Watershed Hydrology

Lesson 2 Fresh Water and its Management in India

2.1. Freshwater Related Problems in India

To safeguard the economic and social prosperity of the country, it is imperative that enough freshwater is available to meet the requirements of agriculture, industries, and the domestic sector in the coming years. Unfortunately, inadequate water planning, lack of water awareness and non-implementation of desired measures, have created a difficult-to-manage situation. As a result an alarming scenario of freshwater scarcity is gradually unfolding in India. The water scarcity is already evident in many parts of India, varying in scale and intensity at different times of the year. This situation is the result of natural factors and human actions. Intense competition among water users – agriculture, industry and domestic sector – is pushing the groundwater table deeper and deeper. Widespread pollution of surface water and groundwater is degrading the quality of freshwater resources.

 

The major issues related to freshwater problems in India are elaborated in the subsequent sections.

 

2.1.1    Uneven Distribution of Water Availability

Water availability in India has large variations– both spatial and temporal. The basin wise per-capita water availability varies between 13,393m³/year for Brahmaputra-Barak basin to about300m³/year for Sabarmati basin. As per the international norms, if water availability is less than 1700m³ per capita/year thenthe country is categorized as water stressed and if is less than1000m³ per capita/year then the country is classified as waterscarce. Growing water scarcity in India can be gauged from thefact that the available water per capita per year has decreasedfrom 6008m³ in 1947 to 2384m³ in 2000. Although India isabove the water stressed category, the real situation of per capitawater availability is more disturbing than what is depicted by theaverage figures.India receives nearly 75–80% of annualprecipitation during the four monsoon months. Of the remainingamount, a large fraction is received during the winter monsoon.Further, out of 8760 hours in a year, most of the precipitation isreceived in about 100 hours. Instances where 10% of annual rainfalls in just 3 hours are not uncommon. Such a high concentrationof precipitation and streamflows makes it imperative to regulaterivers. Moreover, the uneven distribution of rainfall across thecountry at different times of the year makes several parts of India fall under the water stressed, water scarcity and absolute water scarcity category, as shown in Fig. 2.1.

Fig.2.1.Water availability in Indian river basins. (Source: Chitale, 1992)

 

2.1.2    Water Pollution

Water pollution is acquiring serious dimensions in India as almost 70% of its surface water resources and a large proportion of groundwater reserves are already contaminated by biological, toxic organic and inorganic pollutants. Degradation of quality in turn leads towater scarcity as it limitswater availability for human use. Sources of water pollution are diverse: untreated sewage, industrial discharges, leaching from municipal waste, and drainage from the residues of agricultural fertilizers and pesticides. With burgeoning cities and increasing industrialization, the quantum of waste dumped into rivers has also increased.Water pollution varies in severity from one region to the other depending on the density of urban development, agricultural and industrial practices, and the systems for collecting and treating wastewater. Most of the polluted stretches exist in and around large urban areas.

 

Some of the agricultural, industrial and domestic sources of water pollution are described below.

a)    Agriculture:  The indiscriminate use of agro-chemicals has contributed significantly to the pollution of both surface water and groundwater resources. The consumption of pesticides, which rose from less than 1 million tonnes in 1948 to 66.36 million tonnes during 1994–95, was around 43.59 million tonnes during 2001–02. Some of the chemicals in these fertilizers and pesticides, which enter water bodies through runoff and leaching, are considered hazardous by the World Health Organization (WHO). Water quality studies on the Ganga River indicate the presence of chemicals such as HCH, DDT, dimethoate, endosulfan and malathion in quantities exceeding standards set by international organizations. Severe soil erosion and water quality degradation (in the form of increase in sediment load) due to improper land management practices are particularly noticeable in the mountainous regions in northern and western India.

b)    Industry: Although the industrial sector accounts for about 4% of the annual water withdrawals, its contribution to water pollution, particularly in urban areas, is significant. Wastewater generation from this sector has been estimated at 55,000 million m³ per day, out of which 68.5 million m³ is discharged into river streams. Of the total pollution load, 40%–45% is contributed by the processing of industrial chemicals, while nearly 40% of the total organic pollution, expressed as BOD, arises from the food industries followed by industrial chemicals and the pulp and paper industry.

c)     Domestic: The domestic sector is responsible for majority of the wastewater generation in India. About 50 millionm³ of untreated sewage discharged into rivers have contributed towards pollution of India’s fourteen major river systems. The 22 largest cities in the country produce over 7300 million litres of domestic wastewater per day and only about 80% of it is collected for treatment. Inadequate treatment of human and animal wastes adds to the high incidence ofwater-related diseases.

