Hazard potential classification of dams using a simplified methodology

Abstract

The National Dam Safety Policy in Brazil (NDSP) assigns the classification of dams to the regulating agencies, all dams having to be classified in terms of hazard potential. The lack of appropriate basic data, such as topographic maps, makes it impossible to rely on well-established methodologies and requires effort and creativeness to find appropriate alternative approaches. This paper describes a simplified methodology implemented for hazard classification purposes and compares its results with those produced by a standard and more complete model (HEC-RAS) using the same basic data. Downstream valley inundation area assessment is performed considering four dams of different sizes. The results, although denoting some differences, evidence that the simplified methodology produces credible results as far as the affected areas for potential hazard classification are concerned. The simplified methodology was used to classify the whole portfolio of 121 dams assigned to the National Water Agency (ANA) under the terms of the NDSP.