TENNYSON DUNES GROUP

Coastal Significance

Coastal Significance

Dune Importance

These dunes now preserve the only example of the coastal dunes system that once lined and protected the Adelaide metropolitan coastline.

  • These dunes have been described as the largest in height that occurred along the coast.
  • The dunes are a major open space for the Adelaide Plains.
  • Recent plant survey indicates sixteen plants are of conservation status for the Southern Lofty Region and several other plants once common along the coast are now only surviving in these dunes.
  • Unlike other Adelaide dune systems these are probably centuries old.
  • In no other Adelaide dune system do you see zones of vegetation parallel to the coast. To see a succession of plants that occur from the back of the beach, inland, to the rear dunes is unique.
  • They also display a number of floristic groups, which is also unique for the metropolitan coastline and are typical of dunes in southern Australia.

Physical Description

Landform

These are a transverse dune system with well-preserved parallel dune ridges with the highest at 14 metres. The foredune has been heavily scarped and is 2 to 3 metres above the beach. The hind dunes are separated by broad swales (or interdune depressions). Landforms here include foredune, hind dunes, swales, crests, and landward and seaward slopes.

Beach Type: Intermediate to dissipative

Geomorphology

The coast is low to medium energy. Multiple ridges have developed as a result of shoreline progradation being dependent on an offshore sand supply reaching the beach. This building has stopped and the beach is stable to slightly erosional. Ongoing sea level rise and land subsidence in Adelaide contribute to the erosion.

Slope

Dune slopes vary from 6 to 12 degrees.

Soils

Soils are predominantly fine siliceous (quartz) sand with minor carbonate (shell) content (approx. 10%). No pedogenic development and only shallow organic staining in rear dunes. (Erodable without vegetation cover).

Climate

Cool temperate, Mediterranean, winter rainfall, warm to hot summers and cool winters.

The annual temperature maximum is 22.0 C and minimum is 12.1 C. Temperature maximum is 44 C and minimum is -0.4 C. Days over 30 C is 52.2 and over 35 C is 17.6. Average annual rainfall is 533 mm with 120 rainy days that is 32% of the year. Wind is generally on-shore which is the prevailing south-westerly.

Australian Map Grid

Easting: 269850

Northing: 6137300

Cadastre: Hundred of Yatala

Land Owner: A number of Crown ownerships

  • Lot 3 P/S 951, CT 5775/247 – Freehold title by CPB
  • Lot 4 P/S 951, CT 5779/83 – Unalloted Crown Land
  • Lot 4 P/S 951, CT 5761/677 – Unalloted Crown Land
  • Lot 602 P/S 105, CR 5752/720 – Crown record dedicated to the CPB
  • Lot 11 P/S 105, CT 5413/942 – Unalloted Crown Land
  • Lot 41 DP 21017, CT 5538/198 – City of Charles Sturt
  • Lot 32 FP 9708, CT 5481/32 – Freehold title by CPB
  • Lot 10 DP 27747, CT 5421/843 – Unalloted Crown Land

Site area: Approximately 22 hectares

Distance from city: 12 kilometres

Local Government District: City of Charles Sturt