Interbasin transfer

An interbasin transfer is a transfer of water from one river basin to another. The purpose of an interbasin transfer can be to generate hydropower, to alleviate water shortages in the receiving basin or both. The number of interbasin transfers is expected to increase due to increased water demand for irrigation, industry and municipal water supply, as well as because of increased hydrological variability caused by climate change. Interbasin transfers are often large and expensive, involving major infrastructure and the in some cases massive use of energy for pumping. They can also be complicated in legal terms, since water rights are affected, especially if the basin of origin is a transboundary river. Finally, transfers can have significant negative environmental impacts on aquatic ecosystems.

Existing transfers

There are dozens of large inter-basin transfers around the world, most of them concentrated in Australia, Canada, China, India and the United States. The oldest interbasin transfers date back to the late 19th century. Their primary purpose usually is either to alleviate water scarcity or to generate hydropower.

Primarily for the alleviation of water scarcity

Americas

• The California State Water Project transferring water from Northern to Southern California. It includes the California Aqueduct and the Edmonston Pumping Plant, which lifts water nearly 2,000 feet (600 meters) up and over the Tehachapi Mountains through 10 miles of tunnels for municipal water supply in the Los Angeles Metropolitan area.
• From the Colorado River to the Imperial Irrigation District in Southern California
• The Cutzamala System, transferring water from the Cutzamala River to Mexico City for use as drinking water, lifting it over more than 1000 meters. It utilizes 7 reservoirs, a 127 km long aqueduct with 21 km of tunnels, 7.5 km open canal, and a water treatment plant. Its cost was US$ 1.3 billion. See also Water resources management in Mexico

Asia

• The Periyar Project in Southern India from the Periyar River in Kerala to the Vaigai basin in Tamil Nadu. It consists of a dam and a tunnel with a discharging capacity of 40.75 cubic meter per second. The project was commissioned in 1895 and provides irrigation to 81,000 hectares, in addition to providing power through a plant with a capacity of 140 MW.
• The Parambikulam Aliyar project, also in Southern India, consists of seven streams, five flowing towards the west and two towards the east, which have been dammed and interlinked by tunnels. The project transfers water from the Chalakudy River basin to the Bharatapuzha and Cauvery basins for irrigation in Coimbatore district of Tamil Nadu and the Chittur area of Kerala states. It also serverse for power generation with a capacity of 185 MW.
• The Kurnool Cudappah Canal in Southern India is a scheme started by a private company in 1863, transferring wtaer from the Krishna River basin to the Pennar basin. It includes a 304 km long canal with a capacity of 84.9 cubic meter per second for irrigation.
• The Telugu Ganga project in Southern India. This project primarily meets the water supply needs of Chennai metropolitan area, but is also used for irrigation. It brings Krishna River water through 406 km of canals. The project, which was approved in 1977 and completed in 2004, involved the cooperation of four Indian States: Maharashtra , Karnataka, Andhra Pradesh and Tamil Nadu.
• The Ravi-Beas-Sutlej-Indira Gandhi Nahar Project is a system of dams, hydropower plants, tunnels, canals and irrigation systems in Northern India built in the 1960s, ultimately feeding into the Rajasthan Canal to irrigate the Thar Desert.
• The National Water Carrier in Israel, transferring water from the Sea of Galilee (Jordan River Basin) to the Mediterranean coast lifting water over 372 meters. Its water is used both in agriculture and for municipal water supply.
• The Mahaweli Ganga Project in Sri Lanka includes several inter basin transfers.
• Irtysh Karaganda scheme in central Kazakhstan is about 450 km long with a maximum capacity of 75 cubic meters per second. It was built between 1962 and 1974 and involves a lift of 14 to 22 m.
• Numerous transfers in China

Australia

• The Bradfield Scheme and the Reid Scheme in Queensland serving primarily for irrigation
• Three schemes for flooding Lake Eyre
• The 530km-long Goldfields Water Supply Scheme of Western Australia built from 1896 to 1903
• A scheme to supply Perth with water through the Kimberley Pipeline Scheme

Europe

• Various transfers from the Ebro River in Spain, which flows to the Mediterranean, to basins draining to the Atlantic, such as Ebro-Besaya transfer of 1982 to supply the industrial area of Torrelavega, the Cerneja-Ordunte transfer to the Bilbao Metropolitan area of 1961, as well as the Zadorra-Arratia transfer that also supplies Bilbao through the Barazar waterfall (Source:Spanish Wikipedia article on the Ebro River)

The Central Arizona Project (CAP) in the USA is not an interbasin transfer per se, although it shares many characteristics with interbasin transfers as it transports large amounts of water over a long distance and difference in altitude. The CAP transfers water from the Colorado River to Central Arizona for both agriculture and municipal water supply to substitute for depleted groundwater. However, the water remains within the watershed of the Colorado River.

Characteristics of major existing interbasin transfers and other large-scale water trasfers to alleviate water scarcity

	Year of construction	Length	Capacity (Million cubic meters/year)	Costs (US$ bn)
California State Water Project	Eearly 1960s-1990s	715km	25 (10,300 cubic feet/sec)	5.2
Central Arizona Project	1973-93	541km	5 (1.5m acre-feet/year)	3.6
National Water Carrier	1953-64	130km	1.7	?
Cutzamala System (Mexico)	Late 1970s-late 1990s	154km	2.1 (24 m3/sec)	1.3

For the generation of hydropower

• The Drakensberg Pumped Storage Scheme from the Tugela River that flows into the Indian Ocean into the Vaal River in South Africa, which ultimately drains into the Orange River and the Atlantic Ocean. Its purpose is hydropower generation
• The Snowy Mountains Scheme in Australia
• In Canada, sixteen interbasin transfers have been implemented for hydropower development, including at Kemano, James Bay and Churchill Falls.
• The Nam Theun II Project in Laos, whose purpose is hydropower generation
• The Bheri-Babai Multipurpose Project on the Ghaghara River in India (Hydropower and irrigation)

For other purposes

The Chicago Sanitary and Ship Canal in the USA, which serves to divert polluted water from Lake Michigan.

Transfers under construction

The Eastern and Central Routes of the South-North Water Transfer Project in China from the Yangtse River to the Yellow River and Beijing.

Proposed transfers

• A series of transfers in Central and Southern India linking the Godavari-Krishna-Pennar-Cauvery Rivers
• 14 transfers in Northern India
• From the Chalakudy River to the Bharathapuzha River in Kerala, India
• From the Ubangi River in Congo to the Chari River which empties into Lake Chad.
• From the São Francisco River to four northeastern states in Brazil. See also Water resources management in Brazil.
• From Siberia to Central Asia through the Northern river reversal
• The western route of the South North Water Transfer in China, which foresees to divert water from the headwater of Yangtze (and possibly also the headwaters of Mekong or Salween downstream) into the headwater of Yellow River. If the Mekong and Salween rivers were included in the project this would affect the downstream riparian countries Burma, Thailand, Laos, Cambodia and Vietnam.

Literature

• Fereidoun Ghassemi and Ian White: Inter-Basin Water Transfer, Case Studies from Australia, United States, Canada, China and India, Cambridge University Press, International Hydrology Series, 2007, ISBN-13: 9780521869690