Assessment for Tidal Bridge Project in East Flores, Indonesia
The residents and farmers on the island of Adonara have to cross the dangerous Larantuka Strait on small ferries. These ferries only operate during daytime, cannot transport cars, and are capable of carrying only a limited amount of cargo. This poor connection affects the economic potential of the island, and both residents and the regional government are looking for a permanent solution: a bridge. The power supply on the island is also inadequate and power cuts are frequent. This also affects the local economy.
Tidal Bridge B.V., a Dutch consortium, has developed a concept for a bridge across the Larantuka Strait which incorporates tidal turbines. This will solve both issues. With a capacity of 40 MW, the Tidal Bridge will be the largest tidal turbine in the world – and the first of its kind to combine a bridge with tidal power. The tidal turbines will replace two diesel-fuelled power generators.
In collaboration with project partner Bita Bina Semesta, Witteveen+Bos performed an Environmental and Social Impact Assessment to identify and address all the major environmental and social impacts of the project.
Although the Tidal Bridge will bring significant social and economic benefits to this poor part of Indonesia, it is also going to be built in an area where whales are occasionally sighted and endangered turtle species nest. Without appropriate adjustments to the design, the bridge could affect these species. The relocation of some residents and businesses will also be required to allow for wider access roads. Finally, the ferry operators (approximately 75 in number) will lose the source of their livelihood once the bridge has been completed. A compensation payment will be required for these operators.
Witteveen+Bos has identified the affected communities and businesses and provided a framework for restoring their livelihood. We have also suggested a number of design changes to allow for the undisturbed passage of whales and turtle nesting.