Lateral Connectivity Issues Associated With Altered River Systems

A case study of Alabama’s Black Warrior River illustrates lateral connectivity issues attendant to aging and manipulated river systems.  Lateral connectivity is a dimension of a river system’s hydrological linkages, or the surface water exchange between the main river channel and off-channel areas (e.g., backwaters). The research documents the historic change in such connectivity and associated ecosystem health and human impacts.  The study river is considered representative of other manipulated river systems in North America and in other countries with inland waterways altered by locks and dams.  Lateral connectivity is an important inland waterway attribute due to its effect on the ecological (e.g., fishery and broader ecosystem health) and human dimensions (e.g., anglers, boaters, and camp house owners).  Research topics include: historic change in lateral connectivity on inland waterways, environmental impacts (particularly fishery health) related to connectivity, affected stakeholders, and past and current legal authority and management to address associated issues. Conclusions are that the study area’s historic management was largely one-dimensional and main channel-oriented, resulting in a significant deterioration of main river channel connectivity with off-channel areas.  This has resulted in a range of largely negative impacts to the area’s fishery and stakeholder groups dependent on backwater access.