Irrigation: Introduction

3.3 Irrigation
3.3.1 Function, advantages and disadvantages of irrigation; status and
need of irrigation in Nepal

Sanjeeb Baral
JS, MoEWRI
 Definition of Irrigation
• Science of artificial application of water to the land in accordance with the "crop requirements'' throughout
the "crop period" for full-fledged nourishment of the crops.
• Water is main input for higher agricultural production (others inputs are - soil, seed,, fertilizers, insecticides,
suitable atmospheric temperature, human labour, appropriate technology etc.
• The application of water to soil is essential for plant growth and it:
• It supplies moisture to the soil essential for the germination of seeds, and chemical and bacterial processes during plant
growth;
• It cools the soil and the surroundings thus making the environment more favourable for plant growth;
• It washes out or dilutes salts in the soil;
• It softens clods (lump of clay) and thus helps in tillage operations;
• It enables application of fertilizers;
• It reduces the adverse effects of frost on crops;
• It ensures crop success against short-duration droughts.
• The basic objective of irrigation is to supplement the natural supply of water to land so as to obtain an
optimum crop yield. If the water requirement of the crop is met by natural rainfall during the period of
growth, there is no need of irrigation. But in Nepal, the annual precipitation varies from 1500 mm to
2500mm. Out of which, 80% of the rainfall occurs during monsoon season in four months from June to
September (Ashad – Ashoj). Hence, the natural rainfall occurs mainly during monsoon seasons so, irrigation
is essential for the proper growth of plants.
• Irrigation engineering is a science which deals with the artificial application of water to the land along with
the planning and design of various structures required for an irrigation system.
 Function of irrigation
The main function of irrigation is to supplement the required amount of
water to the crop throughout the crop period.
Other functions of irrigation are:
• Ensure equitable and timely water supplies;
• Improve the reliability of the supplies;
• Increase the command area;
• Increase cultivation intensity and finally increase crop production;
• And finally, improve the living standards and social welfare (create
employment opportunities and boost the overall economy of the
country).
 Necessity of Irrigation
• A crop or a plant requires water for its growth. The crop yield from an agricultural land depends upon a
number of factors (such as fertilizer, seed, technology) out of which water is main factor. necessity
irrigation are:
• Inadequate rainfall: If rainfall is less than the crop water requirement, irrigation is required.
• Uneven distribution of rainfall: Irrigation is necessary even when the total rainfall in a region is adequate
(above the crop water requirement) but it is not evenly distributed over time. For example, around eighty
percentage of average annual rainfall occur in four months during monsoon season in Nepal from June to
September and there is rainfall variation during that season so irrigation is required;
• Increasing the yield of crops: the crop yield can be increased substantially by the application of controlled
water by irrigation. Low yielding crop can be grown by the use of the natural rainfall in some area but foe
high yielding crops, higher amount of water in a controlled way and in higher frequency is essential so
Irrigation is required in such case;
• Growing a number of crops: to grow only one crop per year, the natural rainfall could be enough,
however; for to grow two or three crops per year, irrigation is essential;
• Growing perennial crops: Sugarcane is an important perennial crop which need irrigation;
• Growing superior crops: Superior crops and cash crops such as seeds, cotton fruits, vegetables needs
large quantity of water so irrigation is essential;
• Insurance against drought: The crops in some region may not require irrigation during a normal rainfall
year, but in the case of drought, irrigation may be necessary. Irrigation act as an insurance of crops against
drought and famine.
 Advantages (Benefits) of Irrigation
• The main advantages of Irrigation projects are to increase crop production which helps to enhance the economic
growth of the country. There are other direct and indirect benefits of irrigation as mentioned below:
Direct Benefit
• Increase in crop yield: balancing the increasing food demand of the country;
• Protection from famine: Irrigation system provide water during the period of drought. Assured supply of water
provides protection from the famine. In the regions where no irrigation schemes exist, the failure of rains may result
in famine;
• Cultivation of superior crops;
• Elimination of mixed cropping: by mixed cropping, we mean, sowing together of two or more crops in the same
field. Where irrigation is not assumed, generally mixed cropping is adopted. mix cropping is not acceptable because
different crop need different type of field preparation; different watering; and different manurings. Additionally,
during the harvesting, the crops get intermixed. So, If Irrigation is assured, single superior crop can be cultivated
eliminating mixed cropping practice.
