UNIT-5��WATER MANAGEMENT IN IRRIGATION�

Syllabus

Modernization techniques- Rehabilitation – Optimization of water use-Minimizing water losses- On form development works-Participatory irrigation management- Water resources associations- Changing paradigms in water management-Performance evaluation-Economic aspects of irrigation.

Modernization techniques

• Improving irrigation water management, in order to increase productivity and minimize adverse effects such as salinization, is one of the main contemporary issues in the agricultural sector.
• A considerable effort is being made to improve irrigation operations and to reduce costs.
• Society in general and water user associations, particularly where they have to bear the cost of irrigation, are demanding that irrigation become more cost-effective.

Rehabilitation, which consists of re-engineering a deficient infrastructure to return it to the original design. Although rehabilitation usually applies to the physical infrastructure, it can also concern institutional arrangements.

Process improvement, which consists of intervening in the process without changing the rules of the water management. For instance, the introduction of modern techniques is a process improvement.

Defining modernization

Irrigation modernization is a process of technical and managerial upgrading (as opposed to mere rehabilitation) of irrigation schemes combined with institutional reforms, with the objective to improve resource utilization (labour, water, economic, environmental) and water delivery service to farms.

The need for a consistent framework for modernization

1. Increasing water productivity
2. Increasing the cost-effectiveness
3. Increasing the reliability in irrigation deliveries.
4. Increasing the flexibility of deliveries.
5. Consideration of other uses of water
6. Increasing knowledge and human resources development

Obstacles in the way of modernization

• Technical gaps between the requirements needed to implement the improved method (availability of expertise, technical maintenance of equipment) and available local resources.
• Financial constraints resulting from the gap between the cost of equipment for the improved method and the gain in water savings and improved services, as water is generally not priced or charges are low.

Social constraints.

• Human resources are relatively less expensive in developing economies than alternative technological solutions.
• An irrigation agency, often a large employer in the area, has some obligation to maintain local staff.

Institutional constraints.

• Bureaucratic centralized irrigation administrations are not well suited to service-oriented activities.

Model for the modern irrigation enterprise

• Hence modernization can be seen as a means to create and favour modern irrigation enterprises by introducing methodologies which have proved successful in other sectors.
• We advocate that modern enterprises in irrigation require a reengineering of their processes in order to cope with the new challenges faced by irrigation.

Reengineering irrigation system operations

• The reengineering of the irrigation operation should consist of designing the most cost-effective answer to the redefined water service within the scheme.
• The spatial distribution of the effective demand for the water service.
• The spatial distribution of the physical infrastructure characteristics

Flexibility in modernization

• Flexible deliveries can be proposed to users in different forms (on request, free access, etc) at a cost compared to a strict rotational distribution.
• This concept of flexibility leads to abandoning the homogeneous approach of irrigation systems that has so far prevailed.
• Instead, a heterogeneous approach of the demand and of the efforts (inputs) to operate irrigation systems is sought for a closer match of water availability to demand requirements.

Low-cost technologies

The introduction of low-cost technologies, which could be part of the modernization of small-scale irrigation projects, provides another example of the site-specificity of success.

Inexpensive treadle pumps have been successful in some South Asian countries in extracting irrigation water from shallow aquifers.

These pumps have allowed poor farmers to make good use of the available labour in their households and so increase crop production and farm income.

The farmer has full control over the timing and amount of this pumped water, which given the effort involved is used sparingly.

Inexpensive treadle pump

Bucket drip-irrigation kits

• Positive experience has been reported with the introduction of bucket drip-irrigation kits.
• These kits are suitable for the irrigation of small plots of vegetables and fruit trees in peri-urban areas (close to markets).

Rehabilitation

• The renovation of a scheme to meet its original design criteria
• Inadequate operational practices may limit improvements to water supply expected from improved infrastructure.
• Trained and motivated operational staff are needed.
• Farmers must be willing and able to exploit a better supply.

