ABSTRACT
This chapter aims to review stream habitat improvement methodology, describe the main techniques available, and discusses the actual and potential uses of improvement methodology in mitigating the adverse effects of river regulation on fisheries. The effects of river regulation through channelization and impoundment on fish and other aquatic communities can be severe and extensive. River channelization is carried out to increase the capacity and hydraulic efficiency of a stream or river. This is achieved primarily through construction works which straighten, widen, and deepen the river channel. There are two main approaches to environmental mitigation and fisheries conservation in channelized rivers. First, the ecological impacts of the work can be reduced through changes in the design criteria of channelization schemes. Second, habitat lost or degraded through channelization can be restored and rehabilitated using habitat improvement techniques. Most techniques function by either diverting flow away from the bank or stabilizing the banks.
