By *M.MEHTA
(Former COMMISSIONER (GW) Ministry of Water Resources)
Former COMMISSIONER (GW)
Ministry of Water Resources
Groundwater development significantly increased during the second half of the last century in India. This development has been mainly undertaken by a large number of small (private or public) developers and often the scientific or technological control of this development has been neglected. In contrast, the surface water projects developed during the same period are usually of larger dimension and have been designed, financed and constructed by Government Agencies which normally manage or control the operation of such irrigation or urban public water supply systems. This historical situation has often produced two effects:
1) Water Administrations generally have limited understanding and poor data on the groundwater situation and its value in water sector ;
2) In some cases the lack of control on groundwater development has caused
problems such as depletion of the water level in wells, decrease of well yields, degradation of water quality, interference with streams or surface water bodies, ecological impact on wetlands etc. These problems have been sometimes magnified or exaggerated by groups with lack of hydro geological know-how, professional bias or vested interests. Because of this in recent decades groundwater over-exploitation has become a kind of ‘hydro myth’ that has pervaded water resources literature. A usual axiom derived from this pervasive ‘hydro myth’ is that groundwater is an unreliable and fragile resource that should only be developed if it is not possible to implement the conventional large surface water projects.
Another usual ‘hydromyth’ is to consider that groundwater mining – i.e. the development of non-renewable groundwater resources – is always an ‘overexploitation’. The implication of this word is that groundwater mining goes against basic ecological and ethical principles. Five ethical issues are considered relevant in trying to achieve sustainable or reasonable groundwater use.
1) Perverse subsidies to surface water projects
The hidden or open subsidies that have traditionally been a part of large hydraulic works projects for surface water irrigation, are probably the main cause of the pervasive neglect of groundwater problems among water managers and decision makers. Surface water for irrigation is usually given almost free to the farmers; and its wasteful use is the general rule. Progressive application of the ‘user pays’ or ‘full cost recovery’ principle would probably make most of the large hydraulic projects economically unsound. As a result a more comprehensive look at water planning and management would be necessary and adequate attention to groundwater planning, control and management would probably follow.
2) Public, private or common groundwater ownership
Some consider that the legal declaration of groundwater as a public domains a ‘condition sine qua non’ to perform a sustainable or acceptable groundwater management. This assumption is far from evident. For many decades groundwater has been a public domain in a good number of countries e.g. India. Nevertheless, sustainable groundwater management continues to be a significant challenge in many of those countries. Highly centralized management of groundwater resources is not the solution but to promote solidarity in the use of groundwater as a ‘common good’. Groundwater management should be in the hands of the stakeholders of the aquifer, under the supervision of the corresponding Water Authority. The stakeholders’ participation has to be promoted bottom-up and not top-down.
3) Lack of hydro geological knowledge and/or education
Adequate information is a prerequisite to succeed in groundwater management. It has to be a continuous process in which technology and education improve solidarity and participation to the stakeholders and a more efficient use of the resource.
4) Transparency in groundwater related data
Good and reliable information is crucial to facilitate cooperation among aquifer stakeholders. All stakeholders should have easy access to good, reliable data on abstractions, water quality, and aquifer water levels. Current information technology allows information to be made available to an unlimited number of users easily and economically. Nevertheless, India it will be necessary to change the traditional attitude of water agencies of not facilitating the easy access to water data to the general public.
5) The ethics of pumping non-renewable groundwater resources (Groundwater mining)
In some parts of India have very small amounts of renewable water resources but huge amounts of fresh groundwater reserves; e.g. in the Ganga Basin. In such situations, groundwater mining may be a reasonable action if various conditions are met: 1) the amount of groundwater reserves can be estimated with acceptable accuracy; 2) the rate of reserves depletion can be guaranteed for a long period, e.g. from fifty to one hundred years; 3) the environmental impacts of such groundwater withdrawals are properly assessed and considered clearly less significant that the socio-economic benefits from groundwater mining; and 4) solutions are envisaged for the time when the groundwater is fully depleted.
Impact of Climate Change on Ground Water
The studies so far carried out suggest due to climate changes, the incidences heavy down pour towards the end of rainy season will be more. This will affect the ground water recharge. Ground water has become crises management resource and dependence on ground water is increasing during drought, floods, war, and influx of migratory population. In Rajasthan, the major part is drought prone; special attention has to be given for various issues for proper management and governance of meager ground water resources. Further we should be prepared for adverse effects of climate changes, if any. The ground water resources will be affected in many ways such as:
- Increase of incidences of floods in river-likely more recharge and formation of new aquifers.
