Development of a Monitoring Program for the Broken River - M/BUS/230
MDFRC Technical Report
The Broken River is a mid-slope tributary of the Goulburn River which rises in the highlands near Tolmie and flows in a westerly direction joining the Goulburn River at Shepparton. The river experiences variable flows with the period between July and September accounting for over half of the annual flow while historically the river experienced both floods and prolonged periods of low flow. The reservoirs on the river provide water for stock, domestic and irrigation supplies. The objective of the Goulburn Broken Catchment Management Authority (GB CMA) is to protect and improve the ecological health of the catchments land and water resources while maintaining it’s commitment to the sustainability of the region and its community. In developing the Regional River Health Strategy, the GB CMA identified river health and waterway management to be its highest priority natural resource management issue within the catchment. The Broken River was identified as a high priority waterway due to its high value assets of environmental significance, including its populations of Murray cod, Silver and Macquarie perch, and its association with wetlands of national significance. Key actions in the Strategy for the Broken River include: enhance flow regimes; improve passage for native fish species; improve water quality; enhance in-stream diversity; and protect riparian and floodplain zones The purpose of this report is to recommend an appropriate monitoring program to assess the impacts of the management initiatives that the GB CMA implements on the Broken River. A variety of characteristics have been identified as potential threats to high value assets on the Broken River. These include: Barriers to fish migration; Stock Access; Water Quality; Introduced Fauna and Flora; Bed Instability, Channel Modification, Loss of in-stream habitat; Flow deviation; and Degraded Riparian Vegetation. The following suite of indicators is recommended to be monitored to provide information on the success of the management actions implemented; Fish migration; Fish community assemblages; Water quality – including nutrients and temperature; Flow Deviation; and Index of Stream Condition (ISC). More specifically, the Goulburn Broken Regional River Health Strategy (GB CMA 2005) identified desired outcomes from the implementation of their management initiatives, which formed Resource Condition Targets. This monitoring program provides recommendations for monitoring the success of the management initiatives in reaching these Resource Condition Targets. Many of the Resource Condition Targets listed are a change in environmental condition; however there are several Resource Condition Targets that need to be defined that are reliant on either risk assessments, reviews or infrastructure works to be undertaken.
The recommendations in this monitoring program are made considering the two types of monitoring which apply to each resource condition target. These are: monitoring using environmental indicators to detect a change in environmental condition; and compliance monitoring which assess if management initiatives have been implemented. A summary of the recommendations made for monitoring using both methods are as follows: Measure EC, turbidity, pH, DO, TSS samples as part of assessment of current condition; A site immediately above Lake Nillahcootie added to the sites currently being monitored for water quality and nutrients; Nutrients to be monitored for TP. Flow or gauge heights measured to calculate loads; Temperature loggers should be deployed upstream, within and at three sites below Lake Nillahcootie; The gauge downstream of Bridge Creek is upgraded to measure the suite of parameters currently monitored by the other gauges; The ISC monitoring is continued; Conduct Riparian Trend Assessment in between the ISC Streamside Zone Subindex monitoring surveys as an interim indicator of change in Riparian Vegetation; The ISC monitoring is continued; Continue monitoring of Casey’s weir fishway; Install fishway at Gowangardie weir (compliance monitoring); Investigate the installation of a fish way at Lake Nillahcootie (compliance monitoring); Sampling for fish abundance, and richness is recommenced in M2; Sampling for fish to be continued in M1 and L5; Sites for fish monitoring be established in M1 above Lake Benalla; Continue with existing monitoring program for Macroinvertebrates. An overall monitoring framework for each management unit including site and parameter selection, frequency of sampling and justification have been outlined in the following tables which is designed to assist the GB CMA in the implementation of the monitoring program.