• Increase in revenue: overall increase in crop production result the increase in revenue of the farmer.
• Canal plantation and promotion of environment: greenery and wet environment can enhance good environment in
the vicinity of the irrigation project;
• Communication facilities: generally, service road constructed at the bank of irrigation canal can increase accessibility.
In addition to this, water transportation can be operated in large irrigation canal;
• Over all development: Irrigation projects have multiplier effect of development. The employment generation,
increase in production and productivity, benefits obtained by the local farmers contributes to overall balanced
development with sustainable economic growth of the country.
Advantages (Benefits) of Irrigation
Indirect Benefit
• Hydro power generation with irrigation projects;
• Flood control benefits can be achieved because of irrigation project
development;
• Domestics and industrial water supply can be done with irrigation
development;
• Inland Navigation facilities can be done in irrigation canals;
• Increase (conjunctive use of water) in ground water storage or
recharge.
Ill effects (Disadvantages) of irrigation

• Water logging problem can be resulted in some low land because of

the developed irrigation system;
• Damp climate: sometimes, damp climate in long time is not suitable
for some areas;
• Mosquitoes breeding;
• Ground water pollution: irrigation water seepage into the ground
water of the nitrates, which have been applied to the soil as fertilizer.
[up to 50% of nitrates applied sinks into the reservoir].
History of irrigation development
• The history of irrigation development is as old as human civilization. In Nepal, before sixth century BC, In
Kathmandu valley, Litchhivis control water by developing control structures on Dhovighat and Takucha rivers
for irrigation.
• In 17th century, numbers of Raj Kulos (Royal canals) were constructed with state initiatives and financial
supports during Malla period.
• Before 16th century, famers diverted water form streams and small rivers to farm lands after constructing
temporary headworks, such as earthan dam of stones and logs, simple canals and distribution canal within
their financial & technical capabilities. Small to large groups of water users were involved in constructing
irrigation facilities they needed, and norms & codes tested over time.
• Between 19th to 20th Century, farmers developed large irrigation facilities with local resources and initiatives
as they expanded the area under paddy cultivation – these facilities are now called Farmer Managed
Irrigation System (FMIS).
• In 1920 Government initiated irrigation development in the Terai from Chandra canal Irrigation system.
Judda Samser constructed Bandganga – Jagadispur reservoir project in (1939 – 1942) in Kapilibastu & Juddha
Nalar (Manusmara) in (1943 – 46) in Sarlahi.
• After began the plan the period in 1956 (2013) government agencies constructed and managed numerous
small to large surface and ground irrigation scheme and also rehabilitated a few FMIS Using public resources,
grant and loan assistance from bilateral & multilateral agencies.
Four phases of Irrigation Development.

• The Early development phase (Till 1956)

• The infrastructure development phase (1956 – 1970)
• The intensive development phase (1970 – 1985)
• The integrated development phase (1985 to till date)
The Early Development phase (till -1956)
• Mostly farmer managed irrigation system (FMIS) was developed. The main
features of these system were
• year round irrigation system rarely practiced
• Simple structures using indigenous technologies
• Irrigation facilities owned, developed and managed by farmers known as
Farmer Managed Irrigation System (FMIS).
• From 1920 Agencies involved for Irrigation Development.
• Chandra Nahar, Juddha Nahar (Manusmara), Jagadishpur reservoir
(Banganga), Pardiphewa lake in Pokhara were constructed during this
period.
• Bilateral agreement – Sarada agreement was conducted in 1929 to develop
Irrigation Project in Mahakali River and Koshi agreement was conducted in
1954 to develop irrigation project in Koshi River between Nepal and India.
