PRELIMINARY DESIGN SUMMARY
The preliminary design phase of channel rehabilitation projects represents the culmination of a
systematic approach to planning, initiating, and designing channel rehabilitation projects. It is at this point
where all the planning, data assembly, and analysis come together for a channel design that will meet project
goals, insure system-wide stability, and insure that designed and constructed alternatives will operate as
intended without excessive maintenance or replacement before the projected project lifetime.
The methodologies outlined in this chapter represent a systematic and organized process for
approaching and designing channel rehabilitation projects. These methods have one thing in common: a
systematic and comprehensive approach must be taken to solve stream and watershed problems. Although
it may initially appear that mitigating localized problems within a channel may be the best solution, this
limited approach may have a far reaching impact upstream and downstream of the affected area. An
organized, multi-discipline approach is needed to plan and implement background and field study of the
watershed and channel system, to evaluate channel and bank stability, to recognize historical and current
hydraulic and sediment transport trends, and to develop alternatives to meet project goals. Without a
thorough understanding of watershed dynamics and channel processes, designs that are constructed in the
rehabilitation process may create unforseen problems.