Minimum flows proposed for the upper Peace River to ensure that the minimum hydrologic requirements of fish and natural systems associated with the upper segment of the river are met and not jeopardized by withdrawals. The upper segment of the river includes that area between Bartow and Zolfo Springs. The minimum flows are based on the hydrologic requirements of biological communities associated with the upper Peace River system, as well as considering non-consumptive uses including fishing, wildlife observation, general recreation, aesthetic enjoyment, canoeing and boating. The minimum flows will be supported by District water development projects. The District also proposes minimum low and minimum high lake levels, as well as the ten-year flood, and high and low guidance levels for Lakes Jackson, Letta, Lotela and Little Lake Jackson on the Highlands County Ridge and Lakes Clinch, Eagle, McLeod and Wales in Polk County. The High Minimum Lake Level is the elevation that a lake's water levels are required to equal or exceed 10 percent of the time on a Long-term basis. The Minimum Lake Level is the elevation that the lake's water levels are required to equal or exceed 50 percent of the time on a Long-term basis. The High and Low Guidance Levels and the Ten-year Flood Guidance Level are advisory guidelines for lakeshore development of, including water dependent structures and operation of water management structures. A minimum aquifer level is proposed for the coastal portion of the Southern Water Use Caution Area in southern Hillsborough, Manatee and northern Sarasota counties. The minimum aquifer level is to stabilize regional ground water level declines so that long-term management efforts can slow the rate of regional saltwater intrusion in the area.