A Review of Historic Monitoring (river health and water quality) and Research within the Broken River System

"December 2005".

Project Number: Broken River Monitoring Review - M/BUS/88.

MDFRC item.

120 pages.

The mission of the Goulburn Broken Catchment Management Authority (GBCMA) is the cost-effective protection and enhancement of the Catchment's land and water resources to improve social well-being, environmental quality and the sustainable productive capacity of the catchment. Specifically, the GBCMA seeks to protect and enhance natural environmental assets and their ecosystem processes and functions in a way that provides benefits for native biodiversity and the social and economic aspects of the catchment. As part of this goal the GBCMA has commissioned MDFRC to undertake a review of monitoring and research programs on the Broken River, which will contribute to the “‘Mending the Broken: Improving Flows and Habitat in the Broken River” and “Our Water –Our Future“ initiatives. This report reviews existing monitoring activities in the Broken River and Broken Creek catchments, identifies the strengths and weaknesses of these monitoring activities and their capacity to assess changes to stream health resulting from management activities. This information will provide a basis for the design of a comprehensive monitoring program of the Broken River and Broken Creek catchments. Currently, a variety of parameters are measured in monitoring programs within the Broken River and Broken Creek catchments by a number of different agencies. These parameters can be summarised into the following broad groups: Water Quality; Water Quantity; Biodiversity; Algal /Bacterial Populations; Habitat Variables; Climate Variables; The agencies collecting monitoring data operate under various primary objectives. These objectives influence the parameters measured, sites chosen, monitoring frequency, monitoring duration, the resolution of measurements, the statistical robustness of the project design and the comparability of the data with that from other projects. The GBCMA shares some of the objectives of each monitoring agency, but not all. In turn, this influences the applicability of the data to GBCMA’s monitoring objectives. There is great variation in the data sets in terms of spatial and temporal distribution, continuity, quality assurance and duration of data collection. Some data provides an indication of the site health for a discrete time period (snap shots) while other data is more useful for determining changes over time and space (long term monitoring). Analytical methods and data analysis also differ between agencies. The standard of quality assurance imposed by a monitoring program is of great importance when data from a variety of sources is to be used to assess ecological condition, particularly when it is to be put to a use other than that for which it was initially intended.

When the available data is evaluated in terms of the data required for the assessment of future GBCMA management works, it becomes obvious that there are several areas where the data are inadequate. These knowledge gaps are most prominent in the areas of wetland biodiversity and water quality, stream geomorphology and hydraulics and in-stream and riparian habitat assessment. Population and habitat data for icon species and pest species in the Broken catchment are also lacking. The applicability of the existing data to GBCMA’s monitoring objectives will ultimately depend on GBCMA’s specific monitoring requirements, which will vary depending on the reach, management works and expected outcomes. Once specific monitoring requirements are determined the applicability of the existing data may also be determined. GBCMA may benefit from supporting and/or implementing a suite of monitoring programs/projects that are aimed at continuing the collection of long term data, improving the spatial distribution of data, assessing the efficacy of rehabilitation works, and filling knowledge gaps. This suite of monitoring data should include the following types for specific purposes: Descriptive Monitoring – detect change, predict problems, characterise sites; Analytical Monitoring - determine whether management interventions are achieving their objectives and improving knowledge of system response. Where possible, design should be based on conceptual models and hypotheses of how the works influence the system; and Scientific Research (e.g. PhD projects) to fill knowledge gaps. Several conceptual models based on the objectives of the GBCMA for environmental health in the Broken River and Broken Creek catchments conclude this report. Conceptual models are provided as a means of designing monitoring programs and assessing the environmental variables of most direct relevance to restoration works. They can also be instrumental in detecting knowledge gaps, which is information that will be critical for the second phase of the ‘Mending the Broken’ initiative - design of an appropriate monitoring program.