Short essay on Water Management (India)

These spatial and temporal variations in water resources availability pose great challenges for storing and regulating the use of the water resources in the country. There is a wide gap between the potential created and the utilization, i.e., more than 10 M ha at any point of time.

At present, the need of the hour is not only the development of water resources, but also their efficient management in a sustainable manner. The approach of integrated water management to meet the demand of water for agricultural use, drinking and industrial needs, were discussed below:

1. Interlinking of rivers

It was Sir Arthur Cotton who conceived the idea of networking of rivers two centuries ago. But, the idea of interlinking rivers was revived few decades ago independently by M.Visveswarayya, K.L.Rao and D.T. Dastur.

Three years back, in response to the order of Supreme Court of India to complete this mega project costing about 5.6 lakhs crore, the then government appointed task force of scientists, engineers, economists, biologists and policy makers to make a detailed project report.

The following major benefits may accrue to the country with the completion of massive project.

1. Nearly 35 mha of agricultural land can be brought under irrigation additionally using 173 BCM of additional water created thus food security.

2. Raise in ultimate irrigation potential from 113 million ha to 148.150 million ha.

3. Transfer of water from surplus to deficit areas thus flood and drought problems may be mitigated.

4. Production of 34 giga watts of inexpensive and eco-friendly hydropower may be expected.

2. Inter basin transfer

This project was formulated by National Water Development Agency (NWDA). As per the plan, the project is divided in to two broad components.

1. Himalayan component with 14 river links.

2. The peninsular component with 16 river links.

It is planned to transfer 141 km³/yr through peninsular India and 33 km³/yr Himalayan links essentially for redistribution in the Ganga basin and to Western India.

Only small volume of water can be transferred from the Brahmaputra basin. Thus in totality 1660 km³/yr of development water resource can be created which can take care of any exigencies.

3. Methods of water harvesting and groundwater recharge

“The ways of collecting the drops of Palar, i.e., of rainfall, are as unending as the names of clouds and drops. The pot like the ocean is filled up drop by drop.”

(a) Rooftop rainwater harvesting

In this method, the rain from rooftop is fed into tank through a pipe for meeting domestic needs. The building should be designed for this purpose and rooftop should be clean and free from dusty pesticides or corrosive materials etc.

The water should go through a pipe into a community sump tank, which should be purified before supply. Harvesting of rooftop rainwater could meet over 60 per cent of domestic water needs. The potential for rooftop rainwater harvesting has been estimated to be 1 km³/yr.

(b) Water harvesting

It is the collection and storage of rainfall runoff from any catchment or watershed followed by subsequent use. Rainwater harvesting in a given area depends on topography, soil type, depth and slope and vegetative cover etc.

It largely depends on quantity and distribution of rainfall and will therefore, be more successful in areas where rainfall is sufficient. Recharge of groundwater, which is concept of rainwater harvesting, utilizes the structures like pits, trenches, dug wells, recharge wells/shafts, bore wells, check dams and percolation tanks. The water thus harvested through rainwater harvesting can be used for the following purposes:

(i) Used primarily for supplemental irrigation during stress periods of crop growth or when there is a long gap between two rainfall events or to meet any other aberrations during monsoon period allows drought proofing.

(ii) In the states like Punjab, Haryana, Himachal Pradesh and Eastern region, more than 200 water-harvesting dams were already constructed. The harvested rainwater is conveyed to agricultural fields through underground pipelines by gravity, thus there is no need of electric or diesel engines.

(iii) It is an ideal solution of solving water problem in areas having inadequate water resources. Centre for Science and Environment (CSE) estimated that even if half of the average annual rainfall of 1190 mm is captured on 1.12 ha of land in each of the country’s 5,87,226 villages, 6.57 million liters of rainwater thus collected in each village can meet the annual cooking and drinking needs of average population of 1200 per village.

(iv) Harvested rainwater plays a greater role in sustaining surface water supplies on one hand and recharges aquifers on the other. It prevents the soil erosion.

