Incorporating uncertainty in the design of stream channel modifications

The designs of stream channel naturalization, rehabilitation, and restorati on projects are inherently fraught with uncertainty. Although a systematic approach to design can be described, the likelihood of success or failure o f the design is unknown due to uncertainties within the design and implemen tation process. In this paper, a method for incorporating uncertainty in de cision-making during the design phase is presented that uses a decision ana lysis method known as Failure Modes and Effects Analysis (FMEA). The approa ch is applied to a channel rehabilitation project in north-central Pennsylv ania. FMEA considers risk in terms of the likelihood of a component failure , the consequences of failure, and the level of difficulty required to dete ct failure. Ratings developed as part of the FMEA can provide justification for decision making in determining design components that require particul ar attention to prevent failure of the project and the appropriate compensa ting actions to be taken.