New Bullards Bar Dam
Aude Camus, Bentley Systems, with Tim Truong, Chief Dam Safety Engineer, Yuba Water
Establishing a digital twin for automated monitoring of california’s second tallest dam
OWNED and operated by Yuba Water Agency, New Bullards Bar Dam is a 645ft tall concrete arch dam, making it California’s second tallest dam and the fifth tallest in the United States. It is situated in the Yuba County foothills on the edge of Tahoe National Forest with a capacity to hold 1.19 cubic kilometres of water, forming the New Bullards Bar Dam Reservoir that provides flood control and serves as a popular recreation area. Built in 1970, the dam helps to reduce flood risk, generate clean hydropower, and ensure reliable water supply for county residents, the area’s rich agricultural community, and the environment.
New Bullards Bar Dam is a 645ft tall concrete arch dam, making it California’s second tallest dam and the fifth tallest in the United States... Built in 1970, the dam helps to reduce flood risk, generate clean hydropower, and ensure reliable water supply for county residents, the area’s rich agricultural community, and the environment.
Committed to dam safety and improving operational efficiencies and reliability, the client initiated a project to modernise the dam’s legacy monitoring system, implementing real-time data collection, digital visualisation, and automated monitoring. It was hoped it would provide a better understanding the entire performance of New Bullards Bar Dam, especially when dealing with inclement weather and seismic events.
With multiple monitoring prisms and pylons, the smart digitised system provides real-time insight into movement of the dam structure over time as it is exposed to different natural elements, accelerating detection of dam deformation and improving risk assessment and dam safety.
Safety hazards, site constraints, and security
The project involved performing drone surveys and installing automated survey instruments that provide a comprehensive set of capabilities for detecting cracks and 3D deflection of the structure, along with monitoring any propagation. To implement the digital monitoring system, the project team had to establish local survey benchmarks and install reflective target sensors across the dam face, as well as construct a secure enclosure to house and protect the automated motorised total station. This situation presented challenges when obtaining permits and approvals for drilling and installing the devices.
The team also faced challenges with the engineering and construction activities necessary to build the dedicated security enclosure for the survey equipment at a remote location while ensuring visibility of the entire downstream dam face. Compounding these issues was the steep terrain around the dam, accessible only via a narrow, restricted road.
The dam’s previous monitoring system relied on manual, time-consuming data collection that spanned only a portion of the dam at any given time. It also posed fall hazards to the survey team amid the remote terrain therefore a cost-ef ficient and comprehensive smart monitoring system, enabling holistic insight into dam movement and conditions was needed.
To develop their intelligent monitoring solution, they needed integrated reality modelling and digital twin applications facilitating remote, real-time data collection and visualisation with automated alerts of potential issues, while securing the on-site digital survey station equipment.
A monitoring solution
Real-time, automated total monitoring station at New Bullards Bar Dam significantly has improved the monitoring capabilities and provides continued commitment to public safety and infrastructure resilience – nothing is more important than public safety.iTwin IoT was used to establish a digital twin of the entire dam. The digital twin now enables the team to visualise the sensor data and monitor movement and behaviour of the dam structure over time as it is exposed to different elements and perform real-time risk assessments. It meant the dam could be monitored more closely during heavy rainfall and be checked on quickly if earthquakes or other major weather events occur.
The digital twin applications provide the ability to collect monitoring data remotely and automate analysis and alerts based on predetermined thresholds. The team can track the direction of deformation directly on the digital twin.
Working in the iTwin Platform, events can be tracked, providing timely alerts, and reporting to stakeholders all in one platform, while having peace of mind that the secure system locks access to the total station for most of the time that live monitoring is not occurring.
A digital twin
The original approach to the dam monitoring would have taken about one week to get a data point from a target and cost $5,000 USD for each manual data collection event. The new cloud-based system collects a data point from more than 80 prisms twice a day and it is immediately accessible to all authorised users.
Compared to conventional monitoring, the digital twin fully provides insight into how the dam performs in the real world with accuracy over time, optimising risk assessment and driving situational intelligence, paramount to achieving the agency’s goal of ensuring public safety and protecting the environment.
Real-time, automated total monitoring station at New Bullards Bar Dam significantly has improved the monitoring capabilities and provides continued commitment to public safety and infrastructure resilience – nothing is more important than public safety.
Aude Camus, Bentley Systems with Tim Truong, Chief Dam Safety Engineer, Yuba Water