The importance of investing in site characterization in a dam project to avoid impending losses

In dam design, site characterization, aside of providing engineering property values, should be able to capture the variability and complexity of geotechnical, engineering geology, hydrogeology conditions in the dam sites. This information plays critical role as it frequently becomes a basis in selecting different scenarios in the design. This paper presents a case study of a rockfill dam construction in Indonesia highlighting the importance of site characterization in reducing uncertainties. In the early construction stage, additional field investigation was performed and identified the presence of high-porosity confined aquifer layer below dam foundation. This finding urged that the initial design of grouting curtain wall could no longer be applied. Dam redesigning required considerable effort and resulted in time and financial losses. Investing in site characterization is believed to reduce uncertainties that eventually avoiding any imminent negative consequences.