**8. Future Research**

Many shortcomings in the current practice for river relocations have been highlighted in high-profile failures, such as the Morwell River collapse in Victoria, Australia, or in poor attainment of rehabilitation objectives. White et al. [70,72] highlight the need to revise most current river relocation designs to reduce subsequent impacts to adjacent waterways.

The regional characteristics of natural rivers should be considered during the design of new relocated channels [102]. This is particularly true in the rivers demonstrating behaviour that do not fit the planform or criteria found in European and North American rivers. Greater distinction between perennial and ephemeral watercourses is needed to fully understand the mechanisms that control major channel adjustment, such as flash flooding [81,91]. This is particularly relevant where mining operations are located in arid areas with unusual geomorphology and hydrology. The recovery of vegetation in diverted channels should also be a specific area of research.

Globally, the majority of literature surrounding river relocation is derived from grey literature, or environmental impact assessments, with minimal long-term assessment or evaluation of these projects. Our ability to construct an artificial natural channel is a measure of our understanding of natural channels, which can be limited by poor understanding of various river planforms, such as the anabranching channel, or relocated channels constructed in settings that do not fit European or North American perennial rivers. As such, river relocation channels can be considered as large-scale geomorphic experiments. Within Australia, the ACARP guidelines provide criteria for river relocation designs with explicit consideration of stream type and geomorphology, proving hydraulic reference values for future relocation channel designs. However, these values are best suited to Queensland, with other states and territories lacking equivalent criteria.

Concern about environmental values of river relocations are still emerging. Relocation channels were previously constructed to transfer water from one area to another, with limited concern for the river's natural values. Now, river relocation channels are planned with a consideration of regional planforms and characteristics of the natural channel, including the high interannual flow variability of Australian rivers [105].