Infrastructure Development phase (1956 – 1970)
• Nepal entered into era of planned development in 1956.
• Focused on development of basic infrastructure (such as diversion
weir & major canal system) such as – Chatara canal, East- west
Gandak canal, Kamala irrigation project.
• System was designed for supplementary irrigation during monsoon
seasons (ie, FMIS style of development and run of river (ROR)
projects).
• Emphasized on the construction of government financed medium to
large several projects in hill and in terai constructed under India &
American grant.
• Gandak Agreement done in 1959 Between Nepal & India to develop
irrigation project from Narayani Gandak) River.
The intensive development phase (1979 – 1985)
• Intensive developments of command are and comprehensive
approaches to irrigated agriculture were the focuses of agriculture
development in 1970. This includes:
• Expansion of irrigated infrastructure developed earlier with
Government of Nepal/ Bilateral / grant assistance to farm level water
management.
• Financial & technical assistance to rehabilitate and improve farmer-
owned irrigation infrastructure.
• The intensive irrigation system includes development of tertiary
canals & service blocks, development of command area,
rehabilitation of FMIS & introduction of appropriate agricultural
technologies in irrigated areas.
The Integrated development period (1985 to date).
• Integrated development Approach emphasis on
• Renovation, reconstruction & expansion of FMIS.
• Participation of beneficiaries in development & management of irrigation
infrastructure.
• Development of ground water irrigation in areas where surface irrigation
is limited to year round irrigation – consumptive use.
• Involvement of NGOs and private sector in Irrigation development.
• Use of improved & appropriate agricultural technology and material in
irrigated farmlands to maximize outputs.
 Challenges for irrigation development
• Policy aspect: Inconsistent and short-sighted planning resulting lack of focus in the irrigation sector. Some of the issues foreseen by the recent policy such as
collection of irrigation service fee, irrigation development in cooperative model, commercial farming, announcement of Irrigated land and stopping fragmentation
of land, conjunctive use of water etc. has not been started yet. The involvement of private sector, non government sector and users in true sense for the
development and management of irrigation as foreseen by the policy is challenging.
• Nepal’s existing irrigation projects are monsoon supplement irrigation system. There projects are designed to supplement irrigation during monsoon for paddy
field. Only one third of the areas has been getting Year Round Irrigation (YRI). Lack of achieving year round irrigation, failure to provide reliable irrigation water, and
lack of focus to producing high value crops are the reasons
• Coordination among the stakeholders (Integration of irrigation and agriculture, irrigation, agriculture, other infrastructure development agencies, marketing etc)
and lack of supporting culture.
• Lack of commercialization of agriculture – commercial farming in large scale, lack of linkage of agricultural products with market result to increase agriculture
products and productivity.
• Mismatch between the water availability and water requirement (Supply and Demand): in Nepal, huge water resources is available from Major Rivers (Koshi,
Gandaki, Karnali and Mahakali). These major rivers flow mostly through higher Himalays and mountains where there is very less irrigable land. Whereas, the
medium rivers such as Kamala, Kankai, Rapti, West Rapti, Bagmati have limited water availability and huge variation of discharge. These rivers can irrigate more
land in terai but limited flow, sediment issue and less flow during dry period created limitation for irrigation development.
• Lack of appropriate irrigation technology and lack of modernization of existing irrigation systems.
• Raparian issues: Nepal’s most of rivers flow from north to south and ultimately drained to India. Nepal’s large irrigation development in terai area impact on the
reduction in cross boarder flow. Development of reservoir in major river of Nepal can add augumented flow in the river system getting more benefit by lower
riparian country (India). Mutual agreement and consensus is required between Nepal and India to development large irrigation projects of Nepal. Hence, because
of lack of agreement, consensus and interest of India, Nepal’s project has been delayed, suffered and impacted.
• Implementation aspect: Failure of completion of the project within the estimated time or prolonged implementation which delayed the rationalization of benefits
and also suffer from the increase in project cost.
