tank irrigation management system
TRANSCRIPT
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CHAPTER 3
CONCEPTUAL FRAMEWORK FOR SUSTAINABLE TANK
IRRIGATION SYSTEM MANAGEMENT
3.1 INTRODUCTION
In this chapter, a conceptual framework to implement the
restoration scheme of tank irrigation system for sustainable rural livelihood is
developed based on the reviewed literature in the field of tank irrigation
system management and impact of rehabilitation of tank irrigation system.
Sustainable development was defined in the Brundtland report Our
Common Future WCED (1987) as development that meets the needs of the
present generation without compromising the ability of future generations tomeet their own needs. Subsequently, many authors have used the term
sustainable development for specific development activities like sustainable
agriculture, sustainable forestry, sustainable energy development, etc.
A single development may be considered successful if it is weighed
against its specific performance criteria. But to achieve sustainability, all the
different aspects of development should be considered simultaneously.
An integrated approach is essential for this study. Many research
organizations and individuals have defined sustainability with regard to
development in agriculture, forestry, land management, etc. The Consultative
Group on International Agricultural Research (TAC/CGIAR, 1988, cited in:
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Prinz, 1998) states that sustainable agriculture is the successful management
of resources of agriculture to satisfy changing human needs while maintaining
or enhancing the quality. Current irrigated agriculture could not be sustained
until there is an improvement in water conveyance system and upgrading the
irrigation efficiency with a drainage system.
The major deficiencies that influence the sustainability of tank
irrigation system are inadequate maintenance, reduction in storage capacity,
heavy seepage losses in the delivery system and poor water management
techniques. There is a pressing need to evolve and implement appropriate
strategies that management be sound on technical, social, institutional andeconomic dimensions for sustainable development and management of tank
irrigation systems (Arumugam and Mohan 1997).
Farmers involved in implementing tank rehabilitation have to be
helped to meet their felt needs primarily and their utmost cooperation has to
be earned in carrying out rehabilitation program effectively. There are three
factors that qualify the sustainable development of a system, which are: (a)
survivability; (b) sustainability; and (c) efficiency [l/o]. Survivability refers to
the conditions under which a system yields net profits above a certain
minimum level. Sustainability indicates that if the demand increases then the
net profit must also be increased without causing damage to the system,
which results in the sustainable use of the system. Efficiency refers to the
quantity produced in relation to the input use (output/ input) (Arumugam et al,
1997).
The experience with watershed development under the new
participatory approach in India shows that the immediate results are positive
in terms of rise in water tables, crop yields, employment and income of the
participants (Rao, 2000).
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3.2 WATER RESOURCES
Irrigation tanks are one of the major water and common property
resources in Southern Peninsular India. Declination of irrigation tanks
threatens the agriculture productivity and water availability in the South and
South East Asia especially in Southern Peninsular India and Sri Lanka. The
literature on water resources of tank irrigation system identifies numerous
reasons such as socioeconomic, institutional and physical for the decline of
tank irrigation (Von Oppen and Subba Rao, 1980; Reddy, 1990; Reddy et al,
1993; Janakarajan, 1991; Reddy, 1996; Gireesh et al, 1997).
Historically, the decline in tank irrigation is linked with increasing
population density. Tank degradations can be reversed through appropriate
water conservation and management techniques, which enhance groundwater
recharge, agriculture productivity and poverty alleviation in the rural area in
India. These resources need rehabilitation which is given in a framework as
shown in Figure 3.1.
Tank rehabilitation options that can be used to restore to the
original standards should be given priority. Desilting is an important option.
However, as stated earlier in section 2.5, it has been observed that in a 10 year
cycle, for only 3 years the tanks reach full storage, for five years deficit
storage and for two years the tanks fail. Hence, desilting the tank fully is not
economical as the benefits of desilting will be for only three years with tanks
at full supply. Partial desilting can be done nearer to the lower sluice as well
as around the periphery of the tank water spread area (Palanisamy, 2006).
This type of desilting is suitable for system and non-system tanks. Most of the
tanks do not receive an adequate water supply and the chain systems of tanks
have been almost broken. Hence, there is an urgent need to revive the tank-
chains (tank cascade or chain of tanks) through appropriate modernization
strategies for improving the supply channels connecting different tanks.
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This highlight the needs for taking up modernization works at the
chain-level i.e. by considering the entire hydrological boundary as a single
unit rather than viewing individual tanks as separate entities for new
investment (Palanisamy, 2006).
