Code No: TMS117 Price: Rs800/- Category: Water
The great problem of Indian’s rainfall is its large diversity both by geographical divisions and seasons of the year. Added to these are large variations in each geographical division from one year to another resulting in floods in some years and droughts in others. No political unit in the world furnishes such contracts as northern India. In the east, we have Cherapunji with an annual mean rainfall of 1140 cm. occasionally it receives as mush as 100 cm. in a single day. In the west we have Jaisalmer where the annual rainfall is about 21 cm. between these extremes we have every possible variation.
The developing country like ours needs a special attention to providing safe drinking water and assuring waster supply for our drought prone areas to meet the demand of our increasing population. Studies on this subject have previously been carried out by TIFAC to study the technological status of the country on “Water Harvesting and Recharging of Aquifers”. Use present report to update the Techno-Market Survey on “Water Harvesting and Charging of Aquifers”.
Scope and Objectives of the Study
The scope and objectives of the study are:
- Identification of technology areas for further development
- Identification of optimum technologies for the country in selected areas
- Development of implementation action plan including identification of agencies
- Development of technology assessment capabilities in the country.
The main scope of the present updated study is to study and analyze:
- The relationship and the importance of Water harvesting and Charging of Aquifers of the broad area to which it belongs.
- The current status of the technology in the world and in the country.
- Assessment of the technology, resources parameters such as energy, raw materials, infrastructure, manpower etc. to arrive at the proffered technology options available to the country.
- Short term and long term economic aspects of preferred options along with their feasibility.
- Impact of the preferred option and its spinoffs
i) For implementations of preferred technology option(s) identifying critical inputs such as raw material, capital goods and human resources required and their availability, investments required to commercialize, and benefits/returns expected.
ii) For R&D / Technology development identification of requirement of inputs and expected benefits.
* Action Plan for implementation of recommendations alongwith identification of:
a) List of available technologies for Indian industry and
b) The agencies/groups/individuals for implementation.
* Expected impact of recommendations, if implemented.
* Identification of technology areas of further development and the foreign technology and its utility to the Indian scenario.
* Identification of various agencies dealing with water resources development.
* Development and implementation of action plan.
Research Design & Methodology
The methodology adopted for this updated study is very elaborate and a mix of various techniques. The study work has gone through the following stages.
In-depth literature survey was undertaken to identify the various technological details which can be adopted profitably and economically for rain water harvesting and recharging of aquifers. The other information like rainfall, duration of rainfall, aquifers, surface water and groundwater flow and climate of the region was studies very carefully. Some socio-economic factors like population density, afforestation programmes and agricultural production have also been taken into account. The details of literature survey (the books, journals and the research papers) are given in the Bibliography and libraries contacted are given in Annexure – V at the end of the report.
International data base was searched for latest developments in this file and the list of related agencies/research centres contacted for technological details given in Annexure –I.
The data was collected through:
- Structured questionnaires
- Personal interviews
- Literature study
- Group discussions with experts
A field study was conducted to gather the information regarding the developments and the constraints for the implementation of the plans.
The information thus gathered was processed, analysed and compiled under various sub-heads.
A detailed survey of foreign technological advancements was conducted and compared with Indian Technology to find out the one more suitable one for the Indian environment by analyzing the socio-economic, geological, hydrological and other physiographic conditions.
Highlights of the Survey
Study of Previous Reports
After studying the available reports certain important points have been noticed which are as follows:
i) TMS on “Availability of Potable Water-phase II and Harvesting of Rain Water”
The report covers a lot of information in a detailed manner and gives a clear picture of the various water harvesting methods both traditional and the latest. Some of the traditional structures for water harvesting are Nadi, Tanka, Sand filler reservoirs, roof-top collection/ Hill-top collection, Ooranies, etc. The latest technology, which deals with the enhancement of runoff and controlling of evaporation loss has been studies in detail.
