Streams & Rivers

Streams on National Forests in the Pacific Northwest provide much of the best remaining habitat for native fish species.

When one thinks of the Pacific Northwest, most picture deep dark forests with rain-swollen rivers hiding salmon and steelhead fresh from the ocean. Although this picture does mirror many river systems in the Northwest, it really portrays only the western one-third of the States of Washington and Oregon. The diversity of stream types in the Northwest is truly amazing- from desert washes to alpine brooks, to spring-fed meadow creeks, boulder-strewn cascades, and the butte-rimmed rapids of large rivers like the Upper Columbia and Snake Rivers. Over 20,000 miles of these streams in the Region support a wide range of aquatic organisms, including native cold-water and warm-water fish, as well as a number of fish species introduced to provide increased fishing opportunities.

The Forest Service manages stream habitats to support healthy populations of these fish stocks, protect water quality, and to provide opportunities for human uses such as hiking, fishing, educational programs and fish viewing. Management is based on sound scientific information (see Inventory and Monitoring sections) and comprehensive, integrated watershed analyses. Protection is assured through a system of aquatic refugia and riparian reserves. Where watershed analysis highlights impacted areas, restoration programs are developed (at watershed scale) to help recover natural functions and processes. This management applies to all streams regardless of size- in fact, restoration activities tend to focus on small streams (including intermittent tributaries) and headwater areas because of their importance in supplying high quality water and their function as seasonal refuges for aquatic organsims.

"Restoration emphasizes identification and recovery of critical processes and function. Rock Creek, in a burned, logged and grazed area on Mt. Hood National Forest, shows stream and riparian recovery following fencing, planting and in-channel treatments from 1984-1999" (Photos above: 1984 Pre-project, 1986 Post-project and Recovery by 1999).

Restoration

The emphasis for restoration is to identify and fix causes of problems and not symptoms. Therefore, stream restoration typically starts outside the stream channel, from the ridge-tops working downhill, correcting any erosion/slope stability and road related problems (including fish passage and drainage). Riparian and floodplains are usually next, replacing structure/roughness, planting, and/or recovering wetland/off-channel features. Once all these factors have been addressed, restoration of channel features, such as channel form (cross-section profile, length/meander pattern, amount and types of pools) and/or structural attributes (logs or boulders) are considered. An excellent example of channel restoration is Enchanted Valley, where a reconstructed meandering channel has replaced an eroding ditch in a coastal wetland area.

Aquatic Habitat/watershed restoration is guided by a regional restoration strategy (follow this link for the Executive Summary). Refer to Forest Specific for additional examples of stream habitat restoration, and Monitoring for examples of evaluations of stream protection and restoration practices. For additional examples of whole watershed restoration see Whole Watershed.