Estimating Economic Benefits of Entrainment and Impingement Reductions Using Equivalent Loss Models

Under the new §316(b) rule, economic costs and benefits of intake alternatives must be considered in determining Best Technology Available (BTA) for entrainment mortality at each facility.  Costs of BTA compliance are calculated using well-established engineering protocols.  Benefits are estimated from the economic values assigned to eggs, larvae and juvenile fish that are currently being entrained but would be protected by each of the proposed technologies. However, procedures for calculating economic benefits are certainly less familiar to fish biologists involved in §316(b) permitting.

 Equivalent loss models, which are variations of yield-per-recruit models commonly used in fishery management, have a long history of use in making adverse environmental impact assessments for cooling water withdrawals.   These models, when extended to the early life stages, provide a sound basis for calculating economic values of early life stages that are needed for site-specific economic benefits of each technology considered. In this paper, we discuss each of the categories of economic benefits (direct, indirect and non-use) and show how equivalent loss models can be used to estimate the benefits in each category.  Finally, we will provide some real-world examples of how this approach has been successfully employed