River Murray Data

MDBA, through the partner governments, operates and maintains a network of remote hydrometric monitoring stations for the River Murray System. The network records and distributes data via telemetry including river and storage levels, calculated flow rates, rainfall, and various water-quality attributes.

The River Murray Data website provides data access to the public for a range of key monitoring sites and includes both recent near-real-time data (updated on a six hourly interval) and various historic time series data sets for download in CSV format.

The site aims to give an overview of conditions across the whole of the River Murray System but should not be relied upon as a source of information during flood times. MDBA advises that the Bureau of Meteorology website should be used during flood periods for the latest updates of river heights, along with rainfalls, Flood Watches and Flood Warnings.

Data recording interval

The near-real-time data is updated on an hourly interval. Data currency is indicated with an associated date and time stamp.

Data types

There are four key data types recorded at monitoring sites:

  • gauge level
  • rainfall
  • water temperature
  • electrical conductivity

A number of sites record all four types, while some sites do not. Other data types (such as river flow and storage volume) are not directly measured, but calculated using the primary measurements.

Gauge level

Gauge level measurements indicate the current water level on a gauge board at a river or reservoir monitoring site. River levels are used to provide an estimate of river flow based on each site’s latest rating table. Reservoir levels are used to provide an estimate of storage volume based each site’s latest capacity table. Each rating or capacity table is by generated by surveys that measure the bathymetric shape of reservoirs and the cross-sectional area of river channels in order to calculate the river flow or storage volume for any given water height. Monitoring sites are re-surveyed regularly by Field Hydrographers to correct inaccuracies resulting from changes to the riverine landscape that occur naturally over time. The flow and storage values provided by Live River Data are therefore calculated values from the most recent rating or capacity table available. Storage release data values are calculated according to weir, gate or valve settings and are often validated by comparing the data with a gauged flow from a monitoring site located immediately downstream of the structure.

The gauge height figures given for the storages and weirs (as well as the gauges at Peechelba, Echuca Wharf, Swan Hill and Murray Bridge) are water levels in metres AHD (Australian Height Datum). Metres AHD refers to elevation above a standardised measure of mean sea level, which is taken to be zero. Figures given for most other monitoring sites refer to the local gauge height, where the base of the river bed is defined as the local zero level.

Rainfall

Rainfall is recorded at a number of the monitoring sites and is provided in two formats: a rolling one month cumulative graph and as a daily time series of daily rainfall measured at 6 am. Rainfall is recorded to give an indication of catchment wetness at monitoring sites in the upper catchments and to account for flow changes resulting from local rainfall at lower catchment monitoring sites.

Water temperature

Water temperature is measured in degrees Celsius and generally varies on both a daily and annual seasonal cycle. Water temperature is dependent on both changes in the ambient air temperature and flow and storage release patterns. Temperature is also used in the electrical conductivity ‘compensation’ calculation (see below).

Electrical conductivity

Electrical conductivity (E.C.) is measured at a number of monitoring sites and is used to provide an indication of water salinity (there is a strong relationship between E.C. and the concentration of salt in water).  The advantage of using E.C. as a measure of salinity is that E.C. can be recorded continuously, unlike spot samples analysed in a laboratory.  E.C. is measured in micro-siemens per centimetre.

The relationship between E.C. and salt concentration changes with water temperature, so E.C. values are usually ‘compensated’ from E.C. at the measured temperature to E.C. at 25 degrees Celsius.  This makes it possible to compare salinity at different monitoring sites or at the same site over time.

While there are currently no standards for calculating compensated E.C., most agencies in Australia adopt a rule of thumb where E.C. is increased 2% for each degree below 25 degrees Celsius.  This formula is an approximation as the relationship will change depending on other factors, such as the composition of the salts being measured.

Typically, E.C. values below 800 micro-siemens per centimetre are considered desirable in water used for domestic consumption.

Data quality

Data users should be aware of the provisional nature of the near real-time and recent data published on the web. It is uncorrected field data that has not been quality checked and may contain errors and omissions. Data users should exercise caution, as the unpredictable and variable nature of the riverine environment means that the system and provisional data provided is never 100% reliable or accurate. Provisional data values may also undergo future adjustments resulting from data correction processes.

The CSV (Comma-Separated Values) data files available for download contain adjusted or corrected historic time series data. The files are updated and extended with new data every few months.