WATERCOURSE ASSESSMENT REPORTS: A FRAMEWORK FOR INTEGRATED STREAM MANAGEMENT

Watercourse Assessment Reports (WARs) are documents developed by Auckland Council to guide watercourse and stormwater network management in the context of a holistic strategic approach for managing stormwater effects on streams. The WARs represent the most recent iteration in a series of program refinements towards developing a management methodology capable of achieving multiple objectives within realistic environmental, economic and social constraints.

WARs provide baseline data on the existing stream state, and are informed by comprehensive field watercourse assessments. The field-based surveys utilise a remote data collection platform and cloud storage services to capture attribute information in real-time, with the survey scope including assessments on the ecological character of stream reaches, stream mouths, and wetlands; the presence and condition of engineering assets; the identification of erosion and fish passage issues, and enhancement opportunities. In conjunction with desktop reviews, the WAR uses the results of field assessments to identify stream state and catchment issues. Grouping and prioritisation of key issues informs management options and zones for the catchment, supporting the delivery of a targeted works programme that seeks to remedy similar issues on a prioritised basis. The approach ultimately ensures that the most meaningful benefits on a catchment-wide prioritised basis are achieved through identification of where multiple issues exist.

WAR outputs offer a catchment specific framework for watercourse and network management which can inform and support a range of stakeholder aims (i.e. local boards, community groups, developers, infrastructure providers) and related stormwater management and development processes. Within the Auckland region this holds particular value where the WAR’s will play an important role in informing the development process and delivery of watercourse and water sensitive design outcomes.

The paper will explore the refined WAR approach, and an example of the outputs that can be used by infrastructure providers to deliver prioritised catchment-wide network maintenance.