 

2.1.3    Excessive Groundwater Exploitation

Large-scale extraction of groundwater has lead to overdraft and a drastic fall in water table in some basins. This in turn has created a chaotic situation especially in the water scarce hard-rock regions of southern India, where assured sources of surface irrigation are rare and rainfall is non-uniform. Currently, about 32% of the annual utilizable groundwater potential of 432 km³ is actually exploited, and only 8% of the groundwater sources have been exploited above 85% of their potential. However, in states like Punjab, Rajasthan and Tamil Nadu, large areas fall under the dark category. Table 2.1 shows the ten states where the percentage of dark areas has increased considerably between 1984–85 and 1997–98. In coastal regions, e.g., in Tamil Nadu and Gujarat, regional decline in water table has resulted in saltwater encroachment in the aquifer systems. Groundwater sources have been classified in three categories depending upon the extent of exploitation. In the 1st category (termed ‘white’), the level of exploitation is below 65% of the annual utilizable potential. The 2nd category (termed ‘gray’) includes areas and sources in the range of 65% to 85% exploitation levels and the third and the worst category (termed ‘dark’) has the level of exploitation exceeding 85%.

Table 2.1.Blocks with intensive exploitation of groundwater

(Source: Chaddha, 2002)

State	Number of dark blocks
	1984-1985	1992-1993	1997-1998
Andhra Pradesh	0	30	26
Bihar	14	1	11
Gujarat	6	26	28
Haryana	31	51	41
Karnataka	3	18	16
Madhya Pradesh	0	3	3
Punjab	64	70	83
Rajasthan	21	56	94
Tamil Nadu	61	97	103
Uttar Pradesh	53	31	40
Total	253	383	445

2.1.4    Threat to Biodiversity and Wetlands

About 6.5% and 12.5% of the world’s animal and plant species, respectively, can be found in India. Out of these almost 7,000 are endemic to the subcontinent. Unfortunately, habitat destruction in both freshwater and coastal areas has endangered many endemic species. Most vulnerable are the freshwater fish since they are more susceptible to water pollution and environmental change. Other endangered species include freshwater aquatic animals like the Gangetic dolphin and several species of aquatic birds, amphibians, reptiles and insects. Wetlands in India cover a land area of about 4.1 million hectares. Most of these have become degraded due to pollution and development pressures, like conversion of wetlands for agriculture. This is threatening not only the local fauna but also the livelihood of the residents dependent on the wetland ecosystem. In coastal areas, industrial and domestic pollution has severely degraded estuarine and coastal environments.

To summarize, the root causes of the freshwater crisis inIndia are:

1. Rampant pollution of freshwater resources mainly by the agricultural, industrial and municipal activities.
   1. Inadequate attention to water conservation, efficiency in water use, water re-use, groundwater recharge, and ecosystem sustainability.
   2. Very low water prices which do not discourage wastage.
   3. Prevalent system ofwater rights which gives unlimited ownership of groundwater to the landowner, despite the fact that groundwater is a shared resource from common pool aquifers.
   4. Uncontrolled use of the bore-wells that has allowed extraction of groundwater at very high rates, often exceeding recharge.
   5. Communities are not partners in managing water resources.

 

2.2 Strategies for Freshwater Management in India

As per the National Water Policy (2002) of the Government of India, water allocation priorities in the planning and operation of systems should broadly be:

1. drinking water,
2. irrigation,
3. hydropower,
4. ecology,
5. agro-industries
6. non-agricultural industries and
7. navigation

In view of the current status of freshwater in India and the problems that are likely to arise in future, a well-planned long-term strategy is needed for sustainable water resources management in India. Some key aspects of such a strategy are proposed next.

 

2.2.1    Water Conservation

Broadly speaking, water conservation implies improving the availability of water through augmentation by means of storage of water in surface reservoirs, tanks, soil, and groundwater zone. It emphasizes the need to modify the space and time availability ofwater to meet the demands. This concept also highlights the need for judicious use of water. If one looks at utilizable water resources in major river basins, these resources in Indus, Ganga, Brahmaputra, and Godavari basins are 73.31, 525.02, 629.05 and 110.54 km³ per year, respectively.The storages available in these basins, including projects under construction, are 16.28, 54, 3.5, and 30.16 km³. Thus, only a small fraction of available water is being regulated in these basins at present. These basins are subject to frequent flooding, making the argument of storage even stronger. Overall, out of 690 km³ of utilizable surface water, storage capacity created so far is only 177 km³, ongoing projects will add another 70 km³and those under planning 132 km³. Thus, even after completing the planned projects, 45% of the potential will remain unutilized. In viewof rapidly rising population and demands forwater, it will be necessary to conserve adequate quantity of water for later use.

 

No matter how freshwater is used – whether for agriculture, industry, or domestic purposes – there is a great potential for better conservation and management. On the demand side, a variety of economic, administrative and community-based measures can help conserve water. Side-by-side, it is necessary to control thegrowth of population since large population is putting massive stress on all natural resources. Since agriculture accounts for about 83% of all water withdrawn, the greatest potential for conservation lies in increasingirrigation efficiencies.

