FIGURE 3 Average annual overland flows toward Florida Bay across Craighead Basin, Taylor Slough and Eastern Panhandle for the 31-year simulation. Comparison of surface water flows in eastern Everglades National Park (ENP). Flow is generally southward across the Craighead Basin-Taylor Slough-Eastern Panhandle (CB-TS-EP) cross-section (shown in inset map of northeastern ENP; see Figure 1 for larger map). CB, TS, and EP are each an eight-mile long segment of the cross-section. Output is shown for three different simulations: Natural System Model (NSM), 1995 base or “current condition” (95B) and D13R4 (a variation of D13R, which is the year 2050 CERP simulation from USACE, 1999). Short descriptions of these are given in the text; more complete definitions are given in Appendix B. Note: Note: NSM water depths at key ENP gage locations are used as operational targets for most alternatives. NSM flows are NOT targets and are shown for comparative purposes only. Source: USACE, 2002.

The total annual flow is, of course, only one aspect of the data. The distribution of flow between the wet and dry seasons (shown in the Figure 3 graphs) may be important as well. In addition, the simulated averages do not reflect annual variability in discharges; this must be accounted for when analyzing the full 31-year output from the SFWMM and its ultimate interface with Florida Bay modeling. Finally, changes to rainfall-based water management practices that occurred between the mid-1980s and 1995 resulted in increasing the amount of freshwater flow into eastern Florida Bay, relative to rainfall, at least since 1993 (Sklar et al., 2002). The 1995 base is a simulation for the present period since those changes occurred; it does not represent conditions of the preceding decades, which are less well known.

Overall, however, total fresh surface-water inflows to Florida Bay via Craighead Basin and Taylor Slough are predicted to be about the same with CERP as under current conditions. If these predictions are correct, the salinity of this region of the Bay may not change materially. The lack of an operational hydrodynamic model (Chapter 3) increases the uncertainty of such predictions.

Shark River Slough

In contrast to these minor proposed changes to flows in Craighead Basin and Taylor Slough, the CERP plans a dramatic increase in flow down Shark River Slough relative to the current condition (Figure 4). This is significant, because recent measurements strongly suggest that some of this flow eventually will reach the inner parts of Florida Bay. A detailed review by Smith and Pitts (2002)



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement