The Pearl River Delta is the low alluvial plain in Guangdong province, southern China, where the Xi (West), Bei (North) and Dong (East) rivers meet. They drain into the South China Sea through the Pearl River Estuary, which separates Hong Kong and Shenzhen on the east from Macau and Zhuhai on the west. Physically it is two deltas side by side, a maze of distributary channels, dykes and fish ponds, much of it built over since China’s economic reforms began in 1979. The metropolitan region around it, officially the Guangdong–Hong Kong–Macao Greater Bay Area, covers 56,000 km² and had about 86 million people in its nine largest cities in 2022. No single reserve protects the whole delta. Its best-known protected wetland is Inner Deep Bay in Hong Kong, which includes the Mai Po Marshes and was listed as a Ramsar site on 4 September 1995. This guide follows the water downstream, from the gorges where the rivers enter the plain to the open estuary.
Wuzhou to Zhaoqing: The Xi River Arrives
Most of the delta’s water comes from the west. The Xi River begins at Wuzhou, in Guangxi, where the Gui and Xun rivers meet. Counted from its farthest headwater on Maxiong Mountain in Yunnan, though, the Xi system runs 2,271.8 km and carries a different name on each stretch. Measured the same way, the whole Pearl system is about 2,400 km long, the third-longest river in China after the Yangtze and the Yellow River. Its basin covers 453,700 km², and it carries more water than any Chinese river except the Yangtze.
Below Wuzhou the Xi crosses into Guangdong. It starts behaving like a delta river as far upstream as Zhaoqing, although the city is not usually counted as part of the delta. Just east of the Lingyang Gorge the hills fall back and the river comes out onto the plain. The Xi is navigable for its whole length and links the delta cities to the interior. The Lingqu Canal, dug more than 2,000 years ago, joined a Xi tributary, the Li, to the Xiang River, giving boats a continuous route from the delta to the Yangtze valley. About 80 percent of the basin’s rain falls between April and September, so the river runs high in summer and low in the dry months, and droughts are becoming more frequent.
Sanshui and Shunde: Where the Bei Joins and the Channels Split
The second river comes in from the north. The Bei River is 633 km long and begins at Shaoguan, where the Zhen and Wu rivers meet. It enters the delta plain at Qingyuan, but it does not start to divide until it nears Sanshui, a district of Foshan with 803,226 people at the 2020 census. The Xi, which has left the Lingyang Gorge, joins the Bei in this part of the plain. From here the delta becomes a network of waterways. The Tanzhou and Shunde waterways split off and flow out through several mouths on the west side of the estuary. Two other branches, the Lubao Cong and Xinan Cong, leave the Bei further north and join the Liuxi River to form the Pearl River proper just north of Guangzhou.
The Xi, meanwhile, spreads south and east through the western half of the delta, reaching as far east as Nansha and as far west as Xinhui. Its distributaries include the Donghui, Jiya and Hutiaomen waterways. The main branch keeps heading south-east past Jiangmen and Zhongshan and reaches the sea at Modaomen, just west of Macau. Until about 1985 this was mostly farmland and villages. Investment from Hong Kong manufacturers then changed the delta quickly. Dongguan, Zhongshan, Nanhai and Shunde grew so fast from the late 1980s that they became known as the Four Guangdong Dragons. In 2003, Hong Kong companies employed about 11 million workers in the delta.
Guangzhou on the Pearl River Proper
The channel that actually carries the name Pearl River (Zhujiang) is short but wide. It runs through Guangzhou, the capital of Guangdong, about 120 km north-west of Hong Kong and 145 km north of Macau. The name is said to come from pearl-coloured shells in the riverbed as it passes the city. Guangzhou, known in the West as Canton, has a history of more than 2,200 years. It was a terminus of the maritime Silk Road and, for a long period, the only Chinese port open to European traders. That changed when Britain captured the city in the First Opium War and Hong Kong and Shanghai began taking its trade.
The Port of Guangzhou now spreads downstream through the Huangpu, Xinsha and Nansha harbour areas. It is the largest general port in South China and trades with more than 300 ports in over 80 countries. Nansha, the southernmost district of Guangzhou, was cut out of Panyu as a technology zone in 1993, became a district in 2005 and was made a state-level new area in September 2012. It looks south onto Lingdingyang, the open estuary.
