Prof.T.Shivaji Rao,

Director, Centre for Environmental Studies,

Gitam University,Visakhapatnam-530 045 

{Why it is a common practice for Government Experts to oppose cloud seeding that promotes people's prosperity ..?)



The earth’s atmosphere, which works as a giant heat-engine, uses energy from the sun to drive winds and uplift water vapor from the ocean surfaces, forests and natural water courses to deposit in clouds that produce rain.  Almost all the solar energy that is absorbed at the earth’s surface enters the lowest layers of the atmosphere as sensible heat or as latent heat associated with the evaporation of water.  Vast solar energy is stored for a time as latent heat of vaporization.  It will be released later when the vapor condenses into clouds. Hurricanes and thunder-storms are powered by the release of latent heat of vaporization.  However, the energy of the wind is mainly derived from the differential heating of the different parts of the earth’s surface.  Since clouds account for most of the atmospheric water that reaches the earth, cloud modification has become a matter of great practical importance.

Cloud droplets form in the atmosphere by condensing on existing particles (heterogeneous nucleation) rather than aggregation of water molecules from the vapour state to form pure water droplets (homogeneous nucleation). The particles of smoke, dust etc.,  involved are known as “cloud condensation nuclei” (CCN). Populations of CCN fluctuate with time and location and influence the micro-physical characteristics that impact the conversion of cloud-droplets to rain drops. The solid particles placed in a supersaturated solution to promote the precipitation of the dissolved solute (or in a super cooled solution to cause it freeze) are known as “seeds”. Cloud-seeding with artificial chemicals modifies the clouds to produce rain. Just as cloud droplet formation requires the presence of CCN, the formation of an ice-crystal in a cold cloud (with temperatures below freezing level) generally requires the presence of  an ice nuclei (IN). The presence of a giant hygroscopic-nuclei promotes rain formation in a warm-cloud (with temperatures above freezing level and cloud heights limited to freezing level in the sky).

Injecting an artificial chemical or other substances into suitable clouds to produce rain in a chosen place for improving water supplies is known as “artificial rain-making,” “Cloud-seeding” or “Precipitation management”.  Experiments and operations in this field are conducted in more than 30 countries in the world with a purpose of increasing the annual rain-fall, dissipation of fog, suppressing hailstorms and taming cyclones to minimize damage to the environment. In some countries, such as the United States, these weather modification projects were evaluated by the National Academy of Sciences.  Thirteen were successful in more on-target precipitation  than expected, with a 7% to 57% increase in rain-fall compared to nearby untreated controls.  For a practical person cloud seeding is both an art and a science.  It works to improve the health and welfare of people and their environmental assets. A person seeking scientific proof through rates of success and reproducibility for all cloud-seeding experiments must realize that there are dozens of critical parameters subject to constant fluctuations.  Hence it is difficult to expect reproducibility.  However, optimistic scientists interpret theory and experience to present a reasonable guide for action in situations where inaction promises undesirable risks to the society.  This can be seen from experiences of China, Japan, Thailand, Australia, Africa, Israel, Russia, Canada, Texas and USA.

The key role played by a good water supply as an engine of economic growth and as a yard stick of public welfare and national prosperity has been well recognized by the intellectuals of the developed countries like USA who aptly named water as the “Blue Gold”. The more the water wealth of a nation the higher will be the opportunities for achieving high rates of progress in the fields of agriculture production and industrial growth that help in promoting economic wealth, employment opportunities and higher standards of living. Hence the advanced countries are constantly upgrading their water resources by harnessing not only all the ground and surface waters but also by tapping a renewable, virtually unlimited and unexploited sky water resource in the atmosphere in the form of innumerable clouds. Enlightened scientists, bureaucrats, industrialists and statesmen in about 50 countries are frequently using cloud seeding operations for over 40 years for various purposes like

1. Increase of annual rainfall for drinking and agricultural purposes,

2. dispersal of fog in airports and metropolitan city roads

3. Increase of hydro-power generation at the cheapest cost

4. Suppression of hail storms to reduce damage to life, crops and properties

5. mitigation of devastating impacts of recurring droughts

6. mitigation of damaging impacts of global warming and summer temperatures

7. increase of annual rain fall for improving the forests, wildlife and the environment

