Safety Review of Magat, Ambuklao and Binga Dams

Safety Review of Magat, Ambuklao and Binga Dams, Northern Luzon, Philippines

Assessment of Probable Maximum Precipitation (PMP) and Probable Maximum Flood (PMF) and Related Flood Water Levels

Detailed statistical and meteorological PMP assessments and related PMF assessments are crucial for the evaluation of flood safety of three multi-purpose dams in Northern Luzon, Philippines – one of the regions with the most extreme precipitation events on Earth.

Magat, Ambuklao and Binga Dams are multi-purpose dams in Northern Luzon, Philippines. As this is one of regions with the heaviest rainfall events on Earth, flood safety is a crucial issue for these facilities. Original flood design in the 1970ies was based on uncertain hydro-meteorological data. In the framework of comprehensive Dam Safety Reviews, an expanded data base enables updated PMP and PMF assessments. PMP estimations are based on both, statistical and detailed meteorological analyses as advocated by the WMO. PMP is transformed to PMF inflow applying rainfall-runoff models, and resulting flood water levels are estimated based on different flood operation scenarios. Possible future impacts of climate change on the flood safety of the dams are investigated based on most recent climate modelling results.

Safety Review of Magat, Ambuklao and Binga Dams
Safety Review of Magat, Ambuklao and Binga Dams
Scope of Work
  • Review of existing design flood assessments
  • Estimation of PMP with the statistical Hershfield approach
  • Detailed PMP assessment based on WMO meteorological method
  • Rainfall-runoff modelling for determination of PMF inflow
  • Simulation of reservoir flood operation for the assessment of PMF flood water levels
  • Sensitivity analyses for the investigation of possible climate change impacts
Project Impact

Enhanced hydro-meteorological data bases and state-of-the-art methods enable a reassessment of flood safety for three multi-purpose dams. Sensitivity analyses based on climate model data show possible future trends due to climate change.

Facts to Project

Client: SN Aboitiz Power Group


  • Probable Maximum Precipitation (PMP) assessment
  • Probable Maximum Flood (PMF) assessment
  • Assessment of flood water levels
  • Climate change impact assessment

Project period: 2013

Location: Philippines

Philipp Stanzel
Hydrology, Flood Forecast, Climate Impact Research

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