Maintenance activities in a reservoir itself comprise:

• Controlling aquatic weeds,
• Removing large debris (e.g. tree trunks) floating in the water that may damage hydraulic works,
• Monitoring the water quality: not only from the salt content point of view but also from a biological standpoint in order to detect possible sources of pollution
• Surveying the solid deposition in the bottom of a reservoir.

Controlling aquatic weeds

Removing large debris

Monitoring the water quality

Surveying the solid deposition

The retention in good working order of open drains includes the following operations:

• Light deforestation
• Weed control in the canal section
• Seeding grass in the canal section
• Maintenance of flow gauges and other measuring devices
• Removal of silt
• Maintenance of pumping stations where water cannot be evacuated by gravity.

Optimization of water use

Water efficiency of irrigation can be improved by making the right decisions regarding:

• Crop selection
• Irrigation scheduling
• Irrigation methods
• Source of water.

Improving Irrigation practices can:

• Reduce water and pumping costs
• Reduce costs for fertilizers and other agricultural chemicals
• Maintain a higher soil quality
• Increase crop yields − by as much as 100%

Irrigation scheduling

• Irrigation scheduling helps eliminate or reduce instances where too little or too much water is applied to crops.
• However, proper irrigation scheduling involves fine-tuning the time and amount of water applied to crops based on the water content in the crop root zone, the amount of water consumed by the crop since it was last irrigated, and crop development stage.
• Direct measurement of soil moisture content is among the most useful methods for irrigation scheduling.

Good irrigation scheduling requires knowledge of:

• Crop water demand at different growth cycles
• Moisture content of the soil and soil water capacity
• Weather conditions

Soil capacity

• Soil capacity, which is the ability of the soil to hold water between irrigation or precipitation events, is another important factor.
• Determinants of soil capacity include soil depth, ratios of different soil particles making up the soil, soil porosity, and soil water tension.

Climatic conditions

The prevailing climatic conditions, such as average ambient temperature, intensity of solar radiation, humidity, and windspeed also affect both the moisture retained in the soil and the speed by which plants lose water through transpiration.

Accurate monitoring

• Accurate monitoring of water used in irrigation is an essential part of irrigation scheduling and helps reach optimal performance, saving water while enhancing yields.
• Measurement of energy used by irrigation pumps
• End-pressure measurements in sprinkler irrigation
• Elevation differences in irrigation reservoirs or tanks
• Measurement of irrigation time and size of irrigation delivery system.

IRRIGATION METHODS

Once the quantitative and temporal characteristics of optimal water demand have been determined, a method that can make such water available in the most effective way should be selected. There are three main irrigation methods, namely:

1. Surface (or gravity) irrigation
2. Sprinkler irrigation
3. Drip irrigation.

Water losses be control

1. Measure to Reduce Evaporation Loss

a) The reservoir should be constructed of less surface area and more depth.

b) Tall trees should be grown on the windward side of the reservoir

c) The reservoir basin should be surrounded by plantation or forest area so that cooler environment exists within the reservoir area.

d) Certain chemical like cetyl alcohol is spread over the reservoir surface. It forms a thin film on water surface reducing evaporation.

2. Measure to Reduce Absorption Loss

a) The weeds and plants at the periphery of the reservoir should be removed completely.

b) The weeds from the surface of the reservoir should be removed.

3. Measure to Reduce Percolation Loss

a) Geological investigations should be carried out to locate the zones of pervious formations, cracks and fissures in the bed and periphery of the reservoir basin.

b) Suitable treatments should be adopted to stop the leakage of water through these zones.

c) Soil stabilization methods should be adopted if the basin is composed of permeable bed soil.

Water logging

Water logging

Water logging

• In agricultural land, when the soil pores within the root zone of the crops get saturated with the subsoil water, the air circulation within the soil pores gets totally stopped.
• This phenomenon is termed as water logging.
• The water logging makes the soil alkaline in character and the fertility of the land is totally destroyed and the yield of crop is reduced.