• Operation and Maintenance aspect
• Irrigation systems are in vicious cycle in respect to the operation and maintenance. The service delivery of the irrigation system is poor because of lack of
appropriate operation and maintenance, low collection, insufficient amount allocation by the government for operation and maintenance, lack of appropriate
maintenance, poor service. At the same time, the operation and maintenance aspect is poor because of lack of collection of enough Irrigation Service Fee and lack
of allocation of enough budget for operation and maintenance.
• Low collection of irrigation service fee and lack of efficient management of collected fund.
• Less priority for operation and maintenance of the irrigation system then construction of new project.
 Challenges for irrigation development
• Environment and climate change impact
• Poor drainage management in irrigation system results flooding and water logging issues. The increase in water table in the command area result the
pollution in ground water sources.
• Fragile geology, steep topography and high sediment concentrations in river results more effort on sediment issues, siltation problem, and additional
infrastructures resulting more challenges for irrigation development.
• Huge variation in river discharge in the river and rainfall pattern result too much and too less issue of water management. Management of extreme event like
flood and low flow condition in river adds challenges in irrigation development.
• Variation in water availability due to climate change impact, frequent occurrence of extreme events results challenges in irrigation development.
• Financial aspect and other resources
• Low resource base and lack of focus for irrigation sector in Nepal. Mobilization of enough resources for the development of large, multipurpose and basin
diversion projects is challenging.
• Decreasing trend of government’s budget and also support from Donor Partner in Irrigation sector. Donor’s interest is more on management of irrigation
system or software part then irrigation development resulting slow pace of development.
• Human resources management, competency development for multipurpose and basin diversion project development and capacity building
• Institutional aspects: Institutional growth, change and restructuring hasnot been happening to cope the need for irrigation development. After
implementation of federalism, the central government’s institutions are curtailed and limited technical human resources are remains in federal level resulting
difficulty for development of large, multipurpose and basin diversion project.
• Political aspect: Political party’s members have been focusing more on other sector specially on road and urban development than irrigation sector resulting
less priorities for irrigation development. Frequent change in priorities and policies due to frequent change in leadership of Government result to achieve the
intended objectives in irrigation sector.
• In mountain and hill, the marginal agricultural land is available where it is very difficult to develop irrigation system. Scattered land, small command area,
slopy land, isolated community in one side creates difficulty for irrigation development and in another side supplying of other agricultural inputs such as
fertilizers, seeds and also linkages with the market for produced vegetables and other agricultural products are also difficult. High migration rate is there from
hill/ mountain to terai or foreign countries which result the human resources deficiency for farming the existing land. This is major challenges
• Achieving regional Imbalance in irrigation development is really challenging. Most of the irrigation projects are located in terai and in hilly area small marginal
land are available. Province-2 has huge potential for irrigation development whereas, Gandaki and Karnali province has very limited scope for irrigation
development. Hence, achieving regional balance in irrigation sector is challenging.
 Opportunities of Irrigation Development
• Population in increasing; land area is limited for agricultural production; food price is gradually increasing; trade deficit (increased
import) of Nepal for food supply is also increasing, so, we have to focus on the effective and efficient irrigation system to increase
productivity. This is a greater opportunity to develop larger irrigation projects, multipurpose projects, basin diversion projects and non-
conventional irrigation systems.
• Around two third of population as still dependent on agricultural sector which has major contribution on Country’s Gross Domestic
Product (GDP). Development of reliable irrigation to provide year round irrigation will have overall positive impact on positive economic
growth of the country.
• Huge capacity of water resources available in the country about 225billion cubic meter water flow towards India annually and about
6billion cubic meter of ground water can be safely extractable from Terai areas. There is good agricultural land is available in the
southern part of the country. This creates opportunity for greater agricultural production developing the appropriate irrigation system
adopting the conjunctive use using the available water resources within the countries.
• Some multipurpose projects and basin diversion projects such as Bheri-Babai basin diversion project, Sukoshi- Marine basin diversion
project, Bhalubang multipurpose project also generate hydroelectricity which can fulfill some gap of present energy crisis within country.
