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

dominant vegetation zones, mucky soils, and top of bank elevations (Table 5-1).
Collectively, these data indicate that up to an 8% reduction in the flows
necessary to inundate floodplain features of the Alafia River, including those we
have not identified, will result in a 15% or less reduction in the number of days
the features are inundated. However, the plots also show that there are flows,
which occur during Block 3, which do not require that reductions be limited to 8%
to avoid a 15% reduction in the number of days a flow is achieved. Using the
25% exceedance of 374 cfs at the Lithia gage as a cutoff, we can apply a
stepped prescription, which allows an 8% reduction in flows when flows exceed
374 cfs and a 13% reduction in flows when flows are below 374 cfs (Figure 5-8).
While other multiple steps could be made or an algorithm applied to determine
the percent flow reduction allowed, the single step provides a conservative
means assuring that unidentified factors are likely to be protected and that water,
not needed to protect from significant harm, is available for consumptive use.
Flow reduction (%) resulting in a 15% loss of days
25
20
15
10
5
0
0 500 1000 1500 2000 2500 3000 3500
Flow at USGS Lithia gage (cfs
Figure 5-8. Percent-of-flow reductions that result in a 15% reduction in the number of
days flows at the USGS Lithia gage are achieved.
5-11