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 water resource engineering 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, feeding large cities such as Denver and Los Angeles. Since the 20th century many more similar projects have followed in other countries, including Israel and China, and contributions to the Green Revolution in India and hydropower development in Canada.
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.
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.
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.
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) | 1973–1993 | 541 km | 1850.2 (1.5m acre-feet/year) | 3.6 |
National Water Carrier (Israel) | 1953–1964 | 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) | ? |
Narmada Canal (India) | Commissioned in 2008 | 532 km | 11,718 (9.5m acre-feet/year) [7] | ? |
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) | ? |
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:
The Chicago Sanitary and Ship Canal in the US, which serves to divert polluted water from Lake Michigan.
The Eastern and Central Routes of the South–North Water Transfer Project in China from the Yangtse River to the Yellow River and Beijing.
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). [10] [11] [12] [13] [14] 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. [15] 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
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. [22]
The Imperial Diversion Dam is a concrete slab and buttress, ogee weir structure across the California/Arizona border, 18 miles (29 km) northeast of Yuma. Completed in 1938, the dam retains the waters of the Colorado River into the Imperial Reservoir before desilting and diversion into the All-American Canal and the Gila Project aqueduct. Between 1932 and 1940, the Imperial Irrigation District (IID) relied on the Inter-California Canal and the Imperial Canal and Alamo River.
The Colorado–Big Thompson Project is a federal water diversion project in Colorado designed to collect West Slope mountain water from the headwaters of the Colorado River and divert it to Colorado's Front Range and plains. In Colorado, approximately 80% of the state's precipitation falls on the West Slope, in the Rocky Mountains, while around 80% of the state's growing population lives along the eastern slope, between the cities of Fort Collins and Pueblo.
The Balimela Reservoir is located in Malkangiri district, Odisha, India on the river Sileru which is a tributary of the Godavari river. The gross storage capacity of Balimela reservoir is 3610 million cubic meters.
The Klamath Project is a water-management project developed by the United States Bureau of Reclamation to supply farmers with irrigation water and farmland in the Klamath Basin. The project also supplies water to the Tule Lake National Wildlife Refuge, and the Lower Klamath National Wildlife Refuge. The project was one of the first to be developed by the Reclamation Service, which later became the Bureau of Reclamation.
Nagarjuna Sagar Dam is a masonry dam across the Krishna River at Nagarjuna Sagar which straddles the border between Palnadu district in Andhra Pradesh and Nalgonda district in Telangana. The dam provides irrigation water to the districts of Krishna, Guntur, Palnadu, Prakasam and parts of West Godavari districts of Andhra Pradesh and also Nalgonda, Suryapet, Khammam, Bhadradri Kothagudem districts of Telangana. It is also a source of electricity generation for the national grid.
The Indian rivers interlinking project is a proposed large-scale civil engineering project that aims to effectively manage water resources in India by linking rivers using a network of reservoirs and canals to enhance irrigation and groundwater recharge and reduce persistent floods in some parts and water shortages in other parts of the country. India accounts for 18% of global population and about 4% of the world's water resources. One of the solutions to solve the country's water woes is to link its rivers and lakes.
The California State Water Project, commonly known as the SWP, is a state water management project in the U.S. state of California under the supervision of the California Department of Water Resources. The SWP is one of the largest public water and power utilities in the world, providing drinking water for more than 27 million people and generating an average of 6,500 GWh of hydroelectricity annually. However, as it is the largest single consumer of power in the state itself, it has a net usage of 5,100 GWh.
The South–North Water Transfer Project, also translated as the South-to-North Water Diversion Project, is a multi-decade infrastructure mega-project in China that aims to channel 44.8 cubic kilometers of fresh water each year from the Yangtze River in southern China to the more arid and industrialized north through three canal systems:
Navajo Dam is a dam on the San Juan River, a tributary of the Colorado River, in northwestern New Mexico in the United States. The 402-foot (123 m) high earthen dam is situated in the foothills of the San Juan Mountains about 44 miles (71 km) upstream and east of Farmington, New Mexico. It was built by the U.S. Bureau of Reclamation (Reclamation) in the 1960s to provide flood control, irrigation, domestic and industrial water supply, and storage for droughts. A small hydroelectric power plant was added in the 1980s.
The Bear River is a tributary of the Feather River in the Sierra Nevada, winding through four California counties: Yuba, Sutter, Placer, and Nevada. About 73 miles (117 km) long, the river flows generally southwest through the Sierra then west through the Central Valley, draining a narrow, rugged watershed of 295 square miles (760 km2).
The Central Utah Project is a US federal water project that was authorized for construction under the Colorado River Storage Project Act of April 11, 1956, as a participating project. In general, the Central Utah Project develops a portion of Utah's share of the yield of the Colorado River, as set out in the Colorado River Compact of 1922.
