Using Watershed Scale Geomorphic Assessment to Improve Urban Stream Restoration Design

The initial phases of a stream restoration project typically include a watershed geomorphic assessment to classify, identify, and assess a variety of environmental problems that can occur over a fairly large geographic area. There are three phases of geomorphic assessment at the watershed-scale, including the desktop phase, the qualitative field study phase, and the quantitative field study phase. Each phase successively offers more detailed information on system-wide instability; however, each phase also successively requires more resources to implement. An evaluation of the methods involved with each phase of assessment is needed to offer the restoration community guidance on selecting a method or combination of methods that can be used to assess system-wide stability based on time and funding constraints. This paper examines existing quantitative and qualitative assessment techniques, the strengths and weaknesses of those techniques, and their applicability to urban stream restoration design. In particular, those methods that are most beneficial to urban stream restoration are examined and how they can potentially be used to improve the stream restoration design effort by focusing on the watershed scale. An example of the selection and application of qualitative and quantitative assessment techniques to an urban stream restoration design in Bloomington, Indiana is also presented.