Nutrient analysis in the River Murray

 

University of Adelaide Researcher: David Lewis (Chemical Engineering)

 

Objective:

The overall project aim is to provide the project partners (South Australian Murray-Darling Basin NRM Board, SA Water and the EPA) detailed nutrient analysis for the Lower Murray region at three specific locations (Houseboat Marina, north-east of Mannum; Wetland, north-east of Murray Bridge and Woods Point Irrigation Pump Outlet, north-west of Tailem Bend). A comprehensive literature review was completed followed by specific field studies. The field work comprised of temporal and spatial water sampling for a suite of water quality parameters at the above-mentioned field sites.

 

The research identified which areas of the River were providing the most significant impact on water quality within the Lower Murray, and at which depth at each site. The research found that water quality was poor (including elevated nutrient concentrations and low dissolved oxygen levels) from the flows into the River at the three field sites. The small flows that these land-uses contribute to the River Murray in comparison to that of the river itself, means that only small differences were detected in nutrient concentrations upstream and downstream (longitudinally and laterally) of each site.

 

It is evident that longitudinal deterioration of water quality occurs along the River Murray, which will have significant implications for biota, irrigation and domestic water supplies and suggests that either diffuse sources of nutrients or large number of small point sources of nutrients may be contributing significantly to the Lower Murray River nutrient load.

 

Funding: $30,000 from EPA, SA Water, SAMDB NRM Board