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

APPENDIX B - Staff Response to Peer Review
Introduction
Overall the peer review committee endorsed the Districts approach to
establishing minimum flows and levels on the freshwater segment of the Alafia
River. Specifically the peer review committee noted that the assumptions of the
approach are well documented and are reasonable, the tools and methods of
analysis employed are appropriate and utilize best available information, and the
conclusions in the report are based on an impressive field data collection effort
and sound application of findings from the scientific literature. In short they found
"no serious flaws or errors in the methodology or findings documented in the
report" (Cichra et al. 2005, Appendix A). The Panel also found particular merit
with and strongly endorses several novel concepts including;
– Identifying two separate benchmark periods based on
different phases of the Atlantic Multidecadal Oscillation (AMO) .
. .
– Applying multiple, independent approaches to identify the
most protective minimum flow in each seasonal block. . .
– Specifying minimum flows in terms of allowable percent flow
reductions that vary by season and flow conditions.
However, the panel did supply some direction for improving the report.
1. It should be acknowledged, however, that a 15% change in habitat
availability based on a reduction in spatial extent of habitat (as was used
in PHABSIM analyses) may not be equivalent to a 15% change in habitat
availability based on number of days a particular habitat is inundated.
The District acknowledges this and is currently performing a comparison
of temporal and spatial loss of habitat. The results are under review but
preliminarily indicate that on the Alafia River flow reduction required to
effect a 15% spatial loss are greater then those required to effect a 15%
temporal loss (Munson and Delfino in review).
2. A more explicit discussion of the precision and accuracy of HEC-RAS
would be a helpful addition to the report. Specifically, what is the
expected level of uncertainty? Also what steps are being taken to
validate the model?
Appendix B i