Turkey will begin construction in June on a canal, and Istanbul should become an alternative to shipping in the Bosphorus. That’s what Turkish President Recep Tayyip Erdogan said this weekend. The project is worth $15 billion.

The 45-kilometre-long canal will be located west of Istanbul and will connect the Black Sea with the Sea of Marmara. The new waterway should relieve busy shipping in the Bosporus and reduce the risk of accidents. Every year about 50,000 ships pass through the strait that separates the European and Asian parts of Istanbul and is quite narrow at certain points. For example, many Russian oil tankers sail in the Bosphorus.

Erdogan announced plans for the Istanbul Canal ten years ago. He believes the construction will create thousands of new jobs and new towns along the waterway route. Several bridges will cross the canal. According to Erdogan, the project should help Turkey’s economic growth.

“We will start building the foundations of the Istanbul Canal at the end of June,” Erdogan said over the weekend. “We are building two cities on the right and left sides of the canal. With these new cities, Istanbul’s strategic importance and beauty will be enhanced,” said the president.

Erdogan’s political opponents are very critical of the project, which they believe will cost a lot of tax money and negatively affect the environment. Istanbul mayor Ekrem Imamoglu, who is a member of opposition party CHP, has said the project would harm the water supply of Turkey’s largest city. According to him, irreparable damage will also be caused to nature in the city’s vicinity with about 16 million inhabitants.

Imamoglu is seen as a possible candidate to take on Erdogan on behalf of the opposition in the 2023 presidential elections. On Friday, Turkish prosecutors were announced demanding a prison sentence against Imamoglu for insulting the electoral council. He won the mayoral elections in Istanbul in 2019.

In April, ten retired Turkish admirals were arrested for criticizing the canal along with nearly 100 other former naval officers. The waterway could undermine the 1936 Montreux Convention. This treaty is an international regulation of shipping in the Bosphorus and the Dardanelles and guarantees, among other things, the free passage for civil shipping in peacetime. It limits the passage of naval ships from countries outside the Black Sea. Erdogan says he will continue to support the treaty and said warships could start using the Istanbul Canal.