The National Water Initiative undertook a multi-year project to develop a National Framework for the Assessment of River and Wetland Health (FARWH).
The framework seeks to form the basis of national river and wetland health assessments, and enable the bringing together of the results of existing broad-scale assessments conducted at state, territory and basin scales. The FARWH does not generate data itself or replace existing monitoring and assessment programs. Rather, it provides a way to integrate and aggregate the data collected by states for reporting at the scale of water management areas (larger river basins).
Despite the fact that the framework does not drill down to a scale appropriate to local government based natural asset management, this document is worth noting as background material (particularly in the absence of regionally consistent guidance). This is because some of the methods and concepts that form the basis of the national framework may be applicable to finer-resolution condition assessment methods.
The framework proposes six key components (described in section 2.1) to assessing river and wetland health, all of which are considered to represent ecological integrity:
- Catchment disturbance
- Physical form
- Hydrological disturbance
- Water quality and soils
- Fringing zones
- Aquatic biotic habitats
The authors propose that damage to biota is usually the 'final point' of environmental degradation and pollution. Thus, aquatic biota are posited as a fundamental indicator of disturbance to rivers, wetlands and their catchments - including groundwater.
The
AusRivAS (
Australian
River
Assessment
System) assessment methodology was adopted and developed through this project. This uses a macroinvertebrate comparison between a study reach and a reach with no perceived environmental stress, to infer environmental impact. See Related Resources for a link to the AusRivAS website.
The framework does not prescribe indices that should be used to represent the above components.
Section 2.2 discusses conducting assessments at various scales. The authors suggest that condition and health assessments are conducted at the scale of individual reaches or wetlands, whilst being designed to be aggregated to broader spatial scales. Section 2.4 discusses how individual reaches and wetlands might be defined.
Section 2.5 gives a good basic introduction to the concept of the 'reference reach' - whereby the health condition of a river system of interest is referenced to the condition of a river that has not been previously impacted or changed by human activity.
The reamining sections of the report describe methods available to integrate and aggregate data and conduct sensitivity analysis.