Protect, enhance, restore and connect aquatic and terrestrial habitat. Protecting existing quality habitat is as important as enhancing degraded habitats.


Habitat mitigation activities are important for off-site mitigation success and are guided by subbasin plans, which have been developed for most of the subbasins and the mainstem reaches in the Columbia River Basin. These plans include assessments of current physical and biological conditions and also identify factors that limit the productivity and capacity of focal species in priority reaches. Habitat mitigation also includes large-scale, biologically targeted habitat improvement projects, such as those reflected in the Columbia Basin Fish Accords and FCRPS BiOp. Habitat actions can help to reduce the migration of toxic contaminants by reducing erosion and sediment transport to waterways.


  • Build from strength

    Efforts to protect and restore fish and wildlife impacted by hydropower should protect habitat that supports existing populations that are relatively healthy and productive. Adjacent habitats should be expanded if they have been historically productive or have a likelihood of sustaining healthy populations by reconnecting or improving habitat. In a similar manner, this principle applies to the restoration of weak stocks: Restoration should focus first on habitat where portions of weak populations are doing relatively well and then extend to adjacent habitats [see strongholds strategy].
  • Restore ecosystems, not just single populations

    Increasing the abundance of single populations may not, by itself, result in long-term recovery. Restoration efforts must focus on restoring habitats and developing ecosystem conditions and functions, including within blocked areas where reintroduction is being considered, that will allow for expanding and maintaining diversity within and among species. This will help sustain a system of robust populations in the face of environmental variation.
  • Use native species wherever feasible

    Even in degraded or altered environments, native species in native habitats provide the best starting point and direction for needed biological conditions in most cases. Where a species native to a particular habitat cannot be restored, then another species native to the Columbia River Basin should be used. Any proposal to produce or release non-native species must overcome this strong presumption in favor of native species and habitats and be designed to avoid adverse impacts on native species [see non-natives and invasive species sub-strategy].
  • Address transboundary species

    Because about 15 percent of the Columbia River Basin is in British Columbia, including the headwaters of the Columbia and several of its key tributaries, ecosystem restoration efforts should address transboundary stocks of fish and wildlife and transboundary habitats. Where mitigation measures are designed to benefit both American and Canadian fish and wildlife populations, American ratepayer funding should be in proportion to anticipated benefits to the American populations.

General measures

  • The core measures of this strategy include:
    • Removing fish-passage barriers
    • Screening water diversions
    • Protecting and improving riparian habitats in all areas of the Columbia River Basin to improve water quality, reduce contaminant transport, lower water temperature including creating thermal refugia, and reduce sediments through fencing, vegetation planting, erosion control, best land-management practices, and acquisition of land through conservation easements and other types of acquisition
    • Improving the amount, timing, and duration of instream flows through water rights and acquisitions
    • Reconnecting floodplains through passive and active improvements in channel structure and geomorphology and re-establishing natural river processes
    • Acquiring and enhancing terrestrial uplands for wildlife habitat
    • Continuing Bonneville funding to acquire water and pursue water rights in subbasins where water quantity has been identified in subbasin plans as a primary limiting factor and where flow targets have been identified

Mainstem habitat measures

The program focuses much of its habitat efforts in the Columbia Basin tributaries. Given the importance of mainstem habitat to production of salmon and other key species, the Council supports increased investments in mainstem habitat improvements to increase the extent, diversity, connectivity, and productivity of mainstem habitats for mainstem spawning, rearing, and resting. The Council will consider primary mainstem habitat measures including:

  • Coordinating actions with the flow measures intended to improve ecosystem function in the mainstem
  • Enhancing the connections between the mainstem sections of the Columbia and Snake rivers and floodplains, side channels, and riparian zones
  • Continuing actions to reconnect the river to its floodplains wherever possible in the mainstem, with special emphasis on the estuary and lower Columbia River
  • Protecting and enhancing mainstem riparian areas and wetlands to protect aquatic conditions and form a transition to floodplain terrestrial areas and side channels

The Council will consider additional mainstem habitat actions including:

  • Identifying, protecting, enhancing, and restoring the functions of alluvial river reaches in the mainstem
  • Excavating, creating and reconnecting additional backwater sloughs, alcoves, and side channels to the main channel
  • Dredging/excavating lateral channels that have silted in
  • Creating more shallow-water habitat
  • Identifying, protecting, restoring, and managing thermal refugia for salmonid use during high water-temperature periods
  • Acquiring and protecting lands adjacent to the mainstem critical to protecting habitat areas and local water quality
  • Where feasible, reconnecting protected and enhanced lower tributary habitats to protected and enhanced mainstem habitats, especially in the area of productive mainstem populations
  • Increasing the amount of spawning habitat for mainstem core populations of Chinook, coho, chum, sturgeon, and lamprey