Several progressive countries like USA, Australia, China, Thailand, European states, former states of USSR, Latin American states, Arab states, Indonesia and Pakistan are getting highly benefited by employing the advanced cloud seeding technologies for the above purposes. Several Indian states interested in promoting economic growth, agriculture development and public welfare are eager to learn from the successful experiences of other countries like China and USA and adopt those technologies by making necessary modifications to suit the local meteorological, topographical, geographical and other environmental conditions.

Water crisis is brewing all over the world including the South Indian states. The United Nations report shows that 31 countries are now facing water scarcity and 100 crores of people do not have access to clean drinking water. Moreover water consumption is doubling once in 20 years while the existing water sources are rapidly getting polluted, depleted, diverted and exploited by the vested interests in the fields of industry, mining, agriculture and hydro-electricity production. The World Bank predicts that by 2025 about two-thirds of the world’s population will suffer from scarcity of clean and safe water even for drinking purposes. Rather than taking timely remedial action required to protect the precious water resources, the Governments all over the world are retreating from their responsibilities to promote public health and welfare and economic growth that can wipe out poverty and unemployment. Most of the Governments except China were reluctant to realise that national development plans are intertwined with not only the optimal utilization of the existing surface and ground water resources but also large scale harnessing of the abundant sky water resources in the clouds amounting to about 10 times the water in all the rivers.

Drought as a challenge to tap sky-water in the clouds :

Some countries like China, Pakistan and some states in USA are treating drought as a challenging opportunity to promote cloud seeding operations not only to augment rainfall and snow fall but also to drastically control the damage caused by recurring hailstorms. Moreoverthey are using cloud seeding technologies to disperse the fog in airports and major cities and are also fighting the adverse effects caused by global warming. Some countries are using cloud seeding operations to produce water at a very inexpensive cost for municipal, industrial and irrigation use and for hydro power generation. But unfortunately Indian intellectuals are not yet ready to learn from the International experts from China, Israel, Australia, Indonesia, Thailand and Texas on how to fight the crucial impacts of droughts, hailstorms, fogs and global warming impacts by cloud seeding. Unfortunately the vagaries of Indian monsoons are very frequently causing floods in the East and North Eastern states while the Peninsular Indian states are facing recurring droughts and famines which are causing water scarcities that are adversely affecting the health of the human and animal populations, food production, hydro power generation and industrial growth. The damaging effects of droughts on food production in recent years are presented here.

Poor Food Grain Output During 2002-2003 : The shadow of drought loomed heavily on 2002-2003 year’s outcome of Kharif crops The food grain production in 2002-03 was 174.2 million tones compared to 2001-02 year’s production of 212.02 million tones (fall of 18.0 percent). The sharp fall in 2002-03 year’s food grain output, which is the lowest since 1996-97 is mainly due to the decline in Kharif production from 111.5 million tones last year to 87.8 million tonnes is the 2002-03 year (fall of 20 percent). The Rabi food grain production is also likely to drop to 86.5 million tonnes compared to 2001-02 year’s 100.5 million tonnes – a drop of 14 percent. Rice production in the 2002-03 year is likely to be 72.7 million tonnes (93.1 million tonnes last year) and wheat production is likely to be 65 million tonnes (71.8 million tonnes last year) There is also a large decline likely in production of coarse cereals to 25 million tonnes (34 million tonnesin 2001-02) Pulses production too is likely to drop to 11 million tonnes from 13.2 million tonnesin 2001-02 year.

Kharif output in drought years : Low rainfall years in the past have always adversely affected Kharif crop production. The magnitude of decline in production has varied depending upon the severity of the drought. The 2002-03 year’s fall of 19.1 percent in Kharif output compared to earlier poor rainfall years is the highest ever fall since 1972-73. This is explained by the lowest ever rainfall received in July (49 percent fall) which is normally the rainiest month of the season and most crucial month for Kharif crops.