The Klamath Diversion was a federal water project proposed by the U.S. Bureau of Reclamation in the 1950s. It would have diverted the Klamath River in Northern California to the more arid central and southern parts of that state. It would relieve irrigation water demand and groundwater overdraft in the Central Valley and boost the water supply for Southern California. Through the latter it would allow for other Southwestern states—Arizona, Nevada, New Mexico and Utah—as well as Mexico to receive an increased share of the waters of the Colorado River.
River linking is a project of linking two or more rivers by creating a network of manually created reservoirs and canals, and providing land areas that otherwise does not have river water access and reducing the flow of water to sea using this means. It is based on the assumptions that surplus water in some rivers can be diverted to deficit rivers by creating a network of canals to interconnect the rivers.
The Polavaram Project is an under construction multi-purpose irrigation project on the Godavari River in the Eluru District and East Godavari District in Andhra Pradesh. The project has been accorded National project status by the Central Government of India. Its reservoir back water spreads up to the Dummugudem Anicut and approx 115 km on Sabari River side. Thus back water spreads into parts of Chhattisgarh and Odisha States. It gives major boost to tourism sector in Godavari Districts as the reservoir covers the famous Papikonda National Park, Polavaram hydro electric project (HEP) and National Waterway 4 are under construction on left side of the river. It is located 40 km to the upstream of Sir Arthur Cotton Barrage in Rajamahendravaram City and 25 km from Rajahmundry Airport.
The Lake Chad replenishment project is a proposed major water diversion scheme to divert water from the Congo River basin to Lake Chad to prevent it drying up. Various versions have been proposed. Most would involve damming some of the right tributaries of the Congo River and channeling some of the water to Lake Chad via a canal to the Chari River basin.
The Pranahita Chevella Lift Irrigation Project is a lift irrigation project to harness the water of Pranahita tributary of Godavari River for use in the Telangana state of India. The river water diversion barrage across the Pranahita River is located at Thammidihatti village in Komaram Bheem district of Telangana. This lift canal is an inter river basin transfer link by feeding Godavari River water to Krishna River basin. The chief ministers of Telangana and Maharashtra states reached an agreement in 2016 to limit the full reservoir level (FRL) of the barrage at 148 m msl with 1.85 tmcft storage capacity. In the year 2016, this project is divided into two parts. The scheme with diversion canal from the Thammmidihatti barrage to connect to existing Yellampalli reservoir across the Godavari River is presently called Pranahita barrage lift irrigation project. This scheme is confined to providing irrigation facility to nearly 2,00,000 acres in Adilabad district using 44 tmcft water.
The San Juan–Chama Project is a U.S. Bureau of Reclamation interbasin water transfer project located in the states of New Mexico and Colorado in the United States. The project consists of a series of tunnels and diversions that take water from the drainage basin of the San Juan River – a tributary of the Colorado River – to supplement water resources in the Rio Grande watershed. The project furnishes water for irrigation and municipal water supply to cities along the Rio Grande including Albuquerque and Santa Fe.
The Tungabhadra Dam, also known as Pampa Sagar, is a water reservoir constructed across the Tungabhadra River in the Hosapete-Koppal confluence in Karnataka, India. It is a multipurpose dam serving irrigation, electricity generation, flood control, etc. for the state. It is India's largest stone masonry dam and one of the only two non-cement dams in the country, the other being the Mullaperiyar Dam in Kerala. The dam is built of surki mortar, a combination of mud and limestone, commonly used at the time of its construction.
The Narmada Canal is a contour canal in Western India that brings water from the Sardar Sarovar Dam to the state of Gujarat and then into Rajasthan state. The main canal has a length of 532 kilometres (331 mi). It is the second longest canal in India and the largest canal by water carrying capacity. The main canal is connected with 42 branch canals providing irrigation to 2,129,000 hectares farmland. The canal is designed to transfer 9.5 million acre-feet water annually from the Narmada Basin to areas under other river basins in Gujarat and Rajasthan..
Bheri Babai Diversion Multipurpose Project (SUB2Axis64) is a multi-basin irrigation cum hydropower project lying in Surkhet District of Karnali Province in Mid-West Nepal. The water is diverted from the Bheri River and discharged to Babai River. The project aims to irrigate 51,000 ha of land in Banke and Bardiya District throughout the year. The elevation difference between the intake and irrigation area provided an opportunity to install 46.8 MW firm electricity. The project has a tunnel 12208 meters long that was constructed using a tunnel boring machine (TBM) for the first time in Nepal. The project is owned by the Ministry of Energy, Water Resources and Irrigation. Construction of the project commenced in 2015 and is expected to complete in 2023. The project is estimated to cost NPR 30,00,00,00,000.