Additionally. These basin diversion project can also have environmental, tourism, recreation and other benefits.
• The technical expertise gained by the department of water resources and irrigation and also in water resources sector creates
opportunities and confidence to develop large multipurpose basin diversion project. Nepalese human resources, construction industry
and consultants are now competent to develop (design and construction) larger scale projects.
• New innovative technology for irrigation and water management are rapidly evolving. This creates greater opportunity for use of latest
technology and new irrigation system development.
• Local construction materials such as sand, aggregates are readily available in Nepal and lot of cement factories have been established in
Nepal which reduces cement price and the steel industry has also been establishing in Nepal. The availability of material creates good
opportunity for irrigation development.
• Nepal’s climate is favourable to grow wide variety of crops, vegetables and fruits. The produced agricultural goods shall fulfill internal
domestic demand as well as can export to the India increasing production and productivity.
 Present status for irrigation development
• Nepal has total 2.6542 million ha. of agricultural land out of which 1.766 million ha. is Irrigable
land.
• The irrigation infrastructure was already developed to provide irrigation services in around 1.5
Million ha upto the end of FY- 2077/078. (1.014 million ha irrigation from surface irrigation system
and 0.494 million ha. from ground irrigation system so total 1.5 million ha). This is also called
Irrigation potential created or infrastructure developed command area.
• But, due to the capacity and efficiency of the existing developed infrastructure, actual irrigated
area is around 1.2 Million ha. ie, around 20% of the infrastructural developed commend area (ie
0.3 million ha) has not supplied the irrigation water by the existing infrastructure.
• Only around one third of the infrastructure developed area get Year round Irrigation (YRI)
• In the present context, population growth is still high but irrigation command area development
is almost nil. It is challenging to supply production (food) from existing agricultural land to the
high growth population. Trade deficit is increasing by importing more food (agricultural
production) from foreign countries. In this context, increasing production and productivity from
existing available agricultural land is very important. This can be achieved by
• expanding irrigated area;
• increasing irrigation intensity;
• increasing cropping intensity;
• and improving water use efficiency.
 Irrigation policy 2013 (2070)
• After the start of periodic development from the year 2013(BS),
Government of Nepal has been investing sufficiently in this sector by
implementing different policies, plans and programmes. After 2046(BS),
government has implemented Water Resources Act 2049, Irrigation
Policy 2049, first amendment in this policy in 2053 (BS), Irrigation Policy
2060, Irrigation Regulation 2056, first amendment in this regulation in
2060.
• The Irrigation Policy was formulated at first in 1992, which was later
amended in 1997 and reformulated in 2003 and 2013 (2070).
• The latest Policy has a vision of contributing towards enhanced
agricultural productivity by providing year-round irrigation facility to the
entire arable land of Nepal.
 Concept of Irrigation Policy
• This policy is based on the following concepts:
• Develop surface irrigation including the multipurpose projects, groundwater irrigation,
non-conventional irrigation, and lift irrigation systems to provide year round irrigation
service.
• To provide year round irrigation service from the irrigation infrastructures developed in
the past, inter-basin water transfer and reservoir based irrigation projects shall be
developed on the basis of feasibility, and conjunctive use of locally available surface
water and groundwater
• To make water users' associations responsible and accountable in the development
and management of irrigation systems for the effective implementation of
participatory system.
• Institutional reinforcement and human resource development and mobilization to
enhance the effectiveness of irrigation sector.
• Study of adverse effect caused by population increase, immigration, climate change,
and water induced disaster to the water sources and their use in irrigation and
implementation of suitable resilience programmes.
• Increase capability and involvement of local bodies in the development of small
irrigation systems as per the concept of decentralization.
 Objectives of Irrigation Policy 2070
The objectives of this irrigation policy shall be as follows:
• Sustainable development and extension of irrigation area by effectively utilizing
country’s available water resources to support in the increased productivity of
agriculture.
