Environmental Assessment
Volume E-3.8
Tailings Facility
Hydrology
Ambatovy Project
85
January 2006
parameters, the prediction confidence for dry season conditions is considered
low.
3.8.6.3 Monitoring
Continued monitoring of streamflows and suspended sediment concentrations
within the affected basins will be conducted to support an improved
understanding of hydrologic response in the study area. Streamflow records will
be evaluated along with recorded climate data (e.g., rainfall and evaporation) at
nearby Toamasina to further assess water availability for various biophysical and
social needs.
Monitoring of the effectiveness of erosion control measures, slope stability and
reclamation success are described in Volume C, Section 6.
3.8.7
Conclusions
During operation, the tailings facility will have a high environmental
consequence for hydrology in terms of streamflows at downstream locations.
Following closure and the return of runoff to natural receiving water bodies, the
environmental consequence for most locations will be negligible to low for
average conditions, and low for dry conditions. While impacts to hydrology are
considered large, the impact of these changes to associated components
(e.g., water quality, fish and aquatic resources, and land use and socioeconomics)
is variable. These issues are addressed in other sections of this report.
Downstream flooding associated with extreme rainfall events (e.g., the maximum
probable precipitation event, and breach of the water pond embankment) is also
discussed in the Natural Risk assessment (Volume E, Section 3.6, and Volume I
Section 6.1).
