1.0 OVERVIEW OF WATER RESOURCES OF INDIA

Water is prime life sustaining natural resource which cannot be created like other commodities. It is a nature’s gift to all living beings on the earth. Water is the elixir of life. Unfortunately for our planet, supplies are now running dry – at an alarming rate. The world’s population continues to soar but that rise in numbers has not been matched by an accompanying increase in supplies of fresh water. In India, the increasing stress on the availability of water is due to population explosion and improved standard of living. The scarcity is compounded further because of massive agricultural and industrial development coupled with improper and indiscriminate exploitation of groundwater resources.

India has 4% of the world water resources and 18% of the world population. Only handful of countries in the globe can boast of such an extensive river network that our country has. The mighty Indus-Ganga-Brahmaputra in the North, the Narmada-Tapi-Mahanadi in the Central region and Godavari-Krishna-Cauvery in the South have been symbols of existence and growth of our country right from its inception. Yet, the availability of water resources in India has its unique complexities.

Post-independence, the population of the country has increased almost nearly fourfold and growth is expected to continue upto 2050 by which it will stabilize. The economy of the country is also increasing at a fast pace due to rapid urbanization and industrialization. The enormity of the quantum of water required for food production, meeting domestic requirements, and supporting the industrial growth is therefore easily understandable. What is required is an integrated planning, development and management of the water resources with the involvement of all stakeholders and taking into consideration the multi-sectoral needs and the judicious distribution of the water resources amongst various sectors based upon certain priorities. With a view to achieve this vision, the country adopted the National Water Policy in 1987 for the first time. Thereafter this was updated in 2002. This has since been guiding the formulation of policies and programmes for water resources development and its management. During last ten years, since then many new challenges have emerged in the water resources sector which again necessitated the review of the existing National Water Policy. Accordingly, the latest revised 'National Water Policy – 2012' has been adopted to meet the new challenges in water resources sector.

2.0 PRESENT STATUS OF WATER AVAILABILITY

The total precipitation including snowfall, in the country is around 4000 Billion Cubic Metre (BCM). Of this, 3000 BCM precipitation is confined during three to four months (June – Sept). Thus, there is significantly high temporal variation. On the other hand, the spatial variability is also evident from the fact that while on one hand rainfall is of the order of 12,000 mm in Meghalaya, it is merely 100 mm in the western parts of Rajasthan. Taking into consideration the loss due o evaporation/evapotranspiration, soil absorption, percolation etc, the average annual natural runoff is about 1869 BCM. Because of topographical and other constraints only 690 BCM from surface water and 433 BCM from groundwater can be put to beneficial use. Further out of the 690 BCM of utilizable surface water, about 40 percent is in the Ganga-Brahmaputra-Meghna system which drains the states lying in the north and north-eastern regions.

Taking into consideration the population of the country as per 2001 and 2011 census and projections of the population for the year 2025 and 2050, the average annual per capita availability of water is estimated to be 1818, 1567, 1340 and 1140 cubic metre respectively. Thus, there is decreasing trend in the per capita water availability due to increase in population, urbanization and industrialization.

3.0 WATER SHORTAGE AND SCARCITY

The per capita water availability is a widely accepted parameter for gauging the water security for a country. As per the population of 2011, per capita water availability in India was 1567 cu.m. per head annually . As per the International standards if the water availability is between 1000 to 1700 cu.m per year, it is a “water stress” situation and if the water availability is less than 1000 cu m it is “water scarcity “ condition. As per this standard, India is already a water stress nation. By the year 2050, with the population of the order of 1.6 billion, the water availability will further reduce to 1140 cu m , nearing to the “water stress condition”. These are the average figures, but , if we look at the basin wise statistics, except for Brahmaputra, Indus, Brahmani &

4.0 FOOD SECURITY

Food security, as defined by the United Nations, is the condition in which all people, at all times, have physical, social and economic access to sufficient safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life. It is only when we attain self-sufficiency in food and ensure sufficient nutrition for the population that we can progress and develop ourselves. In-sufficiency leads social & economical vulnerability. The constant pressure of circumstances & uncertainty brings trouble and misery on the population and sometimes shame and humiliation for the nation. India suffered two very severe droughts in 1965 and 1966. Subsequent Green Revolution made a significant change in the scene. India achieved self-sufficiency in food grains by the year 1976 through the implementation of the seed-water-fertilizer policy as well as shift in irrigated agriculture adopted by the Government of India. The irrigation infrastructure created so far through major & medium projects were instrumental in making the green revolution & food self-sufficiency a success.