- Ground water withdrawal during summer may decrease because of more rainfall however, during the winters; the demand of ground water will increase.
- More surface water reservoirs will be required to harness floodwaters and will lead to more recharge over longer period.
- Erosion activity will be more
- Evapo-transpiration losses shall be more especially in areas where ground water levels are shallow
- Proper aquifer management will be required to meet the challenges due to climate change. However more data generation, transparency and community participation will be required to mitigating the effect of global warming.
DOCUMENTATION OF SMALL DRINKING WATER BODIES:
In the rural areas of India, small water bodies such as Ponds, Nadi, Talab etc. are still main source for drinking water both for human & animals. No specific technical & social data is available any where for these water bodies. Irrigation departments are maintains the data base only for such water bodies which are being used for irrigation. The revenue departments have some information for small water bodies such as location, area etc. which is also very old. Numbers of small water bodies are being also constructed every year under various government programs but the data is not properly documented as various agencies are involved in construction.
In the state of Rajasthan alone, number of such water bodies may be over 20,000. No data regarding their capacity, depth, catchment, run off, etc. is available.. In Western Rajasthan such water bodies is life line as villagers take water from them & store in Tankas for the use in summer when all such water bodies dries up.
Need for documentation:
- These not only caters the water needs of human but also of cattle
- These also act as recharge bodies for the wells which are the source of water when such body dries up.
- Their location is available in revenue department without any technical data.
- The information available in the revenue records is seldom updated.
- Over the years, encroachment has taken place due to which the catchment area, water holding capacity has reduced considerably
- Neither the government nor the people are actively involved in upkeep of such structures.
- Even the planning for their revival & repair is difficult without specific data.
In order to provide assured water supply in rural areas, it is urgently required to properly document all technical & social data of all such water bodies using the modern technology such as, Remote Sensing, digitized data; so that it is available to every body. Such data base will be very useful for dovetailing with the on going various programs such as drought relief works, minimum employments guarantee scheme etc. Basic information will have to be collected from various agencies but actual site visit & measurements will have to taken to have correct technical data along with present condition. It will provide strong data base to under take repair & renovate such water bodies. Data so collected will have to be digitized so that easy available to all user agencies & also to stake holders.
Revival of ponds:
Traditional water bodies like village ponds have been catering the local human and livestock population since centuries. These water bodies (ponds) show the engineering skill and high degree of community sharing, social awareness to protect and maintain. The basic philosophy for village pond water was “WATER FOR EVERY BODY”. These ponds were being maintained without any code of conduct or rules for many centuries. In the modern times these ponds are being neglected both by the community and government basically due to introduction of public water supply and/or ground water development through tube wells and hand pumps. Most of these ponds in highly mutilated condition and require immediate attention both from the community and government for their revival and restoration.
Pond/ village tank/nadi is local name given for storing the water from adjoining natural catchments during rainy season as traditional and ancient system of harnessing rain water. These water harvesting structures played a vital role even for irrigation. It is estimated that during 1949-50 out of net irrigated area of India, about 20,152 thousand hectares; the contribution of these structures was 3,434 thousand hectares (17.04%). However due to poor maintenance & easy availlibity of other sources of water it declined to 2,983 thousand hectares (17.44%) by 1986-87. In Rajasthan during 1954-55, the contribution of ponds/tanks for irrigation was 359,000 Ha. out of net irrigated area of 3056,000 Ha. i.e. 11.7% & same had reduced to 124,000 Ha. in 1986-87 (34.54% less).
Depending upon the social custom, land use topography, the catchments can be dedicated and /or common agricultural land. Most of villages with flat topography will have their own pond. The site so selected depends on available natural catchments and its water yield. In general the storage capacity of pond is very limited with water availibity for 6 to 8 months. The larger village ponds having more depth (4-5 M) with large catchments, the water lasts round the year.
It is observed that ponds have very large water spread area as compared to total storage due to which, the evaporation losses of total stored volume of water is very high. In general the total evaporation losses accounts around 50-70% of total storage depending upon various factors such as climate, water spread area etc.
