Irrigation Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has been dev ...

is the artificial ''exploitation'' and ''distribution'' of water at ''

project A project is any undertaking, carried out individually or collaboratively and possibly involving research or design, that is carefully planned to achieve a particular goal. An alternative view sees a project managerially as a sequence of even ...

level'' aiming at ''application'' of water at ''field level'' to

agricultural crops A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydroponics ...

in dry areas or in periods of scarce

rainfall Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water ...

to assure or improve crop production.
This article discusses

organization An organization or organisation (Commonwealth English; see spelling differences), is an entity—such as a company, an institution, or an association—comprising one or more people and having a particular purpose. The word is derived fro ...

al forms and means of

management Management (or managing) is the administration of an organization, whether it is a business, a nonprofit organization, or a government body. It is the art and science of managing resources of the business. Management includes the activities ...

of irrigation water at project ( system) level.

History

Scholars such as

Julian H. Steward Julian Haynes Steward (January 31, 1902 – February 6, 1972) was an American anthropologist known best for his role in developing "the concept and method" of cultural ecology, as well as a scientific theory of culture change. Early life and edu ...

and

Karl August Wittfogel Karl August Wittfogel (6 September 1896 – 25 May 1988) was a German-American playwright, historian, and sinologist. He was originally a Marxist and an active member of the Communist Party of Germany, but after the Second World War, he was an ...

have seen the management of irrigation as a crucial factor in the development of many early states (

hydraulic empire A hydraulic empire, also known as a hydraulic despotism, hydraulic society, hydraulic civilization, or water monopoly empire, is a social or government structure which maintains power and control through exclusive control over access to water. I ...

s).

Water management

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:''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

, under nr 10, or from

, under nr. 6 , or directly as PDF

/ref> * the communal type * the enterprise type * the utility type From the point of view of water, the universal law of

water balance The law of water balance states that the inflows to any water system or area is equal to its outflows plus change in storage during a time interval. In hydrology, a water balance equation can be used to describe the flow of water in and out of ...

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, reaching a total area of some 50 million ha worldwide, which is about 1/5 of the present area (see

Irrigation statistics This page shows statistical data on irrigation of agricultural lands worldwide. Irrigation is the artificial ''abstraction'' of water from a source followed by the ''distribution'' of it at scheme level aiming at ''application'' at field level to en ...

). 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

The enterprise type of water management occurred under large landowners or agricultural

corporations A corporation is an organization—usually a group of people or a company—authorized by the state to act as a single entity (a legal entity recognized by private and public law "born out of statute"; a legal person in legal context) and ...

, but also in centrally controlled societies. Both the land and water resources are in one hand.
Large

plantations A plantation is an agricultural estate, generally centered on a plantation house, meant for farming that specializes in cash crops, usually mainly planted with a single crop, with perhaps ancillary areas for vegetables for eating and so on. Th ...

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

banana A banana is an elongated, edible fruit – botanically a berry (botany), berry – produced by several kinds of large herbaceous flowering plants in the genus ''Musa (genus), Musa''. In some countries, Cooking banana, bananas used for ...

s, sugarcane and

cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor p ...

.
As a result of land reforms, in many countries the estates were reformed into a

cooperatives A cooperative (also known as co-operative, co-op, or coop) is "an autonomous association of persons united voluntarily to meet their common economic, social and cultural needs and aspirations through a jointly owned and democratically-control ...

in which the previous employers became members and exercised a cooperative form of land and water management.

Utility type

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: * water was increasingly considered government property owing to the increasing demand for good quality water and the reducing availability * governments embarked on large scale irrigation projects as they were considered more efficient * the development of new irrigation schemes became technically, financially and organizationally so complicated that they fell outside the capabilities of the smaller communities * the import and export policies of governments required the cultivation of commercial cash crops whilst, by controlling the water management, the farmers could be more easily guided to plant these kind of crops. 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 right Water right in water law refers to the right of a user to use water from a water source, e.g., a river, stream, pond or source of groundwater. In areas with plentiful water and few users, such systems are generally not complicated or contentiou ...

s 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

weir A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of l ...

s normally remained the responsibility of the government, mainly because

environmental A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...

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 Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

below).

Water pricing

Tariffs

Irrigation water has a price by which the management costs must be covered. The following

tariff A tariff is a tax imposed by the government of a country or by a supranational union on imports or exports of goods. Besides being a source of revenue for the government, import duties can also be a form of regulation of foreign trade and p ...

(water charge) systems exist:The World Bank, ''Cost Recovery and Water Pricing for Irrigation and Drainage Projects''. Agriculture and Rural Development Discussion Paper 26, on line

/ref> * No tariff, the government assumes the costs * Tariff in labor hours, which holds mainly in communal types of management in traditional irrigation systems * Yearly area tariff, a fixed price per ha per year * Seasonal area tariff, a fixed price per ha per season with the higher price in the dry season * Volumetric tariff, a fixed price per m3 of water; the consumption is measured by Flow measurement, water meters * Block or stepped-up pricing for water use per ha; the price increases as the water consumption per ha falls in a higher block. The use of groundwater for irrigation is often

license A license (or licence) is an official permission or permit to do, use, or own something (as well as the document of that permission or permit). A license is granted by a party (licensor) to another party (licensee) as an element of an agreeme ...

d by government and the

well A well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. T ...

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: * The revenues accrue to a (government)organization other than the one responsible for the management * Farmers and water users have no say in the water management * Lack of communication between farmers and project managers * Poor farmers are unable to comply * Farmers do not receive water according to need; for example insufficient quantity and/or inappropriate time * Corruption at management level

Cost coverage

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

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 A water board is a regional or national organisation that has very different functions from one country to another. The functions range from flood control and water resources management at the regional or local level (the Netherlands, Germany), w ...

in the Netherlands, with the difference that it concerns irrigation rather than drainage and flood control.
An effective development occurred in

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

, 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

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 Water scarcity (closely related to water stress or water crisis) is the lack of fresh water resources to meet the standard water demand. There are two types of water scarcity: physical or economic water scarcity. Physical water scarcity is whe ...

, 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

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 Riparian water rights (or simply riparian rights) is a system for allocating water among those who possess land along its path. It has its origins in English common law. Riparian water rights exist in many jurisdictions with a common law herit ...

. The preferential method of irrigation can be found in

spate irrigation Surface irrigation is where water is applied and distributed over the soil surface by gravity. It is by far the most common form of irrigation throughout the world and has been practiced in many areas virtually unchanged for thousands of years. S ...

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.

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 Rice is the seed of the grass species '' Oryza sativa'' (Asian rice) or less commonly '' Oryza glaberrima'' (African rice). The name wild rice is usually used for species of the genera '' Zizania'' and ''Porteresia'', both wild and domestica ...

, sugarcane, most

orchards An orchard is an intentional plantation of trees or shrubs that is maintained for food production. Orchards comprise fruit- or nut-producing trees which are generally grown for commercial production. Orchards are also sometimes a feature of la ...

) or a low consumptive use (e.g.

cereals A cereal is any grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, germ, and bran. Cereal grain crops are grown in greater quantities and provide more foo ...

- notably

barley Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley ...

millet Millets () are a highly varied group of small-seeded grasses, widely grown around the world as cereal crops or grains for fodder and human food. Most species generally referred to as millets belong to the tribe Paniceae, but some millets ...

, and

sorghum ''Sorghum'' () is a genus of about 25 species of flowering plants in the grass family ( Poaceae). Some of these species are grown as cereals for human consumption and some in pastures for animals. One species is grown for grain, while many ot ...

- or

). In India, such practice is called ''protective irrigation'', 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

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 In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statisti ...

to the relative position of their land in the topography of the scheme.

Tail-end problems

R.Chambers cites authors who have reported tail-end problems. Examples are: * The old ''Sardar canal'' project in the state of

Gujarat Gujarat (, ) is a state along the western coast of India. Its coastline of about is the longest in the country, most of which lies on the Kathiawar peninsula. Gujarat is the fifth-largest Indian state by area, covering some ; and the nin ...

, India, was designed with an irrigation intensity of 32%, but at the upstream part the delivery was at an intensity of 42% (i.e. 131% of the design norm) and at the downstream end it was only 19% (i.e. 59% of the norm), although the project aimed at protective irrigation with equal rights for all. * The ''Sardar Sahayak Pariyojana'' irrigation project, an extension of the Sardar canal project with 1.7 million ha, the head farmers received 5 times more water than the tail-enders, although the project was designed for equal distribution of the scarce water. * The ''Ghatampur'' distributary canal in the ''Ramganga'' irrigation project in the state of

Uttar Pradesh Uttar Pradesh (; , 'Northern Province') is a state in northern India. With over 200 million inhabitants, it is the most populated state in India as well as the most populous country subdivision in the world. It was established in 1950 ...

, India, delivered an amount of water equal to 155% of the design discharge to the ''Kisarwal'' district canal near the head of the distributary and only 22% to the ''Bairampur'' district canal at the downstream end. Ibrahimiya

Also in Egypt, in 1984, considerable differences in the water distribution over the canal systems have been reported: : :*) Period March 1 to July 31. 1 feddan is 0.42 ha. Data from : Egyptian Water Use Management Project (EWUP).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.

References

{{Agricultural water management Irrigation Land management Hydraulic engineering