 The year 2002 was bad monsoon period and the month of July the rainiest month of the year with normal 30% of the monsoon rainfall became the driest month with about 50% shortfall which is a record low in the past 100 years. 18 states in the country including all the southern states suffered drought conditions due to poor rainfall in July.

During 2004, 17 out of 36 meteorological sub-divisions had deficient rainfall. The regions with deficient rainfall include the regions in Gujarat, West Rajasthan, Himachal Pradesh and Telangana. The following table indicates that while some regions received normal and even excess rainfall, some other regions simultaneously experienced water scarcity.

In the last few years India has been experiencing fluctuating food grains production with a steep fall as in 2002-2003 by about 14%. The month of July that normally records highest rainfall received the lowest rainfall in the past 100 years. July normally receives about 30 percent of the monsoon rainfall but the shortfall in 2002 was as high as 49%. Against 75% of the total Full Reservoir Level (FRL) which is the average of last 10 years, the national reservoir storage at the end of the monsoon 2002 stood at 50%. Rainfall during the 2002 monsoon season (June- September) was 19% below the normal, causing disastrous impact on irrigation and agriculture. Drought conditions reigned in 30% of the country and it was severe in South India. .  

The fallen reservoir levels that reduced food production are presented here.

FRL storage designed utilizable capacity of 70 major reservoirs of 132 BCM capacity

Cloud seeding cuts down the rising costs of drought relief :

In order to mitigate the impact of drought in several states the Central Government released Rs.1018 crores from NCCF (National Calamity Contingence Fund) and Rs.1227 crores of Central share of CRF (Calamity Relief Fund) for 2002-2003 to the states of Andhra Pradesh, Jammu& Kashmir, Karnataka, Kerala, Madhya Pradesh, Orissa, Punjab, Rajasthan, Tamil Nadu, Uttaranchal, Uttar Pradesh and West Bengal. This included advance release of 2nd installment of Central share to 13 states. The eleventh Finance Commission had set aside Rs.11,000 crores for calamity relief through CRF and NCCF. The CRF is shared in the ratio of 75:25 percent between the centre and the states. The State Chief Minister of Andhra Pradesh had demandedRs.610 crores financial assistance from the centre and one million tonnes of food grain to carry out necessary employment generation program. The other states have also demanded a more or less similar package from the Union Government. If only a small fraction of the CRF and NCCF funds are diverted for cloud seeding operations, weather modification can be undertaken in proper time by adopting proper surface, ground and atmospheric water resources management methods for making available water for drinking and agriculture. Similarly steps can be taken to seed the band clouds to tame the cyclones on the pattern followed in USA for storm-fury experiments.

Limitations of big dams to sustain agriculture :

Although water diversion works like the anicuts across major rivers like Krishna, Godavari, Pennar and Cauvery constructed by the British rulers under the guidance of eminent engineers like Sir Arthor Cotton at an very inexpensive cost have transformed the South Indian river deltas into bread baskets of India several major dams constructed at a huge cost after 1960s have not proved to be successful in producing food grains as anticipated. Even after constructing 8 lakhs of big and small dams around the world the reservoirs are not able to store more than a fifth of the rain water and the bulk of the remaining water is still running wastefully into the oceans. Even though the state and Central Governments in India have built many dams during  the last 50 years they are not able to store adequate water for irrigation.(See Table-6) Consequently lot of water from rivers like Ganges, Brahmaputra, Mahanadi, Godavari and other west flowing rivers is still going into the sea without being sufficiently used for either food production or hydro-power generation. If a small fraction of this rain water can be stored underground by reducing the velocity of the run-off and providing time for recharge of the ground water supplies in many places could be enhanced significantly. But such a task requires an active aquifer management in which planned drawing down of the water table in the premonsoon dry months like summer is an important element of the water management strategy for enhancing recharge of such aquifers from monsoon rain water and the irrigation return flows. Such pro-active aquifer management is an established practice in industrialized states like Texas in USA. Similarly in several other industrialized countries the artificial recharge of the ground water is taken up by conducting cloud seeding operations and other methods. The share of artificial ground water recharge to total ground water use is 30% in west Germany, 25% in Switzerland, 22% in the United States, 22% in Holland, 15% in Sweden and 12% in England. Even Israel has taken up ground water recharge by cloud seeding on an extensive scale. Southern  Ogallala Aquifer Recharge (SOAR) is carried out by conducting cloud seeding experiments on a regular basis in the southern states in USA at a very inexpensive cost and the cost benefit analysis has been estimated for 2003 at 1:150 for agricultural purposes.