Effects of water logging

• Stabilization of soil
• Lack of aeration
• Fall of soil temperature
• Growth of weeds and aquatic plants
• Diseases of crops
• Difficulty in cultivation
• Restriction of root growth

Methods used for controlling water logging

• Prevention of percolation from canals
• Prevention of percolation from reservoirs
• Control of intensity of irrigation
• Economical use of water
• Fixing of crop pattern
• Providing drainage system
• Improvement of natural drainage
• Pumping of ground water
• Construction of sump well

ON FORM DEVELOPMENT WORKS (OFD)

• The efficient management of irrigation water for maximizing productivity requires both, the efficient on farm water management and the optimization of the use of water and land, through appropriate methods of water application.
• The items of works pertaining to on farm water management are termed as “On farm development works”.

The on farm development works comprise of following,

a) Field channels for conveyance of water

b) Control structures

c) Crossings

d) Surface drainage system

e) Farm roads

f) Field channel protection works and

g) Land forming (Smoothening / grading / leveling).

Systems approach:

• The conveyance system from the dam to the farm gate is one live system and it is necessary that the designs of the different components are matched properly.
• The water management proposed to be adopted on the canal system should always be kept in view as a reference frame.

Sequence of design and execution:

• (a) The ideal sequence of finalization of design would be obviously from the tail to the head.
• First, according to the topography and soil conditions, the land forming of each farm would be decided, so as to ensure efficient irrigation.
• Next, the chak water delivery system and surface drains would be designed so as to ensure adequate water deliveries to the different farms and proper drainage.

(b) The execution of OFD works shall be done only in places where canal water has actually reached. The OFD works get disturbed and deteriorated if these are not put to use immediately.

(c) After construction of OFD works, preparation of work-done drawings of OFD works (record drawings) form the basic record for planning irrigation management.

Functional utility:

• The purpose of the OFD works is to provide timely and adequate supplies of water to each holding and preserve environmental balance as well, by avoiding seepages, leakages and stagnations of water which trigger problems like water logging, causing adverse impact on environment.
• To achieve this functional utility, the planning and design of OFD works has to be hydraulically better and socially acceptable.

Aspects of functional utility of OFD works

• Hydraulic design
• Economy for construction and maintenance
• Social acceptance i.e. User friendliness to community of farmers who will be actually using OFD works and
• Levels of accuracies and quality of construction.

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Farmers Participation:

• Success of canal irrigation depends on the response of the farmer, both as an individual and as a member of the group benefited by the outlet.
• The irrigation facilities should be designed with a view to meet his requirements, particularly in respect of land forming.
• Active participation of the farmer at the stage of design should therefore be encouraged.
• This will also help in building up of an atmosphere of common purpose and thereby in the unification of the beneficiaries into a homogeneous group.

Organizational Coordination:

• The works from the canal head down to the distributory and from the distributory head to the outlet are carried out by the Construction Organization (C.O.) of the Irrigation Department.
• The outlet of a capacity of about 30 litre/second is the last Government structure on the canal system.
• Below outlet, OFD works are the community works.
• Design and construction proceed on the basis of the location of the outlet and its sill level.

Procedure for taking up OFD works:

The OFD works are part of CAD works. The cost estimates for OFD works are generally formulated in two parts.

a) Part I works : Cost estimates for chak water delilvery system, field channel protection works and surface drainage works in a chak.

b) Part II : Cost estimate for land forming works for each holding.

Participatory irrigation management

• The term participatory irrigation management (PIM) refers to the participation of irrigation users, i.e., farmers, in the management of irrigation systems not merely at the tertiary level of management but spanning the entire system.
• Participation should not be construed as consultation alone. The concept of PIM refers to management by irrigation users at all levels of the system and in all aspects of management. This is the simplicity and flexibility of PIM.