• Maintenance of irrigation infrastructures, effective water management, modernization
of irrigation and new construction of irrigation projects to provide year round irrigation
service to the irrigable land;
• Conjunctive use of surface and ground water for irrigation;
• Balanced and collaborated irrigation development in all parts of the country based on
feasibility;
• Organizational improvement and capability development of staff capable to develop
irrigation related technology and implement multipurpose reservoir type projects and
inter-basin water transfer projects.
 Irrigation policy 2013 (2070)
Irrigation Policy 2013 (2070) has following major policy features:
• Declaration of irrigated area so as to protect it from encroachment and discourage them for
non-agricultural use;
• Development and management of irrigation systems on the basis of IWRM principles;
• Use of reservoirs, rain water harvesting and groundwater for year round irrigation;
• Formulation of master plans for inter-basin transfer of water from surplus to deficit basin;
• Development of irrigation systems in conjunction with hydropower projects with
involvement of both public and private sectors;
• Transfer of agency managed irrigation systems to users’ groups;
• Capacity development of local bodies in planning, development and management of
irrigation systems;
• Quantitative measurement of irrigation water for each crop for evaluating the effectiveness
of irrigation and also for determining irrigation service fees (ISF); and
• Legal and institutional reform, including capacity enhancement of involved personnel.
 Policy
Following policies shall be followed to achieve objectives of the irrigation policy.
• To address the issues related to development and extension of irrigation area, national and
district level master plan shall be prepared and implemented addressing the integrated
development and management of river basins.
• Government of Nepal shall declare 'Irrigated Area' where irrigation facility is available in the
area. Provision shall be made for permission of Government of Nepal as per necessity for any
non-agricultural use of land within the declared Irrigated Area.
• Necessary collaboration and partnership shall be made with the governmental and non-
governmental stakeholders and local bodies to increase production in the irrigated area.
• Based on the variation of geography and topography necessity and importance of different
types of irrigation technologies, infrastructures and sources shall be considered and optimally
used. Additional study and research shall be emphasized in this area.
• Principle of integrated water resources management (IWRM) shall be followed during the
planning of irrigation projects.
• Irrigation projects developed in the past to supplement seasonal rainwater shall be developed
to provide year round irrigation by constructing reservoirs, rainwater harvesting systems, and by
developing, maintaining and using groundwater resources.
• Appropriate drainage systems shall be developed in the water logged area of irrigated land.
 Policy
Following policies shall be followed to achieve objectives of the irrigation policy.
• Projects of national importance shall be constructed by mobilizing internal and external
sources.
• Available groundwater reserve shall be developed and utilized as an important source of
irrigation and appropriate methods shall be adopted for its preservation, conservation and
quality control. Organizational reforms as outlined in the National Water Resources Strategy
and National Water Plan shall be made for this.
• Information management system regarding irrigation shall be reinforced.
• The policy of involving private sector, cooperatives and community based organizations in
construction, operation and management of the irrigation system shall be pursued.
• Effective involvement of local bodies and water users' associations shall be emphasized in the
planning and construction of irrigation projects and in the development and management of
local level small irrigation systems.
• Participation of local bodies and water users' associations shall be increased by timely
communicating information related to the project.
• Gender equity, positive discrimination and social inclusion shall be ensured in the irrigation
sector.
 Policy
Following policies shall be followed to achieve objectives of the irrigation policy.
• Poverty alleviation through the development of irrigation sector shall be
emphasized.
• Research and development capability of the irrigation sector shall be enhanced.
• Programmes related to climate risk management (CRM) and disaster risk
management (DRM) shall be implemented to address the effect of climate
change. Adaptation and mitigation measures shall also be considered.
• Improvement in the prevailing legal and institutional provisions shall be made
for the implementation of international agreements and standards related to
irrigation.
• Necessary legal and institutional improvements shall be made to achieve the
objectives mentioned in this policy.
