The Tampa Bay estuarine system is criss-crossed and modified by four 
major causeways and an extensive network of dredged canals. Creation of 
the 35 mile shipping channel resulted in 70 million cubic yards of bay 
bottom being moved and deposited as large spoil island or submerged 
disposal areas in the bay (Figure 4). Previous to dredge and fill 
activities the average depth in Tampa Bay was 11 feet. Due to the extent 
of bay development, the average depth has increased by one foot bay-wide 
and the surface area has diminished by 3.6 percent (Goodwin 1987). 
CLIMATE 
The Tampa Bay Region has a subtropical climate that is 
characterized by long, warm, humid summers and warm winters. In general 
terms, the mild subtropical climate of the watershed is a reflection of 
the low-geographical relief, proximity to the Gulf of Mexico and the 
Atlantic Ocean and the watershed’s relatively low latitude (Schomer, Drew 
and Johnson in press). The slight relief allows an uninterrupted 
movement of wind and rain across the terrain. Because of its history of 
mild climatic conditions and abundant sunshine, the area surrounding 
Tampa and Sarasota Bays has become known as the "Florida Suncoast". 
The average bay area temperature is 23°C (73°F), and freezing 
temperatures are experienced only four nights each year on the average. 
Total rainfall averages 53 inches (134.6 cm) per year. More than half 
the rainfall occurs from June through September, primarily from 
thunderstorms. Approximately 60 to 100 thunderstorms occur in an average 
year, over 85 to 90 days (Lewis and Estevez 1988). 
South Florida has experienced more hurricanes and tropical storms 
than any other equal sized area of the United States. From Cedar Key to 
Fort Myers, eleven (11) storms of hurricane intensity have passed inland 
in recorded history (Schomer et al. in press). The bay area is most 
often hit in the latter part of the hurricane season, usually in 
September and October. 
The primary forces associated with the passage of a hurricane are 
wind, storm surge and rain. In Florida, about 75% of all damage related 
to tropical storms is caused by tidal flooding, with the remaining 25% of 
the damage attributed to winds and rainfall (Schomer et al. in press). 
POPULATION AND SOCIAL FEATURES 
Tampa Bay is bordered by the counties of Pinellas, Hillsborough 
and Manatee, while Sarasota Bay is bordered by Manatee and Sarasota 
Counties. In addition, the two estuaries share twenty-two local 
governments along their peripheries (Figure 5); two regional planning 
councils (Tampa Bay and Southwest Florida); and one water management 
district (Southwest Florida). Population estimates from 1890 reveal that 
6 
