Cypress Lake is in the upper Kissimmee River basin in Florida between Lake Tohopekaliga and Lake Hatchineha. It is remote from urban development and extensive agriculture. Nevertheless, most of the inflow to the lake, about 302,000 acre-ft per year, comes from 2 canals and a creek that drain the upper part of the basin which receives effluent from about 35 percent of the Orlando metropolitan area. With this inflow and a lake volume of 26,100 acre-ft, water in the lake is renewed about every 0.1 year. Cypress Lake has a surface area of 6.4 sq mi, a mean depth of 6.4 ft, an immediate overland drainage area of 29 sq mi and with Lake Hatchineha, receives drainage from 1,162 sq mi. From 1950 to 1964, before locks and dams at the outlets of Lakes Kissimmee and Tohopekaliga regulated water levels at Cypress Lake, water levels fluctuated from 57 ft msl to 48 ft msl, periodically flooding the surrounding area. After regulation from 1964 to 1975, the maximum water level at Cypress Lake was slightly more than 54 ft msl. Specific conductance of the water increased in Cypress Lake from an average of 76 micromho/cm in 1954-65 before regulations to 130 micromho/cm in 1964-75 after regulation. Cypress Lake is classified as a colored alkaline lake with an average color of 79 platinum cobalt units. Emergent marsh vegetation covers almost all the shoreline of the lake. (Woodard-USGS)