To remain self –sufficient in the coming decades, requires to know the prerequisites for food production &

5.0 NEED FOR RESERVOIRS

The reservoirs created through construction of dams were instrumental in achieving the Green Revolution and food sufficiency in India. It also acted as a catalyst for the economic and industrial growth in India. Per Capita availability of water is a vital parameter used worldwide to indicate resilience of the nation against uncertainties of water availability in space and time. Compared to the other developed and developing nations of the world like China, Brazil, USA, South Africa etc. the per capital water availability in India is very low. To sustain the economic growth, to ensure food security and water availability to the future generations, India will need a more reservoirs, at all locations wherever, techno-economically, socially and environmentally feasible. The large reservoirs are also very important to mitigate the uncertainties that are likely to be introduced due to climate change. Adaptation to climate change requires infrastructure that can absorb and even out large variations in hydrological events. Reservoirs are one of important tools to face the challenge of climate change.

6.0 PROBLMES OF SURFACE & GROUND WATER : QUANTITY & QUALITY

6.1 Surface water Scenario

On an average, India receives about 4000 Cubic Kilometers (1 Cubic Km is same as one billion cubic meters, abbreviated as bcm) of precipitation every year. Precipitation means rainfall and snowfall together. As explained above, this precipitation is not uniformly distributed over the entire land area and varies from less 100 mm in Rajasthan to more than 12000 in Meghalaya. Of all the rain that falls on the land and mountains and forests, some evaporates back into the atmosphere, some percolates in the ground and some is used by the forests. The remaining that flows into the rivers is less than 50% on the total precipitation. The total annual water resources availability is estimated as 1869 bcm. The basin wise figures are as follows.

 

 

6.2 Ground Water Scenario

Groundwater is the water that seeps through rocks and soil and is stored below the ground. The rocks in which groundwater is stored are called aquifers. Aquifers are typically made up of gravel, sand, sandstone or limestone. Water moves through these rocks because they have large connected spaces that make them permeable. The area where water fills the aquifer is called the saturated zone. The depth from the surface at which groundwater is found is called the water table. The water table can be as shallow as a foot below the ground or it can be a few hundred meters deep. Heavy rains can cause the water table to rise and conversely, continuous extraction of groundwater can cause the level to fall. Figure below illustrates the major definitions used in the context of groundwater.

The underground (hydrogeological) setting of groundwater defines the potential of this resource and its vulnerability to irreversible degradation. This setting in India can be divided into following categories, which are described below:

1. Hard-rock aquifers of peninsular India: These aquifers represent around 65% of India’s overall aquifer surface area. Most of them are found in central peninsular India, where land is typically underlain by hard-rock formations. These rocks give rise to a complex and extensive low-storage aquifer system, where in the water level tends to drop very rapidly once the water table falls by more than 2-6 meters. Additionally, these aquifers have poor permeability* which limits their recharge through rainfall. This implies that water in these aquifers is non- replenishable and will eventually dry out due to continuous usage.

2. Alluvial aquifers of the Indo-Gangetic plains: These aquifers, found in the Gangetic and Indus plains in Northern India have significant storage spaces, and hence are a valuable source of fresh water supply. However, due to excessive groundwater extraction and low recharge rates, these aquifers are at the risk of irreversible overexploitation.

6.2.1 groundwater availability

Out of the 1,123 BCM/year, the share of surface water and groundwater is 690 BCM/year and 433 BCM/year respectively. The overall contribution of rainfall to the country’s annual groundwater resource is 68% and the share of other resources, such as canal seepage, return flow from irrigation, recharge from tanks, ponds and water conservation structures taken together is 32%.

 

 

6.2.2 Hydrogeological Units And Their groundwater Potential

Hydrogeological map of India and the geographical distribution of hydrogeological units along with their groundwater potential are given figure

 

 

The groundwater behaviour in the Indian sub-continent is highly complicated due to the occurrence of diversified geological formations with considerable lithological and chronological variations, complex tectonic framework, climatological dissimilarities and various hydro-chemical conditions.

