The hydrograph shows the probably flow without inter-valley trade or environmental flows, and the flows attributable to inter-valley trade or environmental flows.
Water captured in Lake Eildon is owned by water holders including irrigators, water authorities, commercial enterprises (for example, hydro-energy) and the environment. Environmental deliveries are only a small proportion of flow in the river.
The hydrograph shows the relative proportions and sources of flow in the lower Goulburn River (between Goulburn Weir and the Murray River).
Environmental releases from Goulburn Weir are defined by scientific studies that identify the timing, size and frequency of flows required to improve the environmental values of the Goulburn River.
Daniel Lovell from the CMA said the information was updated weekly, usually on a Friday, based on information CMA received from Goulburn-Murray Water each week.
Anyone interested in live daily data can find it via a number of sources including G-MW’s water status reports, which can be found on its website, as well as from the Bureau of Meteorology website or at https://data.water.vic.gov.au/
The hydrograph was initially a static internal “tool” developed by Mr Lovell for communication and reports to show the timing and volumes of the different types of flows (water for the environment, IVT, natural etc) in the lower Goulburn River.
“Given the interest shown by other organisations and the broader community in the hydrograph and to help improve understanding of the different sources of water that may contribute to fluctuations in river height, we worked with Water Technology to develop the interactive hydrograph, which is now on our website,” Mr Lovell said.
Development of the hydrograph has been three years in concept and taken about six months to build.
Mr Lovell believes the hydrograph may be unique in Victoria, if not Australia.