(c) Watershed management

Watershed is a natural geo-hydrological unit. It is an area of land and water bounded by a drainage divide within which the surface runoff collects and flows out of the area through a single outlet into a river or other body of water. It must make drought proof the rural landscape by capturing each falling raindrop and save the crop, human beings and animals.

4. Recycling and Reuse of Municipal and Industrial waste water

‘Recycling’ means internal use of water by the original user prior to discharge. While ‘Reuse’ refers to wastewater that discharges from municipalities (75 per cent), industries and irrigation are withdrawn by users other than dischargers. After treatment, reclaimed waters are diverted for irrigation. It is clearly evident in big cities like Delhi where the water scarcity is acute; the municipal sewage water is utilized for irrigating vegetable crops. In Tamilnadu, industrial wastewater is being used for irrigating sugarcane crop.

Water used for domestic purposes (washing, cleaning and bathing etc.) should be collected, cleaned and recycled for non-drinking domestic and industrial purposes. Nearby holy places and temple towns, the water that is used for bathing and washing in tanks and ponds should be channelized towards agricultural fields in adjacent areas (e.g., Mahanadi in Kumool district of Andhra Pradesh). In Israel, water is used 4 to 5 times before it is let off to nature while, it is only once in India.

As of now, 75 per cent of drinking water is used for non-drinking purposes. It is proposed to supply potable water and non-drinking water separately to ease pressure on drinking water supply. Besides, water for non-drinking needs could be met by recycling domestic wastewater.

5. Improving Water Use Efficiency through better technology

Agriculture sector consumes more than 85 per cent of total water in the country. If we are able to save 7 per cent of it, we will be able to meet domestic and industrial demand. Hence it is imperative to adapt less water consuming or water saving methods of irrigations with an aim of producing more crops per drop (WUE).

Such methods include micro irrigation (drip, sprinkler, bubbler, spray and indigenous drip irrigation) methods. By using these methods, two to three times more area can be brought under irrigation with same quantity of water besides improving crop quality and doubling the productivity.

At the same time, increasing salinity and alkalinity problems of irrigation water in coastal areas can be mitigated by using drip irrigation without any adverse effect on crop growth and productivity.

Furrow or alternate furrow method of irrigation for wide spaced crops like sugarcane, tomato, maize and tobacco will save nearly 30 per cent of water use besides reducing crust problem. Basin method of irrigation rather than flooding should be followed for irrigating horticultural crops.

Rice is the most water-consuming crop and 40 per cent of the irrigation water available is used for this crop. Nearly 60 per cent of water applied to rice is lost by deep percolation.

This can be substantially reduced by improved pudding through power tillers with cage wheels. As adopted in China and experimentally proved at many places in India, alternate wetting and drying rather than continuous submergence would reduce water requirement by 30 to 50 per cent.

The very recent popular method of cultivation of rice under System of Rice Intensification (SRI) saves nearly half the quantity of water compared to traditional submerged rice besides saving other inputs including seed, fertilizer and pesticide. Zero titled direct seeded rice in heavy soils saves nearly 35 per cent water against puddle transplanted rice.

This is true even with zero tilled wheat crops, which is becoming very popular in the areas where rice-wheat cropping system is dominant. On the other hand, rice grown under furrow irrigated raised bed system (FIRBS) was found to save water up to 30 per cent.

In water scarce dry farming areas, peasants should be advised to shift from rice to irrigable dry crops like high value pulses and oilseeds based on ecological conditions and market demand. Swaminathan suggested replacement of double paddy crop by one HYV Paddy followed by cotton as second crop. This system helps to maintain overall productivity and profitability and also saves enormous quantity of water.

It also avoids salinity and water logging. Easy to follow and farmer friendly scientific scheduling of irrigation based on critical stage of crop growth, field modification technique, high seed rate and feel and appearance method should be followed for regulating water use and avoiding water logging problems.

