Challenges in developing and implementing ecological standards for geomorphic river restoration projects: a practitioner's response to Palmer et al. (2005).
The authors of 'Standards for ecologically successful restoration' (Palmer et al. 2005) are commended for clearly articulating and discussing the nuances of establishing ecological standards in river restoration practice. We agree that there is a need for better and more thoughtful standards to elevate the practice of river restoration to a science of restoration. As practitioners of fluvial restoration, and students of the sciences of geomorphology, hydrology, ecology and plant sciences, we offer our experiences and observations, noting that the desire to achieve ecologically effective project outcomes is not new. We agree that there are valid questions regarding the application of the term 'restoration' to projects with minimal ecological benefits. We also concur that guiding image development is critical to project success. However, we note that well-intentioned projects often drift from having initially sound restoration objectives to ultimately providing reduced ecological benefit. Our observations suggest that this phenomenon can be attributed to risk aversion and the progressive incorporation of rigid engineered elements. We term this project hardening, where natural channel boundary evolution and change (deformability) is progressively sacrificed. This artificially constrains natural fluvial dynamics and associated ecological function. We agree that meaningful pre- and post-monitoring programmes are essential to understanding project success. We encourage the academic community to make relevant data sets available to facilitate the evolution of restoration science. It is appropriate for sponsoring agencies to require the collection of these data. Synthesis and applications. As practitioners we suggest that more interaction with ecologists and the larger academic community is necessary so that practical experience is communicated and integrated into the emerging science of restoration. While this interaction will advance the common goal of implementing more ecologically effective projects, we also note that project participants outside the scientific community must also appreciate the challenges a project faces in meeting higher standards. These challenges are not insignificant and include convincing project sponsors, practitioners and regulators of the need for standards in project generation, implementation and monitoring on a project-by-project basis.