A perusal of past records reveal that there is a general decline in the water level as observed mostly in northern, north western and eastern parts of the country covering Uttar Pradesh, Rajasthan, Bihar, Jharkhand, West Bengal, Punjab and Haryana and in parts of Tamil Nadu and Andhra Pradesh. It also observed some rise in water level at isolated areas and is attributed to local causes or due to higher rainfall experienced in the area during the period of observation.

The assessment of the resources indicate that the replenishable Groundwater resource is estimated significantly high in the Indus–Ganga–Bramhputra alluvial belt in the North, East and North East India covering the states of Punjab, Haryana, Uttar Pradesh, Bihar, West Bengal and valley areas of North Eastern States, where rainfall is plenty and the aquifers found have high storage capacity and favor the recharge. The coastal alluvial belt particularly Eastern Coast also has relatively high replenishable groundwater resources while in western India, particularly Rajasthan and parts of northern Gujarat the annual replenishable groundwater resources are scanty as the region experiencing the arid climate. Similarly, in major parts of the southern peninsular India covered with hard rock aquifers, the replenishable groundwater recharge is less which is attributed to comparatively low infiltration and storage capacity of the rock aquifers. The Central Indian region is mostly accounted for moderate recharge.

6.2.3 groundwater Utilization

The assessment of groundwater draft is carried out based on the Minor Irrigation Census data and sample surveys carried out indicates the Annual groundwater Draft as 243 BCM. Agriculture sector remained the predominant consumer of groundwater resources. About 91% of total annual groundwater draft i.e. 221 BCM is for irrigation use. Only 22 BCM is for Domestic & Industrial use which is about 9% of the total draft. An analysis of groundwater draft figures indicates that in the states of Arunachal Pradesh, Delhi, Goa, Himachal Pradesh, Jammu & Kashmir, Jharkhand, Kerala, North Eastern states of Manipur, Meghalaya, Mizoram, Nagaland and Tripura, Orissa, Sikkim, and Union Territories of Andaman & Nicobar Island, Dadra & Nagar Haveli, Lakshadweep and Puducherry, ground water draft for domestic & industrial purposes are more than 15%.There has been about 5% increase in the overall estimate of the annual groundwater draft of the country in 2009 as compared to 2004.

6.2.4 Stage of groundwater Development

The stage of groundwater development in the country is 61%. The status of ground water development is very high in the states of Delhi, Haryana, Punjab and Rajasthan, where the Stage of groundwater Development is more than 100%, which implies that in the states the annual groundwater consumption is more than annual groundwater recharge. In the states of Gujarat, Tamil Nadu and Uttar Pradesh and UTs of and UT of Daman & Diu, Lakshadweep and Puducherry, the stage of groundwater development is 70% and above. In rest of the states / UTs the stage of groundwater development is below 70%. The groundwater development activities have increased generally in the areas where future scope for groundwater development existed. This has resulted in increase in stage of groundwater development from 58% in the year 2004 to 61% in 2009.

6.2.5 groundwater Assessment

groundwater resources in the country are assessed at different scales within districts, such as blocks/mandals/talukas/watersheds. groundwater development is a ratio of the annual groundwater extraction to the net annual groundwater availability. It indicates the quantity of groundwater available for use. The overall assessment of resources reveal that out of 5842 numbers of assessed administrative units (Blocks/Taluks/Mandals), 802 units are categorized as Overexploited (>100% development) , 169 units as Critical (>90% and 70% and

 

 

6.3 Water Quality Issues of Surface and Groundwater in India

Most of our water sources are polluted with untreated/partially treated wastes form industry, domestic sewage and fertilizer/pesticide runoff from agricultural fields. Unregulated growth of urban areas, particularly over the last two decades, without infrastructural services for proper collection, transportation, treatment and disposal of domestic wastes led to increased pollution & health hazards. The municipalities and such other civic authorities have not been able to cope up with this massive task which could be attributed to various reasons including erosion of authority, inability to raise revenues and inadequate managerial capabilities. The over-exploitation of groundwater resources is widespread across the country, and is projected to grow with time. The inappropriate land use practices prevalent in the country limit the groundwater recharge potential. Accordingly, the groundwater levels are receding in some regions of the country at an alarming rate. On the other hand, due to excessive irrigation and large water storages, some regions have registered rise in groundwater levels, at times leading to serious water logging problems.

