The State of Health of the 4. Ranges Catchments from a perspective

Water quantity issues in the

Water quantity issues Rain that falls within the During floods the in the Mount Lofty catchments is stored in seven provide a buffer, thereby Ranges Watershed major reservoirs across the ranges. reducing the impacts of flood Gauging stations are used to downstream. With each flood, Many things impact on stream determine the volumes of water more and nutrients flow in the Mount Lofty Ranges, that reach the reservoirs and how reach the reservoirs, affecting including: much is being diverted, via pipes, water quality. •extensive farm to other areas. development throughout the catchments

• and mitigation works

•water transfers (water from the River Murray to pipeline)

•industrial and agricultural landuses

• (towns, rural settlements, freeway runoff)

•release of treated effluent from the Hahndorf, Heathfield, Meadows, Birdwood, and Bird in Hand wastewater treatment plants The first discharge from the River Murray-Onkaparinga pipeline near Hahndorf occurred •extensive land clearance since in 1974. Water pumped from the River Murray is released into the settlement. when Adelaide’s demand for water exceeds what is available at . A similar pipeline supplies the reservoirs of the (EPA). When land is cleared of native vegetation, less water infiltrates the soil and runoff and increases. Current improvements: •Surveys are being undertaken to determine the number and size of farm in the watershed. •Farm dam regulations will be reviewed. •Conditions of approval will be enforced.

A farm dam in the upper reaches of the Onkaparinga catchment with fences used to exclude livestock (EPA).

Farm Dams This altered flow regime has affected the ecological Farm dams hold water that would sustainability of the riverine and otherwise flow into the associated aquatic ecosystems, to feed reservoirs. We do not know such as floodplains, how many farm dams there are in and estuaries. the Mount Lofty Ranges, but there are over 600 dams (mostly holding The environment is a valid up to 5 megalitres) in the Marne user of water resources. Flows River catchment alone. Most dams must be managed to maintain are found high in the catchment aquatic and riparian diversity where rainfall is greatest and, if and health. Low stream flow they are large enough, they can reduces the ability of the system prevent water from flowing to flush out pollutants, thereby downstream or recharging intensifying their adverse effects aquifers. on aquatic environments and water supplies. These dams have substantially altered the flow regimes of waterways and severely limited Size Class Percentage Volume (ML) our ability to calculate the <0.5 ML 25 38.5 0.5–2 ML 53 312.7 amount of water available for 2–5 ML 13 227.9 sustainable use. 5–10 ML 3 154.8 Water extractions from farm 10–20 ML 2 192.9 20–50 ML 2 416.2 dams, pumping for livestock and > 50 ML 2 816.3 domestic use, , and Total 100 2159.4 inputs from the River Murray Percentage of farm dams by their size and pipelines have all modified their total holding capacity within the catchment hydrology, so that Marne River catchment (source: EPA). winter flows have been generally CANON reduced and summer flows AT LY ME D TH AN IM increased. AN PRO IN TH The differences in vegetation cover in these two streams are very distinct. The stream on the right flows past rapidly eroding banks, which increases turbidity. The stream below has a stable bank and clear water. (EPA)

The Cox Creek ‘v-weir’ gauging station within the Onkaparinga catchment (EPA). Note the highly turbid water from recent irrigation water runoff from the Piccadilly market gardens.

OV ED WATER QUALITY .. E M ES. OUNT LOFTY RANG Vineyards– a growing landuse type in the Mount Lofty Ranges (EPA).

The Mount Lofty The Mount Lofty Ranges need The EPA’s Mount Lofty Ranges Watershed a programme of onground work, Ranges Watershed Protection Protection Office clearly defined management Office will be working in close structures and responsibilities, collaboration with landholders The Environment Protection strong planning controls, and other organisations– Agency, operating under the accountability, and an catchment water management Environment Protection Act 1993, enforceable legislative boards, the Mount Lofty and in partnership with other State framework to protect and Ranges Catchment and local government agencies and improve water quality in the Programme, local government, community organisations, will catchments. soil boards, Landcare groups, coordinate a five-year strategy to and other State Government address pollution impacts in the agencies–to provide natural Mount Lofty Ranges watershed. resource management support, technical advice, education for local action planning groups, and on-ground land and watercourse management projects.

Contact the Mount Lofty Ranges Watershed Protection Office at: Telephone 1300 134 810 Suite 2, 85 Mount Barker Road, Stirling, South 5152 Check out the EPA website: www.environment.sa.gov.au/epa/water