Water considerations

The water resources of Kangaroo Island, including surface water and groundwater components, can be divided into six major drainage zones with more than 50 subcatchment areas. Surface water in streams and lagoons in the higher rainfall western part of the Island is usually fresh and plentiful in winter but confined to semi-permanent creeks and waterholes during the summer months when it becomes increasingly saline until flushed out by early winter rainfall. In the lower rainfall eastern end of the Island, surface waters are saline all year round.

Around 30% of the Island has been subject to significant farm dam development that is affecting downstream flow regimes and downstream users. Plantation forestry will lead to reductions in streamflow especially in drier years. In addition, native vegetation clearance in the upper catchments of many streams has increased saline seepage, flooding and significant in-stream erosion.

The socioeconomic values of the Island’s water resources can be classified into recreational, aesthetic, public water supply and industry. The numerous rivers, wetlands and estuaries are an essential part of the character of the Island, and provide recreational and aesthetic opportunities for residents and visitors.

SA Water provides the major public water supply from Middle River Reservoir. This delivers on average 550 ML/yr to around 75% of the Island’s population, in Parndana, Brownlow and Kingscote. Poor water quality has been an issue in the past but a major upgrade in 2007 to the water treatment plant has alleviated the problem. A reliable public water supply is fundamental to the community, and for industry including tourism. Livestock based agriculture is the largest proportion of the Island’s gross regional product and almost entirely dependent on surface water. Irrigation enterprises are still relatively small scale but there is a growing area of viticulture. Inland aquaculture is a small user of water.

Groundwater is generally saline (> 2000 mg/L) and wells are very low yielding (< 1 L/s). There are limited and localised areas where fresh groundwater lenses occur. Groundwater does have an important environmental role in providing stream baseflow during summer/autumn, which maintains aquatic habitat for obligate aquatic biota.

(Source- Kangaroo Island NRM Board)

Key external links for further information

Link icon Kangaroo Island NRM Board - Water management

Link icon Kangaroo Island NRM Board - Water affecting activity permits

Link icon Department for Water - Water licences and permits