Some general observations regarding water quality in coastal river basins follow.
Elevated stream temperature is the most common problem. Streams in poor condition may not be directly harmful to fish, but conditions that limit production of stream invertebrates, which are indicators of water quality, have an indirect effect on the growth and survival of salmon. Small streams in forested areas experience temperature increases when streamside hardwoods are removed in an effort to reestablish stands of riparian conifers. Small streams in agricultural and urban areas appear to contain the highest pesticide levels in some basins. A network of key monitoring sites has been developed under the Oregon Plan to represent the range of water quality throughout the coast.