Willunga Basin; Kaurna Nation Cultural Heritage Association Inc.