PROBLEMS FROM LAND OCCUPANCY 195 



the other hand the flat agricultural lands are inundated by 

 floods at fairly frequent intervals, usually during the hurri- 

 cane season. There is an obvious need for storage of water 

 for dry-season usage, but unfortunately the ground-water 

 reservoirs are not of much help. The rock materials near the 

 surface have a very low permeability, and water from pre- 

 cipitation forms lakes and swamps. The limestones that lie 

 at depths of 400 to 1,200 feet yield highly mineralized water. 

 Lake Okeechobee, however, stores enough water to provide 

 the bulk of the 110 million gallons a day used for irrigation, 

 public consumption, and sugar refining in the Everglades 

 area. 



The soils of the Everglades are predominantly muck and 

 peat, and in the past four decades major efforts have been 

 made to drain a portion of the area for agricultural use, 

 with partial success. The drainage has caused a subsidence 

 of 3 to 6 feet in the organic soils, resulting in complications 

 in the maintenance of drainage. It has also permitted de- 

 struction of the dried peat by oxidation and uncontrolled 

 fires. Moreover, it appears that extensive and indiscriminate 

 drainage has threatened the water supply for municipalities 

 along the coast, by reducing the fresh-water head and per- 

 mitting sea water to encroach into the aquifers. The larg- 

 est cities along the coast east of the Everglades are Miami, 

 Fort Lauderdale, and West Palm Beach. Drainage canals 

 from the Everglades reach the coast near each of these 

 cities. 



The metropolitan Miami area currently uses about 80 

 million gallons of ground water a day, of which 50 million 

 is for municipal use and the rest about equally divided be- 

 tween irrigation and industrial use. Owing to the lowering 

 of water levels brought about principally by the Miami 

 canal and other uncontrolled tidal canals, salt water has 

 moved from Biscayne Bay into the principal aquifer. The 

 tidal canals at times carry salty water inland for several miles. 

 Saline water entered Miami's Hialeah well field (along the 

 Miami Canal) in 1939. As Biscayne Bay receives the un- 