In Southern states the British rulers constructed major dams like Mettur dam on Cauvery river and major irrigation projects like Godavari anicut and Krishna anicut long ago for augmenting water availability for irrigating several lakhs of acres in the delta regions.

Subsequently major dams like Nagarjunasagar, Srisailam and Tungabhadra were constructed to promote large scale irrigation and hydro-power generation. Unfortunately these major projects constructed at a huge cost are not receiving the expected river flows with the result that the agriculture and hydro-power generation is suffering under these projects. In order to improve these conditions cloud seeding operations must be conducted on a large scale by using aeroplanes and ground generators during day and night times for obtaining 20% to 30% additional rainfall in the catchment areas of these reservoirs to restore the agriculture operations and hydro-power generation. The Union Government must cooperate with the Maharashtra, Karnataka, Andhra Pradesh and Tamil Nadu to organize cloud seeding operations for augmenting the annual river flows on a substantial scale. Thus major irrigation projects without the aid of the cloud seeding operations may not be always successful in achieving the desired goals of promoting agriculture and economic development.

Desalination is costlier than other options for water supply:

During 1962-77 the ground water level declined by 2meters in most parts of Delhi. During 1977-83 the water table declined by 4 to 6 meters. But in 1983 the depth to water level declined to 10 meters below ground level (BGL) in general with 26 meters BGL at Mehrauli. By 1995 the ground water level was about 35 meters BGL in Mehrauli area of New Delhi. The reasons for this decline are

1. Rapid growth of urbanization and infrastructure development resulting in reduction in green cover and consequential failure to recharge the aquifers.

2. Increased demand for domestic, industrial and agricultural consumption, unplanned withdrawal from sub-soil aquifer of ground water extraction during drought periods. Several villages in different states across the country are also facing problems of water scarcity even for drinking purposes. In order to meet the growing water scarcity conditions in both urban and rural areas several Governmental Agencies like Baba Atomic Research centre, Central Salt and Marine Chemicals Research Institutes, Jodhpur Research Laboratories and National Chemical Laboratories are engaged in research and development of desalination of water.

Although India with its fortunate location in a tropical region receives abundant rainfall, it is unevenly distributed in time and place and hence many parts of the country face chronicwater shortage problems. In some areas extensive exploitation of ground water is causing the ground waters to become saline. Hence some agencies are planning to augment water resources by adopting desalination and water reuse technologies. Thermal membrane desalination, Reverse Osmosis Membrane Technology and Electro-dialysis methods are used for providing good water

from saline water and brackish waters. Ultra filtration methods are used for waste water treatment for recycling the industrial effluents. Capital cost per million gallons/day of desalination plant is estimated at Rs.10 crores. Sea water desalination costs Rs.45 per cubic meter. Reverse Osmosis plant produces one cubic meter of water with capital and operations cost estimated at Rs.27/- and Rs.45/- respectively.

Augmenting drinking water supplies :

In almost all the states even for metropolitan drinking water supplies we need inter basin water transfers. For instance Madras water supply is augmented by transferring water over long distances from Krishna river in the North and Neyveli and Veeranam reservoir sources in the South. New Delhi gets partial water supplies from Bhimgoda on Ganga (200km) and Bhakra on river Sutlej (300km). Even Calcutta, Bombay, Bangalore and Hyderabad get their water supplies from very distant sources. By 2050 the municipal and industrial water supply needs of several state capitals and major industrial cities will have to be met through long distance water transfer which is causing water disputes because the local farmers and villagers are deprived of their conventional water resources on which they depend for their drinking and irrigation needs. The drinking water needs of many other major towns and cities will have to be met by transporting water not only from long distances but also by using ground water supplies which have to be replenished continuously during southwest monsoon and northeast monsoon by taking up cloud seeding operations on an extensive scale because the urban population is also growing very fast as indicated in the following table.