Groundwater which used to provide guarantee against pollution, has not been spared either. Not only do pollutants from surface sources leach into the aquifer below, but with increasing groundwater exploitation, in-organics like fluoride and arsenic present below the ground also find their way into the extracted water. They cause fluorosis and arsenic poisoning, Groundwater pollution is particularly serious as 80 per cent of domestic water needs are met from this source. Over-exploitation of groundwater is a very serious problem and the water table has steadily been falling in many parts of the country. groundwater is a shared common property resource and there is a need to evolve appropriate institutional mechanisms for its management.

The major WQ issues are ;

1. Pathogenic pollution in both sources
2. Salinity in both sources
3. Fluoride, Nitrate and Arsenic problems in Groundwater
4. Oxygen depletion in Surface water
5. Eutrophication in Surface water
6. Toxicity in Ground and Surface water
7. Ecological Health in surface water

Major causes for water quality degradation are :

1. Domestic Wastewater
2. Industrial Wastewater
3. Rural and Slum Population
4. Wastewater and Pollutants from Un-sewered Towns
5. Pollutants in Agricultural Run-off and Drainage Waters (Diffuse pollution)
6. Deposition of Air-Pollutants

6.3.1 Water Quality Trend

The water quality monitoring results obtained during 1995 to 2006 indicate that the organic and bacterial contamination are continued to be critical in water bodies. This is mainly due to discharge of domestic wastewater mostly in untreated form from the urban centers of the country. The municipal corporations at large are not able to treat increasing the load of municipal sewage flowing into water bodies without treatment. Secondly the receiving water bodies also do not have adequate water for dilution. Therefore, the oxygen demand and bacterial pollution is increasing day by day. This is mainly responsible for water borne diseases.

7.0 WATER RESOURCES DEVELOPMENT – PRESENT SCENARIO

7.1 Creation of Surface Storage

Large parts of the country are endowed with only 45 to 50 rainy days a year. Out of this also the major share of rainfall is concentrated in only a couple of days. Water resources development which received high priority in the successive five year plans initiated after independence has resulted in many achievements that are discernible. Many major, medium and minor water resources projects have been constructed during the past five-six decades. India ranks third in the World after China and USA in terms of number of dams. There are about 4850 completed large dams and another 250 are under various stages of constructions. All these projects have resulted in increasing the live storage capacity from 15.6 BCM at the time of independence to 253 BCM now. Projects under construction are likely to add another 51 BCM. Further 108 BCM is expected to be contributed by the projects under consideration. Storages held in these dams are an insurance against the vagaries of nature.

7.2 Development in Irrigation Sector

The total investment in irrigation sector during the period 1951 to 2012 is of the order of Rs.16000 billion. As a result of this, irrigation potential created by the end of Eleventh Five-Year Plan has gone upto approximately 110 m.ha. against 22.6 m.ha. in 1951. The ultimate irrigation potential is 140 m.ha (58.50 m.ha. by major and medium irrigation projects, 17.40 m.ha. by minor surface water schemes and 64.10 mha. by groundwater schemes). It is estimated that the expansion of irrigation systems alone has contributed to about 60 percent increase in food grains production. As a result the country today is not only self-sufficient, but in a position to export the food grains. The phenomenal development of water resources coupled with introduction of HYV seeds have propelled India from deficit food production at the time of independence to a country which now commands a sizeable share in the World Agriculture Scenario. India’s success story in the agricultural sector largely owes to the number of major, medium and ERM projects accomplished/initiated during the successive plan periods as shown in the Table below.

 

 

Irrigation through groundwater has been achieved, mainly through construction of 9.2 million dug wells and 9.1 million shallow tube wells.

7.3 Domestic Sector - Urban and Rural Water Supply

About 92% of urban population has been covered by safe drinking water. Drinking water requirement of most of mega cities are met from reservoir of irrigation or multi-purpose schemes existing nearby and even by long distance transfer. The rural habitations have been provided access to the safe drinking water from nearly 3 million hand pumps and stand posts and about 0.11million mini and regional piped water supply schemes. More than 85 percent of rural water supply is groundwater based and consumes about 5 percent of the total annual replenishable groundwater.