 Irrigation Development institutions in Nepal
• The Ministry Energy, Water Resources and Irrigation (MoEWRI) is a lead Ministry
to foresee overall energy, water resources and irrigation sector and has three
departments namely Department of Water Resources and Irrigation (DoWRI),
Department of Electricity Development (DoED) and Department of Hydrology
and Meteorology (DHM). Other organizations under the ministry are Water and
Energy Commission Secretariat (WECS), Water Resource Research and
Development Center (WRRDC), Ground Water Resources Development Board
(GWRDB), Alternate Energy Promotion Center (APEC), Nepal Electricity Authority
(NEA), Vidhyut Utpadan Company Limited, Rastriya Prasaran Grid Company
Limited, Hydroelectricity Investment and Development Company Limited etc.
• Among them, following institutions directly involved in water resources and
irrigation development in Nepal.
• Ministry of Energy, Water Resources and Irrigation (MoEWRI)
• Department of Water Resources and Irrigation (DoWRI)
• Water Resource Research and Development Centre (WRRDC)
• Groundwater Resources Development Board (GWRDB)
Department of Water Resources and irrigation (DoWRI)
• Farmers had been developing and managing the irrigation system since the early human civilization. However,
government initiated investing in irrigation from the first plan period. The irrigation infrastructure development was
formally began and modern era of irrigation system was inititated with the construction of Chandra Irrigation Canal in
1979BS. After that, the Juddha canal in Sarlahi; Jagadishpur reservoir in Kapilbastu and Pardi dam in Pokhara was
constructed in around 2000 B.S.
• After the implementation of first five-year plan, planned development of irrigation system was initiated and Nepalese
technocrats involved in this sector. Initially, the projects were developed in starting the central level projects or
development committee. These projects were operated and managed establishing division or subdivisions.
• Initially, four regional directorates were established in 2024 B.S, later number of directorates increased to five in 2037
B.S. After establishment of Canal Department, Irrigation and Water Supply Department, Irrigation and Hydrological
Science Department; Irrigation department was established in 2044 with the responsibility of irrigation development
and river training activities.
• Disaster Prevention Technical Center was established to carry out water induced disaster prevention related activities
which later restructured as Water Induced Prevention Department in 2056 B.S. The name of Water Induced Disaster
Prevention Department was changed to Water Induced Disaster Management Department in 2073.
• Irrigation department was restructured with five regional directorates, 26 irrigation development divisions, 20 irrigation
development sub divisions in 2058 B.S. The number of divisions and subdivisions were increased to 73 and irrigation
management divisions were increased to 13 in 2072B.S.
• After the promulgation of new Constitution on 2072, the irrigation and water induced management sector has been
merged and restructured in federal system. Medium level irrigation system and river training works has been handed
over to Provincial Government and all division and sub division offices are also handed over to provincial government.
Department of Water Resources and Irrigation was established in central level on 2074 B.S with the key objective to
implement large, multipurpose and basin diversion projects. The scope of works that falls under federal government
shall be executed by this department.
Department of Water Resources and irrigation (DoWRI)
The main objectives of the establishment of DoWRI shall be as follows:
• Expansion and development of irrigation services in a sustainable manner for optimum utilization of available
water resources to increase agricultural production and productivity.
• To provide Year Round Irrigation by expansion of irrigation system in the available agricultural land.
• To maintain and modernize the developed irrigation and water induced infrastructure in appropriate manner for
reliability of the services.
• To increase the efficiency of large irrigation system, increase the capacity of the user’s committees for sustainable,
reliable and effective irrigation services.
• To carry out the partial or complete management transfer of the irrigation system after capacity building of
WUAs.
• To minimize the water induced disaster adopting appropriate technology and through the structural and non-
structural measure in river or in watershed scale. The reclaimed land shall be utilized in economical activities.
• To carry out research, study, and other activities to manage the large landslides and minimize the human and
other losses.
• To establish the management information system in irrigation and water induced disaster sector.
• To carry out the capacity building activities, appropriate institutional reform for irrigation, water induced disaster,
and landslide management sector.
• To carry out climate change induced adaptation and mitigation measures to address the impact of climate change
in irrigation and water management.
