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Section 5 Formulation of Alternative Plans

EAA Storage Reservoirs Revised Draft PIR and EIS February 2006

5-42

where QILO -E3 and QILO-E10 refer to Lake Okeechobee stages quality index

values.

As another step, the mean ecological benefits index (MEBI) may be calculated by

adding up the ecological index values for the lake, estuaries, and Greater

Everglades and dividing by four:

MEBI = (EBILO + EBISLE + EBICE + EBIGE)/4

This equation assumes that all four ecological regions are equally important, and

thus equally weighted.

The two water quality performance measures, backpumping and bypass, did not

lend themselves to having the raw data converted to a quality value due to the

uncertainty in correlating the raw data to a particular type of habitat. For those

two performance measures, volume of water was directly used to compare the

alternatives.

5.4.2.2 Summary of Annualized Benefits

The following sub-sections describe the annualized ecological benefits to the four

geographic regions. As previously described, ecological benefit index scores for

each region were multiplied by the acreage of the affected area to obtain Habitat

Units.

5.4.2.2.1 Lake Okeechobee

The Project shows a clear improvement in high water conditions for Lake

Okeechobee compared to the future-without-project condition (Figure 5-7). The

step-wise trend for the 360,000 acre-feet-with-all-CERP reflects the effects of

other CERP storage projects coming on-line according to the MISP. Benefits for

Alternative 2 and 3 begin later than for the rest of the plans due to the

additional time to acquire more lands. The project provides no measurable

improvement in low water conditions in Lake Okeechobee.

The Project shows a reduction in backpumping volumes from the EAA into Lake

Okeechobee through the S-2 and S-3 structures compared to the future without

project condition. This decrease in volume of water between future without

project and with the project is 1,328,898 acre-feet (with-CERP analysis). While

the ecological benefits for this reduction are difficult to define, the decrease in

backpumping will reduce nutrient, trace metal, and pesticide loading to the lake,

thereby improving the overall habitat. In looking at sensitivity runs of the

SFWMM, the team noted a direct relationship between increasing the reservoir

storage volume with the reduction of backpumping to the lake.

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