Impacts to Columbia Basin wildlife as a result of the construction of the Federal
Columbia River Power System (FCRPS) have been quantified by the Northwest Power
and Conservation Council through the completion of "loss assessments" for each
dam. With a few exceptions, BPA has agreed those loss assessments present a
useful guide for establishing FCRPS mitigation goals. Loss assessments identify
"habitat units" lost due to construction. Habitat units are a measurement of
both the quantity and quality of habitat, as indicated by its suitability for
use by target species that typically rely on a particular kind of habitat.
As BPA implements a mitigation activity, it takes credit for its effort. On new
projects, the habitat units are measured or estimated and then counted against
the loss assessment for the project being mitigated. BPA takes one habitat unit
of credit for each habitat unit it mitigates.
See our Mitigation Program Glossary for
definitions of terms by the program. To really understand how wildlife crediting works
we recommend reviewing a set of diagrams illustrating
how habitat units might change over time within a hypothetical wildlife management
Well over half of all FCRPS-related wildlife losses have been mitigated.
To date, mitigation is complete for the construction impacts of Hungry Horse,
Libby, Dworshak, Bonneville, The Dalles, John Day, McNary, Lower Granite, Little
Goose, Lower Monumental, and Ice Harbor dams. BPA continues to work toward mitigation
both directly, through actions aimed at benefiting wildlife, and indirectly, through
actions more broadly focused on ecosystem improvements that benefit both fish
For real-time summaries of Wildlife Mitigation, see the
Wildlife Crediting reports
available from our Report Center.
Bonneville Power Administration
voice: (503) 230-3171