Irrigation management
Encyclopedia
Irrigation
is the artificial exploitation and distribution of water at project level aiming at application of water at field level to agricultural crops in dry areas or in periods of scarce rainfall to assure or improve crop production.
This article is about organizational forms and means of management of irrigation water at project level.
). The land was often private 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.
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 banana
s, 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.
After 1900 governments assumed more influence over irrigation because :
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
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
s 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 charge) systems exist :
The use of groundwater for irrigation is often license
d by government and the well
owner may be permitted to withdraw only a maximum volume of water per year at a certain price.
in the Netherlands, with the difference that it concerns irrigation rather than drainage and flood control.
An effective development occurred in Mexico, where in 1990 a program of WUA's was initiated with tradable water rights. By 1998 some 400 WUA's 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.
The method of rotational turns is typical for the utility form of irrigation management.
From point of view of efficient irrigation water-use this is the most effective system.
.
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.
, 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, 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.
to the relative position of their land in the topography of the scheme.
Also in Egypt, in 1984, considerable differences in the water distribution over the canal systems have been reported :
Irrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...
is the artificial exploitation and distribution of water at project level aiming at application of water at field level to agricultural crops in dry areas or in periods of scarce rainfall to assure or improve crop production.
This article is about organizational forms and means of management of irrigation water at project level.
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 :- the communal type
- the enterprise type
- the utility type
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 statisticsIrrigation statistics
This page shows statistical data on irrigation of agricultural lands world wide.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 enhance crop production when rainfall is scarce.-Irrigated...
). The land was often private 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
Corporate farming
Corporate farming is a term that describes the business of agriculture, specifically, what is seen by some as the practices of would-be megacorporations involved in food production on a very large scale...
, 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 banana
Banana
Banana is the common name for herbaceous plants of the genus Musa and for the fruit they produce. Bananas come in a variety of sizes and colors when ripe, including yellow, purple, and red....
s, sugarcane
Sugarcane
Sugarcane refers to any of six to 37 species of tall perennial grasses of the genus Saccharum . Native to the warm temperate to tropical regions of South Asia, they have stout, jointed, fibrous stalks that are rich in sugar, and measure two to six metres tall...
and cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
.
As a result of land reforms, in many countries the estates were reformed into a cooperatives
Land reform
[Image:Jakarta farmers protest23.jpg|300px|thumb|right|Farmers protesting for Land Reform in Indonesia]Land reform involves the changing of laws, regulations or customs regarding land ownership. Land reform may consist of a government-initiated or government-backed property redistribution,...
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
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 contentious...
s of the members had to be respected.
The exploitation of water resources via large storage dams
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
- that often provided electric power as well - and diversion weir
Weir
A weir is a small overflow dam used to alter the flow characteristics of a river or stream. In most cases weirs take the form of a barrier across the river that causes water to pool behind the structure , but allows water to flow over the top...
s normally remained the responsibility of the government, mainly because environmental
Environmental impact of irrigation
Environmental impacts of irrigation are the changes in quantity and quality of soil and water as a result of irrigation and the ensuing effects on natural and social conditions at the tail-end and downstream of the irrigation scheme....
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).
Tariffs
Irrigation water has a price by which the management costs must be covered. The following tariffTariff
A tariff may be either tax on imports or exports , or a list or schedule of prices for such things as rail service, bus routes, and electrical usage ....
(water charge) systems exist :
- 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 water metersFlow measurementFlow measurement is the quantification of bulk fluid movement. Flow can be measured in a variety of ways.Positive-displacement flow meters acumulate a fixed volume of fluid and then count the number of times the volume is filled to measure flow...
- 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
License
The verb license or grant licence means to give permission. The noun license or licence refers to that permission as well as to the document recording that permission.A license may be granted by a party to another party as an element of an agreement...
d by government and the well
Water well
A water well is an excavation or structure created in the ground by digging, driving, boring or drilling to access groundwater in underground aquifers. The well water is drawn by an electric submersible pump, a trash pump, a vertical turbine pump, a handpump or a mechanical pump...
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:| Country | Cost recovery (%) | Cost coverage (%) | Remarks |
|---|---|---|---|
| Argentine | 67 | 12 | low tariff: $70/ha/year |
| Bangladesh Bangladesh Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south... |
3-10 | <1 | tariffs not enforced |
| Brazil Brazil Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people... , Jaiba project |
66 | 52 | |
| Colombia Colombia Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the... |
76 | 52 | |
| Turkey Turkey Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe... |
76 | 30-40 | |
| Sri Lanka Sri Lanka Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the... |
8 | <1 | tariffs not enforced |
WUA's
From 1980 programs were developed to transfer the operation and maintenance tasks from the government to water user associations (WUA's) that show some resemblance to water boardsWater board (The Netherlands)
Dutch water boards are regional government bodies charged with managing the water barriers, the waterways, the water levels, water quality and sewage treatment in their respective regions...
in the Netherlands, with the difference that it concerns irrigation rather than drainage and flood control.
An effective development occurred in Mexico, where in 1990 a program of WUA's was initiated with tradable water rights. By 1998 some 400 WUA's 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, 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 rightsRiparian water rights
Riparian water rights are system for allocating water among those who possess land about its source. It has its origins in English common law...
.
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.
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. riceRice
Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
, sugarcane
Sugarcane
Sugarcane refers to any of six to 37 species of tall perennial grasses of the genus Saccharum . Native to the warm temperate to tropical regions of South Asia, they have stout, jointed, fibrous stalks that are rich in sugar, and measure two to six metres tall...
, most orchards) or a low consumptive use (e.g. cereals - notably barley
Barley
Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...
, millet
Millet
The millets are a group of small-seeded species of cereal crops or grains, widely grown around the world for food and fodder. They do not form a taxonomic group, but rather a functional or agronomic one. Their essential similarities are that they are small-seeded grasses grown in difficult...
, and sorghum
Sorghum
Sorghum is a genus of numerous species of grasses, one of which is raised for grain and many of which are used as fodder plants either cultivated or as part of pasture. The plants are cultivated in warmer climates worldwide. Species are native to tropical and subtropical regions of all continents...
- or cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
). 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 correlatedCorrelation
In statistics, dependence refers to any statistical relationship between two random variables or two sets of data. Correlation refers to any of a broad class of statistical relationships involving dependence....
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, 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 PradeshUttar PradeshUttar Pradesh abbreviation U.P. , is a state located in the northern part of India. With a population of over 200 million people, it is India's most populous state, as well as the world's most populous sub-national entity...
, 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.
| 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).
See also
- IrrigationIrrigationIrrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...
- Surface irrigationSurface irrigationSurface irrigation is defined as the group of application techniques 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.Surface...
- Irrigation in viticultureIrrigation in viticultureThe role of irrigation in viticulture is considered both controversial and essential to wine production. In the physiology of the grapevine, water is a vital component to function of the vine with its presence or lack impacting photosynthesis, new plant shoot growth, as well as the development of...
- Irrigation statisticsIrrigation statisticsThis page shows statistical data on irrigation of agricultural lands world wide.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 enhance crop production when rainfall is scarce.-Irrigated...
- Environmental impact of irrigationEnvironmental impact of irrigationEnvironmental impacts of irrigation are the changes in quantity and quality of soil and water as a result of irrigation and the ensuing effects on natural and social conditions at the tail-end and downstream of the irrigation scheme....
- Tidal irrigationTidal irrigationTidal irrigation is the subsurface irrigation of levee soils in coastal plains with river water under tidal influence. It is applied in arid zones at the mouth of a large river estuary or delta where a considerable tidal range is present...
- Water rights
- Riparian water rightsRiparian water rightsRiparian water rights are system for allocating water among those who possess land about its source. It has its origins in English common law...
- National Irrigation CongressNational Irrigation CongressThe National Irrigation Congress was held periodically in the Western United States beginning in 1891 and ending in 1916, by which time the organization had changed its name to International Irrigation Congress. It was a "powerful pressure group."...