Streams and Rivers

Characterized by moving fresh water
This refuge stream has a gravelly bottom, riffles and shade from surrounding vegetation creating good habitat for many animals/USFWS Photo
Willapa National Wildlife Refuge has the responsibility for approximately 20 streams with fish populations, as well as intermittent streams. Historically, streams contained large amounts of woody debris that created a complex aquatic environment of riffles, pools, glides, runs and side channels. Habitat features of healthy riverine systems include: large woody debris, an even ratio of pools and riffles, stable stream banks, intact riparian vegetation, and the addition of organic matter from leaf litter and fallen branches. Large woody debris in a stream/river system is an important component that impacts channel formation and channel stability. It traps sediments and creates pools while causing riffles to form downstream. In high energy streams, large woody debris will assist in the retention of spawning gravel as well as provide cover for fish and other species. It also provides habitat as well as nutrient sources for macroinvertebrates and microorganisms that serve as food source for freshwater mussels and birds. Riparian vegetation creates shade that keeps the stream cool.

Refuge streams and rivers support runs of anadromous fish such as chum, coho and Chinook salmon, as well as coastal cutthroat trout. Western brook lamprey are resident in some of the streams as are rare amphibians such as the Columbia torrent salamander and tailed frog. Transplanted populations of western pearlshell mussels are also present in several refuge streams. 

Land use activities and previous land management practices have impacted wildlife habitat values in and along rivers and streams in the Willapa Bay watershed and contributed to the decline of fish runs. Stream processes in many areas have been altered. Degradation of streams, including those on the Refuge, has occurred historically. Problems include loss of connectivity to the estuary due to highway and dike construction, presence of fish passage barriers, water quality issues (such as, temperature and sedimentation), and presence of exotic species. Restoration of riverine habitat is a priority for the Refuge. Learn more about refuge efforts in conserve area streams and the wildlife that depend on them…

Facts About Streams and Rivers

Have large woody debris, pool & riffles, and shade

Experience frequent disturbance from flood events

Healthy streams have cool temperatures and high levels of dissolved oxygen