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Section 7 Environmental Effects of the Selected Plan

EAA Storage Reservoirs Revised Draft PIR and EIS February 2006

7-5

However, the proposed project’s footprint currently is dominated by the

disturbed agricultural land and associated features (roads, staging areas).

According to an interagency wetland assessment of the site, including the area

proposed for the STA placement, 206 acres of functional wetland habitat would

be removed by the project construction (USFWS, 2003).

A 200-foot buffer area is proposed for creation along the east, north, and western

boundaries of the reservoir. This seepage buffer will extend 200 feet from the

base of the embankment. It will provide both seepage control and wildlife

habitat within the project footprint, encompassing a total of 560 acres. The

design of the buffer is to mimic an upland-wetland mosaic and allow for

maintenance of the reservoir embankment. The first 50 feet of the buffer will be

an upland maintenance corridor. From 50 to 100 feet, the buffer area would be

regarded post-construction to the existing grade and allowed to re-vegetate

naturally as a wetland. From 100 to 200 feet, the buffer area would contain a

deeper (-2 feet elevation from existing) excavated wetland interspersed with tree

islands sloped to 4 feet above existing grade. Tree islands will be approximately

50 feet wide, and occupy approximately 75% of the total length of linear feet of

buffer area. Therefore, approximately 95 acres of tree island habitat will be

provided within the buffer. Wetlands created and restored in the buffer

footprint will be approximately 404 acres of wetland habitat. The wetland

portions would be hydrated by rainfall, seepage from the reservoir, and perhaps

groundwater “backed up” from the cut-off walls. The elevated tree islands will

be planted with native tree vegetation of appropriate species.

In addition, a littoral shelf would be constructed within the seepage canal

surrounding the seepage buffer and project site. The littoral zone will be located

along the length of the seepage canal for approximately 110,000 feet. The shelf

would be approximately 30 feet wide. The first 15 foot wide section would be

contoured to a 1V:5H slope. The second 15 foot wide section would be contoured

to a 1V:2H slope. The littoral shelves would be constructed by scraping the peat

layer adjacent to the canals. The shelf should provide an estimated 76 acres of

habitat for fish and wildlife, especially wading birds.

The STA component would convert approximately 1,495 acres of agricultural

land to a shallow, long-hydroperiod, vegetated wetland for the purposes of

removal of nutrients. This will add wetland functionality, but may not be

suitable for wildlife habitat.

A significant EAA study objective is to reduce lowering of Lake Okeechobee for

EAA irrigation withdrawals during the dry season and reduce discharges of

storm water by back-pumping into the Lake during the rainy season. The

overall potential effect is a reduction in extreme lake levels, both high and low;

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Wenger 72944 Dokumentacja Strona 271