History of study area. The lake has undergone a long series of modifications over time and has no natural outlet. It receives the stormwater runoff from a basin of approximately 680 acres through an abandoned combined sewer line from which sanitary flows were diverted in the late 1950s when the Southwest Suburban Sewer District built a facility to treat sanitary sewage before releasing it to Puget Sound. A document written in 2012 that details the lake and watershed history has been included as Appendix B. A shortened account follows. The recent history of the lake began in the 1870s when western settlers arrived in the area and used the open water wetland as a mill pond for holding the timber they harvested. A shingle mill was constructed along the shoreline. After deforestation, the catchment converted to small farms, and a commercial area was developed to the northwest of the lake. The area immediately around the lake was developed as a golf course in the 1920s-30s, and the lake was dredged to provide more storage capacity for holding irrigation water. A combined sanitary and stormwater sewer system with an outfall to Puget Sound was built in the 1930s and then enlarged during World War II when housing was built to accommodate Boeing workers as part of the war effort. In the 1950s, the Southwest Suburban Sewer District divided the sanitary and stormwater flows, directing sanitary flow to a treatment plant before discharge to the Sound. In the late 1950s – 60s, King County and the North Highline School District bought the golf course land and divided it into property for schools and an urban park. Xxxxxxx Lake is contained within the park, and the county built both a swimming beach at the east end of the lake and an adjacent fishing dock as park amenities. In the early 1960s the stormwater flow was diverted into Xxxxxxx Lake, possibly to supply more water to the lake to augment the water supply for recreation. However, a series of high bacterial measurements in the water and increasing algae populations began to limit swimming activities. The beach was closed intermittently due to health and safety concerns, but was permanently closed by the early 1990s. Fish stocking by WDFW began in 1976, but also had ended by 1992. Over the years, large wet weather events sent lake levels soaring in winter, and at times the lake expanded so that a large part of the park was under water. Because the lake has no natural outlet, and the surrounding topography made creating one unfeasible, pump...
History of study area. Land use in the lower Yakima River valley is predominantly irrigated agriculture, heavily reliant on the Yakima River for irrigation water supply. For decades, high suspended solids, turbidity, DDT and other pesticides, high temperatures, and other kinds of pollution have been documented in the lower Yakima River. By the mid-1990s, water quality evaluations by the US Geological Survey (USGS) indicated that some improvements had been made, but beneficial uses were still impaired by sediment and sediment-borne pollutants, like DDT, from irrigation returns (Xxxxxxx et al., 1999). Consequently, several reaches of the lower Yakima River and several of its tributaries did not meet numerous state water quality criteria and federal guidelines. As a result, Ecology placed these water bodies on Washington State's 303(d) list. Water quality issues in the entire Yakima River basin range from fecal coliform bacteria to suspended sediments and turbidity, as well as toxics, pH, nutrients, dissolved oxygen, and temperature. The water quality issues in the basin impact the beneficial uses of the water, potentially making it unsafe for drinking or recreation and threatening the health of aquatic animals and fish living in it. At this time there are two fish species listed as Threatened under the federal Endangered Species Act: mid-columbia bull trout and mid-columbia steelhead. Studies in the upper and middle Yakima River (summarized in Xxxxxx et al. 2009) indicated that temperature, toxic chemicals, and lack of foraging habitat and refuge from predators were creating obstacles for survival of these species. At this time, Ecology's temperature standards are based on the current understanding of survivable temperature ranges. There are a number of water quality improvement projects, mainly in the form of total maximum daily loads (TMDLs), in various stages of development across the watershed. Those projects in the lower Yakima River include: Yakima River: Toxics • Water quality monitoring of DDT, dieldrin, and other chlorinated pesticides (Xxxxxxx et al. 2010).