Huizhou to Dongguan: The Dong River and Hong Kong’s Taps
The third river joins on the eastern side. The Dong River rises on Mount Yajibo in Xunwu County, Jiangxi, flows south through Huizhou, and splits into many branches north-east of Dongguan. Those branches, among them the Dongguan waterway, enter the Pearl River as far north as Luogang and as far south as Humen. On the eastern side the Dong forms a delta of its own, separated from the Xi and Bei delta by the Pearl River itself.
The Dong River also supplies much of Hong Kong’s water. On 15 November 1960 the Hong Kong government agreed with the Guangdong authorities to take 23 million m³ a year from the Shenzhen Reservoir, which is fed by the Dong. Pumping stations and dams raised the amount several times. After upgrades in 1990, the scheme delivered 1.7 billion m³ a year: 1.1 billion m³ to Hong Kong, 493 million m³ to Shenzhen and 150 million m³ for irrigation along the river. Since 1960, twelve supply agreements have been signed, each based on forecasts of Hong Kong’s demand. As pollution worsened, the intake was moved further upstream.
Through the Tiger Gate to Lingdingyang
Below Guangzhou all the eastern water passes through one narrow strait, the Humen, or Bocca Tigris. The name means Tiger Gate and comes from Tiger Island in the middle of the channel. The Portuguese Boca do Tigre became “Bocca Tigris” and, in English, “the Bogue”. Humen divides Shiziyang to the north from Lingdingyang to the south. It was fortified in 1702 because it was the naval entrance to Guangzhou, and eight forts guarded it. The first major battle of the First Opium War was fought at its entrance, the First Battle of Chuenpi, on 3 November 1839, and British forces took the Bogue forts in January and February 1841. Since 1997 the Humen Pearl River Bridge has crossed the strait, with Humen Town in Dongguan on its eastern shore and Nansha on its western shore.
South of Humen the estuary opens into a wide bay. Lingdingyang, the middle channel of the estuary, leads south to Jiuzhouyang, the lower channel, which reaches as far as the southern end of the Wanshan Archipelago. The Hong Kong–Zhuhai–Macau Bridge crosses the Lingding and Jiuzhou channels. This 55 km system of three cable-stayed bridges, an undersea tunnel and four artificial islands opened to the public on 24 October 2018. It is the longest sea crossing in the world. The Shenzhen–Zhongshan Link, about 32 km further north, is of similar length at 49.7 km and opened on 30 June 2024.
Mai Po and Deep Bay: The Estuary’s Wild Edge
Some wetland and wildlife survive at the edges of the estuary. On the Hong Kong side of Deep Bay, where the Sham Chun (Shenzhen) River reaches the sea, lie the Mai Po Marshes. The river has formed part of the boundary since the 1898 Convention for the Extension of Hong Kong Territory. The World Wide Fund for Nature has managed the 380-acre (about 1.5 km²) reserve since 1983. It sits inside the Inner Deep Bay Ramsar site, which is managed by Hong Kong’s Agriculture, Fisheries and Conservation Department. In recent years the reserve has held more than 55,000 migrating birds of over 350 species, including Saunders’s gull and about a quarter of the world’s black-faced spoonbills. Pollution, development plans and mudflats rising as Shenzhen grows on the north shore all threaten the bay.
Chinese White Dolphins off Lantau
Out in the estuary lives the Indo-Pacific humpback dolphin, called the Chinese white dolphin in Hong Kong, Macau and mainland China. It is drawn to the brackish water of the river mouth. The English traveller Peter Mundy described it near the Pearl River in 1637. In Hong Kong the dolphins live mainly off North and Southeast Lantau, around the Soko Islands and near Peng Chau. Their numbers have fallen. Hong Kong conservationists reported a drop from 158 animals in 2003 to 78 in 2011. The nine km² of seabed reclaimed for Chek Lap Kok airport off North Lantau in the 1990s first brought the species to public attention. The dolphin was the official mascot of Hong Kong’s 1997 handover. Collisions with vessels, pollution, overfishing and underwater noise still threaten them.
To compare the estuary’s ports, read our guides to the Port of Guangzhou and the Port of Shenzhen. The crossing at the mouth of the estuary has its own story in our guide to the Hong Kong–Zhuhai–Macau Bridge.