The Eel River is located in northern California, approximately 200 miles north of San Francisco at latitude 40° 38' 32" N, longitude 124° 18' 43" W. The Eel River catchment lies predominantly in Humboldt and Mendocino counties and also extends into Trinity, Glenn and Lake counties.      The mainstem Eel River is approximately 197 miles in length and receives flow from 832 tributaries - adding up to 3,526 miles of stream. It is the third largest river in California with a drainage basin of 3,684 square miles (CDFG 1997). Elevations on the mainstem range from sea level at the mouth to over 6,700 feet at the headwaters. Four principle tributaries are the Van Duzen River, North Fork Eel River, Middle Fork Eel River, and South Fork Eel River.      Because the Eel River catchment is large and complex, the CWPAP team has divided it into several basins for assessment. This report assesses the Lower Eel Basin. The Outlet Creek, Van Duzen River, and South Fork Eel River basins are also currently being assessed by the CWPAP team.      The Lower Eel Basin assessment area is composed of less than 5% of the entire Eel River catchment at approximately 172 square miles and is defined as the watershed area from the mouth, upstream approximately 21 miles. As the Lower Eel Basin comprises the most downstream and depositional section of the entire Eel River catchment, any discussion of watershed processes within the basin must be considered in this larger context.      While the present name of the Eel River reflects the number of so-called lamprey eels that Euro-American settlers observed being collected by the native peoples in the area, its native name summarizes once healthy salmon runs: "...Eel River is called by the Indians, Weeott [sic] - plenty - from the immense quantities of Salmon obtained by them every fall in that stream..." (Humboldt Times September 23, 1854). These large salmon runs allowed Euro-American settlers to establish a lucrative commercial fishery, which by 1858 was supplying markets from California to the east coast, as well as outside the country.      At the same time, this young fishery was described as equal to the Sacramento River fishery, though surpassing it in terms of price (Humboldt Times April 10, September 11, 1858). Indeed, historical records show that the Eel was one of the state’s most productive rivers and is even now considered the third largest producer of salmon and steelhead (CDFG 1997).      However, salmon runs in the Eel River have declined. Defining and quantifying the causes of this decline can be difficult, though most surely they are a result of cumulative effects of human impacts in a dynamic system.      The Lower Eel River Basin is the depositional zone for the entire Eel River catchment, and as such embodies the processes throughout. As part of this highly dynamic catchment, the Lower Eel experiences high levels of sedimentation due to natural hillslope processes including very erodible bedrock and high levels of precipitation (Reynolds et al. 1981). Additionally, the area is situated in a tectonically complex area. Landslides and erosion introduce large quantities of sediment to streams, and are exacerbated by the region’s climate, geology, topography and land use. The Eel has the highest recorded average suspended sediment yield of any U.S. river its size (Brown and Ritter 1971), and in 2002, the US Environmental Protection Agency (EPA) listed the lower portion of the Eel River as an impaired water body due to sediment and temperature.