Uncalculated impacts of unsustainable aquifer yield including evidence of subsurface interbasin flow

Unsustainable withdrawals from regional aquifers have resulted in adverse i mpacts considerable distances from the point locations of supply wells. In one area of the southeastern (SE) Coastal Plain, conservative estimates for repair/replacement of some residential wells damaged or destroyed by unsus tainable yield from the Floridan aquifer system exceeded $4 million. Howeve r, a comprehensive assessment of damage/economic loss to private property a nd public resources due to unsustainable yield from that regional karat aqu ifer has not been made. Uncalculated direct costs to home-owners from damag e attributed to those withdrawals are associated with destruction of homes from increased sinkhole formation, devalued waterfront property, and remova l of diseased and dead trees. Examples of other uncalculated economic burde ns resulting from unsustainable aquifer yield in the SE Coastal Plain inclu de: (1) irreversible damage to the aquifer matrix and concomitant increased potential for groundwater contamination, (2) large-scale wildfires with su bsequent degradation of air quality, debilitation of transportation corrido rs, and destruction of timber, wildlife habitat and property, and (3) destr uction of "protected" natural areas. This paper provides a general backgrou nd of the regional Floridan aquifer system's karst characteristics, example s of known impacts resulting from ground water mining in the SE Coastal Pla in, and examples of additional damage that may be related to unsustainable yield from the Upper Floridan aquifer. Costs of these impacts have not been calculated and are not reflected in the price users pay for ground water. Evidence suggests that the classic watershed management approach must be re vised in areas with mined regional karst aquifers to include impacts of ind uced recharge from the surficial aquifer, and subsurface interbasin flow. L ikewise, associated impacts to surface water and interrelated systems must be calculated The true cost of groundwater mining to this and future genera tions should be determined using a multidisciplinary approach.