Here’s why the Turkish government wants to build another Bosphorus

Canal Istanbul would be 30 miles long and cost between $15 and $35 billion.
Eric James Beyer
The Bosphorus StraitMert Kahveci/Unsplash

The Bosphorus Strait is a top contender for the title of most romantic waterway in the world, dividing the equally beautiful city of Istanbul into its European and Asian identities. 

It’s the strait’s geopolitical significance, however, that has resurfaced in the global consciousness in the last week. Russia’s invasion of Ukraine has, among other things, resulted in the Turkish government’s invocation of Article 19 of the 1936 Montreux Convention, closing off the passage of warships to the Black Sea. By that same treaty’s dictate, the warships of “belligerent” powers already separated from their bases have a right to return to them. 

Prior to the enactment of Article 19, Russia had sent 16 warships through the waterway under the guise of their taking part in military exercises, a claim now revealed to be one lie among many in the run-up to the largest act of war on the European continent since the end of World War II. 

Having a say in these matters means having power on a regional level at the very least. Waterways the world over are of extreme importance to the countries they belong to, and not just geopolitically. The Dardanelles and the Bosphorus, which together make up the Turkish Straits, see around 4 percent of global maritime oil move through their waters each year. 

There are few other places in the world that claim such uniquely influential geographies, whether natural or human-altered. The Panama Canal is one of them, through which roughly $270 billion worth of cargo passes annually. 

In March of last year, when a 400-meter-long shipping vessel got stuck in twhe Suez Canal for a week, it held up an estimated $10 billion of cargo a day and cost the Egyptian government roughly $90 million in lost toll revenue. The effects of the blockage rippled through the global supply chain for months. Nearly 12 percent of global trade and 30 percent of the world’s container traffic pass through the Suez every year.

That the Bosphorus is nature's gift to Turkey in every sense of the word is something that the country's government knows well. It’s one of the reasons that president Recep Tayyip Erdoğan and his ruling party have for years been lobbying for a new infrastructure project, called Canal Istanbul, in the country's most populous city — a project that could quite literally change the face of the world and the geopolitical balance on it. 

What is Canal Istanbul?

The so-called “mega project” is a proposed artificial strait running from the Black Sea to the Sea of Marmara located roughly 18 miles (30 km) to the west of Istanbul’s Bosphorus, a logistical endeavor that would turn one of the world’s most historic cities into an island. 

A woman wearing an orange rain coat and a backpack stands at the railing of a ferry crossing the Bosphorus on a cloudy day with Maiden's Tower in the background.
Mert Kahveci/Unsplash

The scope of the proposed canal is massive. Government estimates claim it will be roughly 30 miles long, around 80 feet deep, and somewhere around 900 feet wide. The artificial canal would begin at the northern end of Lake Küçükçekmece in the city’s west, a natural basin on the Marmara Sea, proceed north to the Sazlıdere Dam and eventually link to the Black Sea.

Soil excavations would provide enough material to build multiple islands in the Marmara Sea, something the government is keen to do. The total cost of the project is expected to top $15 billion with ease, with some estimates putting the cost upwards of $30 billion.  

Why build Canal Istanbul?

The canal has been described by Erdoğan himself as one of his “crazy projects,” and it aligns perfectly with the large-scale highway, bridge, and airport building efforts that have come to define his administration's rule. 

Momentum for the project began building years ago. During a press conference in 2018, the country’s transport, maritime affairs and communications minister Ahmet Arslan presented a three-fold case for the canal to the public: increased safety, modern living developments, and an elevation of Istanbul’s worldwide profile.  

Government estimates claim that, through the creation of new cities along the canal's banks, real-estate zoning would result in nearly $10.5 billion in revenue. A significant portion of the funding for such real estate projects would likely come from Chinese and Arab investors, helping to kickstart an economy whose currency has collapsed in recent years. 

Erdoğan's government furthermore claims the Bosphorus is overcrowded and dangerous. A new more easily navigable canal, they say, would alleviate traffic and get rid of the need to deal with a winding and current-ridden Bosphorus. It would furthermore act as a revenue source for the country.

Under the Montreux Convention, ships have a right to pass through the Bosphorus for a nominal fee, but often need to wait to do so in times of high congestion. Turkish authorities hope ships wishing to jump the queue will be more than willing to pay a larger fee to do so. 

Some of the issues Canal Istanbul could address are indeed worth considering. The Bosphorus is undoubtedly busy. In 2021 alone, 38,551 ships passed through the strait. It’s also a demanding passage, and anyone who has ridden any kind of vessel on those waters knows its currents and sweeping curves can only be navigated by experienced pilots. Accidents can and do happen. In April 2018, a Maltese tanker crashed into an historical Bosphorus mansion causing over $30 million in damages. 

Ships cross the water in this aerial view of the Bosphorus near the Golden Horn
Melih Karaahmet/Unsplash

But such incidents are overall quite rare, the last major disaster taking place in 1979 when a Romanian tanker collided with a Greek ship, killing 41 people and sparking a fire that lasted for days.