Community wells should be installed in the tank water spread area
to provide some supplementary irrigation to the non-well farmers during
critical periods. Again, the farmers level of access to resources plays a
critical role in the acceptability or appropriateness of the various technologies
(John, 2002). If the land is a limiting factor to production, then practices that
reduce the land area are unlikely to be embraced. If the labour is limited, then
the gender division of labour and the timing of the various activities become
critical to the adoption of technologies. And if capital is limiting by
considering the traditional practice experiences of the farmers, experts and
scientists could develop the appropriate technologies jointly with the people.
Siltation over many years generally reduces the tank storage capacity. In the
earlier years, farmers used to desilt the tanks using their bullock carts and
manual labour with the aim of maintaining the tank storage as well as
obtaining manure for their lands.
Presently, it is becoming increasingly difficult to desilt by
themselves due to the lack of bullock carts and the reduced spirit of
Kudimaramath (community repair work). The Government cannot perform
the desilting since it is too expensive to desilt the entire tank capacity. And
also, it is difficult to dispose of silts outside the tanks. Partial desilting that
helps to restore the original (10%) dead storage could be attempted as part of
tank rehabilitation options to increase non-irrigation benefits of tank water
particularly in the non-tank-irrigation season. The recharging of wells could
also be improved. Partial desilting can be done nearer to the lower sluice as
well as around the periphery of the tank water spread area (Palanisamy,
2006). This type of desilting is suitable for system tanks and non-system
tanks.
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Figure 3.1 Framework for tank irrigation system degradation issues
and appropriate management and conservation for
sustainable development
Problems of small water storage
bodies like irrigation tanks, kulams
etc,
Silting and
non-maintenanceof tanks
Chocking of
supply channel
Deterioration of
the traditionalirrigationinstitutions Non-
maintenance of
tanks
Encroachment
of foreshorearea, catchmentarea and supply
channel
Pollution
from
industries
Restoration of Water Bodies
Maintaining and repairing oftank bund, sluice and surplus
weir and improving supply
channel
Desilting of tankbed area
Proper maintenance of tanksystem through farmers
participation aftermodernization and
restoration
SustainabilityImproving water storage,
increasing ground waterlevel through recharge,
preventing encroachment oftank bed area and supply
channel etc
Silting and non-maintenanceof tanks
Social EquityEnsure equity,
adequacy andreliability in
water supply.
Economic efficiencyHighest productivity both
in agriculture and
ecosystem, adequacy andreliability in water supply.
SUSTAINABLE DEVELOPMENT
Issues
Cause
Effect
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In many tanks the supply channels feeding the tanks are heavily
silted, and in several cases they are missing due to the combined effect of
both siltation and encroachment.
Restoration of the supply channels with original capacities will help
capture the run-off water to the tanks. Tank siltation is one of the major
causes for the reduction in the tank storage capacity. This is further
aggravated by deforestation in the tank catchment area, by encroachers for
firewood causing soil erosion during heavy rains. Hence, afforestation has to
be taken up in the catchment area. This is further aggravated by deforestation
in the catchment area, both by encroachers and tank irrigators to beintroduced in the tank.
As per the social forestry programme, the Forestry Department is
planting trees in the tank catchment and foreshore areas. In some cases, the
water spread areas of the tanks are also used for planting the trees and after 10
years the trees will be auctioned off. About 50% of the revenue from the
auction will be given to the local Panchayat (Village level administrative
body), which will be spent on tank and village improvement works.
Supply channel desilting helps to receive the water properly from the
river. Channel desilting also helps in getting the benefit by two ways. The
first one is during rainy seasons. Heavy flows coming from the river may
directly enter the tank and fill it up to its full capacity, which may help the
farmers to achieve high productivity. The recharge of groundwater may also
be at its highest level. The second is during non-rainy seasons. With the sluice
gates closed, water may stagnate in the channel, which can be used for
irrigation by gravity or by pumping. This may also help to recharge the
groundwater.
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3.3 STAKEHOLDER CONTRIBUTION FOR TANK
IRRIGATION MANAGEMENT
Conserved tanks and ponds will serve a long lasting multiple uses
supporting various communities including urban areas. Based on situations,
either conservation or development or both assume significance. The
challenges to conservation and development are technological challenges for
restoration, conservation and development, institutional challenges for
revival, conservation and development, and financial and human resources
challenges for revival and redefining the role of the state, research
institutions, resource institutions and NGOs and the local community(DHAN, 2002).
The situation, therefore, calls for major changes in governance and
management, activism of the locals, research in engineering and tank fed
agronomy, funding by the governments and donors. The desired changes can
be brought about only when the various stakeholders are brought to a
common platform to share their views on the need for a sustained
management. Presently, the tanks have many stakeholders such as the
Irrigation Department, the Local Panchayats, the Revenue Department, the
Agricultural Department, Forest Department and the local people. The
functions of various stakeholders towards sustainable development of tank
irrigation system are highlighted as on Figure 3.2.
