2012 FDOT Mitigation Plan - Southwest Florida Water Management ...

(Figure C), eradicate pasture grasses, conduct extensive planting, and perpetual herbicide maintenance
activities.
B. Brief description of pre-construction condition: Historically, surface water from Banana Lake
maintained a sheet flow hydrology connectivity east through forested and marsh wetland habitat and flowing
into Lake Hancock. During the 1940’s, the construction of the Banana Creek Canal between the two lakes,
along with connecting tributary ditches, substantially drained the wetlands to convert into improved pasture.
In addition, a large levee was constructed along the western property boundary (Figure C). This impounded
water in the forested wetland west of the project area, diverted the ground and surface water away from the
wetlands in the Reserve, and forced water to flow directly into the canal. Spoil material rimmed each side of
the canal, so water in contributing conveyance ditches were also pumped over the berms into the canal to
flow directly into Lake Hancock. The several decades of extensive drainage and dewatering converted the
majority of the historic wetland acreage to improved pastures for intensive cattle grazing (refer to site
photos). This resulted in inadequate hydrology to support appropriate wetland habitat benefits and functions
to benefit wildlife. Prior to restoration construction in 2005-2006, the majority of the remnant wetlands were
associated with a few forested wetlands bordering the pastures and scattered small ephemeral marsh
pockets within the improved pastures. Historically there were additional forested wetlands that were lost as a
result of the altered drainage and subsequent muck oxidation resulting in tree fall. In a complete reversal of
the impounded surface waters in wetlands west of boundary levee, the remnant forested wetlands in the
Reserve no longer had surface water. As a result, the forested areas were used for shade by cattle, with
additional trees routinely falling due to the soil subsidence. Additional information is provided in the
attachments.
C. Brief description of conducted work: After the cattle lease was discontinued in 2001, the dewatering
pump system was removed and with the rains from El Nino conditions in 2003 and Hurricanes Charley and
Frances that crossed near the property in 2004, all drainage was not allowed to be conveyed into the canal in
order to commence partial hydrologic restoration necessary to achieve the desired bahiagrass mortality and
regeneration of hydrophytic vegetation. Construction activities commenced in the fall, 2005. Two pre-existing
north-south berms (Figures B, C –Eastern and Central Roads) were substantially regraded to provide
necessary structural stability and culverts installed at appropriate locations and elevations to convey and
restore the natural sheet-flow wetland hydrology & appropriate hydroperiods. The length of the Central Road
is approximately 3000 ft. and 2300 ft. for the Eastern Road. Fill material for the road berm reconstruction
was obtained from widening the existing borrow pit within the north side of the property and creating the 2-
acre “Gator Pond” marsh within an adjacent upland area. The western access road is a wet crossing
constructed with crushed concrete to match adjacent surface grade elevations. After the two access road
berms and culverts were constructed, the spoil rim material was used to backfill the Banana Creek Canal
segment west of the Center Road and the western boundary levee was removed to restore hydrologic sheet
flow patterns throughout the wetland floodplain. Approximately half of the historic western forested wetland
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