acknowledged that no methodology exists for the selection of a percentage loss of "natural"

habitat, which could be considered acceptable. The state of Texas utilized a target decrease of

less then 20% of the historic average of habitat area in establishing an inflow requirement for

Matagorda Bay (Texas Parks and Wildlife 2005).

 For establishment of minimum river flows, the District has proposed the use of a percent of

flow approach, which identifies the percentage by which a flow may be reduced before the river

system is significantly harmed. This approach preserves natural flow patterns by protecting the

inherent variability of natural flow regimes. The approach accounts for flow seasonality, by

identifying three distinct annual flow seasons and identifying different habitat measures to be

protected during each season. Two distinct benchmark periods, with characteristically higher

and lower flows were used to analyze all measures of habitat loss to assure protection during

both phases of the climate cycle associated with the north Atlantic Ocean.

 In examining the loss of temporal habitat on the three rivers, the comparison in Figure 3-3

suggests that these three rivers respond in a similar fashion to reduced flows. This could be

interpreted as the three rivers having similar flow distribution patterns during the wet season and

thus showing similar responses to declining flows. This is probable because rainfall drives wet-

season flows and since these three rivers are all located in central Florida, it might be expected

that some similarity in watershed-wide rainfall over the period of record exist (at least 60 years

in all three cases). The use of spatial loss instead of temporal loss did not provide a similar

response among rivers (Figures 3-3 and 3-4). Though somewhat similar, there is considerably

more variation in the plots of spatial loss than those of temporal loss. This is likely due to the

addition of morphology into the calculation, albeit implicitly. While rainfall drives the wet-

season flow distribution, floodplain morphology also plays a direct role in calculating loss.