Managing Complex Catchment Systems – Issues of Scale: A Case Study of Flood Management in the Hawkesbury Nepean Region

Abstract

Unplanned urbanisation and natural resource exploitation have transformed the way natural systems function. This is further exacerbated due to climate change, creating uncertainty in the way these systems function. Under this premise, there is a greater need to understand the human-environment nexus to maintain the adaptive capacity of these systems to abrupt changes. This thesis focuses on the management of complex Socio-Ecological Systems (SES), discussing primarily the environmental and social barriers to adaptive capacity. It emphasises that in order to effectively manage these complex SES, there is a need to identify and address these barriers through an adaptive governance framework.

The Hawkesbury-Nepean catchment was chosen as the case study and complexities of the SES are addressed by examining the flood management issues in the catchment. In this catchment unique geographical characteristics create an environmental barrier making it susceptible to flooding which is likely to worsen with climate change enhanced weather variability. The socio-political barriers, on the other hand, emerge from a complex multi-tier system of governance that restricts flood management at jurisdictional scales. It also ignores cumulative impacts of development and is predominantly governed by a top-down technocratic mode of managing floods in the region.

This research emphasises that the complexity of managing a large catchment system such as the Hawkesbury-Nepean is strongly embedded in the way professionals and communities perceive the problem of flood management. This difference in perception has led to coordination and communication issues for effective adaptive management of flooding in this socio-ecological system. The research also identifies potential opportunities that could help to overcome these barriers. In doing so, it examines two regional scale models in Australia, the Catchment Management Model in Victoria and the Biosphere Reserve model in Noosa, Queensland. These models present opportunities for a more integrated regional scale management framework.

This research was applied and exploratory, requiring the use of a multi-methods approach for data collection and analysis. This research concludes that as a result of climatic variability and future uncertainties there is a strong need to manage floods at a regional scale to enhance the adaptive management of this complex Socio-Ecological System. This is possible if the system of governance is adaptive and integrates learning from different interest groups. Consequently an adaptive framework can be established through the formation of a regional entity that enables communities to be involved at local and regional scales of flood risk management; functions as a brokering organisation between different scales of management to enhance coordination; and integrates flood risk information with ensured access and utilisation by different interest groups.