• "Participation in irrigation management involves a larger role for farmers, water groups, and other stakeholders.
• There have been increasing efforts to use participation in various forms to improve the quality, effectiveness, and sustainability of irrigation systems.
• The phad system of Nasik and Dhule districts and the Malgujari tanks of Chandrapur and Bhandara districts in Maharashtra, the Ahar-Pyne system of Bihar, the Kuhl system of H.P. and the Kudimaramath of Tamilnadu are some of the important examples of PIM under traditional irrigation.

Water resources associations

International Water Resources Association (IWRA)

• IWRA is a non-profit, non-governmental, educational organisation established in 1971.
• It provides a global, knowledge based forum for bridging disciplines and geographies by connecting professionals, students, individuals, corporations and institutions who are concerned with the sustainable use of the world’s water resources.

INDIAN WATER RESOURCES SOCIETY

• Department of Water Resources Development and Management, IIT Roorkee

American Water Resources Association (AWRA)

• Established in 1964, the American Water Resources Association (AWRA) is the preeminent multidisciplinary association for information exchange, professional development and education about water resources and related issues.

The European Water Resources Association (EWRA)

• The European Water Resources Association (EWRA) was initially established as ECOWARM (European Committee for Water Resources Management) and on September 14, 1992, its name was changed to European Water Resources Association.

The Canadian Water Resources Association (CWRA)

• The Canadian Water Resources Association (CWRA) is a national registered charity comprised of members from the public, private and academic sectors who are committed to promoting responsible, innovative and effective water resources management.

The Tamil Nadu Water Resources Department (TNWRD)

• The Tamil Nadu Water Resources Department under Public Works Department is entrusted with the responsibility of development of water resources of the State for catering to irrigation purposes and also for maintenance of physical infrastructure.
• The WRD is also responsible to upkeep the drainage system clean to adequately drain the rain water and excess irrigation from the crop fields.

Changing paradigms in water management

• World water demand by the turn of the century is likely to reach almost half of the total global runoff water annually available.
• By then, 21 ten million plus metropolises the world over will have to draw fresh water from sources further away or by pumping deeper with adverse environmental effects. Yet, the efficiency of water use remains abysmally low.

• An estimated 60 per cent of irrigation water is lost even before it ever reaches a plant.
• In cities, more than onethirds of the treated water never reaches the customer because of wastage and leakage.
• This situation cannot continue if development and the environment are to sustain.
• Demand management through economic, technical and educational means could greatly improve the efficiency of water use and reduce consumption.

7 good ways to reduce water consumption in cities

1. Introduce water metering and a tariff policy which is fair and which encourages conservation
2. Promote the use of water and sanitary fittings which reduce water usage'
3. Initiate a leak detection and repair programme within the city
4. Encourage water recycling in industries to reduce pressure on freshwater
5. Explore the possibility of reusing treated wastewater for crop production and fish farming
6. Engage the public through appropriate "save water" campaigns through local leaders
7. Ensure that school children develop respect for water

Performance evaluation

Irrigation Performance can be;

Operational performance- the degree of fulfilment of either a specific quantified output target , typified by such things as yield , water use efficiency and cropping intensity, or a specific input target such as discharge , water level, or timing of irrigation deliveries.

Strategic performance – looks at the process by which available resources are utilised in order to fulfil the eventual outputs of the system, and involves assessment of the procedures by which targets are set in relation to both available resources and the objective setting process.

• Performance assessment can be done at various system levels such as water delivery system, individual irrigation system, the irrigated agriculture system and up to the national level.
• Each level has a set of goals that may or may not co inside , and each requires a different set of performance parameters.
• Ideal level of performance can only be achieved when targets are achieved , objectives are fulfilled , and there is efficient use of available resources.

Engineer/ designer- to be able to compare the actual performance to the intended design.

Irrigator – to assess if the system is performing well enough to enable adequate irrigation

Maintenance crew- as a diagnostic tool to identify what is wrong with the system or to prevent the system from malfunctioning or breaking down.

Introduction to monitoring and evaluation

Monitoring and Evaluation (M&E) of a programme or a project or, in our case, an irrigation scheme is important in order to provide information about how it is performing.

