Panama ? Panama’s president will ask voters to approve a multibillion-dollar plan to supersize the Panama Canal, the waterway’s biggest modification since it opened in 1914.

President Martin Torrijos planned to outline the project today, giving details on adding a third series of wider locks, expanding the canal basin fed by the Chagres River and building a system to recycle some of the water that now is allowed to flow out to sea.

Voters will have the final say in a referendum later this year.

The government has not yet put a price tag on the proposal, but independent analysts estimate it would cost $5 billion to $8 billion for work expected to take at least six years. That would be a significant undertaking for a government with an annual budget of $6.5 billion.