And while the strait is crowded, transit numbers have dropped significantly since the late 2000s, when over 50,000 ships made the transit annually. Most vessels hire independent navigators to help them make the journey, the use of automatic navigation systems is prohibited by law, and ships carrying hazardous materials may only pass one at a time. Wait times average around 14 hours. 

The case against the canal

The case against the canal is, to some, far more compelling than the one supporting it. 

Politically, building a new canal means completely rethinking the country's commitment to the Montreux Convention, as the new canal would be outside the treaty's authority. Turkey relies on Montreux in cruicial ways, as it was built to establish a reliable framework regarding who can pass through the Bosphorus under a variety of conditions. Without it, the possibility of regional actors using the strait as a way to mire Turkey in conflict rises significantly. 

Erdoğan has expressed on numerous occasions that he is less than a fan of the treaty, however, saying his administration would potentially review it and draw up plans for a new one if they deem it necessary. Many are wary of opening up such a geopolitical black box, as it's unclear what a renegotiation of the status quo would even look like.  

On the economic front, critics accuse the project of being little more than a giant rent-seeking endeavor to save a wounded economy, typical of an administration that came to power largely on the shoulders of promised and often-delivered infrastructure investment and development. Real estate speculation has exploded in the areas the project is expected to cut through, with prices in some neighborhoods jumping from $25 to $800 per square meter of land. 

Environmentalists see a disaster in the making. The Bosphorus Strait links the Black Sea with the Marmara Sea, and the interaction between the two is only partially understood. Scientists do know that saltier water from the Marmara flows to the north at the bottom of the strait, while the surface carries water from the Black Sea to the south. 

Introducing an entirely new connecting route between the two could potentially upset the balance between the seas and destroy the ecosystems they support, the full effects of which not even the region’s experts can predict with any accuracy. Likewise, Istanbul’s water waste treatment system in part relies on this flow. Some fear that altering it could leave the city smelling of sewage. 

While government ministers claim they have taken the potential environmental effects of the canal into consideration, critics remain unconvinced, and many of Turkey’s environmental experts say they have not been consulted by a government that has over the years become increasingly less receptive to external expertise. 

Logistically, the project is enormous. Cutting through some of the densest parts of Istanbul, building the canal would mean reconfiguring roads, power and gas lines, and potentially eliminating 33 million cubic meters of water from the city's reservoirs. 

Ships navigate the Bosphorus Strait while trees and building fade into the horizon.
Mert Kahveci/Unsplash

The state of those reservoirs is of particular worry. Istanbul’s water supply, much of which comes from forested regions north of the city, is precarious at best. The city has long struggled with supplying water to its nearly 16 million inhabitants. Droughts are not infrequent. In January 2021, its reservoirs contained just enough water to supply the city for the next 40 or so days. That wasn’t the first time the city has dealt with such thin water margins, and it won’t be the last. 

Many efforts have been made to plot out the city’s future in a sustainable way. In 2009, a master plan for Istanbul was put together by the city municipality, then headed by the same political party that now runs the country. The idea was to limit the city’s population and ensure development didn’t overtake the last remaining green areas to its north. 

Speaking with National Geographic, Akif Atlar, a city planner for the Istanbul Planning Agency, explained that the city’s spread was to take place along a lateral axis. “The conclusion was that there should be no more settlements in the northern forest, and that water and culturally important land must be protected. Further development would be east and west, not north.”

However, the country’s management abandoned that idea, and subsequent revisions to the master plan have significantly altered its focus and priorities. It now includes Canal Istanbul

Despite the controversy surrounding the project, the government seems committed to seeing it through. Last June, Erdoğan attended a ground-breaking ceremony for a bridge over a river that would constitute the southern end of the canal.

Canals around the world 


Red rooftops shine in the sun as the Bosphorus stretches into the distance.
Svetlana Gumerova

The Bosphorus shares economic salience and geographic exceptionalism with the Suez and Panama Canals, but that's about where their similarities end.

Without the Suez canal, ships would have to make a 5,500 mile journey that takes anywhere between one to two weeks to complete. The presence of the Panama Canal saves ships a lengthy, 8,000 mile trip around Cape Horn in South America. It's for this reason they are essential parts of the global economy. Constructing a new canal just a few miles away from one that already exists will yield no such benefit.  

Turks themselves are torn on the issue, as is their leadership. Just last summer, metro cars in downtown Istanbul were playing videos that displayed sweeping drone footage of the city from above, shots of the dwindling northern forests near the Black Sea, stretches of coastline hills, and the large lakes in the south that commuters and travelers see when driving west towards Bulgaria and Greece. 

Text stretched across the view. “If Canal Istanbul is approved,” it read, “the city’s water reservoirs will be threatened." The video then presented the viewer with a choice: "It’s either the canal, or it's Istanbul."

It was a staunchly anti-canal campaign, produced by the city’s local government, a municipality headed by Istanbul mayor Ekrem Imamoğlu, Erdoğan’s highest-profile political opponent. 

Walk onto public transport today and you'll find the ads for that campaign gone, replaced with bright, digital renderings of seaside canal neighborhoods dotted with modern apartment complexes and stores nestled up to the shore. The video talks about future investment, revitalizing the economy, and increasing standards of living. The polarity is palpable.