Water for future

How do we conserve water so we do not have to face acute shortage in the future?
Water is a precious commodity. (Source: IWP Flickr photos)
Water is a precious commodity. (Source: IWP Flickr photos)

Water, the most precious commodity is being abused to such an extent that there is fear that this might lead to another world war or it may be difficult even to get drinking water. Water is indeed an integral part of human body as it accounts for 66 percent of it. The only liquid that quenches thirst satisfactorily is water and a mere two percent dehydration reduces performance by 20 percent.

The rapid increase in global population and simultaneous decrease of freshwater resource combined with mismanagement, wastage and pollution have threatened the very survival of human race on earth. United Nation estimates that 75 percent of the world population won't have reliable clean water by 2025. It is therefore just not a mere scientific pursuit but deserves a nobler perspective at this juncture.

Global freshwater availability percentage, even though small, holds not only the humans but the industrial sector by its cuff when it is short of desired demand. Compulsions both at the domestic and the industrial level have led us to introspect into the consumptive patterns for optimising and conserving them. India's annual per capita of 1850 m3 is just about one fourth of the world average of 7690 m3.

Looking at the hydrological network along the course of principal rivers over decades tells us that they have been transformed due to either encroachment or cultivation or urbanisation--Yamuna (the main flow) in Delhi has shrunk so much that one has to struggle to acquire even the original floodplain along this river. The story, I am sure is no different with other rivers in the country. 

The alternative to reviving water potential of any area lies in understanding the current hydrological network and creating artificial ponds for diverting the monsoon water into them which is otherwise being wasted recklessly. A model plan of an arid zone would initially be more useful for replication elsewhere. The scientific understanding is that the creations of such ponds enhances the moisture content of the surrounding soil and promote natural plant growth which would facilitate retention of moisture in the soil for longer periods than otherwise.

Water availability 

If we look at the distribution region wise, Asia accounts for 30.6 percent of the world (Table 1) total followed by South America (27.6 percent) and North America (17.9 percent) respectively. Asia is earth's largest and most populous continent, located primarily in the eastern and northern hemispheres with an area of 44.58 million km2 and a population of 4.436 billion (2016). As the biggest continent in the world, Asia includes 50 independent countries. The largest of the Asian countries by area is Russia, which occupies about 30 percent of the total territory of the continent. The smallest one of the independent states is the Maldives. Fifty countries of Asia banking on 30.6 percent of global water distribution leave roughly 0.5 percent for each country. 

It is understandably a huge task to imagine a vast country like India with diversity of culture and population of almost 1.5 billion to sustain agriculture, industrial and domestic demand for water.

Table 1: Distribution of water
Continent or region River runoff (km³/year) Percent of world total
1.  North America 7,800 17.9
2. South America 12,000 27.6
3. Europe 2,900 6.7
4. Middle East and North Africa 140 0.3
5. Sub-Saharan Africa 4,000 9.2
6. Asia (excluding Middle East) 13,300 30.6
7. Australia 440 1.0
8. Oceania 6,500 14.9

When we look at the water available on earth, we find that a mere 2.5 percent of fresh water is what is available to humans. While 68.7 percent of this accounts for glaciers and ice cap, we are left with 30.1 percent of groundwater and just 1.2 percent of surface water. Humans, being selfish, have recklessly been exploiting this for agriculture, industrial and domestic consumption so rapidly that he permits no time for its recharge. Adding to this is another major activity--construction which in itself plays a major role planning the limited resource for additional population to be accommodated. If the current trend continues (as it would certainly) the day then is not far off when the ‘sustenance of life’ commodity may be unavailable EVEN for drinking. It is thus imperative, that we need to undertake serious measures IF we have to extend human life on this planet earth.

Amount and composition of water on earth

Total Volume of water on Earth – 1386 million km2 – Oceans (94.5%)/Fresh Water 2.5%/Groundwater (saline) 1%

Fresh Water (2.5%) – Polar Ice (68.7%)/Ground water (30.1%) / Surface Water(1.2%)

Table 2: Amount and composition of water on earth

Total volume of water on earth

(1386 million km2)

Oceans (94.5%)  
Fresh water (2.5%) Polar ice (68.7%)
Groundwater (30.1%)
Surface water (1.2%)
Groundwater saline (1%)  

Nearly 20 percent or 1.1 billion people in the world still do not have access to safe water. Teeth cleaning requires just a quarter litre of water. While, average bath requires 80 litres, average shower uses just 35 litres. Agriculture accounts for the highest usage of 70 percent followed by industry (22 percent) and domestic (8 percent) respectively. 

The most popular 'financial audit' principle seems to have caught up with almost everything in the modern context like energy audit, professional audit, etc. It is therefore appropriate that we look at 'water audit' as well in view of the crisis that we are likely to end up with sooner or later IF; our lifestyles continue the way it has been until today, particularly in the urban centres.

