SHRINKING GROUNDWATER

Groundwater is the water found underground in the cracks and spaces in soil, sand and rock. It is stored in and moves slowly through geologic formations of soil, sand and rocks called aquifers.
How do we cope with the changing ground water is a question that need to be asked.
Although our domestic water requirement varies from 50 – 200 litre per capita per day depending on our life style, the quantity of water actually used for drinking is just about 4 litres per capita per day.
This water, however, has to be of best quality. For those who can afford, our drinking water in future would come essentially from specially treated bottled water or through high technology household level water treatment units.
The proposal for having water supply in duel qualities; one for domestic use and the other with recycled water for non-domestic use are to be taken seriously.                          
Roof Top Rain Water Harvesting (RTRH) has also been found to be a viable alternative source of fresh water. Therefore, in time to come, rainwater harvested from roof top particularly in high rainfall (1000 mm) areas is likely to become a convenient and economic source of fresh water supply.
Excess rain water harvested from roof top, if any, could also be used for artificial groundwater recharge. For this reason it should be made compulsory for all future housing projects to make provisions for collection and diversion of rain water from the roof top to a common location for further use.
Roof tops are also likely to be used for solar panels in the future. There would be no conflict if the solar panels are installed on stilts on the roof top. Procuring large scale fresh water by desalinization using the process of evaporation and condensation is another alternative source of fresh water.
Large scale desalination no doubt is expensive but would gradually become more and more acceptable as availability of fresh groundwater would become more and more scarce.
Solar desalination units are of low cost and free from any operating cost but the available units at present in the country produce only a few litres per day, not even adequate for a large family.
There is a scope for improved designs. Although, slightly polluted and treated waste water can be used conveniently for agriculture but water with TDS more than 2000 ppm is harmful to most crops. Besides, presence of heavy metals and unbreakable chemicals in irrigation water can cause health problems by concentrating these in the foods grown.
In many cities, vegetables are grown using drain water (sewage) directly. This practice must be discouraged as the vegetables are likely retain harmful microbes. If an advantage of the drain is to betaken at all, the water should be tapped indirectly through shallow dug wells constructed in the vicinity.
The Ground Water polluters should be forced to invest in adequate treatment facilities for the polluted effluents produced by them. So far the Pollution Control Authorities had been lenient in enforcing the norms under the Acts. Similarly, the Water Authorities have not been able to cope up with the gigantic task of treating urban effluents adequately. More progress are to be made in the direction of promoting water conservation practices, decentralized effluent treatment facilities, recycling of waste water, conservation of water bodies and watershed management.      
Climate Change resulting from Global Warming is feared to be bringing in unpredictable changes all over the country in the distribution of water. The frequency and intensity of floods and droughts are expected to increase. To cope with the changing situations, it is strongly recommended that all water users are made aware about the impending dangers and their capacity to cope with the situation is enhanced.
Another popular recommendation is to create a large number of surface water reservoirs as insurance against climate variability.
Artificial groundwater recharge assumes greater importance in this regard.
Groundwater reservoirs have more storage capacity than all the surface water put together. Moreover, groundwater is not open to evaporation and do not occupy any valuable surface area.
At per the continuing trend, the demand for groundwater would continue to increase even though its availability would be shrinking. As a result of which water related conflicts would be on the rise.
In future, only the rich and resourceful would be able to extract the remaining available groundwater in the country using advanced technologies depriving the poor users at large.
It is time that we the common groundwater users understand the challenges and undertake compensatory groundwater recharge for every drop we extract.
The future of groundwater scenario in our country in general appears to be very bleak. There is no doubt that at the present level of groundwater extraction, the water table in most part of our country would continue to fall.
The blanket moratorium under the Environmental Protection Act (1997) on construction of new tube wells is logical and helpful but this at best would merely stabilize the present level of extraction. However, it should be noted that there should be no such undue restrictions in areas which are rich in groundwater occurrence and are categorized as “Safe” zones.
