This site features several watercourses and wetlands, many of which are permanently inundated. It includes two main flow components—the Upper Pike River and Mundic Creek area, and the Lower Pike River and Rumpagunyah Creek—and extends from the Col Col embankment to the downstream confluence of the Murray River and the Pike River.

Water enters the system continuously from Lock 5 via two modified channels, first filling Mundic Creek and then flowing to the Upper Pike River. The Upper Pike River diverges to join the Murray River and the Lower Pike River. At elevated river levels, water spreads into low-lying wetlands and woodland areas adjacent to Mundic Creek, Tanyaca Creek and the Murray River.

The aquatic habitats of the Pike-Mundic Wetland Complex are diverse, ranging from permanent fast-flowing anabranches, to slightly brackish, slow-flowing anabranches, backwaters and temporary billabongs. It has been divided into eight ecological assets; flowing watercourses, permanent wetlands, temporary wetlands, red gum woodlands, lignum shrublands, chenopod shrublands/grasslands, black box woodlands and dunes. The assets each correspond to a different hydrological regime, and together they comprise all of the terrestrial and aquatic habitats present in the ecosystem.

Ecological values to be protected

This site provides a diverse range of aquatic and floodplain habitats that support populations of diverse flora and fauna, including rare, endangered and nationally threatened species.
Several species found on these floodplains are listed as threatened or vulnerable under the Environment Protection and Biodiversity Conservation Act 1999, including the southern bell frog (Litoria raniformis), malleefowl (Leipoa ocellata), Murray cod (Maccullochella peelii peelii) and regent parrot (Polytelis anthopeplus). The site also includes 21 state-listed animals, 17 state-listed plant species, and provides likely habitat for Murray hardyhead (Craterocephalus fluviatilis).

The site supports a number of distinct vegetation communities, depending on the inundation frequency. These communities range from the relatively frequently inundated areas nearest to the main Murray River channel (with extensive reed beds and relatively healthy red gum woodland communities), through to black box woodland, then lignum and chenopod shrublands as flooding frequency declines on the floodplain fringes. These communities provide resources and habitat for macropods, waterbirds, hollow-dwelling bats, mammals, frogs and reptiles, as well as species of aquatic macroinvertebrates, zooplankton and fish.

Despite its isolation from the Murray River by a series of barriers, Mundic Creek provides a deep, permanent water body that supports a diverse fish population and a healthy macroinvertebrate community. This area also provides significant feeding and breeding habitat for waterbirds, fish and other fauna. In particular, waterbirds seek refuge from the drought on many of these permanent wetlands, and the ephemeral wetlands are used for breeding in times of flood.

Many of the habitat features of this floodplain have been degraded elsewhere, and the protection of this system would preserve an important complex of interrelated habitats at a single location.

Key threats

The key threats include increased floodplain sedimentation and water salinity, lack of native fish passage, grazing by stock, kangaroos and pest animals (particularly carp). Eligible actions to address key threats:

  • Pest animal control
  • Incorporation of carp screens or traps in wetland regulators.
  • Weed control
  • Habitat restoration
  • Establishment of new plantings, improved management and streambank protection
  • Revegetation in degraded areas, especially riparian zones
  • Stabilisation of the riverbed and banks to improve native fish passage for locally endemic species.

Management

The majority of the floodplain is owned by the Crown through the South Australian Minister for Environment and Conservation, with a significant portion under annual lease to private operators. The remainder of the site is conservation reserves (including Pike River Conservation Park) and land owned by the National Trust of South Australia. There are also small parcels of private freehold property.

An agreed management plan for the Pike River was developed through consultation with irrigators, graziers and government agencies. This plan presents an integrated approach, with many of the actions addressing multiple issues and providing multiple social, environmental and economic outcomes. Through the Pike River Land Management Group and the Renmark to the Border Local Action Planning Association, the community continues to play an integral role in developing and implementing the Pike Implementation Plan.

Agreed management plans and strategies in place include: