Interbasin transfer

Interbasin transfer or transbasin diversion are (often hyphenated) terms used to describe man-made conveyance schemes which move water from one river basin where it is available, to another basin where water is less available or could be utilized better for human development. The purpose of such designed schemes can be to alleviate water shortages in the receiving basin, to generate electricity, or both. Rarely, as in the case of the Glory River which diverted water from the Tigris to Euphrates River in modern Iraq, interbasin transfers have been undertaken for political purposes. While ancient water supply examples exist, the first modern developments were undertaken in the 19th century in Australia, India and the United States; large cities such as Denver and Los Angeles would not exist as we know them today without these diversion transfers. Since the 20th century many more similar projects have followed in other countries, including Israel, Canada and China. Utilized alternatively, the Green Revolution in India and hydropower development in Canada could not have been accomplished without such man-made transfers.

Michigan Ditch in northern Colorado carries water from the North Platte River watershed over Cameron Pass to the South Platte River watershed.

Since conveyance of water between natural basins are described as both a subtraction at the source and as an addition at the destination, such projects may be controversial in some places and over time; they may also be seen as controversial due to their scale, costs and environmental or developmental impacts.

In Texas, for example, a 2007 Texas Water Development Board report analyzed the costs and benefits of IBTs in Texas, concluding that while some are essential, barriers to IBT development include cost, resistance to new reservoir construction and environmental impacts.[1] Despite the costs and other concerns involved, IBTs play an essential role in the state's 50-year water planning horizon. Of 44 recommended ground and surface water conveyance and transfer projects included in the 2012 Texas State Water Plan, 15 would rely on IBTs.[1]

While developed countries often have exploited the most economical sites already with large benefits, many large-scale diversion/transfer schemes have been proposed in developing countries such as Brazil, African countries, India and China. These more modern transfers have been justified because of their potential economic and social benefits in more heavily populated areas, stemming from increased water demand for irrigation, industrial and municipal water supply, and renewable energy needs. These projects are also justified because of possible climate change and a concern over decreased water availability in the future; in that light, these projects thus tend to hedge against ensuing droughts and increasing demand. Projects conveying water between basins economically are often large and expensive, and involve major public and/or private infrastructure planning and coordination. In some cases where desired flow is not provided by gravity alone, additional use of energy is required for pumping water to the destination. Projects of this type can also be complicated in legal terms, since water and riparian rights are affected; this is especially true if the basin of origin is a transnational river. Furthermore, these transfers can have significant environmental impacts on aquatic ecosystems at the source. In some cases water conservation measures at the destination can make such water transfers less immediately necessary to alleviate water scarcity, delay their need to be built, or reduce their initial size and cost.

Existing transfersEdit

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, with an exceptionally old example being the Roman gold mine at Las Médulas in Spain. Their primary purpose usually is either to alleviate water scarcity or to generate hydropower.

Primarily for the alleviation of water scarcityEdit



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, though transferred into the Gila sub-basin.


  • 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 meters 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.[5]
  • 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 serves for power generation with a capacity of 185 MW.[5]
  • The Kurnool Cudappah Canal in Southern India is a scheme started by a private company in 1863, transferring water from the Krishna River basin to the Pennar basin. It includes a 304 km long canal with a capacity of 84.9 cubic meters per second for irrigation.[5]
  • 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.[5]
  • The Indira Gandhi Canal (formerly known as the Rajasthan Canal) linking the Ravi River, the Beas River and the Sutlej River through a system of dams, hydropower plants, tunnels, canals and irrigation systems in Northern India built in the 1960s to irrigate the Thar Desert.[5]
  • 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.
  • The Irtysh–Karaganda Canal 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.[5]
  • The South–North Water Transfer Project in China, as well as other smaller-scale projects, such as the Irtysh–Karamay–Ürümqi Canal.
  • Part of the water flowing northwards down Tung Chung River in Northern Lantau is diverted across the mountain ridge to Shek Pik Reservoir in southern Lantau.



  • 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. See Water supply and sanitation in Spain).
  • The North Crimea Canal (Ukraine), transporting water from the Dniepr River to the Crimean Peninsula.

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

Year of construction Length Capacity (Million cubic meters/year) Costs (US$ bn)
California State Water Project (USA) Early 1960s-1990s 715 km 25 (10,300 cubic feet/sec) 5.2
Colorado River Aqueduct (USA) 1933–1941 392 km 1603.5 (1.3m acre-feet/year) ?
Central Arizona Project (USA) 1973-93 541 km 1850.2 (1.5m acre-feet/year) 3.6
National Water Carrier (Israel) 1953-64 130 km 1.7 ?
Cutzamala System (Mexico) Late 1970s-late 1990s 154 km 2.1 (24 m3/s) 1.3
All-American Canal (USA) 1930s 132 km 64 (740 m3/s) ?
Periyar Project (India) Commissioned in 1895 ? 3.5 (41 m3/s) ?
Indira Gandhi Canal (India) Since 1958 650 km ? ?
Telugu Ganga project (India) 1977–2004 406 km 10.1 (3.7 bn m3/year) ?
Irtysh-Karaganda scheme (Kazakhstan) 1962–1974 450 km 6.5 (75 m3/s) ?