Water conserving potential

Atypical urban household consumes water for kitchen, shower, utensil wash, laundry, toilet plus leakages. The consumption for a family of five could be summarised as under: Converting these figures into weekly consumption would lead us to a total of 6157 litres of water or about 920 litres per day. However, there is the following potential for conservation:
  • Shower 10 litres of water per minute; 8 minutes a day 400 litres / day
  • Kitchen 2.83 litres per minute; 15 minutes running 212 litres / day
  • Laundry 140 litres of water per load; 5 times a week 140 litres / load
  • Toilet Single flush uses 9 litres of water; 15 times per day 135 litres / day
  • Leakage one pipe leak of 0.0225 litre/minute flow 32 litres per day
  • Shower 400 litres / day - Shower duration reduction, low flow showers or sensors would save 50%
  • Kitchen 212 litres / day - Careful washing with appropriate flow, smart fixtures save 50%
  • Laundry 140 litres / load - Water efficient, front loaders machines use less than 120 litres per load
  • Toilet 135 litres / day - Modern dual flush, smaller tanks would require 3 to 6 litres per flush
  • Leakage 32 litres per day - Timely Fixing of leakages would save this wastage

In addition to the above measures, there are what are termed as ‘smart taps’ which would record the water consumed from different taps during the day to caution you of further conservation. Flow of water through taps is replaced by either jet or sprays with conservation in mind.

Industrial and agricultural sectors similarly have been compelled to adopt conservative measures through innovative technologies of the modern times.  

Current scenario of an arid zone: Kolar

  • The UN estimates that the amount of wastewater produced annually is about 1,500 km3, six times more water than exists in all the rivers of the world. (UN WWAP 2003)
  • Lack of adequate sanitation contaminates water courses worldwide and is one of the most significant forms of water pollution. Worldwide, 2.5 billion people live without improved sanitation. (UNICEF WHO 2008) 
  • Over 70 percent of these people who lack sanitation or 1.8 billion people live in Asia.
  • Unsafe or inadequate water, sanitation, and hygiene cause approximately 3.1 percent of all deaths worldwide, and 3.7 percent of DALYs (disability adjusted life years) worldwide. (WHO 2002)

The best example to evaluate this potential could be an arid zone as measures undertaken here would perhaps motivate others particularly, urbanites to emulate them for a better water management practice. Kolar in Karnataka falls under the arid zone and the findings through published literature indicate that the situation seems to be worse compared to a few decades back due to innumerable reasons.

Despite these, we still need to pay attention to the colossal waste of water during monsoon as they are now allowed through drains into sewage line. Kolar is crying for a permanent source of water. In fact, the depth of groundwater in Kolar has dropped from 15.03 m in 2006 to 61.48 m in 2016 (in a matter of 10 years). Despite three river basins namely, Palar, Ponnaiyar and Pennar which carry water during monsoon only, the water scarcity persists in the town. Added to this, the erratic monsoon--in 2005, the annual rainfall was recorded at 1194 mm which fell to just 521 mm in 2016. The farmers under these circumstances were forced to depend on borewells in the early 2000 which increased by 64 percent between 2011 and 2015. The figure of 84287 borewells by the Central Ground Water Board is countered to the factual figure of at least 125,000. Farmers further changed the crop pattern--switching over to mulberry, millet and vegetable cultivation from water intensive crops like paddy and sugarcane. The story did not end there--as 33715 of the 84287 borewells went dry, understandably the depth of borewell increased from 91 m (2000s) to 393 m. Imagine the cost! Rs 2319 crores at the rate of Rs 688,000 for these 393 borewells.

In addition to this water problem, the state government has been adding to the woes through eucalyptus plantation under the afforestation programme. Eucalyptus can extract 15-20 litres of water per day. The tree which matures in seven years provides lucrative returns (A return of Rs 40,000/ha against an investment of Rs 8,800/ha. In order to check this rampant eucalyptus cultivation, the forest department introduced bamboo and tamarind as replacement.

Two projects have been initiated to divert water--Yettinhole Project for water diversion from the tributaries of westward flowing Netravathi is one. According to a recent report (2015), it is estimated that it can only generate 7.5 TMC water against 24 TMC. The second one is K. C. Valley Project which is aimed to divert treated effluent water from Koramangala Challghatta Valley. Residents fear amplification of waterborne diseases already prevalent.

Although about 200 individual and 20 community farm ponds were built under National Horticulture Mission, the scheme ignored the fact that the ponds are full only during two rainfall months. The paradox is that 1500,000 million cubic feet (TMC) of water from Krishna and Cauvery drains into the sea every year whereas, Kolar needs just 100 TMC annually.

