Why is Hydraulic Engineering Expertise an Integral Part of Ecosystem Restoration of Rivers?

Ecosystem restoration of any environment requires the expertise of engineers, biologists, environmental professionals, managers, economists and the society as a whole. All these experts and stake holders do and will contribute in one facet or another to the overall goal of the restoration or revitalization of streams and rivers to recapture or reestablish the ecosystem functions. This paper will concentrate on how the hydraulic engineers do and can play a vital role in this endeavor. Channelization of a meandering river does result in the reduction of deep water habitats in the pools and the high velocity area within a riffle. Stabilization of stream banks with stones or riprap could damage the covers that are essential for aquatic habitats. Changing river regime may alter the flow structure and the velocity distribution which could result in fish egg mortality and reduced habitats for the fish fries. Construction of dams will eliminate the upstream migration of the fishes depriving them their spawning habitats. These are just some of the examples where hydraulic design could have adverse impacts on the streams, rivers and lakes. However, with some slight modifications of the hydraulic design, these and other hydraulic structures may enhance the aquatic habitats rather than being detrimental to it. This paper will show some practical examples of how hydraulic engineers could play a vital role in the ecosystem restoration of the streams, rivers, and lakes.