Dams Foundations Rehabilitation - Membran Walls

Inspection of existing dams world-wide frequently reveals the need for remedial works. Most of the works are required because of the gradual deterioration of the dams and their associated structures/equipment, combined with the imposition of stricter requirements for flood, seismic and dam break analyses.

The Department of Hydro Services undertook necessary rehabilitation and betterment works on a number of dams for which safety concerns existed. Our involvement in the design phase of a project includes the conceptual design for all rehabilitation and betterments works.

Rehabilitation works include:

• raising of earth embankments and concrete dams
• Upgrading of draw-off towers and tunnels
• provision of new, enlarged spillways and intakes
• provision of emergency drawdown facilities
• strengthening works
• leakage reduction measures
• installation of instrumentation-performance monitoring
• water quality monitoring / water treatment
• spillway modification

We make extensive use of advanced hydrological techniques, including both numerical and physical hydraulic modelling. This enables us to accurately route floods through the reservoirs and existing spillway structures. Increasingly these investigations are now supplemented by seismic and dam break analyses, which often did not form part of the original design for the existing dams. We have been responsible for the design and specification of remedial, improvement, abandonment and discontinuance works at many existing dams and service reservoirs