When appearing in this part or in any rule, regulation, or order adopted pursuant thereto, the following terms mean:(1) “Dam” means any artificial or natural barrier, with appurtenant works, raised to obstruct or impound, or which does obstruct or impound, any of the surface waters of the state.
(2) “Appurtenant works” means any artificial improvements to a dam which might affect the safety of such dam or, when employed, might affect the holding capacity of such dam or of the reservoir or impoundment created by such dam.
(3) “Impoundment” means any lake, reservoir, pond, or other containment of surface water occupying a bed or depression in the earth’s surface and having a discernible shoreline.
(4) “Reservoir” means any artificial or natural holding area which contains or will contain the water impounded by a dam.
(5) “Works” means all artificial structures, including, but not limited to, ditches, canals, conduits, channels, culverts, pipes, and other construction that connects to, draws water from, drains water into, or is placed in or across the waters in the state.
(6) “Closed system” means any reservoir or works located entirely within agricultural lands owned or controlled by the user and which requires water only for the filling, replenishing, and maintaining the water level thereof.
(7) “Alter” means to extend a dam or works beyond maintenance in its original condition, including changes which may increase or diminish the flow or storage of surface water which may affect the safety of such dam or works.
(8) “Maintenance” or “repairs” means remedial work of a nature as may affect the safety of any dam, impoundment, reservoir, or appurtenant work or works, but excludes routine custodial maintenance.
(9) “Drainage basin” means a subdivision of a watershed.
(10) “Stormwater management system” means a system which is designed and constructed or implemented to control discharges which are necessitated by rainfall events, incorporating methods to collect, convey, store, absorb, inhibit, treat, use, or reuse water to prevent or reduce flooding, overdrainage, environmental degradation, and water pollution or otherwise affect the quantity and quality of discharges from the system.
(11) “State water quality standards” means water quality standards adopted pursuant to chapter 403.
(12) “Watershed” means the land area which contributes to the flow of water into a receiving body of water.
(13) “Dredging” means excavation, by any means, in surface waters or wetlands, as delineated in s. 373.421(1). It also means the excavation, or creation, of a water body which is, or is to be, connected to surface waters or wetlands, as delineated in s. 373.421(1), directly or via an excavated water body or series of water bodies. (14) “Filling” means the deposition, by any means, of materials in surface waters or wetlands, as delineated in s. 373.421(1). (15) “Estuary” means a semienclosed, naturally existing coastal body of water which has a free connection with the open sea and within which seawater is measurably diluted with fresh water derived from riverine systems.
(16) “Lagoon” means a naturally existing coastal zone depression which is below mean high water and which has permanent or ephemeral communications with the sea, but which is protected from the sea by some type of naturally existing barrier.
(17) “Seawall” means a manmade wall or encroachment, except riprap, which is made to break the force of waves and to protect the shore from erosion.
(18) “Ecological value” means the value of functions performed by uplands, wetlands, and other surface waters to the abundance, diversity, and habitats of fish, wildlife, and listed species. These functions include, but are not limited to, providing cover and refuge; breeding, nesting, denning, and nursery areas; corridors for wildlife movement; food chain support; and natural water storage, natural flow attenuation, and water quality improvement, which enhances fish, wildlife, and listed species utilization.
(19) “Mitigation bank” means a project permitted under s. 373.4136 undertaken to provide for the withdrawal of mitigation credits to offset adverse impacts authorized by a permit under this part. (20) “Mitigation credit” means a standard unit of measure which represents the increase in ecological value resulting from restoration, enhancement, preservation, or creation activities.
(21) “Mitigation service area” means the geographic area within which mitigation credits from a mitigation bank may be used to offset adverse impacts of activities regulated under this part.
(22) “Offsite regional mitigation” means mitigation on an area of land off the site of an activity permitted under this part, where an applicant proposes to mitigate the adverse impacts of only the applicant’s specific activity as a requirement of the permit, which provides regional ecological value, and which is not a mitigation bank permitted under s. 373.4136. 
