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

Table 2-2. Land use and land cover (by percentage) changes in the Alafia River watershed
(269,986 acres) for three time periods, 1972, 1990 and 1999.
Alafia River Watershed 1972 1990 1999
Urban 10.9 13.9 17.6
Citrus 9.1 4.9 4.7
Other Agriculture 26.9 21.8 18.4
Uplands 30.7 12.8 10.1
Wetlands 9.3 12.1 10.7
Mines 10.9 32.8 35.9
Water 2.3 1.8 2.5
Land Use/Land Cover - Alafia River Watershed
Area
(acres)
120000
100000
80000
60000
40000
20000
0
Urban Citrus Other
Agriculture
1972 1990 1999
Uplands Wetlands Mines Water
Figure 2-10. Comparison of land use and land cover changes in the Alafia River
watershed.
2.2.1 South Prong Sub-Basin
The South Prong sub-basin is the second largest sub-basin delineated for this
report. Total area is 88,303 acres (138 square miles). The USGS gage on the
South Prong is located some distance upstream so that it captures runoff from
107 square miles or approximately 78% of the sub-basin watershed. The largest
increase in mined area between 1972 and 1999 occurred in this sub-basin (see
Figure 2-11). During this time, mined acreage increased from 7,824 acres to
55,216 acres, an increase of approximately 74 square miles over a 28-year span.
Mined land increases were largely offset by decreases in uplands (45 square
miles) and agriculture (22 square miles). The decline in urban land use in the
South Prong Sub-Basin was due to change in the resolution of the data sets.
Acreage of land use / cover changes are shown in Table 2-3 and Figure 2-12.
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