Line 3 of the Guangzhou Metro or Southern-Northern Express Line (Chinese: 南北快线; pinyin: Nán Běi Kuài Xiàn) is a 67.3-kilometer (41.8 mi) rapid transit line connecting Panyu Square to Tianhe Coach Terminal. The whole line, including all track and stations, is situated in underground tunnels. Top longest tunnels in the world. Its 60.4 km (37.5 mi) main branch, excluding the 6.9 km (4.3 mi) branch between Tianhe Coach Terminal and Tiyu Xilu, is the longest continuous subway tunnel in the world, and the longest rail tunnel of any sort (surpassing the Gotthard Base Tunnel in Switzerland).
For quite some time, large areas in the Eastern Cape experienced severe water shortages due to little rainfall in the arid Karoo. The situation was aggravated by the decrease in capacity of most of the existing dams as a result of heavy silt deposits. The Orange-Fish Tunnel, together with its network of canals, weirs and balancing dams, has enabled these areas to be restored and has made the irrigation of tens of thousands of hectares of additional land possible. The main purpose of the tunnel is to divert water from the Gariep Dam to the Eastern Cape for irrigation, household and industrial use.
The Delaware Aqueduct is the most recent of the New York City aqueducts. It will take water from the Rondout Reservoir through the Chelsea Pump Station, the West Branch Reservoir, and the Kensico Reservoir, ending at the Hillview Reservoir in Yonkers, New York. The aqueduct was constructed between 1939 and 1945, and carries approximately 50% of the New York City water method of getting 1.3 billion US gallons (4,900,000 m3) per day. At 85 miles (137 km) long and 13.5 feet (4.1 m) wide, the Delaware Aqueduct is the world’s longest tunnel.
The Päijänne Water Tunnel, situated in Southern Finland, may be the world’s second longest tunnel (after the Delaware Aqueduct in the USA). It’s 120 kilometers (75 mi) long and runs 30–100 meters underneath the surface in bedrock. The objective of the tunnel is to offer fresh water for the million plus people in Southern Finland in the cities of Helsinki, Espoo, Vantaa, Hyvinkää, Järvenpää, Kerava, Kauniainen, Kirkkonummi, Sipoo, and Tuusula. The former Porvoo Rural Municipality, now merged with the municipality of Porvoo, also took part in the building of the scheme but has never drawn water as a result for domestic use.
The Dahuofang Water Tunnel, situated in Liaoning Province, China is definitely an 85.3 kilometers (53.0 mi) tunnel eight meters in diameter which provides water from the Dahuofang Reservoir to the cities of Shenyang, Fushun, Liaoyang, Anshan, Panjin, Yingkou, and Dalian. As of 2014 it is the 3rd longest tunnel in the world.Top longest tunnels in the world. Boring of the tunnel began in September 2006, was completed in April 2009, and cost 5.2 billion yuan (about $750 million).