There are four distinct reasons for carrying out M&E:

• To keep track of the progress of development activities during implementation.
• To determine the relevance, efficiency and effectiveness of development activities
• To learn lessons for future development planning
• To share progress and results with others

Monitoring

• Is the collection of information and the use of that information to enable management to assess the progress of implementation and take timely decisions to ensure that progress is maintained according to schedule.
• Assesses whether inputs are being delivered, are being used as intended and are having the initial effects as planned.
• Is an internal project or scheme activity, an essential part of good management practice and therefore an integral part of day to-day management.

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• The purpose of monitoring is to achieve efficient and effective project or scheme performance by providing feedback to the management at all levels.
• This enables management to improve operational plans and to take timely corrective action in case of problems.
• Monitoring is a continuous or regular activity.

Evaluation

• Evaluation is a process of determining systematically and objectively the relevance, efficiency, effectiveness and impact of activities in the light of their objectives.
• It is an organizational process for improving activities still in progress and for aiding management in future planning, programming and decision-making.
• While monitoring is a continuous or regular activity, evaluation is a management task that takes place at critical times of the life of a project or programme.

Indicators

• Indicators are a way of measuring progress towards the achievement of the goal, i.e. the targets or standards to be met at each stage.
• They provide an objective basis for monitoring progress and evaluation of final achievements.
• A good indicator should define the level of achievement, specifically: how much? (quantity), how well? (quality), by when? (time).
• One set of indicators needs to be formulated to monitor and evaluate the process.

The following six areas of M&E are important for irrigation schemes:

• Technical performance
• Agronomic performance
• Financial performance
• Socio-economic performance
• Environmental and health performance
• Managerial performance

Technical performance indicators

• Technical M&E should be carried out periodically in order to ensure a technically sound and efficient irrigation scheme.
• The M&E indicators to be measured depend on the irrigation system (surface, sprinkler or localized).
• The objective concerning the technical aspects of irrigation is to fulfil the crop’s need of water without causing harmful side effects.

Guides for the development of indicators for the technical M&E are:

• Quantity and quality of constructed infrastructure
• Energy consumption rate of equipment
• Pump discharge rate
• Distribution of uniformity of irrigation water
• Condition of equipment, canals, reservoirs and other structures
• Condition of land grading
• Frequency of breakdown and repairs of equipment
• Quantity of water used for irrigation
• Irrigation efficiencies

Agronomic performance indicators

Guides for the development of indicators for the agronomic M&E are:

􀁙 Type of crops grown and area per crop grown

􀁙 Crop quality

􀁙 Cropping intensity

􀁙 Type, quality and quantity of agricultural inputs used

􀁙 Cultural practices used

􀁙 Yield levels

􀁙 Pests and diseases encountered and control measures

􀁙 Timeliness of operations

Guides for the development of indicators for the financial M&E

• Cost of energy
• Cost of water
• Other costs, for example hiring security guard
• Cost of repairs and servicing of equipment, canals and structures (operation & maintenance cost)
• Cost of inputs, for example seed, fertilizer, chemicals, transport
• Prices of produce
• Marketing costs, for example packaging
• Access to credit – source, interest rates, etc.
• Gross margin per crop and per area
• Increase in farmer’s income

Socio-economic performance indicators

􀁙 Asset ownership

􀁙 Nutritional status of the family

􀁙 Change in living conditions

􀁙 Ability to pay school fees

􀁙 Employment creation

􀁙 Advancement of women

􀁙 Backward and forward linkages

􀁙 Food security status of the area

􀁙 Improvement in service provision

􀁙 Appropriateness of technology

􀁙 Adoption rate of technology

Environmental and health performance indicators

• Environmental and health factors have an impact on the short- to long-term performance at field level.
• Equally important are environmental impacts from irrigation schemes on the external environment and the impact from external factors on the irrigation scheme.