 Among the several water uses, agriculture at present uses 80 to 85% of the water  available as surface flows and under ground water. 80 to 90% of the water is consumed for agriculture operations and the remaining 10 to 20%of the water returns back to rivers as regenerated flow or it recharges the ground water. Low water is consumed in case of navigation and hydro-power generation. The water use in different sectors by 2000AD,2025AD and 2050 AD is estimated as shown in the following table.

In respect of agriculture development the ultimate irrigation potential is presently estimated at 140 Mha comprising 58 million ha from major and medium irrigation projects, 17 Mha from minor irrigation schemes and 65Mha by ground water schemes. By the end of 1996-97 an irrigation potential of about 92 Mha comprising 34 Mha by major and medium projects, 12 million ha by minor schemes and 46 Mha by ground water schemes has been realised. The ultimate potential is expected to be achieved by 2025 AD. The present irrigation water use is about 660 BCM which will grow upto about 1250 BCM by 2025 AD and to about 1650 BCM by about 2050 AD.

The present population of the country which stands at 1000 million has been projected to reach 1400 million by 2025 AD and 1650 million by 2050 AD. The food requirement is estimated to reach 450 to 500 million tones by 2050 AD. The present productivity is about 2.5 tonnes/ha for irrigated agriculture land and 0.5 tonnes/ha for rain-fed agriculture lands. Assuming that these productivity levels go upto 3.5 tonnes/ha and 1.0 tonne/ha respectively by 2050 AD, it becomes necessary to create an irrigation potential of 160 to 165 Mha to be able to meet the food demands of the country by 2050 AD. Thus 25 Mha in irrigation potential has to be created.The Ground water is extensively used for drinking,industrial and agricultural purposes and consequently ground water is fast depleting and it has to be replenished by the most inexpensive method of cloud seeding.the magnitude of the problem can be seen from the  following Central Ground Water  Organisation's web- site:

The irrigation water requirement by 2050 AD is expected to touch 1070 BCM level. This additional irrigation potential has to be created by non-conventional technologies like inter basin water transfer by linking the rivers in different regions of the country and also by artificial recharge of ground water by various measures as followed in other developed countries. Similarly water availability in the ground and surface water resources has to be augmented by squeezing the atmospheric water in the form of clouds by following the example set by United States.

The present utilisable surface and ground water is estimated at 1122 BCM. and  consequently there is bound to be a water deficit of 126 BCM by 2025 AD and 534 BCM by 2050 AD. The anticipated water deficit can be partially met by purification through recycling of municipal and industrial effluents, ground water recharge, evaporation-suppression and desalination of sea water. However these methods are very costly.

Population, agriculture and irrigation :

In order to understand the causes for the impending water and food famines in India in general and the Southern states in particular by 2025 AD it is necessary to study the gradual changes in land use, cropping pattern, irrigation and food production since 1950 as presented here.

Since there is substantial waste land it is necessary to bring it under cultivation and grow fruit gardens to make available more nutritious food and minerals by using fruits and better vegetables for human consumption. For this purpose cloud seeding operations can be taken up to provide more water during different seasons to supplement the natural rainfall. The production of Rice, Wheat, coarse cereals and pulses since 1950 in million tonnes along with the their projections upto 2050 AD are presented in the following table.

All the figures are in Million tons.

The data in these tables clearly indicates that there is an urgent need to provide more food to meet the minimum nutritional requirements of the fast growing population of India. Such an effort will be successful if only more water is made available for agriculture not only by conserving the existing ground and surface water resources but also by tapping the abundant sky water in the clouds through cloud seeding operations. The land used for different crops and the productive levels in 1996-97 are presented in the following table.

