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NEED FOR EFFECTIVE DAM SAFETY MEASURES IN NIGERIA
Dams and storages are built to serve the
community and the environmental health of our streams.
Therefore, the maintenance and safety of these assets is crucial
both in terms of sustainable development of the economy and
preservation of the environment.
Nigeria is well endowed with water resources. Both surface and
underground water abound in the country. Rivers Niger and Benue
and their numerous tributaries as well as other river systems,
such as Gongola, Hadejia-Jamaare, Kaduna, Cross River,
Sokoto-Rima, Ogun, Osun , Imo and others are good sources of
surface water.
The existence of these rivers has enabled the construction of
several dams in Nigeria for purposes of municipal and industrial
water supply, irrigation, power generation and flood control,
while most of the natives use the rivers for fishing.
The catastrophic nature of potential dam-failure devastation
cannot be underestimated; therefore there is a need to address
this issue critically. The large-scale flood damage and loss of
life usually have larger societal and infrastructure impacts
than merely adding up incremental damages.
The purpose of dam safety program is to verify throughout the
operating Life of the project, the structural integrity of the
dam and appurtenant structures, assuring protection of human
life and property. Periodic surveillance discloses conditions,
which might disrupt operation or threaten dam safety, in time
for them to be corrected. When such conditions are encountered,
it is necessary to determine the adequacy of structures and
facilities to continue serving the purpose for which they were
designed, and to identify the extent of deterioration as a basis
for planning maintenance, repair or rehabilitation of such dams.
In conformity with laid down procedures of dam surveillance
practice, one need to ask whether there are records of 5 –
Yearly Comprehensive inspection (formal inspection), in-House
routine dam surveillance, Emergency/Specific Inspection and
Informal Inspection of any of our dams.
It is the opinion of this writer that if these procedures are
not implemented in our dams efforts should be made to implement
them.
The social costs and environmental impact of dams are felt
mainly at the local level. These impacts are in different folds
with one leading to the other.
With the dam failure and collapse and the resultant losses of
lives and properties, most of Nigeria's staple food such as
cowpea, rice, maize, and vegetable production are threatened.
It is against this background that there is the urgent need for
study of dams’ safety in Nigeria. The study should look into the
following areas: sedimentation; siltation; availability of
reliable records of dam operations; existence of dam operational
manuals and its implementation. River hydrology; factors
contributing to release schedule; qualifications and experience
of staff with key technical responsibilities; past performance
and history of dams in terms of over- topping; flooding, major
and minor rehabilitation work, adequacy of installed
instrumentation in terms of reliability, state of disrepair, and
recordings and monitoring should be addressed.
The study should also include remedial work undertaken to
address critical concerns such as erosion, sedimentation,
siltation, seepage, etc. availability of an emergency
preparedness and response plan in case of failure, existing
status and adequacy of spillways vis-ŕ-vis design assumptions
and financial resources/budget.
For record and sustainable capacity building purposes research
institutions can be commission to carry out this task as is
usually done in the developed countries.
The catastrophic nature of potential dam-failure devastation
cannot be underestimated; therefore, there is a need to address
this issue critically. The large-scale flood damage and loss of
life usually have larger societal and infrastructure impacts
than merely adding up incremental damages.
Engr. J O Akanmu
Unilag PO Box 235
Civil & Environmental Engineering Department
University of Lagos
Phone:08077449034
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