River Restoration Managing the Uncertainty in Restoring Physical Habitat

For many years scientists and river practitioners have recognized the severity and extent to which aquatic ecosystems have been degraded by a variety of human disturbances and activities (Gregory and Park, 1974; Sear and Arnell, 2006). In turn, realization of the widespread nature of the problem has more recently elicited a surge of interest in the possibility of undertaking corrective interventions, such as flow restoration and channel modifications, to restore or rehabilitate lost and/or damaged ecosystem functions (Brookes and Shields, 1996; Wissmar and Bisson, 2003).