Showing that risk of damaging waves couldn’t be overcome economically
MDL France and Bouygues consortium
Our project partner in France teamed up with the Bouygues group, a major French constructor and concession operator to bid for a project to build and operate a marina. The location was Publier, a small town on the French shore of Lake Geneva (Lac Leman) near Evian.
Publier had a small harbour, but the community had a vision to create a 200-berth leisure marina and facilities. This would complement a residential and commercial development that was already under construction.
The marina would be located in relatively sheltered water on a lake, but in extreme weather studies and models were predicting damaging waves at the marina site. The development was not considered viable without some form of wave protection. This added significant cost to the project, especially considering the relatively deep water just a short distance from the shore.
Our challenge was to optimise the design of the marina to provide as many berths as the market would sustain but working within the site’s physical constraints – all of this while keeping the build cost at an economic level.
For this project, we worked closely with MDL France and Colas (France), part of the Bouygues Group, to appraise the development opportunity.
The deep water meant that a fixed breakwater wasn’t viable – it would cost too much, and increased the cost of the floating structure due to more complicated anchorage requirements. Much of our study focused on finding cost-effective solutions to these concerns. Moving the breakwater closer in shore helped so that we could work in shallower depths, but restricted the berth capacity and hence revenue potential. The solution had to be a delicate balance.
We developed different layout options working within the site constraints and evaluated each one for cost and income. We looked at different floating breakwater designs balancing performance (and hence risk) against cost to find the best solution. Following this, we produced an overall optimised layout and produced a financial projection for the project.
Despite investigating all possible solutions and working to really optimise the design we concluded that the project was not going to be economically viable. Reaching this decision quickly was important for the team, saving further abortive work and exposure to increasing costs.
We understand that all bidders pulled out and the town later reconsidered the brief for the project to improve its commercial potential.
If you’ve got a marina project or development in mind, let’s discuss how we can help.