For the generation of hydropowerEdit



  • The Snowy Mountains Scheme in Australia, built between 1949 and 1974 at the cost (at that time) of A$800 million; a dollar value equivalent in 1999 and 2004 to A$6 billion (US$4.5 billion).
  • The Barnard River Scheme, also in Australia, constructed between 1983 and 1985.


In Canada, sixteen interbasin transfers have been implemented for hydropower development. The most important is the James Bay Project from the Caniapiscau River and the Eastmain River into the La Grande River, built in the 1970s. The water flow was reduced by 90% at the mouth of the Eastmain River, by 45% where the Caniapiscau River flows into the Koksoak River, and by 35% at the mouth of the Koksoak River. The water flow of the La Grande River, on the other hand, was doubled, increasing from 1,700 m³/s to 3,400 m³/s (and from 500 m³/s to 5,000 m³/s in winter) at the mouth of the La Grande River. Other interbasin transfers include:

British Columbia
New Brunswick
Newfoundland and Labrador
Northwest Territories
Nova Scotia


  • The Nam Theun II Project in Laos from the Nam Theun River to the Xe Bang Fai River, both tributaries of the Mekong River, completed in 2008.

For other purposesEdit

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

Transfers under constructionEdit

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 transfersEdit

Nearly all proposed interbasin transfers are in developing countries. The objective of most transfers is the alleviation of water scarcity in the receiving basin(s). Unlike in the case of existing transfers, there are very few proposed transfers whose objective is the generation of hydropower.


From the Ubangi River in Congo to the Chari River which empties into Lake Chad. The plan was first proposed in the 1960s and again in the 1980s and 1990s by Nigerian engineer J. Umolu (ZCN Scheme) and Italian firm Bonifica (Transaqua Scheme).[7][8][9][10][11] In 1994, the Lake Chad Basin Commission (LCBC) proposed a similar project and at a March, 2008 Summit, the Heads of State of the LCBC member countries committed to the diversion project.[12] In April, 2008, the LCBC advertised a request for proposals for a World Bank-funded feasibility study.





From the Ebro River in Spain to Barcelona in the Northeast and to various cities on the Mediterranean coast to the Southwest

Ecological aspectsEdit

In this experiment, juvenile green sturgeons are being dragged into an unscreened water diversion pipe operated under conditions like those found in the Sacramento river.

Since rivers are home to a complex web of species and their interactions, the transfer of water from one basin to another can have a serious impact on species living therein.[19]

See alsoEdit


  1. ^ a b Texas Water Report: Going Deeper for the Solution Archived 2014-02-22 at the Wayback Machine Texas Comptroller of Public Accounts. Retrieved 11 February 2014.
  2. ^ Cecilia Tortajada and Enrique Castelán:Water Management for a Megacity: Mexico City Metropolitan Area, Ambio, Volume 32, Issue 2 (March 2003)
  3. ^ "New York City's Water Supply System Map". New York City Department of Environmental Protection. Retrieved 2009-09-03.
  4. ^ "Northern Water C-BT Project". Retrieved 2019-03-07.
  5. ^ a b c d e f National Water Development Agency of India:Existing Experience with Interbasin Transfers
  6. ^ Drakensberg Pumped Storage Scheme Archived 2008-10-17 at the Wayback Machine
  7. ^ Journal of Environmental Hydrology, Vol. 7, 1999
  8. ^ New Scientist, March 23, 1991 Africa at a Watershed (Ubangi - Lake Chad Inter-basin transfer)
  9. ^ Umolu, J. C.; 1990, Macro Perspectives for Nigeria’s Water Resources Planning, Proc. of the First Biennial National Hydrology Symposium, Maiduguri, Nigeria, pp. 218-262(discussion of Ubangi-Lake Chad diversion schemes)
  10. ^ The Changing Geography of Africa and the Middle East By Graham Chapman, Kathleen M. Baker, University of London School of Oriental and African Studies, 1992 Routledge
  11. ^ Combating Climate Induced Water And Energy Deficiencies In West Central Africa (Ubangi - Lake Chad Inter-basin transfer) Archived 2011-05-26 at the Wayback Machine
  12. ^ Voice of America News, March 28, 2008 African Leaders Team Up to Rescue Lake Chad
  13. ^ City of Hickory:Interbasin transfer information
  14. ^
  15. ^ National Water Development Agency of India:Proposed Interbasin Transfer Links - Peninsular Component
  16. ^ a b M.S. MENON: A case for inter-basin transfer of water, in:The Hindu, Nov. 19, 2002
  17. ^ National Water Development Agency of India:Proposed Interbasin Transfer Links - Himalayan Component
  18. ^ Siberian River Project Revived 08-Sep-06
  19. ^ Mussen, T. D.; Cocherell, D.; Poletto, J. B.; Reardon, J. S.; Hockett, Z.; Ercan, A.; Bandeh, H.; Kavvas, M. L.; Cech Jr, J. J.; Fangue, N. A. (2014). Fulton, Christopher J (ed.). "Unscreened Water-Diversion Pipes Pose an Entrainment Risk to the Threatened Green Sturgeon, Acipenser medirostris". PLoS ONE. 9 (1): e86321. doi:10.1371/journal.pone.0086321. PMC 3893286. PMID 24454967.

Further readingEdit