control of Yolo county. The northern end of Clear Lake adjacent to Rodman Slough and Middle Creek was blocked off with levees, between 1900 and 1940, and the land was "reclaimed" for agricultural use. During the summer months, Clear Lake provides irrigation flows for agricultural operations in Yolo County. Management of the lakebed is provided by the County of Lake, in accordance with authorities granted by the State Lands Commission in 1973. A project is currently under way to breach the levees, and restore of lake and wetland. Bloody Island will again be an island. The additional water resulting from the increased lake area will be allocated to municipal districts drawing water from the lake. Yolo's water allowance under the Solano decree may also be increased. The management of the lake level is thus designed to avoid flooding, provide water to Yolo County and local water companies, and maintain enough water for recreational use. Sewage from many Lake County towns no longer flows into the lake; instead, it is pumped to The Geysers geothermal plant. On September 15, 2014, the lake level fell to on the Rumsey gauge, the lowest level since the 1977 drought. When full, the lake level measures . Environmental issues Agriculture and wetlands The Clear Lake Watershed contains both freshwater marshes and vernal pools. The freshwater marshes are characterized by emergent vegetation including tules and cattails among other species. Ecologists have identified over 1500 vernal pools in area, largely located on private lands. The largest remaining wetlands include Anderson Marsh State Park and Rodman Slough. Wetlands in the Clear Lake watershed serve a variety of important ecological functions including providing habitat for local fish and wildlife as well as filtering sedimentation entering the lake from streams. Due to increased agricultural and urban land use, Clear Lake’s historic wetland habitats have been reduced by 79%. Agriculture has been a significant form of land use in the region since the mid-19th century. Analysis of sediment cores drawn from the lake indicate that the increase in sedimentation rates corresponds with an increase in the use of heavy agricultural equipment in the 1930s. Other agricultural activities such as stream channelization, groundwater pumping, application of fertilizers and pesticide use have contributed to lake sedimentation, hillside erosion and floodplain encroachment. The primary pollutant of concern associated with agriculture in the area is nitrate, with elevated nitrate levels having been identified in the