Irrigation is the artificial exploitation and distribution of water at project level aiming at application of water at field level to agricultural crops[1] in dry areas or in periods of scarce rainfall to assure or improve crop production.[2]
This article discusses organizational forms and means of management of irrigation water at project (system) level.

History

Scholars such as Julian H. Steward and Karl August Wittfogel have seen the management of irrigation as a crucial factor in the development of many early states (hydraulic empires).[3]

Water management

Communal maintenance of a diversion dam in a stony river bed, Baluchistan
Communal maintenance of a diversion dam in a stony river bed, Baluchistan

The most important physical elements of an irrigation project are land and water. In accordance with the propriety relations of these elements there may be different types of water management:[4]

From the point of view of water, the universal law of water balance must be obeyed for any Water Use System, including an irrigation system.

Communal type

Until the end of the 19th century the development of irrigation projects occurred at a mild pace,[5] reaching a total area of some 50 million ha worldwide, which is about 1/5 of the present area (see Irrigation statistics). The land was often private ha "privates" property or assigned by the village authorities to male or female farmers, but the water resources were in the hands of clans or communities who managed the water resources cooperatively.

Enterprise type

Slave labor in a cotton plantation
Slave labor in a cotton plantation
Labor in a sugarcane plantation
Labor in a sugarcane plantation

The enterprise type of water management occurred under large landowners or agricultural corporations, but also in centrally controlled societies. Both the land and water resources are in one hand.
Large plantations were found in colonised countries in Asia, Africa, and Latin America, but also in countries employing slave labor. It concerned mostly the large scale cultivation of commercial crops such as bananas, sugarcane and cotton.
As a result of land reforms, in many countries the estates were reformed into a cooperatives in which the previous employers became members and exercised a cooperative form of land and water management.

Utility type

Irrigation canals of the Gezira Scheme, Sudan, from space, 1997, with the utility type of management. The water comes from the Blue Nile
Irrigation canals of the Gezira Scheme, Sudan, from space, 1997, with the utility type of management. The water comes from the Blue Nile

The utility type of water management occurs in areas where the land is owned by many, but the exploitation and distribution of the water resources are managed by (government) organizations.
After 1900 governments assumed more influence over irrigation because:[4]

The water management signified a large subsidy on irrigation schemes. From 1980 the operation and maintenance of many irrigation projects was gradually handed over to water user organizations (WUA's) who were to assume these tasks and a large part of the costs, whereby the water rights of the members had to be respected.

The exploitation of water resources via large storage dams - that often provided electric power as well - and diversion weirs normally remained the responsibility of the government, mainly because environmental protection and safety issues were at stake.

In the past, the utility type of water management witnessed more conflicts and disturbances then the other types (see water delivery practices below).

Water pricing

See also: Water pricing

Tariffs

Irrigation water has a price by which the management costs must be covered. The following tariff (water charge) systems exist:[6]

The use of groundwater for irrigation is often licensed by government and the well owner may be permitted to withdraw only a maximum volume of water per year at a certain price.

Cost recovery

The recovery of water charges may be below target, because:[6]

Cost coverage

The cost recovery is often insufficient for full cost coverage, for example:

Country Cost recovery (%)   Cost coverage (%)   Remarks
Argentine[7]   67   12 low tariff: $70/ha/year  
Bangladesh[8]   3-10   <1 tariffs not enforced
Brazil, Jaiba project [9]     66   52
Colombia[7]   76   52
Turkey[10]   76   30-40
Sri Lanka[11]   8   <1 tariffs not enforced

Water User Associations (WUAs)

From 1980 programs were developed to transfer the operation and maintenance tasks from the government to water user associations (WUAs) that show some resemblance to water boards in the Netherlands, with the difference that it concerns irrigation rather than drainage and flood control.
An effective development occurred in Mexico,[12] where in 1990 a program of WUAs was initiated with tradable water rights. By 1998 some 400 WUAs were in operation commanding on average 7600 ha per WUA. They were able to recover more than 90% of the tariffs, mainly because they had to be paid in advance. Government subsidies to the water distribution and maintenance reduced to only 6%   See also Irrigation in Mexico#Legal and institutional framework. Similar efforts were made in Peru, see Irrigation in Peru#Legal and institutional framework, but the progress is not yet at the level of that in Mexico.

