are so abundant, it is essential to limit the discussion to those areas where 

 ongoing water quality analysis data are available. The major water courses in 

 Southwest Florida and significant water quality violations within each 

 designated major Class III system are discussed in the following paragraphs. 



WATER QUALITY AND POLLUTION STANDARDS OF RIVERS (CLASS III) 



As a group, the Class III major rivers and streams in Southwest Florida 

 have relatively lower water quality than northwest and north central Florida 

 streams. Dissolved oxygen (DO) concentrations in Southwest Florida streams 

 range from a low of 2.8 mg/1 in Weeki Wachee River, second lowest in the 

 State, to a high of 7.6 mg/1 in the Upper Alafia River. The lower Kissimmee, 

 Myakka River, and Peace River all had organic nitrogen concentrations above 

 1.0 mg/1. The North Prong of the Alafia River had the lowest mean (1.6 mg/1) 

 in the State. Ammonia varied from 0.08 mg/1 in Weeki Wachee River run to 

 0.86 mg/1 in the Little Wekiva River (highest mean concentration in the 

 State). The highest concentrations of nitrates and phosphorus were in the 

 Alafia, Peace, and Hillsborough Rivers. The Upper Alafia River had the lowest 

 coliform density in the State (1,316/100 ml) whereas the North Prong of the 

 Alafia River had the second highest coliform density (76,800/100 ml). 

 Turbidity and suspended solid concentrations were low in most rivers. Most 

 biological diversity values ranged from 2 and 3. Overall, streams in this 

 region exhibited a wide range of water quality; however, major riverine sys- 

 tems such as the lower Peace, the Weeki Wachee, and Hillsborough Rivers 

 generally had above average water quality. 



Because of the central importance of these rivers in Southwest Florida, a 

 brief summary of the most relevant water quality characteristics in each major 

 watershed area is given in the following sections. These data are taken from 

 publications of the Florida State Department of Regulation (1979a and 1979b). 



Caloosahatchee River Basin 



The Caloosahatchee River runs westward approximately 45 mi from the Moore 

 Haven Locks on Okeechobee Lake to the Franklin Lock on Lake Okachopatee and 

 then about 30 mi into an estuary system of the Gulf of Mexico. Land use in 

 the Caloosahatchee Basin is dominated by agriculture and wetlands. Intensive 

 truck gardening there requires heavy application of biocides and fertilizers 

 which indirectly affect water quality. The City of Fort Myers is located on 

 the Caloosahatchee River approximately 15 mi from the gulf. Major sources of 

 pollution include sewage effluent, industrial point source, and runoff from 

 rangeland, agricultural land, and urban areas. Nutrient concentrations down- 

 stream from LaBelle vary greatly but sometimes are excessive. Concentrations 

 of total phosphorus and NO3-NO2 also was high in some areas. Dissolved oxygen 

 (DO) averages near State standards for most of the river's length. Violation 

 of water quality standards for DO, pH, mercury, cadmium, lead, and total alka- 

 linity are common in the Caloosahatchee River. A comparison of historical and 

 recent data indicates no overall temporal trends. In general, water quality 

 in the Caloosahatchee River is sometimes serious, but not critical. 



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