Upgrade of telemetry and dam safety monitoring at Lake Margaret, Tasmania
Client: Hydro Tasmania
Location: Lake Margaret, Tasmania, Australia
Date: 2019
Upgrading hydrometric and dam safety monitoring equipment to improve offsite monitoring of a remote dam
Background
In Tasmania’s remote, rugged west is Lake Margaret - Hydro Tasmania’s oldest hydropower dam, constructed in 1914. The dam safety monitoring and hydrometric assets required upgrading to improve data acquisition for monitoring of dam conditions. Previously, only water level and rainfall data was gathered via telemetry and the data was delivered via a costly satellite telemetry link.
Improving remote dam safety monitoring reduces the need for regular site access by personnel, alleviating the logistical challenges of the difficult driving and walking required to reach the site, often in wild and changeable weather.
Solution
To upgrade the hydrometric and dam safety monitoring assets at this remote site, the project team needed to undertake significant planning, logistics, and health, safety and environment (HSE) activities. Good weather with low lake levels was needed for successful project delivery, as was regular consultation across disciplines and enhanced project management.
Works onsite included upgrading the lake level instrumentation, gauge board infrastructure (bracing) and also the associated protective conduit housing the air bubbler and cable lines. Then a lengthy cable/conduit run across the dam spillway was installed and rigged to enable wired remote camera capability. Solar infrastructure was installed at the main dam monitoring hub. In addition, the seismic monitoring and rainfall monitoring sites were upgraded – the former with a new rain gauge stand, solar power and data logging/telemetry system; the latter with solar backup to existing 240v power and upgraded telemetry system.
Next, three new tilt-up masts with dam surveillance cameras (able to tilt, zoom and pan) and an updated telemetry repeater link were installed to improve data quality and delivery. This involved transporting large, heavy tower infrastructure, equipment and plant to the site. Equipment and plant (including core drills, generators and tilt-up masts) were slung into site by helicopter or via diesel pipeline trolley.
To install the towers the team drilled 36 precise core holes into the local Owen Conglomerate rock (one of the hardest rock types in Tasmania, if not the world) to enable installation of the camera and repeater masts – which were lifted into place via helicopter and secured by newly engineered base plates that are larger and stronger than the manufacturer’s design.
Services provided
- Project and logistics management
- Engineering design
- Remote data acquisition and dam monitoring equipment/instrumentation upgrades, including design, remote mobilisation, testing and installation
- Remote camera image acquisition and display
Outcome
The new and upgraded dam monitoring and telemetry equipment now allows remote capture of data for use in near-real-time dam safety analysis and decision making. The new telemetry repeater link gives access to 4G, allowing cost-effective high-speed data transfer.
As well, the new masts and camera equipment enable the capture of detailed images, which will augment ‘in person’ dam safety checks of Lake Margaret Dam and greatly improve employee safety and efficiency by enabling near-real-time on-site conditions to be viewed from the office.
