INGENIEUR
INGENIEUR
●●
The dam safety management system does not exist or is inadequate.
●●
The dam safety management processes, procedures or plans are not documented or followed.
●●
Appropriate dam safety governance, oversight and enabling arrangements do not exist.
●●
Roles and responsibilities are not adequately defined and understood.
●●
Lacking experienced and qualified personnel to implement appropriate dam safety management programmes.
●●
Surveillance inspectors are not adequately qualified and trained.
●●
Dam safety issues are not resolved within a time frame to reduce risk.
●●
Dam safety management system recordkeeping is inadequate, e. g. design, construction, operation, maintenance, surveillance or testing records are limited or unavailable.
●●
Emergency action plan does not exist, is inadequate, or is not tested.
●●
Dam safety regulatory requirements are not met.
Accountability The overall accountability for a DSMS remains with the dam owner and senior management of the organisation whether a public authority or private company. The DSMS should have a dam safety policy statement which provides the organisation’ s directive to its personnel who are responsible for implementation of the dam safety management system. Effective dam safety requires responsibilities to be fulfilled at all levels in the owner’ s organisation, from senior management to field personnel. A clear line of authority and accountability for dam safety in an owner’ s organisation is needed to ensure effective dam safety management.
Personnel Competencies The effective management of dam safety generally involves a wide range of skills. On the ground routine surveillance and monitoring is commonly completed by the owner’ s permanent staff.
Evaluation of the surveillance and monitoring results, the assessment of performance, and the completion of dam safety reviews should be undertaken by people competent in the evaluation of surveillance and monitoring results.
Operation and Maintenance In most cases operators do not understand the parameters within which their reservoirs are to be operated for normal, unusual( e. g. flood) and extreme( e. g. earthquake) and emergency conditions( i. e. conditions that could result in dam failure if appropriate actions are not taken).
From the dam safety perspective the operation of a reservoir should not present undue risk to the people and their property and the environment downstream of the dam in the river system. There must be a sufficient margin to ensure safety of the dam under all loading conditions and foreseeable operational scenarios. Sufficient freeboard must be available to prevent overtopping or flooding during extreme weather events. There may be a need to limit the rate at which the reservoir level is lowered to ensure the stability of the dam and that the reservoir shoreline is not affected.
Operating personnel should be able to recognise significant threats to the safe performance of the dam and signs for the development of its potential failure modes, and understand how to initiate appropriate response actions and when to seek specialist technical advice.
Surveillance A sound surveillance process is the owners’ first line of defence for the safety of their dams. It includes routine visual inspections, instrument monitoring, data reviews and evaluation, and reporting on the safety of the dam. The United States Federal Guidelines for Dam Safety( FEMA 2004) includes the following statement: Monitoring existing dams and reacting quickly to inadequate performance or to danger signals is a continuing critical aspect for dam safety. Careful monitoring and quick response can prevent failures, including those caused by poor construction. In most cases, the surveillance exercise is hampered by lack of records such as‘ as-built’ drawings, design reports, construction reports
46 VOL 69 JANUARY-MARCH 2017