Classification of Irrigation Projects
• Classification of Irrigation projects based on the size
• Based on the size (command area), (Irrigation policy 2070, mentioned the
threshold of the size for the classification the projects based on the capacity)
• Major Irrigation Project/System: "Major Project/System" means the
project/ system having more than 1000 hectare of irrigation area in the
hills and 5000 hectare in terai and inner terai.
• Large Irrigation Project/System: "Large Project/System" means the
project/ system having 500 to 1000 hectare of irrigation area in the hills
and 2000 to 5000 hectare in terai and inner terai.
• Medium Irrigation Project/System: "Medium Project/System" means the
project/ system having 25 to 500 hectare of irrigation area in the hills and
200 to 2000 hectares in terai and inner terai.
• Small Irrigation Project/System: "Small Project/System" means the
project/ system having less than 25 hectare of irrigation area in the hills
and less than 200 hectares in terai and inner terai.
 Classification based on technology used
• Based on the technological uses, the irrigation project can be classified as
• Conventional Irrigation Project/scheme: irrigation water is taken from the surface and
ground water source and distribution is conducted under gravitational system is called
conventional irrigation technology.
• Non-conventional Irrigation Project/scheme: irrigation technologies, which differ from the
conventional canal systems and are relatively modern methods, can be regarded as non-
conventional technology. Non-conventional Irrigation System means any one or few or all of
the systems of water collection, conveyance, storage, distribution and use meant for
irrigation which is different from conventional technology. Non-conventional techniques may
include range of water acquisition and application technologies such as sprinkler, drip, tank,
Pond, pipe hose, treadle pump and so on.
• The agricultural land situated in the hill slopes and Northern Tarai of Nepal lack viable water source for
conventional canal irrigation.
• But potential to irrigate significant portion of land through the development of small water sources
including rain water harvesting, drip and sprinkler systems.
• The main objective of promoting these technologies is to provide irrigation facilities in the marginal
lands where irrigation by surface methods is not feasible due to socio-technical and environmental
reasons.
• Suitable in water scarce areas but with opportunities for growing high value cross
 Classification based of the mode of management
For the use of management, the Irrigation systems have been classified as follows:
• Systems operated by the users: Users Operated Irrigation System means the systems fully
operated by the users association after having been constructed by the governmental or
non-governmental organizations. This kind of project or scheme also called Famers Managed
Irrigation System (FMIS).
• Traditional irrigation systems: Traditional Irrigation System means the system constructed
and operated by the farmers including those irrigating through canals by constructing dams
in the rivers, streams or other water sources and those irrigating through tubewells using
groundwater.
• Systems transferred by the government or nongovernmental organizations to the users’
association.
• Systems operated by the Government of Nepal: Also called agency Managed System (AMIS)
• Systems operated in joint management by the Government of Nepal and water users’
association.
• Systems operated in joint management by local bodies and water users’ association.
• System operated in private level.
Classification based on the service block of
command area
In Nepal, irrigation systems are categorized into three types based on the
smallest service block of command area.
• Extensive Development Schemes (ED): those irrigation systems which
incorporates the main and secondary canals only. The tertiary canal system
shallnot be covered. Service block of size 300 to 500ha shall be included in
this system.
• Intensive Development Schemes (ID): Those which incorporates the main,
secondary and tertiary canals. Service block shall be of size 30 to 50ha.
• Command Area Development schemes (CAD): all scheme covering the
intensive development schemes (ID) plus quanternary. Service block size 3
to 5ha.
Classification based on the availability of
water source

Based on the elevation of availability of water source and irrigation

field, irrigation may broadly be classified into:
• Surface/Flow irrigation system
• Lift irrigation system
Classification based on the water source from
which water is drawn
Depending upon the source from which the water is drawn, flow or
surface irrigation can be further subdivided into:
• Direct irrigation (River canal irrigation): Diversion scheme
• Storage irrigation (Reservoir or tank irrigation): Storage scheme
• Combined storage and diversion scheme.
• Inter basin water transfer (Basin diversion irrigation scheme)
Thank You!