7.4 Hydropower Development

Only 24 % of the hydropower potential of the country has been harnessed so far and 8% is under various stages of development. The total potential harnessed/under harnessing would thus be about 49,000 MW. The share of hydropower in the overall energy mix has been declining over the years. Against an ideal hydroelectric-thermal mix of 40: 60 it presently stands at 24:76.

In sharp contrast to what we have achieved in hydropower development, the continents of North America, Europe and Oceania have developed sizeable percentage of their respective practicable hydropower. India, even lags behind the world average.

7.5 Industrial & Other Uses

Water requirement for industries in India, is quite small compared to the quantity of water needed in agriculture. Only about 3 to 4 percent of present water use is for industrial purposes. However, when industrial demand is concentrated in specific locations, heavy point loads are created on available water resources. There are no fixed norms for water demand for industries but rather a range of values determined by the technology used, selection of plant and process, practice in providing maximum recycling to reduce demand and pollution. The requirement of water for other uses such as navigation, ecological recreation, etc., though not so significant in terms of consumptive use, will continue to be important and will have specific quantity and temporal needs.

7.6 Projected Water Demand

The present water utilization and the probable trend for future water requirement for various sectors, as assessed is shown below in the table below:

 

 

8.0 ISSUES AND CHALLENGES IN THE WATER RESOURCES DEVELOPMENT AND MANAGEMENT

The pressure on our water & land resources is continuously increasing with the rise in population, urbanization and industrialization. Consequently, a number of issues have cropped up in water sector which call for timely and effective redressal. Some of these issues are being briefly brought out below:

8.1 Spatial and Temporal variation in water availability

The spatial unevenness and temporal variation in precipitation has led to complex situations like the distinctly different monsoon and non-monsoon seasons, the high and low rainfall areas and the drought-flood-drought syndrome.

8.2 Declining per capita water availability

The declining per capita water availability is a cause of serious concern. Though from the point- of-view of the National level scenario, India may be above the Internationally accepted standards of water scarcity, yet the figures at the basin level vary widely from 13636 cu.m per year in Brahmaputra-Barak basin to 298 cu.m per year in Sabarmati basin. The situation is projected to get even more serious in 2050 when, about 22% of the area and 17% of the population in the country may be under absolute scarcity condition.

8.3 Rising multi-sectoral water demand for food production, energy generation etc.

The signal of the dwindling gap between availability and water demand is evident from the projections made for the coming decades. The projections clearly indicate that in 2050, the water demand may be significantly higher in comparison to the utilisable water resources of the country. Judiciously catering to this ever increasing multi-sectoral water requirement will be the most stringent challenge in the days ahead.

8.4 Reducing trend of Budget outlay for Irrigation sector

Declining budgetary allocation to irrigation sector in successive plan periods has resulted in the slow progress in completion of projects and delayed accrual of benefits. The States need to give higher priority to the irrigation sector and provide increased budget allocation.

8.5 Inequitable water distribution

Inequitable distribution of water among the head and the tail reaches of the command area has led to problems in bridging the gap between irrigation potential created & utilized as well as waterlogging and salinity.

8.6 Low Irrigation Efficiency

The irrigation efficiency in our country is of the order of only 25% to 35% in most irrigation system, with efficiency of 40% to 45% in a few exceptional cases. Some of the prime reasons for low irrigation efficiency are completion of dam/ head works ahead of canals, dilapidated irrigation systems, unlined canal systems, lack of field channels, lack of canal communication network, lack of field drainage, improper field leveling etc.

8.7 Deteriorating Water Quality

Water pollution is a major environmental concern in India. The main sources of water pollution are discharge of domestic sewage and industrial effluents, which contain organic pollutants, chemicals & heavy metals and run-off from land based activities such as agriculture and mining. Non-availability of minimum flow in the rivers has also reduced natural purification capacity of rivers thus increasing pollution.

