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IP08 Habitat Equivalency Analysis for Natural Resource Damage Assessment
(IP066) Key Issues for Use of Habitat Equivalency Analysis in Scaling Compensatory Restoration Projects.
Ginn, T.1, Bodishbaugh, D.1, 1 Exponent, Bellevue, WA, USA
ABSTRACT- Habitat equivalency analysis (HEA) is evolving as the method preferred by both resource trustees and potentially responsible parties for scaling compensatory restoration projects as part of natural resource damage assessments (NRDAs). However, the two sides frequently have very different views on the overall structure of the model, underlying assumptions, and key input variables. These differences in approach result, in part, from a lack of detailed evaluation of the basic model in the published literature and relatively few published NRDA settlements based on HEA. Certain assumptions, approaches, and input parameters can have substantial effects on the calculated restoration requirements, making resolution of any differences critical if HEA is to be used as the basis of a successful settlement negotiation. Overall HEA results are highly dependent upon the specification of fractional service losses for each resource category. Site-specific data on service losses are often unavailable, so that professional judgment and literature-derived values must be used. Although a 3 percent discount rate may be generally acceptable for past injuries, there is strong evidence that this rate may be inappropriate for future injuries or restoration services. The use of equivalency factors for non-'in kind' services provided by allegedly injured resources and restoration projects enhances the applicability of HEA. However, in the absence of site-specific data, professional judgment is usually the basis for these critical inputs. Similarly, arbitrarily limiting the duration of services provided by restoration projects may result in a substantial underestimate of the actual benefits of a restoration project that may continue in perpetuity. Other key decision points of HEA include the specification of natural recovery rates for injured resources and the maturation rates for restoration projects. Examples are provided contrasting alternative HEA calculations for each of the key factors identified.
Key words: hea, nrda, restoration
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