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Regulatory Frameworks for Dam Safety
underwater inspections and inspections required during initial reservoir impounding • Requirement and frequency of alignment and deformation surveys The program of inspections, including the frequency of inspections, should be devised based upon the dam classification, industry standards, manufacturers’ recommendations, operating history and condition of particular structures and equipment. As a general guideline, “routine” inspections should be performed by project staff as a regular part of their maintenance activities. Such inspections should be carried out weekly or monthly as appropriate for the item being inspected. Reduced frequencies may be selected to suit seasonal restraints. “Intermediate” inspections are intended as more formal inspections, generally annual or semi-annual, performed by the appropriate representative of the owner responsible for safety surveillance. Comprehensive inspections (Dam Safety Review) should be performed by an independent expert or panel of experts at regular time intervals.1 The review should include the O&M Plan and the EPP to determine any modifications thereof. Procedures, including definition of responsibility, should be in place for evaluating data (obtained from visual inspections, instrumentation and design reviews of current operating conditions such as spillway capacity, freeboard, drawdown, maximum water levels) to confirm structural and operational safety and to identify areas requiring deficiency investigations. These procedures should include an “action code” to ensure that appropriate action will be taken, depending on the severity of the observed deficiency. B.4.3. Special Inspections Special inspections shall be performed following potentially damaging events. Instructions and procedures for the dam should describe special inspections and other surveillance and procedures required after floods, windstorms, earthquakes and unusual observations such as cracks, settlements, sinkholes and slopes failures. The responsibility to undertake these special inspections
1. Review period depends on the consequence classification of the dam: Consequence category: Very High High Low Period between reviews: 5 7 10 (years)