8.8 Over-exploitation of groundwater resources

Rapid pace of groundwater development has resulted in a number of problems. In many arid and hard rock areas, overdraft and associated water quality problems are increasing. The unscientific development of groundwater in some coastal areas in the country has led to landward movement of seawater fresh water interface resulting in contamination of fresh water aquifers. In addition to problems caused due to human interference, natural factors like occurrence of high content of fluoride, arsenic and iron also affecting the groundwater quality in several parts of the country.

Apart from these there are also governance issues like addressing the growing conflicts amongst the users of various sectors as also different regions, lack of coordination among the agencies involved in water sector; policy issue like shift from project specific planning to integrated approach with basin or sub-basin as a unit; and administrative issues like problems of land acquisition and Environment & Forests clearance of projects.

8.9 Climate Change and Water Resources

Climate change is predicted to have profound impact onto water resources. Temperature drives the hydrological cycle, influencing hydrological processes in a direct or indirect way. A warmer climate may lead to intensification of the hydrological cycle, resulting in higher rates of evaporation and increase of liquid precipitation. These processes, in association with a shifting pattern of precipitation, would affect the spatial and temporal distribution of runoff, soil moisture, and groundwater reserves and increase the frequency of droughts and floods. The future climatic change, though, will have its impact globally but likely to be felt severely in developing countries with agrarian economies, such as India. Surging population, increasing industrialization and associated demands for freshwater, food and energy would be areas of concern in the changing climate. Increase in extreme climatic events is of great consequence owing to the high vulnerability of the region to these changes.

The impacts of climate change are :

1. Climate change makes extreme hydrological events more severe and more frequent at unexpected times.
2. Likely to alter hydrological cycle.
– Change in total amount of precipitation and its magnitude
– Impact on regional water resource affecting river flows water supply
– Change in floods and droughts situation
3. Likely to aggravate water scarcity condition.
4. High risk of Violent conflicts.

9.0 STRATEGIES FOR FACING THE CHALLENGES

There is urgent need for addressing the above-stated issues effectively. Broadly, the approach route for mitigating the issues & challenges can be categorized into three principal heads.

1. Developmental activities to reduce Gap between availability and utilization
2. Management Practices to bridge Gap between creation and utilization of facilities
3. Research & Development to mitigate Gap between demand and availability

It is to be however noted that the proper implementation of all the activities identified under each category is of paramount importance to eradicate or even dilute the looming threats being mounted by those steep challenges. Therefore, cooperation and coordination among all the agencies involved in the water sector is a prerequisite for achieving any success in the future.

9.1 Developmental Activities: Gap between availability and utilization

1. Storages
2. Inter-basin transfers
3. groundwater recharge
4. Watershed development
5. Rainwater Harvesting
6. Pollution Control
7. Desalination of water
8. Etc.

Severe spatial and temporal variations in rainfall prompted that creation of storages be given due priority within the overall plan for water resources development. The successive Five year Plans initiated after independence, therefore laid significant emphasis on creation of storages that resulted in many remarkable achievements. Even after such relentless persuasion to create more storages, till date, the present level of development of the country, in terms of creation of live storages is only just more than 13.5% of the average annual water resources potential of the country.

The level of creation of storages in India is decisively lower compared to some other nations in the world. The per capita storage in the country which is about 207 m3 is way below the storage achieved in many of the countries such as Russia (6103 m3), Australia (4733 m3), Brazil (3145 m3), United States (1964 m3), Turkey (1739 m3), Spain (1410 m3), Mexico (1245 m3), China (1111 m3) and South Africa (753 m3) and there is an urgent need to vigorously pursue the case for creating storages, wherever feasible, given it’s projected rise in population, urbanization & industrialization.

Restoring natural and manmade water bodies such as lakes, tanks, ponds and similar structure that have fallen into disuse is also extremely important. The Ministry of Water Resources has issued Guidelines for restoration of these water bodies. The exploitation of groundwater has been a matter of serious concern particularly in coastal and semi-arid areas causing salinity and depletion of groundwater levels. Systematic development of groundwater therefore needs to be fostered with right earnest.

