Conservation of Freshwater Ecosystem Values (CFEV) Validation Report (National Water Initiative – Australian Government Water Fund. Report 1a/6 Report to the Conservation of Freshwater Ecosystem Values Project, Water Resources Division, Department of Primary Industries and Water)

The Tasmanian Conservation of Freshwater Ecosystem Values (CFEV) framework(DPIW in prep.) was developed by the Department of Primary Industries and Water(DPIW) in order to rate the conservation value and management priority of allmapped examples of freshwater ecosystems in the state. A systematic approach wasused based on the ‘CAR’ principles of Comprehensiveness, Adequacy andRepresentativeness, and a set of data which identified the natural biophysicalcharacter and condition of the ecosystems in a standardised way.The data used was based on the most up to date spatially attributed features andcondition measures available that could be systematically applied across the entirestate. This required existing data sets to be updated and/or extended in many cases. Italso required new data to be collated, and frequently attributed to ecosystem unitsbased on mapping rules and or modelling.Natural feature data (CFEV ‘biophysical classes’) was used to represent thebiophysical character or type of an ecosystem based on the pre-European natural‘reference’ state. i.e. it represents what would have been present in the absence ofEuropean settlement and development. These data were developed for as wide a rangeof ecosystem components as possible (e.g. fish, vegetation, hydrology, etc.) in orderto adequately characterise each ecosystem unit. Data from each of these componentswas then attributed directly to each mapped ecosystem unit, without integration acrosscomponents or the use of surrogates.Condition data (CFEV ‘naturalness’) was used to quantify the degree of change in thebiophysical state of each ecosystem unit since European settlement. Only a few datasets were available on direct measures of biophysical condition which could beapplied to more than a few ecosystem units. Thus a systematic way of ratingbiophysical condition was needed, which could include measures of both biologicaland physical condition and integrate them into a single condition or ‘Naturalness’rating. A range of biological and physical inputs to this rating were identified. Somedata (e.g. macroinvertebrate condition) were mapped after modelling relationshipsbetween real measures of condition and data sets on a range of possible ‘drivers’.Other data sets (e.g. geomorphological condition) had to be based on a set ofrelationships between drivers of change and ecosystem condition based on expertopinion.These data on condition and natural features were developed for two purposes:Conservation Value assessment: The primary purpose was to characterise theecosystem units as an input into a spatial selection and rating process in order toquantify their relative conservation value. The conservation value was based on therelative rarity of the features and their condition. An ecosystem unit was rated ashaving a higher conservation value if its biophysical features were both rarer and inbetter condition than other examples of that ecosystem. In this way every mappedexample of an ecosystem (e.g. wetlands) were given a rating of relative conservationvalue.Reporting and Interpretation: The secondary purpose of these data was to allow usersto interrogate the database for data on the natural features and condition of single ormultiple ecosystem units for a variety of purposes. These include state ofenvironmental reporting, catchment management planning, water managementplanning, and scoping for evaluation of developments (e.g. dams) and environmentalimpact assessment.The former use placed more emphasis on spatial consistency in attribution of featuresand condition across the state. While absolute accuracy is valuable, it is relativerelationships that are important. The latter use places considerable emphasis onaccuracy and precision at the scale of management interest. This is often at the localor single unit scale.There is a range of data types within the CFEV condition and features datasets. Thesedata differ in their spatial reliability, spatial scale, and precision. Many input data setsto CFEV have an established provenance and data quality (e.g. digital elevationmodels, hydrology data, etc). There was however little opportunity during thedevelopment of the CFEV framework to conduct on-ground validation of many of thedata sets that were inputs to the conservation value assessment.On-ground validation of CFEV data is needed in relation to both the use of the datafor reporting and interpretation at local scales and to provide guidance in the ongoingrefinement and development of the CFEV assessment framework and associateddatabase.A project was therefore initiated by DPIW to perform some ground-based validationof CFEV data on condition and natural features, with a focus on rivers and wetlands.This project was funded by the National Water Commission’s Australian GovernmentWater Fund as part of the National Water Initiative.