This report also explain, how the structures like percolation tanks, anicut/check dams, sub-surface dams/barriers, etc. helping storage of water and recharging of aquifers. The storage of water in the aquifers and the various artificial methods for recharging of aquifers i.e. spreading, injection and Induced recharge have also been dealt with.
ii) TMS on “Surface Water Harvesting and Recharging of Aquifers”
This report was more scientific and informative which contains in-depth literature analysis and intensive filed survey. The report covers water resources management and various harvesting technologies traditional and emerging for our agricultural lands, low investment schemes for the development of new projects and harvesting of water with an immediate effect.
In mechanical surface treatment is discusses the methods like surface roaded catchment, smoothing and compacting the soil surface, clearing sloping surface etc.
IICT technology which is one of the recent technologies, can harvest water within 10 minutes with the marginal soaking for two minutes. This also gives information about recent advancements like mechanical surface treatment (soil compaction by adding various additives to block seepage loss) and chemical surface treatment (application of monomolecular film, agrifilm, geo-membranes like LDPE, HDPE, PVC, Butyl rubber, EPDP) and recharging of aquifers alongwth their environmental and social benefits and problems.
i) About 70% of the earth surface is covered by water, amounting to some 1384x12015m3. of this only 1% is fresh water, out of which 99% is located underground, much of it more than 900 meters deep. Rivers and streams which supply most of man’s water needs account for only one hundredth of one percent of the total reserves, and that is being most quickly contaminated through man’s own activities.
ii) The total amount of surface water available to India is 1880 km3 which is 4% of World’s surface water resource, whereas the country’s population is about 16% of the World population. India’s water wealth is about equal to that of USA although the area available is only 4% of the latter. India is using presently 17.4% of surface water, the rest flows down into the sea. Indian rivers carry 80 to 90% water during monsoon months. Unless this water is conserved through surface and underground reservoirs, it would continue to run waste into the sea, after causing disastrous floods.
iii) The total current demand for water is about 552 km3, where as in future the requirement will go up to 750 km3 in 2000 A.D., 1050 km3 in 2025 A.D. and 1150 km3 in 2050 A.D.
iv) The present requirement of community for domestic use if estimated to be 25 km3. Water demands of the community have been estimated to be about 33 km3 by the year 2000 A.D. This may increase to 52 km3 by 2025 A.D. and further to 60 km3 by 2050 A.D.
v) The water demand for irrigation is about 460 km3. The water demands for irrigated agriculture will go up to 630 km3 in the year 2000, 770 km3 in the 2025 and 800 km3 in the 2050.
vi) The present requirement for industrial use is estimated to be 15 km3. This demand may go upto 30km3 by the year 2000 A.D. and 120 km3 by the end of 2025 A.D. and 130 km3 by the end of 2050 A.D.
vii) For hydro-power generation, the consumption use of water is only by way of evaporation from reservoirs, which is estimated to be of the order of 15km3. This would be of the order of 27 km3 in the year of 2000 A.D., 71 km3 by the end of 2025 A.D. and 130 km3 by the end of 2050 A.D.
viii) The western part of our country i.e Rajasthan receives only 100 mm of rainfall which is very less than the average rainfall of the country i.e. 117 cms; while in Cherapunji it is over 11000mm, which is much more than the average. Nearly 9% of the country is arid. Due to the aridity condition, even one good crop is not possible in normal rainfall years. Abut 40% of the country is semi-arid. Because of vagaries of monsoons, these regions are drought prone and, therefore, only one good crop is expected and that too is frequently lost under conditions of scanty rainfall.
ix) National water policy recommends that water resources be planned and developed on an environmentally sound basis.
- Water should be transferred from a surplus basin to a deficit basin and multipurpose projects should be developed.
- The coordinated developments of surface and groundwater and their conjunctive use should be envisaged right from the project planning stage.
x) Ponds, Nadis, Talabs, Haffirs, impounding ponds etc. are old age practices for rain water harvesting and storage for multipurposes.