In Rajasthan, there is an urgent need for revival & restoration of traditional water harvesting structures like ponds, nadi, and talab as area is dry. These structures are in depleted condition resulting water becoming dirty and un- suitable for human consumption. As the region suffers from acute water scarcity, people are forced to use this water for drinking as well as for bathing, washing and also for animals.
In general following are the reasons for deterioration of ponds:
- Neglected by community
- Easy availibity of alternative source of water
- Normal tears and wears due to use
- Lack of awarness, knowledge & commitment
- Weathering over the years from rain fall, wind etc.
- Damages by trees, rodants, and pests
- Inadequate provision of finance both by government and community
- Will full damages cause by people having vested interest e.g. tanker lobby
Sewage Management:
It is main challenge foe urban areas, as huge volume sewage is being generated and if not properly managed causes pollution to ground water and soil. In the industrial and urban areas, at times there are no sewage lines, especially in new & upcoming areas. The entire sewage in such areas is disposed in soak pits or sewage pits, which adds to ground water pollution. In the urban & industrial areas; ground water quality shows alarming increase of Nitrate, phosphate etc. Further in industrial belts adjoining to urban areas, the sewage is also being discharged into open unlined channels/drains; which cause pollution. At times from such drains polluted water is being directly used without any treatment for growing the vegetables to cater needs of urban population. As this water is highly polluted having even carsogenic elements such as lead, hexavalent chromium, mercury etc. goes in food chain through such vegetables and affects the human beings. Proper treatment technology and efficient management and disposal of urban and industrial sewage/effluent through water treatment technology is required so that treated water can be used for other purposes including irrigation, maintenance of green areas, flushing of toilets etc. Such management practices not only reduce the stress on public water supply but also will also control the ground water pollution and act as water conservation It is well established that if proper conservation & treatment technology is adopted, the present water consumption can be reduced up to 40% for domestic and industrial sector. Re-cycling of water is one the major way through which this can be achieved. Sewage Treatment Plants (STP), Effluent Treatment Plants (ETP), dual pipe line system in housing complexes for flushing, are the methods through which around 40-50% of water used can be conserved and re-cycled. This will reduce the stress on ground water resources but will also control the ground water pollution, increase the availability of water and fewer loads on common pool of water supply.
Implementation Strategy of Rain Water Harvesting & Artificial Recharge
Rain Water Harvesting & Artificial Recharge To ground water are the need of day not only to mitigate prevailing water crises but also such efforts will result in saving of energy to lift water from wells, improvement in ground water quality, reduction in pollution of surface water bodies, water logging & over flowing of storm water drains in urban areas, controlling of sea water movement in coastal areas, etc.
State governments have made policies & notified that rain water harvesting is mandatory for certain size of lots/buildings but operative principles, guidelines & related infrastructure for approving the design, capacity building is lacking due to which such laws are not effective. Builders are giving the design but it is not sure they have constructed & implemented the structures in true sense. It there for suggested that it is high time to translate the policy/laws in practical aspects for which following are suggestions:
- Identify the persons including architects, engineers, Hydro geologists; NGO’s who can provide such assistance to public. A panel expert for each state/district/city to be prepared & registered.
- There should be intensive training of such registered practitioner which can before the registration. In the training all aspects of climate, rainfall, peak rain fall intensity evaporation hydrogeology to be explained. Since each area will have different hydrogeology setting, the design of recharge structure shall also vary. So detail guide lines along with different structures suitable to the area should be explained.
- Basic charges for preparing the design by the parishioners to be fixed which can be as per roof area etc & also to be notified along with the list of registered parishioners. No body can provide free services & even if it is provided it will not have any value.
- Once the design is provided, the completion certificate has also to be given by same agency.
- Formats for design & completion can be developed in local language. It is also suggested that vide publicity may also be given for need & also for basic information regarding property such as roof area, building plan etc. to be supplied by the owner as & when he approaches.
- In big cities, district HQ a centre can also be opened for such facility which can be self sustainable to provide training and design. Help of NGO for such activity will be very useful.
Sum up: In order to meet the ever growing demand of water for various usages, ground water plays a major role for supply. Its continuation increases specially at the time of droughts which are very common in Rajasthan. Holological approach has to be adopted for proper management and governance of this vital resource. Public participation coupled with scientific and technical approach and political will can only [provide sustainable ground water resource at the time of crises. The progress of any society/ state will be controlled by water as “ Samridhi salila adhineh”.
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