THEY PAVED PARADISE AND PUT UP A PARKING LOT— HOW 100 YEARS OF DEVELOPMENT IN THE EASTERN EVERGLADES HAVE AFFECTED COASTAL GROUND-WATER HYDROLOGY IN SE FLORIDA, USA

Successive land-use change in southeastern Florida parallels twentieth century, global anthropogenic modification of a former pristine land cover. Large parts of the natural Everglades were drained to promote tropically based agricultural development; cultivated lands were subsequently converted for urban and residential development purposes corresponding to explosive population growth between 1940-2004. A canal drainage system has severely impacted the extent and character of the coastal ecosystem and the Everglades. Mining activities increased to meet construction demand, but competition for land has placed both industries in conflict with ecosystem and municipal water-supply needs.

Historic uncontrolled drainage of the Everglades, peat-muck soil loss due to oxidation and compaction, lowering of the water table within a peat mantle and underlying karst aquifer, and coastal well field withdrawals all contributed to a landward advance of saltwater, its most severe effect evident during the 1940s. An engineered drainage system affected coastal ground-water hydrology and ecosystem by increasing the flow of surface water from the Everglades to the Alantic Ocean, simultaneously decreasing ground-water discharge to coastal bays because of lower water levels.

Today, surface water impounded in conservation areas west of a protective levee system sustains a remaining ecosystem, keeps overland sheetflow from flooding urban-agricultural areas, and serves as a water supply. Coastal areas are drained for flood control. Maintained canal stage and ground-water levels mitigate saltwater intrusion and aquifer overdrainage. Canal discharge to the ocean is declining, rerouted to secondary canals, and lost as induced recharge to a karst aquifer subject to large well withdrawals. Higher production levels and the inland relocation of well fields to mitigate intrusion increases concern that wetland ecosystems are adversely impacted. Alternate sources of water and means of storage are considered critical to Everglades Restoration. Proposed conversion of borrow-pit mines to in-ground reservoirs has created public health and wetland seepage concerns. The technical feasibilty and efficacy of proposed levee seepage barriers and an ASR infrastructure of unprecedented scale remains uncertain.