Landscapes disturbances made in central Florida’s landscape of karst rock are understood to have dire consequences due to possible sinkhole formation. The Florida peninsula is well known for both sinkhole formations and karst rock. It is necessary to understand karst rock strengths and weaknesses when planning to disturb the landscape in central Florida. "Disturbing" the landscape is defined as adding or removing large amounts of mass in one particular area such as building large structures or surface strip mining, respectively.
Most of the central Florida landscape is formed in karst rock and is prone to sinkhole formation. This fact is well known but not necessarily understood (4). Sinkhole formation occurs because of a surface collapse. The surface can collapse when groundwater amounts change dramatically, such as over-pumping and removing large volumes of groundwater by Florida’s phosphate industry. Collapses can occur when adding large amounts of mass, such as the phosphate industry’s highly toxic phosphogypsum stacks as well.
When the surface collapses, the earthen materials forming the landscape fall into a hollow cavity. The cavity can be a hydrogeological structure containing water. A cavity full of water is referred to as an aquifer or groundwater containment structure, in this case. The cavities, while full of water can support the surface materials because water is not compressible. When a near surface cavity empties of water, a surface collapse can occur above the cavity due to decreased back pressure from lack of water.
Understanding Urban Development Is Dependent On Karst Landscapes
Central Florida’s "urban development" should be managed based on karst rock topography attributes. When urban development planning disregards Florida’s karst topography attributes or features, sinkholes may occur unexpectedly. Karst landscapes display many unique challenges regarding water and land management due to possible sinkhole formation. (1) Understanding or managing karst features is critical to long term water and land resource management in central Florida. Surface collapses due to karst rock structures are well documented and understood. Dramatically changing the landscape, such as phosphate strip mining activities has serious negative effects on karst rock landscapes. The mines stress the landscape because surface mining adversely affects groundwater movement which in turn can degrade natural water and land resources. (4)
Central Florida’s karst landscape is nature’s way of controlling groundwater movement. Phosphate strip mining dramatically changes the landscape and causes water movement to re-route, slow, or stop flowing completely (3). It is clear; stripping the central Florida landscape and over-pumping wells can cause severe environmental catastrophes.
Florida’s phosphate industry’s environmental foot print is extremely large and growing daily causing serious environmental impacts to central Florida’s landscape. Phosphate industry officials understand this as well. They know of the possible environmental impacts before they occur because their engineers understand karst landscape topography, features, advantages, disadvantages, and disregarding them as collateral damage is also known.
Their engineers and scientist understand the effects of hydrogeological movement of groundwater and the effects of removing large volumes of water from groundwater reserves. (2) Fluid dynamics is well understood by engineers today. Applied fluid dynamics is fundamental and all graduate engineers understand fluid dynamics by definition. Meaning, all professional engineers working in the phosphate industry understands fluid dynamics by definition long before earning a professional engineers license.
It is fair to say phosphate industry engineers understand central Florida’s karst rock landscape features are based on fluid dynamics. They understand the effects of dramatic landscape modifications or removing too much groundwater per day has on the local environment.
The Florida phosphate industry has over 100 years of hands on experience in dramatic landscape changes. If the phosphate engineers understand all the applications mentioned, then industry officials also know and understand the effects of strip mining the central Florida earth.
In the early 1970’s, Florida’s elected officials passed regulations on consumption of groundwater and land resources by the phosphate industry. The legislation passed requires the phosphate industry conduct extensive landscape and groundwater research. This is to determine the extent of adverse strip mining effects on the landscape, including reclamation projects.
The regulations require industry to submit their environmental research findings to Florida’s water and land management officials for approval. Without approval, phosphate industry officials will not be "permitted" to continue their strip mining projects. (4)
The permits required by Florida’s water management officials will only be issued after impact studies are shown and adequately (1) supported by engineering, geologists, chemists, and biologist. Central Florida’s phosphate industry is issued particular permits as required by, in this case, Southwest Florida Water Management District officials (state officials). Permits are necessary for both new construction and existing facilities by Florida’s phosphate industry.
Florida’s phosphate officials understand the environmental devastation caused by strip mining the central Florida earth. They also understand mined land reclamation cannot restore the existing hydrogeological framework of the central Florida landscape. Officials understand the devastating environmental effects of strip mining in central Florida. Phosphate officials are aware of all the environmental impacts mentioned above, before the first shovel of dirt is moved.
The state regulations mentioned above require impacts studies on surface water, aquifer systems, both shallow and deep and, including reclamation projects. The permit required by industry is called, Regional Impact Statement and Consumptive Use Permit. I will spare us both on the specific details needed for the permits. However, the permits needed require extensive research on the surrounding landscape and groundwater resources (4).
Understanding Environmental Impacts
Florida phosphate officials understand the severe environmental effects of strip mining, but historically continue the same industry practices for over 65 years. These out dated industry practices will continue in the foreseeable future. The phosphate industry practices historically cause severe environmental impacts. Officials also understand their industry’s technology cannot reclaim mined lands on an acre for acre (4) basis as described by Florida law. Existing reclaimed mined lands are not restored to the original hydrogeological framework in Florida’s landscape and ecosystems because the technology to do so does not exist.
1. 1954, The drawdown of the water table under non-steady conditions near a pumped well in an unconfined formation: Proceedings of the Institution of Civil Engineers
2. 1964, Discussions on the analysis of data from non-equilibrium pumping tests allowing for delayed yield from storage: Proceedings of the Institution of Civil Engineers
3. Water development for phosphate mining in a karst setting in Florid, USGS - Survey Office of Groundwater.
4. Florida Department of Environmental Protection