There are many stakeholders in the tank and tank related programs,
of which the Government agencies, farmers and technologists are important.
The Government officials, institutions and farmers should be invited for a
meeting to listen to each others views on the tank systems. The meeting
should focus on the status of tanks, tank fed agriculture, tank improvement,
tank administration and encroachment.
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Figure 3.2 Tank restoration schemes for sustainable management of
tank irrigation
Multi stake holder decision making for
restoration of tanks
Technologist
Maximising Tank
water Productivity
Techniques of
groundwater
recharge
Farmers Government
Status of tanks and its
improvement needed
Past uses of tanksTank restoration and
its need
Awareness
Training
Performance
support
Performance
evaluation
Changes in livestock
economy, changes inhousing facilities,
changes in farms and
house hold assets,
growth of socialinstitution, changes in
farm and nonfarmactivities, employmentopportunities etc.
Productivity (yield) ofland, value of land andlivestock holding, family
income and Employment
Social Development
Economic wellbeing
Environmental
sustainability
Changes in
groundwater table
Changes in cropping
pattern throughimproved
groundwater table
Cause
Effect
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Based on these aspects, an enabling solution has to be decided.
Perspectives of technologists are important, which should get integrated in the
decision making to increase the farm productivity. Recent technologies have
been used to improve the tank irrigation and also they have been used for
maximizing tank productivity, groundwater recharge and other tank services.
Micro-irrigation encompasses drip and sprinkler technologies.
The intended framework considers three key areas as equally
important. Figure 3.2, presents the relationship among the three key network
of active stakeholders (Technologist, Government and Farmers), as well as
the three objectives to be achieved (social equity, economic efficiency andenvironmental sustainability). The multi stakeholder involvement in decision
making is very important for achieving all the three objectives.
Different stakeholders are involved in tank irrigation and hence,
any decision towards the tank renovation program should be finalised after a
consultation among the different stakeholders. Encroachments and siltation in
waterspread areas and the supply channels, catchments degradation,
deterioration of the traditional irrigation institutions, improper water
management at farm level are some of the major problems confronting tank
irrigation in the State.
Restoration program is carried out before understanding the general
characteristics about tank system and perspectives of farmers, technologists
and the Government. Integration of stakeholders (Government, farmers and
technologists) in decision making for rehabilitation/restoration/renovation,
modernization and desilting etc., is very important for achieving long term
sustainability. Lacking of any one of the stake holder participation in
decision-making may lead to immediate short-term benefit, but it will lead to
long term unsustainability.
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3.4 RESTORATION SCHEMES OF TANK IRRIGATION
SYSTEMS
Managing tank irrigation systems is a complex phenomenon.
Therefore, its management requires a variety of physical, social and economic
policies and techniques, all aimed at minimizing the adverse consequences of
natural disaster events to improve and enhance the quality of life of the
community. Rehabilitation of tank irrigation systems results in an augmented
supply of irrigation water, better recharge of groundwater, improved quality
of drinking water, increased production and productivity, enhanced
employment opportunities and better well-being of the stakeholdercommunities. For a sustainable tank irrigation system management through
development (restoration) programme that the restoration programmes should
be sound on environmental, social and economic dimensions. Any restoration
programme must start with identifying the problems of tank irrigation system
through perspectives of farmers, improvement of the tank water productivity,
groundwater recharge and other tank support services, which should be
collaborated by the perspectives of technologists and finally the government
should allocate the funds not only for infrastructure development but also for
institution building and awareness programmes (Deivalatha and Ambujam,
2010).
Now a complete rehabilitation is not possible due to the fact, that
tanks are very old structures. Certain limited components of rehabilitation
works like partial desilting of tanks, desilting of channels, tank bund
strengthening etc. may be possible to get the expected benefits of agricultural
productivity through increased groundwater recharge. However, the major
stakeholders involved to implement these restoration works have to be made
aware of the expected positive impact. Results of the these restoration works
being the benefit of environmental well being through increased agricultural
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irrigated land, socio economical benefit of food security, productivity of
yield and profitability of farm income and also the investment amount is
financially feasible, which are clearly indicated in Figure 3.3.
Figure 3.3 Restoration schemes for tank irrigation systems
Stakeholders involved in implementation of
restoration schemes of tank irrigation
system
Stakeholders of
Tank Irrigation
System
Water user groups,
NGO, Technologists
and Government
officials
Restoration works like partial desilting oftanks, desilting of supply channel and tank
bund strengthening etc.
