We surveyed 1000 reaches in 250kms of streams in four major subcatchments in Sutherland Shire and developed prioritised works plans for rehabilitation of these urbanised waterways. Lessons learned from this project were carried forward to similar projects in Auburn, Parramatta and Ryde LGAs. For clients, the big questions are: How much will it cost? Where do we spend the money first? What will we get for our money? Where can we get funding from? Project development is informed in part by the need to work within client requirements and expectations, and the logistics of managing large datasets to provide ecologically valid prioritised works plans.
Predisturbance condition was initially proposed as a benchmark for restoration outcomes; however this may be difficult to determine, and often provides unrealistic and unsustainable goals in an urban setting. Condition scores are best treated as informative, rather than definitive, for developing rehabilitation priorities. Thus works prioritisation is influenced by predisturbance condition and overall condition scores, but may be affected by condition upstream and downstream, and availability of followup management. It needs to incorporate restoration principles from several paradigms, including vegetation management, erosion control and water quality management.
We believe that effective rehabilitation of urban streams can be achieved through the application of reconciliation ecology principles, and that “success” is best measured through developing a sustainable equilibrium condition that incorporates as much of the original environment as possible, yet requires limited ongoing resources to maintain this state in the presence of a range of ongoing urban-derived perturbations.