Alafia River Minimum Flows and Levels - Southwest Florida Water ...

Table 2-3. Land use and land cover (by percentage) in the South Prong sub-basin of the
Alafia River watershed (88,303 acres) for three time periods, 1972, 1990 and 1999.
Alafia - South Prong 1972 1990 1999
Urban 6.3 1.7 2.3
Citrus 11.0 5.0 4.5
Other Agriculture 22.2 14.8 12.8
Uplands 38.3 9.5 5.5
Wetlands 12.4 13.7 10.9
Mines 8.9 54.7 62.5
Water 1.0 0.8 1.5
Land Use/Land Cover - Alafia - South Prong
Area
(acres)
60000
50000
40000
30000
20000
10000
0
Urban Citrus Other
Agriculture
1972 1990 1999
Uplands Wetlands Mines Water
Figure 2-12. Comparison of land use and land cover changes in the South Prong subbasin
of the Alafia River watershed.
2.2.2 North Prong Sub-Basin
The North Prong sub-basin is 141 square miles (90,115 acres) in size. Most of
this sub-basin is located upstream of the USGS gage which captures flow off
approximately 135 square miles. As with the South Prong, the largest change in
land use since 1972 has been in the amount of sub-basin area mined. In 1972,
16 percent of the sub-basin had been mined; by 1999 an additional 17,592 acres
or 25 percent of the sub-basin had been mined (Figure 2-13). Although heavily
mined (35% of the entire sub-basin), considerably more acreage has been mined
in the South Prong of the Alafia River (55,216 acres versus 31,776 acres or 63%
versus 35%). As will be discussed, a comparison of flow changes between the
North and South Prongs and the Alafia River at Lithia offers some insight into the
potential effects of increasing mined lands on river flows.
2-22