Ituango Hydroelectric Dam Geotechnical Instrumentation Audit

Construction of the 2,400-megawatt Ituango Hydroelectric Dam began in 2010 to significantly expand Colombia’s electrical generation capacity. A diversion tunnel collapse in 2018, during construction, required flooding of the unfinished powerhouse and accelerated dam construction to ensure the safety of the downstream population. As a result of the collapse and subsequent re-insurance requirements, the dam owner/operator sought GZA’s expertise to audit the existing instrumentation and monitoring system and make recommendations for improvement.

Challenge

This massive infrastructure project had produced millions of data points to be reviewed. The duration of the construction and the predominantly manual data collection and monitoring methods further complicated the audit process. After the 2018 collapse, the design team replaced many instruments with alternate manufactures; instruments continue to be added on weak rock slopes and within the underground structures.

Solution

Prior to a five-day visit to the site, GZA’s team reviewed all available as-built and monitoring data. During the site visit, GZA met with individual project teams, toured all aspects of the site, and observed installation, data collection and processing procedures first-hand. Key issues identified included serviceability of instruments, such as installation technique, sensor type, and monitoring method; management and communication of data findings; alert response timing; and refinement of data calculation and processing.

Benefit

Because of GZA’s experience in geotechnical instrumentation design, installation, and implementation as well as dam engineering design and construction the firm was well-positioned to conduct the audit of this extraordinary project. GZA’s comprehensive audit report is designed to benefit the project team and increase the effectiveness of the overall instrumentation program.