Innovative river action planning for the Upper Collie catchment, Western Australia

摘要

In River Action Plans (RAPs) ecological condition is presented as a series of maps that may also indicate river values and threats. RAPs also offer advice to landholders and others about river and foreshore management. This paper describes the development of a RAP for the main rivers of the Upper Collie Catchment in southwest Western Australia (WA). Ecological condition considers foreshore vegetation, weeds, erosion, sedimentation and water quality. In the Upper Collie it was found that 21% of rivers in the Upper Collie were in 'pristine' condition, 24% were in 'degraded' condition and 55% were in 'eroded' condition. Of the total riverbank length (161.8km), 66% was unfenced, 24% was fully fenced and 10% was partially fenced. According to the Waterways Management Prioritization Framework on-ground actions should secure, stabilise and maintain high-value sites before attempting restorative work on lower-value sites. Of the 217 survey sites assessed, 9.3% were classed Priority 1 (requiring immediate protective management), 26.2% were classed Priority 2 (worthy of strategic management) and 64.5% were Priority 3 (beyond viable restoration). Issues identified were: loss of vegetation; weeds; erosion/sedimentation; water extraction; water quality; and support to landholders in planning protection and rehabilitation. Banks that retain native vegetation (especially those identified as Priority I) should be protected e.g. fencing to control livestock. Revegetation should be done using local native species (trees, shrubs, sedges, rushes, herbs and native grasses). Best management techniques should be employed to minimise soil erosion and nutrient loss, e.g. buffer strips, soil testing and fertiliser management plans.