The health of the River Murray is critical to the current and future wellbeing of South Australia. The Murray provides Adelaide with 50% (past 5-year average) of its drinking water and depending on rainfall, and storage in the Western Mount Lofty Ranges, this figure can range from 10–80%. Drinking water is also piped south to Keith and west to the Eyre Peninsula. The river also supports diverse aquatic ecosystems, including RAMSAR wetlands, provides much of the state's irrigation and stock water, and is used for swimming, water skiing and other recreation activities.
Managing water quality
The main water quality problem in the River Murray relates to water management and the need to maintain sufficient water levels in the main channel to limit saline inflows upstream and problems associated with Lower Murray Irrigated Reclaimed Area (LMRIA) discharges in the lower weir pool (downstream of Mannum).
The Millennium Drought highlighted that low river levels will exacerbate water quality risks in terms of some metal exceedences of drinking water standards. Modelling and water quality testing undertaken by the EPA and Department for Environment and Water (DEW) indicated plumes of saline, low pH, metal laden turbid water leaving LMRIA drains into the River Murray and eventually dissipating through dilution within the main channel. The Murray–Darling Basin Authority, DEW, SA Water and EPA have been monitoring these water quality risks since the Millennium Drought and will continue to do so on an ongoing basis.
Other sources of pollution of concern to the EPA include:
- septic leakage from housing adjacent to the river and floodplain areas
- contaminated stormwater runoff from developed land areas
- sand dumping from creating beaches (often associated with vegetation removal)
- managing black and grey water from vessels
The EPA is working closely with stakeholders including industry bodies to ensure that they follow the Environment Protection Act 1993 and associated policies and codes of practice relating to the listed activities.
This legislation ensures that a person or persons must follow their general environmental duty by taking all reasonable and practicable measures to prevent or minimise environmental harm from undertaking an activity that pollutes or might pollute waters. Investigations and compliance measures are invariably undertaken by the EPA when apparent pollution issues arise or whenever the general environment duty is not followed by industries or individuals.
The EPA provides advice and recommendations in response to various development applications (DAs) that are submitted to local government from water protection areas, including the River Murray, Lower Lakes and the Coorong region. Any advice provided is intended to ensure that best practices are met and that pollution risks to the River Murray are avoided or mitigated from different types of development that may affect waters.
The Environment Protection (Water Quality) Policy 2015 (Water Quality Policy) was implemented to facilitate best environmental management practices for the benefit of current and future generations. Regulation of this policy includes River Murray issues such as the management of polluted stormwater, septics runoff, wastewater management for vessels and sand dumping.
River banks and sand dumping
Sand dumping is the practice of dumping beach or other sand on a river bank to create an artificial beach or embankment. Sand is often dumped when unstable mud or rocks on the river bank are exposed.
Unfortunately sand dumping can harm the environment and create safety hazards (eg riverbank collapse). There are alternative methods for stabilising your river bank that are far less harmful and dangerous.
Dumping sand is illegal and very harmful while the river is low. Depositing sand into the riverbed contravenes Section 34(2) of the Environment Protection Act 1993, in this instance through a breach of Clause 11 of the Water Quality Policy), which states:
A person must not discharge a class 2 pollutant into any waters.
Soil, clay, gravel and sand are class 2 pollutants listed under Schedule 3 of the policy. Also, according to clause 3(2), the discharge of waste or a pollutant into a watercourse that is temporarily dry will be regarded as the discharge of the waste or pollutant into waters.
Similarly, dumping sand into the river is also a breach under the River Murray Act 2004.
Where sand is found to be causing a problem, the owner may be asked to remove the sand and deposit it in a place from which it is unlikely to enter any waters (including by processes such as seepage or infiltration, or carriage by wind, rain or stormwater). Penalties may also apply, such as an expiation notice or an environment protection order.
In extreme cases, where pollution of the River Murray is regarded as intentional or reckless, penalties of up to $30,000 for an individual and $120,000 for a company may apply.
Methods to stabilise river banks
Alternative methods for stabilising your river bank that are far less harmful and dangerous.
Geotech sheets, shadecloth, temporary plastic floor tiles or sand stabilisation products can be secured over any exposed mud to allow access to boats and the water. However, these must only be used on a daily, as-needed basis and removed after use.
All proposed permanent works, including cutting, filling, excavating, permanently positioned geotech 'pillow' bags, dredging or any construction on the river edge will require a Development Application. Please contact your local council directly, or visit the links below.
Alternative materials and methods for stabilising your riverbank include:
- a retaining wall constructed of stone, timber or similar
- bank restructure using sand bags or similar (see pictures below)
- secured synthetic turf or geotech fabrics (which can support sodding or seeding of fast growing vegetation).
These materials are more stable and less vulnerable to erosion. Shadecloth and carpet are not recommended as they will perish and break down with long-term immersion and sun exposure. Pontoons and jetties are being actively discouraged, with few new structures being granted permission to be built.
Synthetic materials must be firmly secured to the bank with pegs/staples, sand bags or other appropriate means and must be UV stable and not break down or rot. Many fertiliser bags will break down in sunlight (see pictures below).
|Excellent examples of sand and river edge management|
|Poor examples of sand management: Sand that can still wash into the river when using non-UV stable bags.|
There are many suppliers of geotech materials, plastic flooring and other materials, which can be found through the Yellow Pages or an internet search.
Local councils along the River Murray
- Alexandrina Council
- Berri Barmera Council
- Coorong District Council
- District Council of Karoonda East Murray
- District Council of Loxton Waikerie
- Mid Murray Council
- Rural City of Murray Bridge
- District Council of Renmark Paringa
For further information, please contact the EPA on 8204 2004 or email.