Environmental Assessment
Volume B-4.3
Mine
Fish and Aquatic Resources
Ambatovy Project
260
January 2006
1st order streams and the Torotorofotsy Wetlands) is low. The prediction
confidence for impact ratings for habitats within the mine disturbance area is
high, as there is very limited potential for mitigation. The prediction confidence
for impact ratings for habitats downstream, in particular the Torotorofotsy
Wetlands, is considered moderate because of the limited understanding of the
ecological functions of the wetlands and generally qualitative information
available.
Table 4.3-7 Potential Effects and Residual Impacts for Aquatic Habitat
Project
Period
Potential Effects
Mitigation
Residual Impacts
direct displacement and loss of
critical riparian, instream and
ephemeral pond aquatic habitats
high magnitude/long-term
modification of local water bodies
and watercourses within the mine
disturbance area
effects on downstream flow and
water quality during construction of
water management infrastructure
low magnitude / short-term habitat
disturbance during infrastructure
construction
construction
effects on aquatic and riparian
habitat during water pipeline and
road construction
local water management
erosion control
reduce footprint /
disturbance on
Torotorofotsy basin
low magnitude /long-term loss from
footprint of some facilities (water
intake, bridges)
continued clearing, removal and
disturbance of important aquatic
features associated with drainages
on the ore bodies
high magnitude / long-term
modification of local mine area water
bodies and potential low-magnitude
modification of other LSA water
bodies near the mine due to
groundwater drawdown
potential alteration of downstream
watercourse habitats for aquatic
biota as a result of water flow and
water quality changes
low magnitude / medium-term
modification of downstream
watercourses and wetlands
operation
potential effects on Torotorofotsy
Wetlands as a result of changes to
watershed flows and water quality
water management plan;
containment ponds
azonal protection area
erosion and sediment
control
long-term, positive impact from
protection of ephemeral ponds and
1
st
order drainages in azonal
protection areas
closure
changes in the landscape and
development of surface water
features to support productive
aquatic habitat
water management;
erosion control
on-site reclamation
/construction of riparian
areas and water bodies
low magnitude / long-term
modification of reclaimed
topography and drainage system
Closure and reclamation goals will include surface water bodies (end pit lakes) or
the remnants of the surface runoff containment ponds and connector streams.
Depending on the success of revegetation and development of forest cover, these
habitats may be suitable to support re-introduced endemic fish species. The
ephemeral pond habitats, however, will be permanently lost.
An overall residual impact classification is presented in Table 4.3-8; the overall
environmental consequence scores were based on the screening system described
in Volume A, Section 7.
