A dam’s instrumentation furnishes data for determining if the structure is functioning as intended and continuing surveillance to warn of any unsafe developments. Monitoring physical phenomena that can lead to a dam failure may draw on a wide spectrum of instruments and procedures ranging from very simple to very complex. Any program of dam safety instrumentation must involve proper design consistent with other project components. The program must be based on prevailing geotechnical conditions at the dam, and must include consideration of the hydrologic and hydraulic factors present before and after the project is in operation. Instrumentation designed for monitoring potential deficiencies at existing dams must take into account the threat to life and property that the dam presents. Thus, the extent and nature of the instrumentation depends not only on the complexity of the dam and the size of the reservoir, but also on the potential for deaths and property losses downstream.
The objective of dam instrumentation and surveillance is to make a timely and precise diagnosis of dam behavior that allows for the prevention of undesirable consequences. The monitoring system and surveillance programs have to be designed or redesigned considering potential failure modes associated with the higher levels of risk. They should be able to identify any abnormal behavior which could lead to potential reduction of safety.