Orange City Council is developing an Urban Waterways Rehabilitation Action Plan that will improve water quality and the condition of the natural environment. The plan will focus on guiding future development, rehabilitation and restoration of urban waterways. This project was stage 1 of this process and provides research, field analysis and recommendations to shape the City of Orange’s Urban Waterways Rehabilitation Plan.
A review of the historic context and current condition of each catchment in the study area was undertaken and drew heavily on a range of existing resources, providing information on waterway location, stormwater reuse; historic and current land use; geology, geomorphology and soils; vegetation communities, threatened species, and key threatening processes.
A primary focus of this project was to develop an assessment tool or field protocol by which Orange City staff can undertake a detailed rapid assessment of creek reaches across the city. Desktop analysis indicated that 63 discreet reaches across 30 kilometres of urban and peri urban streams would require assessment. Applied Ecology completed assessment of 6 reaches or ~10% of reaches in the study area. A photographic record was made, and sketch maps drawn indicating the location of key aspects of each reach. Data was collected to inform an assessment of assets and problems, based on catchment setting, geomorphic condition, hydrology, instream habitat, riparian vegetation, water quality and fauna present. Completed field work included 15 detailed assessment sampling points and 5 macroinvertebrate sampling points. Results of field analysis is presented in individual reach proformas in Volume 2 of this report and should be viewed and read in conjunction with Volume 1.
Data analysis involved developing a scoring system that provides a robust comparative indication of overall stream health. Streams were categorised based on their assets and problems using a method adapted from the Australian Streambank Rehabilitation Manual (Rutherford et al, 1999).
Works plans were developed for each reach, based on field assessment and underpinned by desktop analysis of the reach subcatchment. Rehabilitation works are designed to move each reach closer to its predisturbance condition, with a particular emphasis on establishing and maintaining a sustainable ecosystem condition. Types of work required are included in reach proformas (Volume 2). Vegetation communities, if any, in each reach were identified and lists of local native species suitable for revegetation have been included.
Completion of reach assessments in the future will enable Orange City Council to prioritise actions aimed to protect reaches with important assets, contain and reduce the detrimental impacts of reaches in poor condition on the downstream environment, and improve the condition of reaches in between.