Changes in Groundwaterrecharge
Changes in well water level
Pumping duration of wells,
Well yield
Changes in irrigated area etc.
Changes in crop yield
Changes in farm income
Changes in income for landless labours
by increasing employment opportunity
Increased water
availability
Improved agricultureproductivity
Socio Economic
Impact
Food security
Productivity ofcrop yield
Profitability offarm income
Ecological Impact
Increasing irrigated cropping
area and cropping intensity and
fodder availability for protecting
environmental well being by
conserve the basic natural
sources of agricultural land and
rural water bodies
Financially
feasible
Investment
scheme of tank
irrigation System
Tank irrigation system management through restoration scheme for
Sustainable livelihood
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3.5 IMPACT OF IMPLEMENTATION OF RESTORATION
SCHEME IN TANK IRRIGATION SYSTEM
For a successful and sustainable tank irrigation system
management, it should be protected from the issues of degradation and
maintained for a good production. It should involve the relevant stakeholders
in implementing the tank restoration schemes particularly the community
from problem identification to all levels of planning. It should give combined
benefit for a solution of the restoration project.
For a tank irrigation system to be sustainable through restoration
schemes, multidimensional impacts of ecological, social and economic
benefits all need to be assessed as explained in Figure 3.4. These
multidimensional impacts of the restoration scheme of tank irrigation system
project are studied in detail.
Sustainable benefits of technical measures for ecological impact,
social and economic measures for socio economic impact and economic
feasibility are also studied in detail and the factors indicating the
sustainability of each element are determined.
The conceptual framework outlined here can be applied to
developmental schemes of tank irrigation systems not only in Tamil Nadu but
also elsewhere in the world with similar situations, which will be explored
and explained in the following sections. The overall performances of tank
irrigation system developmental programme have been examined in the state
of Tamil Nadu. It is pointed out that tank irrigation system developmental
activities have made significant positive impacts on bio-hydrological aspects
such as surface runoff water harvesting, production and productivity of crops,
changes in cropping pattern and cropping intensity.
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Figure 3.4 Multidimensional impacts of tank irrigation system
restoration schemes
Multidimensional impact of Restoration
schemes of tank irrigation systems
Technical Measures Social Measures
Changes in groundwater
recharge
Changes in well water level
Pumping duration of wells,
Well yield
Changes in irrigated area etc
Changes in literacy rate
Changes in farms and house hold
asset
Changes in farm and nonfarmactivities
Employment opportunity
Ecological Impact
Increasing irrigated cropping
area and cropping intensity
and fodder availability forprotecting environmental well
being.
Economic Measures
Socio Economic Impact
Food Security
Productivity of crop yield
Profitability of Farm income
Changes in crop yieldChanges in farm income
Changes in income for landless labours
by increasing employment opportunity
Increment benefit of
crop farm income bycropping area, cropping
intensity and
crop yield
Investment amount ofrestoration schemes
Investment Appraisal
techniques
IRR
Benefit Cost Ratio
Pay Back Period
Benefit Cost Index
Financial Feasibility
Tank irrigation system management through restoration schemes forSustainable rural livelihood
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These activities have shown significant positive impact on water
table, recharging wells and employment opportunities for rural people, food
security, water availability for cattle and other domestic purposes etc. The
overall economic impacts have been evaluated in terms of Net Present Value
(NPV), Internal Rate of Return (IRR) and Benefit Cost Ratio (BCR). There is
no single indicator to evaluate the success of tank irrigation system
developmental activities. Hence, a feasible approach may be to compare the
performance of a variety of indicators. Such performance indicators may
reflect the diversity of the project objectives. These include raising agriculture
productivity, recharging groundwater for irrigation and drinking, reducing
productivity of non-cultivable land, increasing cultivable land, creating
employment, promoting collective action and building or strengthening social
institutions.
3.5.1 Evaluation Measures for Tank Restoration Schemes
Technical measures: Some technical measures may include the changes in
groundwater recharge, changes in well water level, pumping duration of
wells, irrigated area, and additional area brought under cultivation and
protecting environmental well beings
Socio economic measures: Socio economic measures are used to evaluate the
restoration schemes of tank irrigation systems. Social measures are changes in
literacy rate, changes in farms and household asset, changes in farm and
nonfarm activities, employment opportunity and food security etc. Economic
measures are changes in crop yield, changes in farm income and changes in
income for landless labourers by increasing employment opportunity are
using for assessing the socio economic impact of restoration scheme for tank
irrigation system management.