 

In urban water supply, for example, almost 30% of the water is wasted due to leakage and other losses, while most metro cities face deficit in supply of water. It is, therefore, imperative to prevent wastage.

 

2.2.2 Watershed Management

Watershed management aims to establish aworkable and efficient framework for the integrated use, regulation and development of land and water resources in a watershed for socio-economicgrowth. Typical objectives of watershed development programsinclude:

a)    Raising the productivity of rain-fed agriculture and non-arable lands

b)    Encouraging the sustainable management and optimal useof surface and groundwater,

c)     Reducing soil erosion,

d)    Conserving forests and other natural vegetation,

e)     Creating employment (both directly and indirectly), and

f)      Promoting increased individual and collective responsibility for natural resources management and strengthening the social institutions.

 

2.2.3 Water Quality Conservation and Environment Restoration

To preserve our water and environment, we need to make systematic changes in the way we grow our food, manufacture the goods, and dispose off the waste.

a)    Water quality: In India, agriculture is the biggest user and polluter of water. If pollution by agriculture is reduced, it would improve water quality and would also eliminate cost incurred for treatment of diseases. This would entail learning how to use less chemicals while boosting yields, e.g., eliminating use of fungicides by planting more diverse varieties of grains and switching to organic farming so that fewer chemicals are introduced on farms. Industries need to carefully treat their waste discharges. Manufacturers may reduce water pollution by reusing materials and chemicals and switching over to less toxic alternatives. Industrial symbiosis, in which the unusable wastes from one product/firm become the input for another, is an attractive solution.

b)    Environment Restoration: Environmental improvement and restoration should be planned and implemented such that the freshwater resources are protected and their quality is maintained. Model efforts in this direction include the capture, storage and safe release of water and the prevention of accelerated soil erosion through hydraulic structures and vegetation. While utilizing water and land resources, their ability to serve other uses is often degraded either inadvertently or due to carelessness. Efforts should be made to restore landscapes and ecosystems to more efficiently protect water quality, aquatic andwildlife. On the legislative front, we require laws to check litteringas well as to implement “polluter pays” principle.

 

2.2.4    Inter-basin Water Transfer (IBWT)

The vast variation, both in space and time, in the availability of water in different regions of India has created a food-drought flood syndrome with some areas suffering from flood damages and other areas facing acute water shortage. The drought prone area assessed in the country is of the order of 51.12 million hectare, while the area susceptible to floods is around 40 million hectares. The States of Karnataka, Tamil Nadu, Rajasthan, Gujarat, Andhra Pradesh and Maharashtra are the worst drought prone States. The States of Uttar Pradesh, Bihar, West Bengal, Orissa and Assam face severe flood problems. Inter basin transfer of water in India is a long-term option to partly overcome the spatial and temporal imbalance of availability and demand of water resources. The transfer of water from surplus areas to deficit areas is not a new concept. Many such schemes have been implemented all over theworld. In India too, projects like Periyar –Vaigai system, Indira Gandhi canal, and Telugu Ganga stand as classic examples of inter-basin water transfer. In the seventies, the Garland Canal proposal of Captain Dastur and the Ganga – Cauvery Canal proposal of Rao (1973) were received with considerable attention. A National Perspective Plan (NPP) for water resources development was formulated by the Government of India in 1980s. The distinctive feature of the NPP is that the transfer of water is essentially by gravity and only in small reaches by lift pumping (not exceeding 120 m). This plan comprises of two components:

1. Himalayan Rivers Development, and
   2.Peninsular Rivers Development

 

While the second component will be an inter-state venture, the first will involve neighbouring countries too and thus will be an international venture. Some of the major benefits expected from inter linking of the rivers are:

1. Irrigation potential is to increase from 140 to 175 million ha,
   1. Drinking water availability is to increase by about 12 km3,
   2. Peak flood discharge to get reduced by about 30% due to construction of reservoirs,
   3. Generation of 34000MW of electricity, and
   4. Possibilities of inland navigation to provide cheap transport.

 

While planning interbasin transfer of water, it may be noted that water has to be shared in two ways:

1. between its different uses (energy, cities, food production, environment, etc.), and
2. between users (administrative blocks or states sharing a river basin or aquifer).

Many regions and cities rely on upstream users for water flow and any downstream user will be dependent on the action of the upstream users. Measures used to allocate water between competing uses may include:national strategy and/or legislation on inter-sectoral allocations, tariff disincentives and targeted subsidies, abstraction management, application and enforcement of water-quality objectives, reservoir operating rules, multi-use reservoir management, multi-reservoir system management and reservoir compensation flow releases (UN, 2003). A diagram depicting how IBWT will lead to increased utilization of water resources is shown in Fig. 2.2.

