Inspections of Embankment Dams

Cross-sectional diagram depicting possible areas of concern within an embankment dam

As with any other structure, dams require regular inspections to identify and prevent any damage or deterioration of its many components. The regularity with which a dam may require inspection depends on the jurisdiction of any regulatory agencies as well as the hazard potential classification of the dam.

Inspections can range from those required by dam safety agencies, those required by the owner and other stakeholders, as well as general observations recorded by operations and maintenance staff. Observations from inspections help build a performance history of the dam spanning different seasons and consecutive water years against which future observations can be compared to identify any changing conditions.

“As the term ‘periodic inspection’ implies, evaluation of the safety of a dam and its appurtenant works is a never-ending process. While detailed onetime investigations that involve drilling, testing, and analysis are important and can provide much information that is necessary to help assess dam adequacy, they cannot be wholly conclusive by themselves, nor are the conclusions drawn necessarily valid for all time. As noted above, ensuring that one knows everything about an existing structure and its foundation is never possible; therefore, observation and evaluation of continuing performance are essential to help close the gaps in this knowledge”. ^[1]

“Furthermore, the condition of a dam or its foundation can change with time, due either to a natural ‘aging’ process or to the effects of such outside influences as earthquakes, long-term impoundment, or extreme weather variations. Again, observation and evaluation of continuing performance can provide the clues that something is taking place that requires further investigation and may require correction. Thus, field examinations, record reviews, the provision of additional data when required, and periodic reevaluation assume a paramount role in maintaining dam safety”.^[1]