Section 373.042, F.S., requires the District to establish minimum flows and levels for water bodies located within the District’s boundaries. Section 373.0421(3), F.S., further requires the District to periodically reevaluate and revise adopted minimum flows and levels. This rulemaking will revise the minimum levels for Lakes Bird, Crystal and Hobbs, which are located within the Hillsborough River Groundwater Basin and hydrologically connected to the Upper Floridan aquifer ground water system. In addition, flow from these lakes contribute to the surface water flow of major tributaries to the Hillsborough River. The establishment and periodic evaluation of minimum levels is required by statute to ensure that the minimum hydrologic requirements of the water resources and ecology of these lakes and the Hillsborough River are maintained. The revised minimum and guidance levels for Lakes Bird, Crystal and Hobbs have been developed using previously peer-reviewed, Governing Board adopted methods.