The most important step required to improve the groundwater availability in the over-exploited regions (including semi-critical and critical) of the country is to take up large scale artificial groundwater recharge activities. Although the concept is well appreciated but any major initiative for large scale construction of artificial recharge structures has so far remained neglected.
In countries where such programmes are going on, the implementation may be said to be tardy at best. The usual emphasis of Government programmes on low cost designs and high target is not very helpful. Unless, there is emphasis on quality and effectiveness, such efforts are likely to create a large number of poorly functioning and rapidly deteriorating structures.
Conversion of an abandoned dug well in to an artificial groundwater recharge (AGR) structure by connecting a rain water collection channel through a silt retention pit is basically a make shift arrangement. These structures may not be very effective but there are no harm if these are done in large numbers and maintained by the farmers themselves.
But in large scale national level programmes for construction of AGR structures under Government funding, the structures must be made more site specific, effective and durable. Programmes should also be designed to encourage the present groundwater users to construct compensatory AGR structures in their respective areas.
Presence of buildings and covered surface areas in metropolis do not allow much groundwater recharge as these produce high run-off.
The urban run-off known as storm water generated in large volume usually go away as waste water. Arrangements should be made in all metropolises to collect and divert the storm water in to various parks and available open space to form new water bodies.
All the existing water bodies in urban areas should also be cleaned and maintained as these are very important source of groundwater recharge.
As consumption of stored rainwater is still not acceptable in most urban areas, the roof tops must therefore be used necessarily to collect rainwater and divert the same exclusively for groundwater recharge through an appropriate structure. Large scale groundwater pollution on the other hand has been making a considerable quantity of fresh water permanently unsuitable for human use.
Decentralized waste water treatment plants are to be installed in all industries, hotels, housing societies and all places of mass water consumption for recycling. Treated sewage and waste water are to be used as far as possible for agriculture and similar other non domestic use. Industries should bring in technologies to enhance water conservation and recycle treated water.
All sewage and waste water must be treated adequately before releasing into the nearby rivers. Pollution control Acts for water are to be implemented more vigorously to protect our rivers.
It is true that groundwater has been over-exploited in most parts of the country. But this is not the case in some selected regions falling under large alluvium basins such as Ganga and Brahmaputra and similar other river basins.
As per groundwater zoning these areas fall under “Safe” category. Consequently, there should not be any undue restrictions in these areas for construction of new tube wells nor any need for undertaking artificial groundwater recharge programmes. In fact more and more groundwater should be extracted from the flood prone areas to create extra space within the groundwater reservoir.  
Should a common person bother to understand groundwater? We all are groundwater users. Farmers use it for irrigation, industries for production and a vast majority of population use it for drinking and domestic purposes. Groundwater, although a renewable resource but is limited in its occurrence in time and space.
The mindless pursuit for extracting more and more groundwater by all the users has already started exerting tremendous pressure on this limited resource. A good part of groundwater is also fast becoming unfit for human use both due to natural and anthropological activities.
As water level is falling at an alarming rate in most part of the hard rock areas of the country, farmers are continuously struggling to cope up with the situation.
Millions of open dug wells have either gone dry or are yielding little water, and that too mostly seasonally. Deepening of a dug well in hard rock areas is expensive and difficult (needs blasting).
Even after that, there is no guarantee that regional water level will not go down any further in the near future demanding more deepening. In the absence of proper guidance many farmers in their desperation take a chance and invest in drilling deep bore well. Unfortunately, many a times this gamble does not pay as the bore well fails to yield the requisite quantity of water. A failure like this not only causes a huge financial burden to the farmer but also takes away his spirit and hope for a longtime to come.
In order to have a dependable source of water, most farmers,industries, housing colonies and others construct their own bore well. But such ventures are not free from problems as the users face frequent financial losses and inconveniences due to associated uncertainties. Questions like what should be the depth and diameter of the well, how to find a good location for a yielding well, what would be the expected quantity and quality of water from the well etc continue to arise and remain unanswered.
As a common man starts understating the basics of groundwater occurrence and the associated limitations, future management of this vital resource become a more feasible task.