Guides for the development of indicators for the environmental and health M&E

• Changes in water quantity and quality
• Changes in soil salinity, alkalinity, sodicity, acidity and fertility
• Erosion occurrence (soil loss/accumulation)
• Water pollution, for example nitrates in streams􀁙
• Presence of water-related diseases, such as malaria and bilharzia, and degree of human infestation, in relation to the status before the introduction of irrigation
• Water logging/poor drainage

Managerial performance indicators

• Management and entrepreneurial skills are critical for success.
• A common problem is the lack of long-term thinking.
• When assessing the overall managerial performance, questions can be asked such as: Are they able to supervise the scheme activities effectively? Have they established the necessary linkages with governmental agencies and private organizations? Are they task-oriented? Are the human and material resources properly utilized?

Guides for the development of indicators for the managerial M&E are:

• Management structures, roles, responsibilities and skills
• Knowledge management and training at all levels
• Conflict resolution
• Farmer organization and management ability (self management)

Economic aspects of irrigation

• The economics of crop production with different irrigation sources was worked out to compare the economic feasibility of irrigation investment with existing and improved technologies.
• Different irrigation technologies, input and output prices and break-even yields could be important to justify the future of irrigation technology transfer and uptake.
• Worldwide, irrigation water consumes the bulk of renewable fresh water resources.

• As water demand increases with rising living standards and population growth, and as prospects for water diversion (extraction) are limited in some regions and nonexistent in others, the course of water policy left open is to increase efficiency of water use.
• This requires taking account of the full cost of water and the way to achieve this goal inevitably leads to some form of water pricing.
• Yet, water policy makers and economists are far from agreeing on what constitutes the “right” price of water in any given circumstance and how this price is to be charged.

Impacts of Irrigation

1. Environmental
2. Social
3. Economic

Environmental Impacts of Irrigation

1.Soil Erosion

• –e.g. Due poor designed or operated Furrow irrigation.
• Mitigation- proper design and O&M, sound drainage, land levelling, practicing soil and water conservation,

2.Water logging

Mitigation- Correct application rate, proper design and O&M, sound drainage, lining of canals, land levelling,

3.Salinisation of Salts

Mitigation- Flash irrigation water to leach the salts out of the root zone, Grow salt tolerant crops depending on severity of problems, Install drains so that during flashing or heavy rains , the salts will be washed away,

4.Leaching of nutrients →Eutrophication.

• Results: e.g. in algal blooms and weed proliferation
• Mitigation– Minimise washing way of nutrients from fields into water sources-Correct water and fertiliser application.

5. Deterioration of water Quality Downstream

• Mitigation - Apply correct amounts of chemicals , fertilizers and irrigation water, Impose water quality standards on return flow.

6. Reduction of Downstream flows

Mitigation - Damming, regulating abstraction, compensatory measures e.g. Supplement with borehole water downstream

7. Over pumping of ground water.

Mitigation - Artificial recharge of ground water , ensuring safe abstraction levels.

8. Alteration/ destruction of wildlife habitats

Mitigation– relocate affected species if possible, relocate project.

Social Impacts of Irrigation

1. Impediment of movement of livestock and humans

Mitigation - Create movement corridors, stretches of forests etc,

2. Threat to historical and cultural sites/ aesthetics

Mitigation - relocate project, salvage or protect sites e.g. relocate graves etc.

3. Dislocation of populations and communities

Mitigation - Resettlement programmes, relocate project,

4. Introduction/ Increase in water related diseases.

Mitigation - Avoid stagnant water in irrigation schemes, Undertake rigorous disease prevention , control and treatment e.g. Establish clinics in irrigation areas,

5. Water supply related conflicts

Mitigation - ensure equitable distribution of water.

Economic Impacts of Irrigation

• Increased agricultural production and productivity,
• Employment creation,
• Boosted rural development
• Improved standards of living,
• Increased food security at household and national levels,
• Increased food self sufficiency at household and national levels,
• Increased forex earnings,
• Increased GDP

Discussions ?