Which environmental assets will we protect?
The River Health and Environmental Flow (RH&EF) project team are building a strong foundation for effective decision-making about how environmental flows should be implemented across China. This includes assessing and defining environmental water needs appropriate to China’s situation, how to trade stream flow requirements against the needs of other users, and how to define and identify environmental assets.
Environmental flows are those elements of a flow regime needed to achieve a certain desired state of river health, as determined by government and/or the community. China recognises the importance of environmental flows, and seeks to balance the needs of the environment with other demands on the water resource.
The growing need for energy and fresh water is being addressed through infrastructure projects, such as hydropower developments and interbasin water transfers. These projects directly compete with maintaining appropriate environmental flows.
The revision of the river basin masterplans for China’s major river basins is involving the identification of environmental flows in the water allocation arrangements for the river basin. Providing for environmental flows within China’s water management framework will involve changes to the way water is allocated and managed at a basin and local scale, to how hydropower systems are operated, and to the planning and development of projects at a basin scale. Each of these elements will need to be informed by an improved scientific understanding of how flows and the river ecology relate.
To effectively evaluate river health, environmental flows and water reallocation, IWC researchers recommend using an asset-based approach to environmental flows assessment. This approach is outlined in Figure 2, and is designed such that it can be applied to any river and any environmental flows issue.
This framework can accommodate any form of environmental flow assessment, any analytical tools, any size river, any existing constraints, any existing or proposed river uses, and any balance of scientific or social input to the process. Choosing not to use some components of the framework won’t prevent a result being obtained, but it may weaken confidence in the result.
A key part of this eight-step process is to identify what assets need to be protected. Environmental assets are important because of the services they provide. For example, water for irrigation may need to be balanced against stream flows that maintain a healthy environment for fish, or minimum flows required to enable navigation.
The hydrological modelling in Step 5 of the framework relies on establishing relationships between flow and ecology. As a first step, IWC researchers recommend developing a regional or national scale classification of natural river flow types. This is because streams or rivers with similar river flow types are likely to share particular ecological features or ‘assets’.
Interested parties will ultimately decide on the trade-off between river health and security of supply for non-environmental users of river water. But the trade-off should relate back to the original agreed desired state of river health.
The method of assessing environmental flows will continue to be discussed and developed. But one thing is certain – by allocating water to environmental flows, China is ensuring that the benefits rivers and streams offer can be maintained and enhanced.