9.2 Management Practices; to bridge a Gap between Creation and utilization of facilities

1. Efficient water distribution network
2. Equity and demand based management
3. Participatory Water Management
4. Cropping pattern
5. Realistic water rates
6. Waste water treatment
7. Recycle and reuse of waste water
8. Use water efficiently and share fairly
9. Conjunctive use of surface and groundwater
10. Extension, Renovation and Modernisation of old schemes

Improvement in water use efficiency is increasingly perceived to be a very important strategy for mitigating the receding gap between availability and demand. This is even more relevant in case of irrigation sector since a small improvement in the efficiency can lead to considerable saving of water that can be utilized for catering to the demand from other sectors. Different water management practices need to be followed in different sectors depending on their suitability, however, a few of them are discussed below.

9.2.1 Irrigation Sector

At present irrigation sector consumes as much as 83% of available water resources. With the demand from other sectors rising at a faster pace, the availability of water for irrigation would reduce. It is, therefore necessary to improve the performance of existing system. Higher degree of efficiencies in the management of water use in irrigation sector is required to be achieved to sustain production of crops. Some of the management practices that needs to be taken up in right earnest are implementation of restructured CADWM programme in States, participatory irrigation management (PIM), modernisation of irrigation system and performance improvement, rationalization of water rates, benchmarking of irrigation systems, conjunctive use of surface and groundwater, on farm management, etc.

9.2.2 Domestic Sector

There are real and apparent losses in domestic sector. Real loss is the actual loss of water due to leakages in distribution systems, service connections, storage tanks etc. apparent loss comprising of unauthorized use, meter/ record inaccuracies etc., is not a loss in actual sense but needs to be accounted for. Investigations suggest that accounted and unaccounted losses are as high as 50% of the total flow in the distribution system.

Thrust on water conservation in domestic supply sector will have twin benefit of saving of water over and above the saving in cost required for treatment and for supply to far off places. To improve the efficiencies in domestic sector various measures such as water audits, mass awareness programmes, water pricing, proper maintenance and improvement in supply, control on leakages, prevention of unaccounted use of water, etc.. Furthermore water conservation measures like artificial groundwater recharge, rainwater harvesting, public awareness & participation, reuse of water also need to be taken up vigorously.

9.2.3 Industrial & Other sectors

The water requirement of the industries used to be very small compared to other sectoral demands in earlier years. The rapid industrialization has changed the scenario. Most of the industrial production processes require large quantities of water. Adoption of most appropriate technology to ensure efficient use of cooling and process water apart from sound maintenance practices including leakage control is necessary for water conservation. Some of the action points towards water conservation for improving efficiency in industrial sector could be setting up of norms for water budgeting, modernisation of industrial process to reduce water requirement, recycling water for cooling purposes, rational pricing of industrial water to compel adoption of water saving technologies, proper treatment of effluents and use of treated water by industrial units.

Other major consumer of water is energy sector. The water requirements in the power sector are mainly met from the surface water resources. There is need to maintain the water use to the prescribed norms and reduce evaporation losses which would result in efficient water use. Recycling of water in pump storage plants would conserve water and should be encouraged, wherever feasible, for generation of peaking power.

The other miscellaneous water requirements are for recreation, navigation etc., most of which are non-consumptive. Necessity for maintaining minimum flow may arise out of the necessity to maintain water quality, river regime, maintenance of river eco system or other public necessities such as bathing etc. Maintenance of minimum flow in river can also be considered as a water use since it restricts the quality of water that can be diverted for other uses. The quantity will vary according to river regimes.

9.3 Research & Development : to mitigate Gap between demand and availability

1. Advanced Irrigation techniques
2. IT tools for water distribution
3. Development of Modelling Tools
4. Less water consuming gadgets
5. Water saving Technologies
6. Research in desalination & wastewater Treatment
7. Developing water resistant crop varieties
8. Policy Research, Etc.

The finite water availability and the ever rising demand due to rise in population, urbanization, industrialization etc. requires a well-focused Research and Development Programme to gauge the intensity of the problem as well as its remedial measures. Some of the areas where R&D activities could be concentrated are.

1. Development of crops, which require minimum water and can sustain poor quality saline water.
2. Biological control of drainage congestion in waterlogged areas.
3. Improving energy efficiency of water pumps used for irrigation.
4. Technology upgradation like using micro irrigation, micro sprinkler and micro sprayer, bucket kit drip irrigation system for small farm, auto irrigation system etc.

