The Nile Delta is the fan-shaped plain in northern Egypt where the Nile divides into branches before reaching the Mediterranean. It begins just north of Cairo and spreads about 160 km north to the sea and about 240 km along the coast, from Alexandria in the west to Port Said in the east, covering some 22,000 to 24,000 km². Today the river reaches the sea through just two branches, the Rosetta and the Damietta. The delta is one of the most intensively farmed and densely populated places on Earth, home to roughly 40 to 50 million people. Since the Aswan High Dam stopped the river's sediment in the 1960s, it has been shrinking at the coast and sinking inland.
Why It Is Called a Delta
The word comes from the Nile itself. The Greek historian Herodotus, writing in the fifth century BCE, compared the triangle of land between the river's branches to the Greek capital letter delta, Δ, and the name was later applied to every similar river mouth in the world. The Nile Delta is the classic arc-shaped, wave-dominated delta. Mediterranean waves and currents have smoothed its seaward edge into a broad curve, rather than the long branching fingers of the Mississippi, which builds into calmer water. Our explainer on what a delta is compares the main types.
Seven Ancient Branches, Two Today
In antiquity the Nile reached the sea through several major branches. Classical writers usually listed seven, from the Canopic in the west, which flowed past the site of Alexandria, to the Pelusiac in the east, near today's Suez Canal. Over the centuries, silt, shifting channels and human engineering closed all but two. The Rosetta branch now flows to the sea at Rashid, the town where French soldiers found the Rosetta Stone in 1799. The Damietta branch reaches the sea at Damietta. Between and around them, a dense network of canals and drains, much of it built in the nineteenth and twentieth centuries, now distributes the water across the delta. The old channels survive as canals and as lines of towns that once stood on their banks.
Lower Egypt: Kingdoms of the Delta
For the ancient Egyptians, the delta was Lower Egypt, one of the two lands united by the first kings around 3100 BCE and symbolised by the red crown and the papyrus plant. Several dynasties ruled from delta cities. Tanis was the royal capital around 1000 BCE, and in 1939 French archaeologists found intact royal tombs there, with gold and silver treasures that rival Tutankhamun's but are far less famous. Sais was the capital of the twenty-sixth dynasty in the seventh and sixth centuries BCE. Bubastis was the centre of the cult of the cat goddess Bastet. Much less of this history survives than in Upper Egypt, because the delta's wet soil and rising water table have destroyed buildings and papyri that the desert preserved further south.
The delta was also Egypt's door to the Mediterranean. Greek traders settled at Naucratis in the seventh century BCE. Alexander the Great founded Alexandria on the delta's western edge in 331 BCE, and it became the largest city in the Mediterranean world. In the Middle Ages, Crusader armies landed at Damietta in 1218 and again under Louis IX in 1249, trying to conquer Egypt through the delta.
Cities of the Modern Delta
The delta is dotted with large cities as well as farms. Alexandria, on its north-western edge, is Egypt's second city and main port, with more than 5 million people. Tanta, in the middle of the delta, is home to the mosque of the thirteenth-century Sufi saint Ahmad al-Badawi, whose annual mawlid festival is one of the largest religious gatherings in Egypt. Mansoura, on the Damietta branch, was founded in 1219 and named "the victorious" after the defeat of the Fifth Crusade, and in 1250 Egyptian forces captured Louis IX of France nearby. Mahalla al-Kubra is the centre of Egypt's cotton textile industry, with one of the largest spinning and weaving companies in Africa. Zagazig stands beside the ruins of Bubastis. On the eastern edge, Port Said was founded in 1859 as the Mediterranean entrance to the Suez Canal, which runs south along the delta's eastern margin, as our guide to the Suez Canal explains.
The Richest Farmland in Egypt
About 95 per cent of Egyptians live on a small fraction of the country's land, in the Nile Valley and the delta, and the delta holds most of Egypt's farmland. For thousands of years it was fertilised by the annual flood, which left a fresh layer of silt every autumn. In the nineteenth century, Muhammad Ali's government transformed it into an export economy. New canals, including the Mahmoudiya Canal to Alexandria, and barrages across the river at the head of the delta allowed year-round irrigation, and long-staple Egyptian cotton, introduced in the 1820s, became famous worldwide. Today the delta grows cotton, rice, wheat, maize, vegetables and fruit, with rice concentrated in the wetter north. Rice needs so much water that since 2018 the government has limited the area farmers may plant with it. Even so, the delta cannot feed Egypt's population of more than 100 million, and Egypt is one of the world's largest importers of wheat.
The farmland is under pressure from the growing population. Towns and villages have spread over the fields for decades, with a great deal of fertile land lost to building. That is why Egypt has put so much effort into reclaiming desert on the delta's fringes.
What the Aswan High Dam Changed
The single biggest change to the delta came from 1,000 km upstream. The Aswan High Dam, completed in 1970, ended the Nile's annual flood and gave Egypt year-round water and hydropower. But the reservoir behind it, Lake Nasser, traps almost all the sediment the river used to carry to the sea, which had been more than 100 million tonnes a year. Without that supply, the delta stopped growing. The Mediterranean began to eat into its coast, which the river no longer replenished. The Rosetta promontory retreated by tens of metres a year in the 1970s and 1980s, until Egypt built massive seawalls in the early 1990s. The dam's wider story is told in our guide to the Aswan High Dam.
Sinking Land and a Rising Sea
The delta is also sinking. Its thick layers of young, water-soaked sediment compact under their own weight, and in some parts of the north-east the land is subsiding by several millimetres to around a centimetre a year, faster than the sea is rising. At the same time, global sea level is rising, and much of the northern delta lies less than a metre or two above the sea. Salt water is already seeping into the groundwater and soils of the lowest land, damaging crops. Studies have estimated that a sea-level rise of half a metre to a metre could flood or salinise large areas of farmland and displace millions of people, although estimates vary widely. Egypt has responded with coastal defences, including large projects to protect Alexandria and the lower delta.
A Lotus Seen From Space
From orbit, the delta is one of the most recognisable shapes on Earth. In daylight satellite images, a dark green fan spreads out from Cairo against the pale desert on either side, with the narrow green line of the Nile Valley leading south. Egyptians have long compared the shape to a lotus flower, with the valley as its stem and the delta as its bloom. At night the resemblance is even stronger. Astronauts photograph the delta as a dense web of lights from towns and villages spread across the whole fan, with Cairo shining at its point, and the desert on each side completely dark.
The Lagoons of the North
Along the coast lie four large shallow lagoons, Manzala, Burullus, Edku and Mariut, separated from the sea by sand bars. They have long supported fisheries and millions of migratory birds on the route between Europe and Africa. They have also shrunk dramatically. Much of Lake Manzala, the largest, has been drained for farming or fish ponds or choked by pollution from Cairo's drains. The birds that pass through include pelicans, flamingos and waders. Lake Burullus, which is in better condition, is protected under the Ramsar Convention as a wetland of international importance.
A River Shared With Ten Countries
The delta's water comes from far away. The Nile basin covers parts of eleven countries, and about 85 per cent of the water reaching Egypt comes from the Ethiopian highlands via the Blue Nile. Under a 1959 agreement with Sudan, Egypt claims 55.5 billion cubic metres a year. Upstream countries have never accepted that deal, and Ethiopia's Grand Ethiopian Renaissance Dam, filled in stages from 2020 and inaugurated in 2025, has become one of Egypt's most serious foreign policy concerns. For the delta, whose farms and cities depend on every cubic metre that reaches the Mediterranean, the question of how the river is shared upstream is a question of survival. The river's full course is described in our guide to the Nile.