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The economic measures are also used to evaluate worth of the
project by comparing the values of goods and services generated or conserved
with the cost for assessing its effect on social welfare need and viability.
There are various undiscounted and discounted measures available to evaluate
the projects (Gittinger, 1982).
The undiscounted measures ignore the time value of money and
simply evaluate the worth of the projects. Discounting measures such as Net
Present Worth (NPW), Benefit Cost Ratio and Internal Rate of Return are
used for this purpose.
Key points from the above frameworks are summarized given in
table 3.1. It was used to know about problems of irrigation tanks, solutions to
siltation and evaluation tools for the impact of restoration of irrigation tanks.
Table 3.1 Summary of key points for conceptual framework for
sustainable tank irrigation system
Sl.
no Description
key points for
analysis Output for the study Remarks
1 Water Resources
Declination of
small water bodies
like lakes,
reservoirs,
irrigation tanks
etc., threatens
agriculture
productivity and
water availability
in the South and
South East Asia
especially in
Southern
Peninsular India
and Sri Lanka.
Maintaining and
repairing of tank bund,
sluice and surplus weir
and improving supply
channel. Partial
desilting can be done
nearer to the lower
sluice as well as
around the periphery
of the tank water
spread area. Proper
maintenance of tank
system through
farmers participation
after modernization
and restoration
Sustainability
Improving water
storage, increasing
ground water level
through recharge etc
Social Equity
Ensure equity,
adequacy and
reliability in water
supply.
Economic efficiency
Highest productivity
both in agriculture
and ecosystem,
adequacy and
reliability in water
supply.
Problems and
solution for
tank irrigation
system
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2 STAKEHOLDER
CONTRIBUTION
There are many
stakeholders in the
tank and tankrelated programs,
of which the
Government
agencies, farmers
and technologists
are important.
Solution for problems
of water storage
bodies i.e. Silting and
non-maintenance of
tanks ,Chocking ofsupply channel,
Deterioration of the
traditional irrigation
institutions Non-
maintenance of tanks,
Encroachment of
foreshore area,
catchment area and
supply channel and
Pollution from
industries
Sustainability
Social Equity
Economic
efficiency
Problems and
solution fortank irrigation
system
3 DECISIONMAKERS FOR
RESTORATION
SCHEMES
Technologist
Farmers
Government
officials
Technologists
Maximising tank
water productivity and
techniques of
groundwater rechargeFarmers
Status of tanks and its
improvement neededPast uses of tanks
Tank restoration and
its needGovernment officials
Awareness, Training
Performance supportand
Performance
evaluation
SocialDevelopment
Economic
wellbeing
Environmental
sustainability.
Problemsand solution
for tank
irrigation
system
4 STAKEHOLDEROF TANK
IRRIGATION
SYSTEM
Identifying the
problems of tankirrigation system
throughperspectives of
farmers,
technologists andgovernment
Restoration works like
partial desilting of
tanks, desilting ofsupply channel and
tank bund
strengthening etc.Increased water
availability Improved
agricultureproductivity
Ecological
Impact,
Socio Economic
Impact
Financially
feasible
Sustainable
livelihood
Problems and
solution for
tank irrigationsystem
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5 IMPACT OF
IMPLEMENTAT
ION OF
RESTORATION
SCHEME
Multidimensional
impact of
Restorationschemes of tank
irrigation systems
Technical Measures
Social MeasuresEconomic Measures
Socio Economic
Impact Food Security
Productivity of crop
yield
Profitability of
Farm income
Ecological Impact Increasing irrigated
cropping area and
cropping intensity
and fodderavailability for
protecting
environmental well
being.
Financial Feasibility IRR Benefit Cost Ratio
Pay Back Period
Benefit Cost Index
Analysis for
sustainabilityof system
after
restoration
3.6 SUMMARY
Sustainability means maintaining environmental assets or at leastnot depleting them. Rapid depletion of essential resources coupled with the
degradation of land and atmospheric quality indicates that man has not only
exceeded its current social carrying capacity, but actually reduced the future
potential and biophysical carrying capacities by extinguishing essential
natural capital stock (Rwelamira, 1999).
To attain sustainable rural livelihood through restoration schemes
for tank irrigation system, the multi stakeholders have to be involved in
implementing the restoration programme. To achieve sustainable management
of tank irrigation systems for livelihood and the conservation of natural
resources as well as poverty alleviation, there is a need to identify appropriate
technologies for tank irrigation system management that are affordable and
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cost effective. Sustainable tank irrigation system management needs to be
supported by adequate institutional arrangements and must be economically
viable. The framework developed in this chapter can be used to evaluate tank
irrigation system projects.