What is a catchment?
A catchment area or basin is land that is bounded by natural features, such as hills or mountains from where all run-off water flows to a low point. This low point will be a dam, a location on a river, or the mouth of a river where the water enters a bay or the ocean. Catchment areas vary in size and make-up. Large catchment areas, such as those drained by the Burdekin and Fitzroy Rivers in Australia are bordered by mountain ranges and include major drainage networks of creeks and rivers. Large catchment areas are made up of hundreds of smaller ‘sub-catchment’ areas. These can be bordered by low hills and ridges and drained by only a small creek or gully.
Challenges
Land use change, flow alterations, urbanisation, population growth and climate change are each negatively effecting the health and productivity of catchments. Stressed catchment systems are increasingly fluctuating between drought and flood, stream flows are altered, recharge of groundwater systems depleted and aquatic habitats threatened.
Degradation of catchments directly impacts on the services that they provide to society, such as safe drinking water, habitats for biodiversity or places for spiritual, cultural and recreational use. The Brisbane Declaration (2007) highlighted evidence of the global dimensions of freshwater ecosystem degradation and its links to human water security. Ten years later, the 2018 Declaration was revisited and highlighted accelerated declines in freshwater biodiversity and continued loss of vital ecosystem goods and services.
The drivers of degradation are diverse and interconnected with beneficial human uses. Water and land use for agriculture, energy and human health, for drinking water and for sanitation and hygiene, each has potential to negatively impact on the health of fresh water ecosystems.
A better way?
The concept of a catchment management or river basin management has gone through several iterations. While embedding the concept on a hydrological unit remains a constant, the patterns of management (from centralised to decentralised) and the varying degrees of participation and balance of social, economic and environmental outcomes is different from country to country and even from region to region. Catchment management is also influenced by internal norms. A current major influence across the world is the 2030 Agenda for Sustainable Development, set by the United Nations.
The 2030 Agenda
The 2030 Agenda establishes a framework for an integrated response to development challenges and identifies 169 targets for 17 different but connected development goals. Goal 6 is focused on water quality, quantity and supports the adoption of integrated approach to management of water.
The goals were developed through a collaborative process, where different sectors and groups of society influenced the final set of goals. This has in turn resulted in implementation being driven by sectoral actors. Water actors, for instance, focus on the water goal. Agricultural actors focus on food security goals and so on. Each goal has an established set of indicators, that can re-enforce sectoral approaches. For example, the dedicated food security and human health goals (SDGs 2 and 3 respectively) have no water-related indicators that address this inter-linkage. This complexity highlights the challenges in effective management of catchment for multiple outcomes.
Cutting through the complexity
There are better ways to secure economic benefits without degrading our ecosystems. The concept of a catchment, or river basin, as a management unit is well established, but is often seen to be overly complex or too challenging to demonstrate the benefits and outcome from actions. Our challenge is to work with stakeholders to validate their understanding and to test opportunities for the uptake of better management practices.
We work with communities, governments, users, businesses to generate understanding of water as a scarce and valuable resources that need to be collectively managed for the environment and societal benefits. We challenge current paradigms and approaches, and test assumptions as to who benefits from different management choices.
This starts by embracing the complexity of catchment management, and by building an understanding of the key elements that form, maintain and transform the health and productiveness of a catchment. A systems approach allows for consideration of how these diverse processes and elements need to be considered for adaptive and integrated management.
While this may start with understanding the biophysical processes and the interplay between land, water and ecological elements, it must also include the social, economic, cultural and spiritual uses. It is the interplay between these processes and their management that makes catchment restoration and catchment management so challenging.
Our experience has demonstrated that deliberate collaborative processes lead to the better uptake and implementation of findings. Processes that are developed by engaging multiple users, and that are informed by evidence, guided by principles and build social learning are more likely to withstand change and last over time.