There is also a belief that the aquifer recharge through water tank filling could be one of the solutions.

Future course of action

As mentioned earlier, there are no perennial rivers in Kolar district. The district is drained by Palar, Ponnaiar, North Pennar (North Pinakani) and South Pennar river basins, the tributaries of which are small and are monsoon fed. However, the drainage map (Fig.1) looks encouraging.Source: Ministry of Water Resources: Central Ground Water Board –Groundwater Information Booklet – Kolar District, Karnataka (South Western Region, Bangalore August 2012)

Annual rainfall is around 857 mm in Kolar--southwest monsoon contributing 55 percent while northeast accounts for 30 percent. Out of the 14 stations for pre-monsoon water level observation, five present rising trend (0.012 m/year to 0.298 m/year) while the remaining nine show falling trend (0.004 m/year to 0.298 m/year). The post monsoon observation is similarly nine out of 18 show rising trend (0.025 to 0.777 m/year) and the remaining show falling trend (0.31 to 0.700 m/year).

There are positive indications of the ‘artificial recharge’ experiment that the CGWB undertook in Gauribidanur and Mulbagal taluks of Kolar district--de-silting of two percolation tanks; watershed treatment in two areas; gravity recharge experiments in two well fields and rooftop rain harvesting structure and point recharge studies at five locations. The experiment showed favorable results in building up storage in the area to the tune of 3 m to 7 m and resulted in an improvement in the productivity of irrigation borewells. It has been estimated that there is a potential for 16 subsurface dams, 532 percolation tanks, 3150 check dams and 142 point recharge structures in the district.

Taking a cue from this successful experiment. Kolar can benefit to a great extent IF only, the residents and administration join hands in focusing their attention to the immediate desirable measures for perpetual water abundance. This effort would perhaps ease even the threat of fluoride and nitrate concentrations, in the long run.

1. Roof top rain harvest

Residents themselves could reduce the burden on the water supply authorities by adopting roof top rain harvesting which would meet the household water requirement not only during the monsoon but later also.

Source: Ministry of Water Resources: Central Ground Water Board –Groundwater Information Booklet – Kolar District, Karnataka (South Western Region, Bangalore August 2012)

The amount can be calculated based on the annual rainfall of the area: Roof area x Annual rainfall (mm) x Coefficient of runoff for the roof. In case one has to calculate just the drinking water requirement of five members (10 litres per person) of a family then, for a rooftop of 100 sq.m and annual rainfall of 600 mm--100 x 0.6 x 0.85 (Co-efficient) = 51 cu.m or 51,000 litres.

 

2. Desilting of the existing ponds

 

There have been innumerable success stories of desilting existing ponds in the country. This enhances not only the water holding capacity of the existing ponds but also improves the moisture content in the surrounding area encouraging proper afforestation plan to promote natural cycle of evapotranspiration bringing back the same as rain.

 

Diversion of existing nalas 

 

Considering the hydrology of Kolar, one has to work out detailed plan of diverting nalas into the existing ponds OR create new water holding ponds. This activity ensures not only the constructive utilisation of wasteful monsoon water but also ensures steady water supply both for a better agriculture and domestic consumption.

 

This of course is nothing new as one could witness these examples in many of our ancient temples and even villages.

 

This reservoir cut into rock was used centuries ago to hold harvested rainwater:

 

3. Water holding potential of existing rivers

Looking at the hydrological network along the course of principal rivers over decades tells us that they have been transformed (main course of the river) due to either encroachment or cultivation or urbanisation--Yamuna (the main flow) in Delhi has shrunk so much that one has to struggle to acquire even the original floodplain along this river. The story, I am sure is no different with other rivers in the country. Therefore, the scope for tree planting along these river flood plain is conceived wrongly. Moreover, mere haphazard planting along the floodplain does not serve the purpose of flooding of rivers during erratic monsoon to the surrounding areas.

The only option before us is to widen the ‘main river course’ through desilting and creating bunds along the main course of the river.

It is evident that this precious commodity is under severe threat due to various reasons. If we do not pay serious attention now, it will be too late to ensure continuance of humanity on this planet.

REFERENCES:

  1. List of Countries in Asia 
  2. Water Distribution on Earth
  3. World Water Day 2010 – Clean Water for a Healthy World 
  4. WATER: Essence of human and industrial survival  “ENERGY BLITZ”, Vol.I(V),   April – May 2012, Pages : 45 – 49.
  5. Ground water information booklet – Kolar District, Karnataka Govt. of India, Ministry of Water Resources, CGWB,  South Western Region, Bangalore 2012
  6. At Rock Bottom 

Disclaimer: The views and opinions expressed in this article are those of the author/s and do not necessarily reflect the policy or position of India Water Portal.

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