2016
About the document
This report is the product of the first year of monitoring and evaluation in the Lower Murray River under the Commonwealth Environmental Water Office’s Long Term Intervention Monitoring (LTIM) Project. The report evaluates the contribution of Commonwealth environmental water to environmental outcomes in 2014-15, complementing previous short term monitoring and evaluation work undertaken in 2010-11, 2011-12, 2012-13, 2013-14.
The Lower Murray River LTIM Project identified a number of key environmental outcomes achieved in 2014-15, including:
- Increased transport of nutrients and phytoplankton to the Coorong and Lower Lakes which is likely to significantly increase productivity as a result of Commonwealth environmental water.
- Reduced salinity concentrations in the Murray Mouth and increased export of salt as a result of Commonwealth environmental water.
- Intermittent increases in supplies of organic material, which are deemed critical to the food webs of rivers. The increases were linked to return flows from the inundated Chowilla floodplain using The Living Murray environmental water, supported by the concurrent delivery of Commonwealth environmental water through the main channel.
- Increased water velocity in main river channel. Commonwealth environmental water contributed to the prevalence of flowing water habitats, important for riverine fishes such as Murray Cod.
- Increased water levels, which may have in turn increased inundation of the riparian zone and low-lying wetlands.
The report is presented in three parts: an executive summary; a non-technical synthesis report; and technical appendices which provide detailed methods, analyses and results for each indicator.
This report is the first of five to be produced for the Lower Murray River Selected Area under the LTIM Project, with monitoring and evaluation being undertaken from 2014-15 to 2018-19. The data and evaluation report from this project are being combined with those from six other LTIM Project Selected Areas within the Basin, as part of a Basin-scale evaluation of the contribution of Commonwealth environmental water to the environmental objectives of the Basin Plan being led by the Murray-Darling Freshwater Research Centre.
In addition to assisting the Office to demonstrate environmental outcomes, the LTIM Project is designed to allow adaptive management of the water holdings. As such, identified outcomes and limitations are used to inform environmental watering in future years leveraging the best available, contemporary scientific knowledge.
Redressing environmental decline that has occurred over decades is going to take us some time – it will be at least ten years before we can show lasting change and improvements to the health of the rivers, floodplains and wetlands, consistent with the long-term targets of the Murray-Darling Basin Authority’s Basin-wide environmental watering strategy.