Identifying corridors of river recovery in coastal NSW Australia, for use in river management decision support and prioritisation systems

by Danelle Agnew, Kirstie Fryirs

By connecting corridors of river recovery, resilience can be built into river systems to mitigate against future floods and droughts driven by anthropogenic disturbance or climate extremes. However, identifying where these corridors can be built is still lacking in river management practice. The Open Access NSW River Styles database contains comprehensive information on geomorphic river condition and recovery potential. The database can be used to systematically analyse where corridors of river recovery could be created via conservation or rehabilitation. Analysis was undertaken in ArcGIS using the recovery potential layer along 84,342 km of freshwater stream length, across 20 catchments of coastal NSW. We identified 4,905 km of reach connections, defined as an upstream to downstream section of river that is connected end-to-end, and 17,429 km of loci connections defined as more isolated sections of river from which recovery can be seeded and extended into adjacent reaches. There was significant spatial variability in the types and lengths of connections made across the catchments. Some catchments have significant potential to build corridors of recovery along large sections of river, whereas other catchments are more fragmented. These results provide practitioners with a user-friendly distillation of where river conservation and rehabilitation activities could be focussed when working with river recovery in practice. Combined with local on-ground knowledge, this information forms an important input to evidence-based prioritisation and decision making in river management.