The above data clearly indicate that the yield of the different crops must be increased and for the purpose better farming methods must be used along with better irrigation facilities. The following table presents the historical growth and the future projections for population, land use and food production for forecasting the potential for food scarcity

The above statistics indicate the urgent need to bring more land under irrigation for making available more food grains to meet the nutritional requirements of the fast growing population. Unless timely action is taken to make available more water and more land the inevitable scarcity for water and food will cause damage to public health and welfare and national development. The graphical representation on the population growth, land use and food production is presented below. 

The above figure presents the full details on the population growth, food production and land use from 1950 onwards for the projected time period upto 2050 and this clearly must open the eyes of the state and Central Governments to make united efforts to promote irrigation and food production by interlinking of rivers in different stages and also augment water availability by diverting the water from the West flowing rivers into the East flowing rivers like Godavari, Krishna, Pennar and Cauvery and also to further augment the annual rainfall in these river basins by 25% to 30% by cloud seeding.

The population growth in the Southern states along with the demand, production and scarcity for Rice is presented below for assessing the nature and magnitude of the impending food shortage.

The above population and food production statistics in South Indian States point out the urgent need for a meeting of the Chief Ministers of Southern States to put up a united effort to take up extensive cloud seeding operations for making available more water for drinking, irrigation and hydro-power generation in Southern states.

The above tables clearly show that unless timely action is taken to increase food production by providing accelerated irrigation facilities on a war footing the people of South India will have to face mal-nutrition, under nutrition and famine conditions of an irreversible nature. In order to avert this impending crisis of water and food shortages, the central and state governments must plan for optimum utilisation of both the dependable as well as the flood flows of river Godavri and also plan for substantial augmentation of annual flows in the river and its tributaries by conducting cloud seeding experiments in all the river basin states .

The ultimate irrigation potential of India is estimated at 140 million ha. Irrigation under conventional surface and ground water schemes includes 58 million ha. under major and medium projects. 7 million ha. under minor irrigation projects and 65 million ha. under ground water schemes. By 1997 irrigated area covered 92 million ha. including 34 million ha. under major and medium projects, 12 million ha under minor irrigation projects and 46 million ha under ground water schemes. The present population of about 1000 million in India will reach 1400 million by 2025 AD and 1645 million by 2050 AD as per UN projections.

Many environmentalists and economists emphasize that the country is fast moving towards severe food shortage, famine and starvation deaths. About half of the children under 3 years of age are under-weight due to malnutrition and upto 50% women and 74% children are anaemic. The annual rate of growth of food grain production during the 9th plan was low at about 1% per year while the annual population growth was about 2% and per capita food grain availability per day dropped from 5 grams in 1991 down to 4.4 grams in 2001. Crop production growth rate fell from 3.7% per annum during the decade 1979-1980 to 1989-90 down to 2.3% per annum during 1989-90 to 1999-2000. The rate of growth of productivity fell from 3% per annum in 1980s to 1.2% per annum in 1990s. The share of agriculture in GDP during the last 5 decades declined from 61% in 1950-51 to 24% in 2001-2002, even though about 70% of the population still depend upon agriculture for their livelihood. About 100 million ha of land is either drought-prone or flood-prone.

But India has to feed about 16% of the global population although it has only 2.4% of the total land and about 4% of the global water resources. However only about 40% of the net sowing area of about 143 million ha has been brought under irrigation and the remaining extensive land has to depend upon the rainfall. Ground water is fast depleting due to poor water harvesting and poor recharging of ground water. In addition, the scarcity of water in rain fed areas is a serious threat to growth of crops. Out of the total geographical area of 328.7 million ha. an area of about 107.4 million ha is estimated as degraded land. The higher irrigation water charges and electricity bills will adversely effect both the productivity and crop production in agriculture.

By 2050 AD the food grain requirement will be 450 million tonnes per year at the present levels of consumption. Assuming that there will be a moderate rise in consumption the production of food by 2050 must be between 500 to 550 million tonnes per annum If improved technologies raise productivity from 2.5 to 3.5 tons per ha. for irrigated lands and 0.5 to 1.0 ton per ha. for rain-fed irrigation, it is necessary to create additional irrigation potential of 25 million ha, taking the total to 165 million ha. by 2050 AD and this additional potential can be created only by inter-basin water transfer and augmentation of surface and ground water sources by conducting cloud seeding operations on an extensive scale to tap the abundant sky water in the clouds.

