What are the reasons for dam heightening in Switzerland?
In Switzerland, a lack of supply during cold winters and the increased importation of electricity from neighbouring countries were the motivation to heighten some of the dams. An increase in the seasonal storage capacity of reservoirs provided a boost to production in the winter and consequently improved Switzerland’s energy security.

What Dam heightening and rehabilitation services do we propose ?
Our team of multidisciplinary experts can perform comprehensive inspections and review all aspects of the design and construction of dam heightening and strengthening projects. Our services include:
- All design stages from preliminary design to detailed construction design
- Comprehensive inspection and condition assessment services
- Seismic hazard assessment
- Concrete analysis and specifications for new concrete
- Thermo-mechanical analysis
- Finite element modelling
- Site access and materials transport studies
- Materials specification, construction method and scheduling, tender design, tender document preparation and procurement assistance
- Conceptual modelling of deformations summarizing the knowledge resulting from measurements performed
- Works supervision and construction management
- Comprehensive operations and management support including training
- In-situ testing, non-destructive testing, leak and crack detection
- Blasting and excavations supervision
- Impounding supervision
- Appraisal of the dam behaviour before and after strengthening or heightening
- Risk assessment: breaking point scenarios and process, consequences
- Design and specification of monitoring and alarm systems
What experience do we have in dam heightening and rehabilitation?
The heightening and strengthening of existing dams and associated structures is one of our specialisations. A selection of our recent projects include :
Nant de Drance Pumped Storage scheme in Switzerland
specifically the heightening of the Vieux Emosson gravity arch dam, originally 45-metre high, heightened by 21.5 metres, increased reservoir volume by 15 million cubic metres
Heightening of Cambambe dam heightening project in Angola
(See the cover photo) The existing 60-metre high arch dam was heightened by 28 metres along with a complete redesign of the spillway with the addition of 5 gated orifice spillways.
Strengthening of Les Toules Arch dam in Switzerland
A safety assessment found that the 86-metre high dam was subject to an irreversible displacement. In order to ensure the dam safety against seismic hazard, the arch dam was reinforced and the foundation deepened (see the image below).