Guidelines for Technical Review of Instream Projects
Instream project reports generally include an analysis of existing conditions, design (such as for habitat restoration) or description (such as for an intake or other facility) of the project, evaluation of impacts on existing conditions and mitigation design (if required). The question of whether or not the project is needed or should be built is not addressed. Instead, technical review examines whether or not the approaches, methods and assumptions adopted for the project are appropriate.
Technical review works best if divided into two phases. The first phase considers the appropriateness of the methods; the second phase determines whether or not the technical analyses carried out under the methods are correct. The first phase considers three questions with respect to the project report:
1. Are the proposed methods or designs consistent with Federal and State policies and guidelines?
2. Has the project analysis considered all of the potential impacts on existing conditions?
3. Are the proposed analytic methods or designs consistent with standard practices in biology, geomorphology or engineering?
The project report should list the governing guidelines and policies for that particular project and clearly describe how they were incorporated or addressed. If such a section is missing or incomplete, the report should be considered deficient. To adequately address this question, the reviewer requires a good understanding of the various regulations governing the instream environment.
The report should also identify and describe potential project impacts on existing conditions. These may occur on hydrology and hydraulics (instream depths and velocities) and also on local bed scour, stream morphology, sediment supply or sediment transport regime, temperature, biological communities, riparian vegetation, etc. If key components of the instream environment are not addressed clearly in the project report, it should be considered deficient. Note that not all instream components may be significant for a particular project but all should be considered in the report.
Evaluation of the appropriateness of analytic methods generally requires some discipline expertise and, often, a team approach to the review. For example, depending on the nature of the project, different hydraulic models – one-dimensional, two-dimensional, steady or unsteady – may be required to adequately describe existing and project conditions. If the adopted model is inappropriate, the results should be viewed with skepticism and the report considered deficient. Similar comments apply to models and methods adopted to assess other components of the instream environment.
The second phase of the review only begins when the above three questions have been adequately addressed. Under this phase, a detailed review of the technical analysis begins. Assumptions in the report are reviewed and models or calculations are checked to ensure they are consistent with the reported results. Such a review often requires that models or spreadsheets developed by the proponent are made available and that the reviewers have the required software and expertise to confirm they are correct. Given typical constraints on the time for reviews and the expertise often required to review models, the second phase will seldom be carried out.
By Ken Rood who has over 30 years' experience in the areas of fish habitat restoration, storm water hydrology and hydraulics, floodplain mapping, erosion assessment and design, and review and permitting of bank improvement projects in private consulting for public projects. M.S. Geomorphology 1980, B.A. Geography 1976, Simon Fraser Univ. British Columbia, Canada.