Cloud seeding for inexpensive hydro-power generation :

Union Power Minister admitted in the Parliament on 11-3-2005 that there was an overall power shortage in the country and that the surplus Eastern region was supplying the electrical power to the National grid to meet the needs of the deficit regions. On an average the electrical power shortage in the country declined from 8.8% in 2002-2003 to 7.1% in 2003-2004 and 6.8% in 2004-2005. The 10th plan target was expected to generate 41,110 MW . The per capita electrical power consumption increased from 15 units in 1947 to about 600 units in 2005 while the power generation increased from 1362 MW in 1947 to 1,16,000 MW in 2005. During 2004-2005 there was a shortage of 920 MW in the Northern region, 375 MW in the western region, 88 MW in the Southern regions and 1602 MW in the North Eastern region and only the Eastern region met its power generation target of 1210 MW. Hence all the Indian states must make genuine attempts to remove the electrical power shortage by conducting cloud seeding experiments to augment production of hydro-electric power as practiced during the last 40 years by Tasmania state in Australia which is producing power at the cheapest rate with a benefit to cost ratio 13:1 as presented in the website elsewhere.

Cloud seeding for water pollution control :

Most of the rivers like Ganges, Yamuna, Krishna, Cauvery and their many tributaries are subject to water pollution due to discharge of untreated and partially treated liquid wastes from many polluting industries and urban settlements located on their banks. Agricultural wastes from farm houses and fertilizer and pesticide residues from agriculture are entering into the natural water courses and are getting concentrated into food chains and food webs of the aquatic eco-systems. The water from these rivers is diverted from various anicuts and reservoirs built across these rivers and their tributaries through irrigation canals into village tanks and agricultural fields. During summer the water flows in these rivers and streams is very much reduced and there is no corresponding reduction in the quantities and quality of the industrial and municipal effluents that are entering into them. Consequently these natural water courses are highly polluted with the result that neither the people nor the animal population can use them for drinking and other purposes. There is a large scale death of fishes in these water courses. Hence there is a need to restore a reasonable degree of purity in these stream waters to protect public health and the environment.

For restoration of stream water quality during the diminished flows of summer season some countries build dams and reserve sufficient water in the reservoirs for maintaining a minimum flow even during the summer season for ecological purposes. In a public interest litigation case on control of pollution in the holy waters of the Ganges and the Yamuna rivers, the Supreme court of India ordered the state and Central Governments that even during the summer season a minimum flow of 10 cumecs (350 cusecs) in Yamuna river and 40 cumecs (1400 cusecs) in Ganga river must be maintained for ecological and environmental purposes for ensuring drinking water for human and animal populations and normal flows with sufficient oxygen for the survival of aquatic flora and fauna including fisheries. The detailed information on this public interest litigation case may be seen from the following websites.

River water storages must be increased to overcome the difficulties caused by frequent failures of monsoons and also to meet the ever growing demands of summer seasons. The present live storages of about 174 billion cu.m. constitute about 10% of the total water potential available in the country. Even if a low estimate of future water requirements of 1300 billion cu.m. is to be met, a storage of 600 billion cu.m. is required. In order to maintain minimum summer flows to dilute the impact of treated waste water discharges from municipalities and industries, additional storage is needed. Further 50 billion cu.m. is needed to maintain ecological balances in water courses. In addition to the above mentioned live storage the projects under, construction and those under consideration envisage additional storages of 75 billion cu.m. and 130 billion cu.m. respectively. Thus there is an urgent need to conserve river waters by transferring the surplus flows from rivers like Ganges, Mahanadi and Godavari to water deficit rivers like Krishna, Pennar and Cauvery and also to augment their yields by cloud seeding.(See the details for Godavari-Cauvery river water-grid elsewhere).