New Canal Liner Materials
Conventional lining techniques are relatively expensive and cost prohibitive for small irrigation districts. Reclamation (US Dept of the Interior) needs lower cost canal lining alternatives that can reduce seepage in a cost-effective manner.
Reclamation has over 1,600 miles of main canals, and 37,500 miles of water delivery laterals. Most of these canals and laterals are unlined and lose up to half of their irrigation water to seepage. Much of this seepage is lost to beneficial use. These water losses are especially critical during periods of drought when water is scarcest. Canal lining can reduce seepage by up to 95 percent. Canal lining can also significantly reduce salinity and selenium concentrations in irrigation return water (drain water).
Construction costs for traditional canal linings (concrete with sealed joints, buried geomembranes, compacted clay) range from $5 to $10 per square foot. Previous Science and Technology (S&T) research has developed canal lining alternatives that cost only $1 to $3 per square foot, with benefit-cost ratios of 3 to 5 (Reclamation 2002). New technologies promise to reduce costs significantly further.
Polyacrylamide (PAM) is a new canal-lining technology that promises to seal canals for as little at $0.004 per square foot. PAM is a polymeric powder that acts as a soil floculent to form a soil-polymer seal on the canal perimeter. PAM is typically reapplied annually as a slurry in the spring just before the canal is filled with water. Preliminary results indicate that PAM can reduce short-term seepage by 25 to 75 percent. This S&T research project will investigate improved application techniques and equipment, re-application requirements, short-term and long-term effectiveness, and total costs to determine benefit-cost ratios for comparison with other canal-lining techniques.
South to North Transfer in China - Reversing the Grand Canal- $6 to $50 million per kilometer Costs depending upon section
The South–North Water Transfer Project is a multi-decade infrastructure project of the People's Republic of China to better utilize water resources available to China. This is because heavily industrialized Northern China has a much lower rainfall and its rivers are running dry. The project includes a Western, a Central and Eastern route. All three routes aim to divert water from the Yangtze River to the Yellow River and Hai River. The eastern route uses the course of the Grand Canal; the central route is from the upper reaches of the Han River (a tributary of Yangtze River) to Beijing and Tianjin; and the western route is in the western headwaters of the rivers where the Yangtze River and the Yellow River are closest to one another. This project will divert 44.8 billion cubic meters/year of water from South to North. A controversial spin-off plan calls for the capture and diversion of water from Brahmaputra River, located in Yarlung Tsangpo Grand Canyon north of India.
The complete project is expected to cost $62 billion – more than twice as much as the Three Gorges Dam.
The Eastern route is the most advanced in terms of construction. It consists of an upgrade of the Grand Canal. Water from the Yangtze River will be drawn into the canal in Jiangdu, where a giant 400 m³/s.( 12.6 Billion m3/year if operated continuously) pumping station was built already in the 1980s, and is then fed uphill by pumping stations along the Grand Canal and through a tunnel under the Yellow River, from where it can flow downhill to reservoirs near Tianjin. Construction on the Eastern Route officially began on December 27, 2002. It is equipped with 23 pumping stations with a power capacity of 454 megawatts. It includes two 9.3m diameter horizontal tunnels 70m under the riverbed of the Yellow River
The eastern route, which will be put into service in 2013. It takes water from the Yangtze River and carries it up the seaboard provinces. The 1467-kilometer-long canal will be the longest in the world; it will initially be capable of pumping 8.8 million megaliters of water annually, enough to fill 28 000 supertankers. Future expansions will eventually increase its capacity to 14.8 million ML per year.
The total cost for the eastern route is expected to top US $8.5 billion, which includes nearly $2.5 billion for water treatment facilities. That’s necessary because the canal travels through a number of industrial zones and densely populated areas, and water pollution is a serious problem. Other possible consequences of the eastern route are water shortages in the south, damage to the Yangtze watershed, and high water prices in the north (as a result of the project’s massive expenses)
The project’s central route, which will bring water to Beijing and Tianjin, may be completed in 2014. That canal may cost another $37 billion, according to the ministry, and it requires the expansion of a reservoir and the resettlement of about 345 000 people. A third and final route in the west would transport water from the Tibetan plateau, but the Chinese government has reportedly postponed that technically challenging and politically controversial route
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