A Case Study On Gerugu Dam Overtopping Under Different PMP Scenarios

  • Heng Hock Hwee
  • Hii Ching Poon


A hydrological dam safety inspection was carried out for existing Gerugu dam (CA= 14 km2) by evaluating the hydrological performance of the bellmouth spillway in light of two different sets of Probable Maximum Precipitation (PMP).  For safety reason, it is utmost important that the flood rise does not exceed the embankment dam crest level (ECL).  Gerugu dam (CA= 14 km2) is a small catchment earthfill zoned embankment dam that supplies raw waters to the water treatment plant downstream. 

This study selects both “coastal” type of PMP [13], [14] which is mostly representative of the extreme precipitation parameters adopted in the design of the dam and a recent set of PMP under NAHRIM [11] study.  A catchment routing procedure is then used to translate the PMPs to PMFs for 1- to 120-hour duration and a conventional reservoir routing in tandem to estimate the outflows and corresponding flood rise over the full supply level (FSL) of the reservoir. The dam is considered safe under both coastal and NAHRIM [11] PMP scenarios as the flood rises for all cases are confined below the embankment crest level (ECL), i.e. +33.0 m msl. 


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How to Cite
Hock Hwee, H., & Ching Poon, H. (2013). A Case Study On Gerugu Dam Overtopping Under Different PMP Scenarios. Journal of Civil Engineering, Science and Technology, 4(1), 40-49. https://doi.org/10.33736/jcest.107.2013