Surface water monitoring

Surface water (such as water in rivers, lakes, wetlands and estuaries) is a limited resource in South Australia and its sustainable management is vitally important to the environment and the economy of the state.

Surface water data recorded through monitoring assists with the:

• efficient operation of the River Murray (by the department)
• implementation of water planning and management across the state (by the department and the Natural Resources regions)
• management of South Australia’s hazards, such as flood and black water events (by government hazard agencies)
• monitoring and reporting of the quality of the state’s surface water resources (by the Environment Protection Authority), such as the annual aquatic ecosystem condition reports.

Water level, discharge rate and volume, salinity, pH, dissolved oxygen and turbidity are measured at 245 gauging stations in watercourses in South Australia. The majority of the sites provide a near real time continuous dataset. Ecological monitoring is undertaken in conjunction with these parameters at some sites.

Measuring streamflow

Streamflow – the volume and rate of flow of a water body – can be derived from water level data. By recording the water level at gauging sites, we can mathematically estimate the streamflow of a water body. To do this we accurately measure stream flow at various water levels at each gauging site, and establish a relationship between them.

How we measure streamflow

Run of River salinity survey

Since 1985, the department has conducted the Run of River salinity survey, which captures continuous salinity data from upstream of Lock 6 (near the NSW/Victorian border) to Lock 1 at Blanchetown in South Australia, a distance of about 400 river kilometres.

The survey data tells us where saline groundwater is entering the River Murray and how this saline water disperses over time. This information supports the operation of the River Murray, helps to focus salinity mitigation efforts, and provides data for audited purposes.

At times, the survey is also undertaken upstream of Lock 6 between the townships of Iraak and Lock 7. In addition, the survey has been tailored to suit some of the River Murray tributaries and river reaches below Lock 1 that extend to Wellington.

Mobile Water Monitoring Capability

A fully-equipped mobile hydrometric monitoring station is installed within a secure trailer that can be readily taken to most field locations across the state and easily set up to gather the required data.

The mobile monitoring station is fully automated, meaning it can be left to operate unattended for short or long periods, with all data logged and available in real time via telemetry.

Parameters monitored by the mobile station include:

• level
• salinity
• flow velocity
• stream discharge
• temperature
• dissolved oxygen
• nutrients
• rainfall.

The mobile station also has a camera for recording specific events of interest.

The design of the mobile station makes it an ideal choice for use in natural resources management and water science projects, compliance monitoring projects, and reservoir and dam inflow monitoring projects. The mobile station will suit:

• high flow or flood events where response times do not allow for conventional monitoring stations to be installed

• shorter-term water monitoring projects where budget or time constraints do not allow a more permanent solution to be utilised
• longer-term water monitoring projects in locations where the development of permanent monitoring structures is not supported or approved.

It’s expected that the mobile station will deliver time and cost savings to projects, reduced potential for environmental site impacts, and quality water data from locations that have not previously been monitored. This data will inform our emergency response to flood events, support South Australia’s water planning and management, and contribute to the sustainable development and equitable distribution of the state’s water.