Yum Balisi Sustainable Luxury Resort - Department of Environment

The greatest environmental impact associated directly with the land filling activities is the
potential for the ecology of the ponds (PC2, IP1, PL1, and PL3) to be affected by siltation
from the run-off from the dewatering of dredged material and heavy rains. This silt has the
potential to smother the tunicate, sponges, and other marine life living on the prop roots of
the fringing mangroves. To mitigate against these impacts retaining walls made of geo-textile
material will be placed around the area to be filled and on the edge of the ponds to contain
spoils.
The dredging method to be applied utilizes a ‘Suction’ Dredge. Suction dredging of the
intended area will result in a relative small plume at the point of suction. In addition, during
dredging silt curtains will be deployed around the cutter head to prevent siltation of adjacent
areas. The excavated material, which is calcareous and coarse coralline sand, is to be pumped
from this burrow site to the caye. This material will then be deposited within a retaining wall
lined by a fine-meshed geo-textile polymer held in place by wooden stakes every five feet
apart. This will allow for the de-watering of the dredged spoils, while constraining the return
of highly turbid outflows to the surrounding seas.
The turbidity and sedimentation influences are associated with the burrow pits, as well as the
spoil discharge pipes and return flows from the retaining walls. It is expected that the net
flow of the turbidity plume will be towards the south and east, which is coincident with net
current movement in the area. This is in the direction of the open sea and avoids much of the
nearby fringing corals.
The primary sedimentation and turbidity impacts have been assessed as major because of the
sensitivity of the area. The estimated volume of 40, 0000 m 3 although much smaller than
those associated with similar type development of islands in the south of the country has the
potential to significantly impact the area’s ecology if appropriate measures are not
implemented. To ameliorate these impacts the activity would need to be closely supervised
and sediment curtains must be deployed to accompany the dredging operation.
Environmental Impact Assessment –November 2010
E 7