Proper leveling of agricultural fields also help in avoiding water logging thus saves water. Scientists should breed HYVs, which are less water consuming, and drought resistant and such seeds should be made available for large section of farming community.

6. Reducing seepage losses and de-silting of tanks

Poor maintenance of water bodies encourages water loss through seepage resulting in low water use efficiency of 25-40 per cent against the target of 65 per cent. Hence, proper lining of water retaining structures should be taken up.

Simply constructing dams across rivers for storing water for subsequent use is not enough, periodical maintenance is also necessary.

The main problem that most of them face is silting. Neglect of desalted dams and tanks will drastically reduce their storage capacity. A review of siltation across the country reveals the pitiable condition of these water-storing structures.

This is the common problem in most of the Indian dams and canals because of which tail end farmers are not receiving water following reduction in storage capacity. Hence steps should be initiated to desalt these Temples of Modern India.

The canal banks and field channels should be provided with cement lining to prevent leakage and seepage, which account for about 30 per cent loss of water. If these measures are initiated, water could be put to better use in all four irrigation systems in India.

7. Arrest over exploitation of ground water and rationalized water rates

Few states are providing electricity free of cost to farming community. Even where it is not free, the charge for electricity is a fraction of the average cost, not based on metered use. No or under pricing led to over exploitation of groundwater and subsequently serious depletion of water table in many parts of the country.

This also leads to inequitable of water between head and tail end areas and big and small farmers. Besides, bore wells have created more havoc. With the mushrooming of bore wells, open wells dried up.

Sometimes, they are dug beyond 500 ft, which affect water structures/aquifers, erode perennial character of streams and reduce surface moisture content. So, banning of bore wells should be given serious thought. In order to reduce wastage, metered water pricing also should be implemented just like in metros (Delhi).

8. Avoid all forms of pollution

Industries based on chemicals, fertilizers, garments, skins, leather, textile, liquor, soft drinks, paper, jute, steels, alloys and coal release hot water, coloured water and waste material into near­by surface water bodies like rivers, lakes, ponds, tanks and wetlands thus making them unproductive and non-potable. Such waters will become unfit for further use even after treatment. For instance:

1. The great rivers like the Ganga, the Godavari, the Cauvery and the Yamuna have become polluted to a large extent.

2. Many of the wetlands across the country have been under threat.

3. Industries in Delhi release millions of gallons of waste, polluted and coloured water into sacred river, the Yamuna converting into sewage drain.

These can be avoided only when there is political will through formulation and imposition of strict regulations for release of effluents and waste into water.

It should be made compulsory for all industries to have their own treatment plants and release effluents only after proper treatment. At the same time, concerned authority should be empowered to take severe action against those going against rules and regulations. Effective implementation of Ganga and Yamuna Action Plans will help in cleaning of these sacred water bodies.

9. Revise Warabandi system

This in its present form failed to fulfill the objective of equitable distribution of water due to non-consideration of seepage losses between head and tail end of water courses. For this, the warabandi has to be revised by considering actual discharge, after accounting for seepage losses.

In order to compensate for the seepage losses in the water courses, the allocation time to tail end farmers is increased and to keep the same the volume of water allocation per unit area, the allocation time to head end farmers is decreased (Mandal et. al. 2004).

10. Deficiencies Allowed by Management

This is known as Deficiencies Allowed by Management (DAM). Generally, whenever there is inadequate water stored in tanks and reservoirs in a bad rainy year, usual practice is to limit the command area.

The better method would be adopt ‘DAM’ concept and irrigate the total command area. This involves supply of reduced amount of water during non-critical stage of crop growth and supply full requirement of water during the critical flowering and yield formation periods.

In this method, yield on individual field may be less by 5-10 per cent but overall production in the command area will be more by 50 per cent (Hanumantha Rao, 2001).

11. Participatory irrigation management

Despite massive expenditure on canal irrigation over the years, the water distribution remained inequitable and inefficient. Recognizing the need for decentralized irrigation management, the first national Water Policy (1987) called for farmers’ participation in irrigation management.