Water delivery principles

Irrigation water delivered at the farm
Irrigation water delivered at the farm

Rotational turns

In large irrigation schemes, the distribution of irrigation water and the delivery at the farm gate is often arranged by rotational turns (e.g. every fortnight). The quantity of water to be received is often proportional to the farm size. As the canals usually transport constant flows, the water is being received during a period of time proportional to the farm size (e.g. every fortnight during 2 hours).

The method of rotational turns is typical for the utility form of irrigation management.

On demand

In smaller irrigation schemes the water delivery may be arranged "on demand" with water charges are on a volumetric basis. This requires a precise bookkeeping system. As the demand may be fluctuating over time, the distribution system and infrastructure is relatively expensive because it must be able to cope with periods of peak demand. During periods of water scarcity, negotiations are due to regulate the supply or restriction agreements must have been made.

From point of view of efficient irrigation water-use this is the most effective system.

Preferential rights

Cumulative frequency analysis of the variable annual discharge of a river. Data analyzed with the CumFreq program [13]
Cumulative frequency analysis of the variable annual discharge of a river. Data analyzed with the CumFreq program [13]

In projects with an uncertain supply of water due to annual variations in river discharge, water users at the top (the head users) of the irrigation system (i.e. near the system's take-off point) often have preference, to a certain extent, over users at the tail-end. Hence, the number of farmers that are able to grow an irrigated crop may vary from year to year according to the riparian water rights.

The preferential method of irrigation can be found in spate irrigation systems. It is likely that the irrigators near the headworks, or their ancestors, did contribute more to the construction and maintenance of the works than the others, and therefore acquired the preferential rights.[14]

Protective duty

In regions with a structural water scarcity, the principle of water duty is often applied, whereby the duty per ha per season is only a fraction of the full irrigation need per ha (i.e. the irrigation intensity is less than 100%). Thus, farmers can irrigate only part of their land or irrigate their crops with a limited amount of water, whereby they may choose between crops with a high consumptive use (e.g. rice, sugarcane, most orchards) or a low consumptive use (e.g. cereals - notably barley, millet, and sorghum - or cotton). In India, such practice is called protective irrigation,[15] which aims at equal distribution of scarce means and prevention of acute famine.

The method of protective irrigation is typical for the utility form of irrigation management.

Owing to competition for water, the water delivery practices may deviate from the principles.

Water delivery practices

The old diversion weir in the River Nile at Assiut, Egypt
The old diversion weir in the River Nile at Assiut, Egypt

Competition

In practice the distribution of irrigation water is subject to competition. Influential farmers may be able to acquire more water than they are entitled to. Water users at the upstream part of the irrigation system can more easily intercept extra water than the tail-ender. The degree of farmers' influence is often correlated to the relative position of their land in the topography of the scheme.

Tail-end problems

R.Chambers [16] cites authors who have reported tail-end problems. Examples are:

The Ibrahimiya irrigation canal near Minya, Egypt
The Ibrahimiya irrigation canal near Minya, Egypt

Also in Egypt, in 1984, considerable differences in the water distribution over the canal systems have been reported:[17]

Lateral canal Water supply in m³/feddan *)
Kafret Nasser 4700
Beni Magdul 3500
El Mansuria 3300
El Hammami (upstream)   2800
El Hammami (downstream)   1800
El Shimi 1200
*) Period March 1 to July 31.   1 feddan is 0.42 ha.   Data from : Egyptian Water Use Management Project (EWUP).[18]