Fig.2.2. Diagram showing the effect of IBWT on utilization (Curve for the future depict expected scenario) of water resources. (Source: Thatte,2003)

 

2.2.5 Groundwater Management

To protect the aquifers from overexploitation, an effective groundwater management policy oriented towards promotion of efficiency, equity, and sustainability is required. The exploitation of groundwater resources should be regulated so as not to exceed the recharging possibilities, as well as to ensure social equity. Integrated and coordinated development of surface water and groundwater resources and their conjunctive use should be envisaged right from the project planning stage and should form an integral part of the project implementation. Over exploitation of groundwater should be avoided, especially near the coasts to prevent ingress of seawater into freshwater aquifers.

 

The government can initiate a variety of programs and controls for recharge and discharge and implement regulatory measures such as well spacing norms, control drilling of new wells by issuing permits, regulation of water intensive crops, and pricing of electricity for lifting groundwater. To the extent possible, conjunctive use of surface water and groundwater should form an integral part of groundwater management policy. In critically overexploited areas, bore-well drilling should be regulated till the water table attains the desired elevation. Artificial recharge measures need to be urgently implemented in these areas. Amongst the various recharge techniques, percolation tanks are least expensive in terms of initial construction costs. Many such tanks already exist but a vast majority of these structures have silted up. In such cases, cleaning of the bed of the tanks will make them reusable.

 

2.2.6    Rainwater Harvesting

Rainwater harvesting is the process to capture and store rainfall for its efficient utilization and conservation to control its runoff, evaporation and seepage. Some of the benefits of rainwater harvesting are:

1. It increases water availability,
2. It checks the declining water table,
3. It is environmentally friendly,
   1. It improves the quality of groundwater through dilution, mainly of fluoride, nitrate, and salinity, and
   2. It prevents soil erosion and flooding, especially in the urban areas.

 

2.2.7    Recycle and Reuse of Water

Another way through which we can improve freshwater availability is by recycle and reuse of water. Use of water of lesser quality, such as reclaimed wastewater, for cooling and fire fighting is an attractive option for large and complex industries to reduce their water costs, increase production and decrease the consumption of energy. This conserves better quality waters for potable uses. Currently, recycling of water is not practiced on a large scale in India and there is considerable scope and incentive to use this alternative.

 

2.2.8    Desalination of Water

Since 1970, there has been significant commercial development using various desalination technologies, including distillation, reverse osmosis, and electrolysis. This technology is suitable for use in areas where freshwater is scarce, but saline water is available and energy is cheap. Compared to water recycling technologies, desalination presents fewer health risks.

 

2.2.9    Environmental Flow Requirement (EFR)

An environmental flow (EFR) is the water regime provided within a river, wetland or coastal zone to maintain ecosystem and their benefits where there are competing water uses and where flows are regulated. Environmental flows normally include the flow requirements in rivers and estuaries for maintenance of riverine ecology.

 

2.2.10  Dealing with Climate Change

Climate change is likely to result in hydrologic conditions and extremes of a nature that will be different from those for which the existing projects were designed. Some recommendations to cope up with the problems in a systematic and a planned manner are:

1. A nationwide climate monitoring program should be developed;
2. While formulating new projects that influence climate, it should be ensured that no action is taken which causes irreversible harmful impact on the climate;
3. Improved methods for accounting of climate related uncertainty should be developed and made part of decision making process;
4. Existing systems should be examined to determine how they will perform under the climate situations that are likely to arise;
5. Water availability and demands in all regions, particularly in water scarce regions should be reassessed in the new climate scenario;
6. Are-examination of the operating rules should be taken up to see how these need to be updated to handle likely extremes.

 References

• Jain, S.K., Sharma, A. and Kumar, R. (2004).“ Freshwater and its management in India.” Intl. J. River Basin Management Vol. 2, No. 3, pp. 1–12.

• Chitale, M.A. (1992). Population and water resources of India.Umesh Communications, Pune, 452 pp.

• Thatte, C.D. (2003). ICID-CPSP: Indian National Consultation, International Commission on Irrigation and Drainage, New Delhi.

• Chaddha, D.K. (2002). State of art of artificial recharge applied in village level schemes in India – Country Report. In: Proc. Seminar on Management of Aquifer Recharge and Sub-surface Storage – Making Better Use of Our Largest Reservoir(Wageningen, Dec. 2002). NNC-IAH Publ. No. 4, pp. 19–24.

Suggested Reading

• Water Management Forum (2003). Inter-basin transfer of water in India – prospects and problems.WaterManagement Forum. The Institution of  Engineers (India), New Delhi.

• IWRS (1996). Theme paper on “Inter Basin Transfers of Water for National Development – Problems and Prospects.” Indian Water Resources Society, Roorkee.