Fall Creek Lake (Lane)
Reachcode: 17090001001050 | Area: 1715.7 acres | Shoreline: 22.1 mi | View on Interactive Map
(From Atlas of Oregon Lakes, Johnson et al. 1985). Fall Creek Lake, one of 13 multi-purpose water resource projects built and operated by the U. S. Corps of Engineers in the Willamette Valley, is located on a small tributary of the Middle Fork Willamette River in the rolling hill country southeast of Eugene. It became operational in 1966 and exists primarily to control downstream flooding on the Willamette River. As such, the water level fluctuates throughout the year. From spring until late summer the water level is kept high (maximum depth = 161 feet) and the lake is heavily used for recreation. Beginning in late summer and through the winter, the water level is drawn down to as much as 100 feet below full pool to provide storage for flood waters. It is then less satisfactory for recreation because of the extensive mud flats exposed around the shoreline.
The impoundment is shaped by two main arms, the southern arm fed by Winberry Creek and the northern arm by Fall Creek. A dense, coniferous forest blankets the slopes in the upper part of the drainage basin. In the lower reaches, natural vegetation patterns have been altered by logging, grazing, and agricultural practices. Short-term visual scarring may result as public and private forest management agencies harvest timber resources near the lake. There are some farm sites immediately upstream from the lake in the broad, tributary flood plains. The Corps of Engineers manages the shoreline, while Lane County operates two day-use parks with swimming, boating, and picnicking facilities. Sky Camp (Springfield Kiwanis Youth Camp) has been developed on the south shore in cooperation with the Corps and local school districts. Fishing at Fall Creek Lake is primarily for stocked rainbow and native cutthroat trout that drift down from the tributaries. A fish trap is used at the base of the dam to collect migrating Chinook salmon and steelhead which are then transported upstream to complete their spawning cycle.
Water in Fall Creek Lake is generally high quality, chlorophyl and phosphorus concentrations are low, and biological productivity is low. However, there have been serious problems in the past. Hydrogen sulfide developed in the hypolimnion of the newly constructed reservoir during the summers of 1966 and 1967, and caused a significant fish-kill downstream following the late summer draw-down. Eventually the problem resolved itself as preimpoundment accumulations of organic bottom debris decomposed, and gradual disappearance of these materials allowed a continuous improvement in hypolimnetic oxygen content. Blue-green algal blooms are occasionally a problem, reducing the water transparency. Based on a combination of indicators Fall Creek Lake is classified as mesotrophic.