See also

References

  1. ^ Yapa et al 2020, http://ejournal.ukm.my/gmjss/article/view/41236
  2. ^ Compare: "irrigation". Oxford English Dictionary (1st ed.). Oxford University Press. 1933. "irrigation - [...] The action of supplying land with water by means of channels or streams; the distribution of water over the surface of the ground, in order to promote the growth and productiveness of plants."
  3. ^ Claessen, H J M; Skalník, Peter, eds. (1978). The Early state. New Babylon, studies in the social sciences. Vol. 32. Walter de Gruyter. p. 11. ISBN 978-90-279-7904-9. Retrieved 2012-03-21. [...] the effective management of large volumes of water made an efficient organization indispensable. Once this organization existed, a 'hydraulic economy', characterized by the division of labor, intensive cultivation and cooperation on a large scale [...], and in which the state eventually assumed the managerial role, inevitably developed.
  4. ^ a b Effectiveness and Social/Environmental Impacts of Irrigation Projects: a Review. In: Annual Report 1988, International Institute for Land Reclamation and Improvement (ILRI), Wageningen, The Netherlands, pp. 18 - 34 . Download from web page : [1] , under nr 10, or from : [2] , under nr. 6 , or directly as PDF : [3]
  5. ^ Bruce Sundquist, 2007. Chapter 1- Irrigation overview. In: The earth's carrying capacity, Some related reviews and analysis. On line: "Archived copy". Archived from the original on 2012-02-17. Retrieved 2012-02-17.((cite web)): CS1 maint: archived copy as title (link)
  6. ^ a b The World Bank, Cost Recovery and Water Pricing for Irrigation and Drainage Projects. Agriculture and Rural Development Discussion Paper 26, on line: [4]
  7. ^ a b Svendsen, M., Trava, J. and S.H. Johnson III. 1997. “Participatory Irrigation Management: Benefits and Second Generation Problems.” International Irrigation Management Institute, Colombo, Sri Lanka.
  8. ^ Govt. of the People’s Republic of Bangladesh. 2000. “National Water Management Plan Project.” Draft Development Strategy, Vol. 5. Ministry of Water Resources. Dhaka.
  9. ^ Azevedo, L.G.. 1997. “Brazil.” In Water Pricing Experiences An International Perspective, ed. A. Dinar and A. Subramanian. Technical Paper Number 386, World Bank, Washington, D.C.
  10. ^ Dinar, A. and Mody, J. 2004. “Irrigation water management policies: Allocation and pricing principles and implementation experience” Natural Resources Forum 28 (2) 112.
  11. ^ Easter, K. W. 1993. “Economic Failure Plagues Developing Countries’ Public Irrigation: An Assurance Problem.” Water Resources Research 29(7): 1913-22.
  12. ^ Palacios, E.V. 1999.Benefits and Second Generation Problems of Irrigation Management Transfer in Mexico. Economic Development Institute Participatory Irrigation Management Case Studies Series, Economic Development Institute, World Bank and Irrigation Water Management Institute.
  13. ^ CumFreq, a program for cumulative frequency analysis, free download from : [5]
  14. ^ R.J. Sevenhuijsen, R.J. Oosterbaan and K. Zijderveld, 1988. : The Punata-Tiraque irrigation project near Cochabamba, Bolivia. International Institute for Land Reclamation and Improvement (ILRI), Wageningen, The Netherlands. On line: [6]
  15. ^ M.Jurriens, PP.Mollinga and P.Wester, 1996. Scarcity by Design: Protective irrigation in India and Pakistan. International Institute for Land Reclamation and Improvement, Wageningen, The Netherlands. On line: [7]
  16. ^ R. Chambers, Managing Canal Irrigation: practical analysis from South Asia. On line: [8]
  17. ^ ILRI, 1999. Impacts of the Irrigation Improvement Projects in Egypt. Egyptian-Dutch Advisory Panel and International Institute for Land Reclamation and Improvement (ILRI), Wageningen, The Netherlands. On line: [9]
  18. ^ EWUP (Egyptian Water Use Management Project), 1984. Improving Egypt’s Irrigation System in the Old Lands, Final Report. Colorado State University and MPWWR, Mar. 1984.