The techniques like roof-top harvesting have been primarily used fo drinking purposes and the runoffs, inundation methods, khadinas, cisterns, submerged tanks, embankments and farm ponds have been used for agriculture purposes.
xi) Traditional waster harvesting systems should the upgraded for water harvesting
xii) The various problems associated with water harvesting and recharging of aquifers are silting, seepage, evaporation and submergence of cultivable land.
xiii) Run off induced by surface treatments is one of the important aspects of “water harvesting and recharging of aquifer”. The various surface treatment processes are:
- Clearing surfaces of vegetation and loose material
- Improving vegetation management by planting different species or by cropping.
- Mechanical treatment of the soil, including smoothing and compacting the surface, as on contour steps and microcatchments,
- Making a hard surface using traditional soil stabilization techniques.
- Using various chemicals for water conservation.
xiv) Various technological aspects are discussed for upgradation of water harvesting structures. Some of he new methods are discussed along with their economic analysis and suability to Indian Condition.
xv) Several methods for artificial recharge are discussed very elaborately along with their suitability of Indian condition. Some of the methods discussed below:
1) Spreading methods
2) Pit method
3) Induced recharge method
4) Well method
xvi) Various problems associate with the artificial recharge are also discussed very elaborately to help take the precautionary measures.
Recommendations and Action Plan
The action plan and suggestions are as follow:
- New technology should be developed and adopted for rain water harvesting and recharging of aquifers.
- The policy for water harvesting and aquifer recharge are supposed to be formulated by the Government body, NGO’s and premier educational institutions.
- Exploitation of water resources should be in the right proportion, ensuring the hydrological balance.
- Conservation of forests, afforestation and conservation of he soil profile should be undertaken into account for better management of water balance and to check the siltation in the water reservoirs.
- Plans for Command Area Development should be taken into account.
- Eco-friendly chemicals should be used for he water treatment.
- General public should be involved for ensuring a success of the development of the water harvesting projects.
- The evaporation loss should be minimized through various processes such as chemical treatment, hydrophobic coatings and other mechanical methods.
- Seepage loss should be minimized by using developed geomembranes/super plastics.
- Domestic roof top harvesting of water should be encouraged.
- Aquifers recharging programmes should be initiated for better water harvesting.
- Existing aquifers should be optimally used only during the scarcity period.
- In drought prone area, crops requiring less water and of short duration ad of drought resistant variety should be planted so as to cover large area and population.
- Desilting of tank beds, check dams, contour bunding within catchment areas, construction of percolation tanks for recharging groundwater should be carried out.
- To save on industry related water uses alternate production processes and technology can be adopted.
- State of art on use of chemicals for reducing evaporation losses from water surfaces be pushed forward by intensifying research to make them cost effective and environmentally safe.
- Groundwater development programme should be limited to replenishable quality. Artificial recharge should be provided in areas where such technology is available. Percolated tanks are of special interest in this connection and it should be planned taking geological and hydrological features into account.
- Conjunctive use of surface and groundwater is of special value in drought prone areas and should be insisted upon and water thus saved should be made available to the needy areas.
- Participation of farmers, community and voluntary organizations is highly necessary for a large scale practice of water harvesting, water conservation and recharging of aquifers.
- All efforts should be made to save water in all Command Areas by modified cropping, conjunctive use and modernization of irrigation system and water harvesting structures.
- Integrated watershed Management approach is recommended for optimum development of land, water and plant resources within the natural boundaries of a drainage area to meet the basic minimum needs of the people in a sustained manager.
- In planning water management for arid and semi-arid areas, value per unit of water should also be considered and optimized.
- Existing aquifers should be optimally utilized by storing water during rainy season.
- Specific programmes should be initiated to locate suitable topographical, hydrological and geological sites which should be developed as water resources by converting them into aquifers.
- Evolve methods to be used to check the evaporation and see page of water.
- Suggested suitable change I cultivation habits so that water logged and drought affected lands are properly utilized.