Cua Dai Beach

A salty wind blows in from the water, and waves break steadily at the edge of the sand. Right here, a very long river comes to its end. At Cửa Đại, the Thu Bồn River pours into the sea. The name Cửa Đại means the great mouth, and this is the largest of the river's mouths.

The river begins in the Ngọc Linh massif, on the border of Quảng Ngãi and Da Nang. It flows past Mỹ Sơn and past Trà Kiệu, an old capital of Champa. Champa was an ancient kingdom on the central and southern coast of what is now Vietnam. Then the river passes Hoi An and meets the sea at this very spot.

Its basin covers 10,350 square kilometers, one of the largest of any river that lies wholly inside Vietnam. For more than a thousand years, this river was the main artery of a whole civilization in central Vietnam.

In old Vietnamese records, Cửa Đại was called Đại Chiêm Hải Khẩu. It was once a major seaport of Champa. Trading ships from China, Arabia, India and Java sailed in and out with ceramics, silk, agarwood and edible bird's nests.

After Champa weakened in 1471, Cửa Đại remained the main sea gate for the trading port of Hoi An. The port flourished under the Nguyễn lords. For many centuries, this place served as the international doorway of central Vietnam.

But the biggest story at Cửa Đại in recent years is not its distant past. It is a lesson about the environment and climate change, playing out right in front of us.

Before 2014, Cửa Đại was the leading tourist beach of Hoi An. Dozens of upscale resorts, such as Vinpearl, Palm Garden, Sunrise Premium and Victoria, stood side by side along the shore.

Then, from 2014, the erosion turned severe, and the waves tore at the sandy shore. The worst years came from 2014 to 2017. In some places, the shore lost 30 meters every year.

Many resorts had to close, move people out, or rush to build seawalls.

Scientists have traced the erosion at Cửa Đại to five causes that add up.

First, from the 2000s on, many hydropower dams on the upper reaches of the Vu Gia and Thu Bồn rivers held back their silt. Sông Tranh 2 and A Vương are among them. So is Đắk Mi 4. The water reaching the sea no longer carried the mud and sand that used to build up the shore.

Second, sand mining on the Thu Bồn River took away even more. Third, the natural currents of the sea slowly carried the sand southward.

Fourth, resorts built right at the water's edge blocked the sand that moves back and forth between the beach and the sandbars offshore. Fifth, climate change and rising seas made storm waves stronger.

All together, these causes wore the coastline away, a meter of sand at a time, one storm season after another, like a coat pulled apart thread by thread.

The story of Cửa Đại is a clear example of climate change combined with human interference at a river mouth.

The good news is that people did not give up. From June 2020 to September 2024, Quảng Nam province carried out three projects with a total budget of 550 billion dong.

The centerpiece is an underwater breakwater 2.3 kilometers long. It lies 250 meters from the shore, hidden beneath the surface of the sea. It breaks the waves from the open sea before they can reach the beach, yet it does not block the view of the water.

Crews also pumped in more than 100,000 cubic meters of sand to rebuild the beach.

And the beach at Cửa Đại has clearly come back to life. Part of the fine sand that gives softly underfoot here was pumped in, the result of a long restoration effort.

An even larger project is worth 42 million euros. It includes a loan of 35 million euros from the French Development Agency. The European Union adds 2 million euros in aid. The goal is to protect the whole Hoi An coastline for the long term.

It is an international effort against climate change, so that Vietnam does not have to face the sea alone.

Off to one side, the large bridge spanning the river is the Cửa Đại Bridge. It opened in 2016 and runs about 1.5 kilometers over the Thu Bồn, linking Hoi An with the land to the south.

The speedboat pier in the distance is where boats leave for Cù Lao Chàm. The island lies 15 kilometers from here, only about 20 minutes away by speedboat.

Cửa Đại is far from dead. It is learning to live with the sea.

Waves lap at the sand that has just come back to life, and the thousand-year-old river flows quietly out to the open sea. This was once the sea gate for the trading ships of Champa. Today it still stands wide open, welcoming the wind, the sunshine, and everyone who comes here.