Since, after implementation of all the development as well as management strategies, the total utilizable water resources of the country may not be able to match the water demand by the year 2050 and therefore, exploration of newer concepts for augmenting the available resources is an equally vital area where the country needs to concentrate as a part of the long term strategy. Some of these are recycling & reuse of water, Inter-basin transfer of water, Artificial Recharge of groundwater, Desalination of seawater etc.

9.4 Economic Development and Water Resources Management

One of the main input for economic development is water, India is largely an agrarian economy, moreover, industrial, energy and service sectors are also booming and a profound development are expected in the next few decades. In fact, India is amongst the BRIC block countries, which are going to be the drivers of the world economy. Further, the economic development is possible only if the entire water users sector get sufficient amount of the water required for its activities. The overall total requirement of water is getting exceeded with the total water availability. For sustainable economic development, water demand management will have greater impact on water user sector. Economic Development of India will depend how effectively the water is managed by the various water users. Huge water use efficiency is required in agriculture sector, industry and service sector too need to move on from the mere water user to a sector which comes up with an efficient water saving technologies, addressing the water quality issues, adopting recycling and reuse of water and alternative production processes. Conversely, economic development is going to have larger impact water resources sector in terms of increased demand and water quality.

10.0 NEED FOR WATER CONSERVATION AND MANAGEMENT

It is estimated that with increasing demand from other competing sectors, the availability of water for irrigation sector is likely to reduce progressively to about 75 percent in future. Irrigated agriculture which consumes the major part of the total water being used should be the focus and fore-runner for achieving maximum conservation in its use. Even a marginal improvement in the efficiency of water use in this area will result in the saving of a large volume of water which can be utilized either for extending the irrigated area or for diverting to other beneficial purposes. The inevitable reduction in loss in availability of total water for irrigation sector has to be offset by improvement in irrigation efficiencies. However, improvement in water application efficiencies and productivity levels alone will not be sufficient and it is an imperative to create additional potential and bring more area under irrigation. Therefore, there is urgent need to create more storages for conserving water which is available during monsoon period only, for its use during lean period.

To meet the increased competing demands of various sectors, it is essential to affect economy in industrial use of water. Most of the industrial uses being non-consumptive, recycling and reuse of water plays an important role for economizing water use in industries. For affecting efficient and economical use of water, the tariff rates have to be such as to compel the industry to look. into technological interventions leading to reduced use per unit production of waste water. Some of the important issues pertaining to water conservation are incorporation of alternate production processes and technologies for reducing water use, recycling and reuse of water, ensuring sound plant maintenance practices and minimizing spills and leaks and appropriate pricing of water.

This scenario of rising competing demands for various sectors and mismatch of water availability and demand highlights the need for conservation of water. Water conservation has three dimensions:

i. Water resources conservation- efficient management of available water through proper storage, equitable allocation and transfer to scarcity areas for use. Preservation of the quality of the resource including ecosystem conservation.
ii. Water use conservation -water supply and distribution with minimum losses and consumption through prevention of wastage.
iii. Efficient use of water through adoption of water saving technologies and cropping patterns.

To achieve the objective of conservation of water in the agricultural and industrial sectors focus of attention will have to be on-augmentation and creation of additional resources, performance improvement of existing systems, coordination amongst various agencies, provision of adequate funds for creation of additional resources and conservation measures, ensuring users' participation, giving impetus for Benchmarking of irrigation system, creating mass awareness for better management of availability and demand and environment protection. Strategies will need to focus on augmentations and optimum utilization without sacrificing on quality with people's participation.

11.0 CONCLUSION

Water resource development is to be seen not merely as a single-sector-end objective, but as a prime mover in developing larger systems with multiple linkages. This calls for a well set out multi-disciplinary agenda covering not only technological issues but also issues of social, economic, legal and environmental concerns. Therefore the planning, development and management of water resources has to be taken up in an integrated manner for addressing the concerns facing the water sector. This integration has to be a multi-disciplinary approach which would take care of all the conflicting issues and deliver solutions that would be technically feasible, economically viable, socially acceptable and ecologically & environmentally sound. Water use, in turn, has its impact on water quality and therefore utilization of water has to be so managed as not to contribute to the deterioration of water quality that may seriously jeopardize its future availability.