Rain Water Harvesting and Conservation

1. National Seminar on Rainwater Harvesting and Water Management 11-12 Nov. 2006, Nagpur
STATE OF THE ART LECTURE
1. Rain Water Harvesting, Conservation and Management Strategies
for Urban and Rural Sectors
* Dr. R. K. Sivanappan
1. Introduction Nabateans and other people of the Middle east.
Water is essential for all life and used in many While the early water harvesting techniques used
different ways, It is also a part of the larger natural materials, 20th century technology has made
ecosystem in which the reproduction of the bio it possible to use artificial means for increasing runoff
diversity depends. Fresh water scarcity is not limited from precipitation.
to the arid climate regions only, but in areas with Evenari and his colleagues of Israel have
good supply the access of safe water is becoming described water harvesting system in the Negve
critical problem. Lack of water is caused by low desert. The system involved clearing hill sides to
water storage capacity, low infiltration, larger inter smooth the soil and increase runoff and then building
annual and annual fluctuations of precipitation (due contour ditches to collect the water and carry it to
to monsoonic rains) and high evaporation demand. low lying fields where the water was used to irrigate
The term water harvesting was probably used crops. By the time of the Roman Empire, these runoff
first by Geddes of the University of Sydney. He farms had evolved into relatively sophisticated
defined as the collection and storage of any form of systems.
water either runoff or creek flow for irrigation use. The next significant development was the
Meyer’s of USDA, USA has defined it as the construction of roaded catchments as described by
practice of collecting water from an area treated to the public works Department of Western Australia
increase runoff from rainfall. Recently Currier ,USA in 1956. They are so called because the soil is graded
has defined it as the process of collecting natural into ditches. These ditches convey the collected
precipitation from prepared watershed for beneficial water to a storage reservoir. Lauritzan, USA has
use. Now a days water harvesting has become a done pioneering work in evaluating plastic and
general term for collecting and storing runoff water artificial rubber membranes for the construction of
or creek flow ,resulting from rain in soil profile and catchments and reservoirs during 1950’s. In
reservoirs both over surface /under surface. 1959,Mayer of water conservation laboratory, USA
Previously this was used for arid and semi arid areas, began to investigate materials that caused soil to
but recently their use has been extended to sub humid become hydrophobic or water repellent. Then
and humid regions too. In India water harvesting gradually expanded to include sprayable asphalt
means utilizing the erratic monsoon rain for raising compounds, plastic and metal films bounded to the
good crops in dry tracks and conserve the excess soil compaction and dispersion and asphalt fiber glass
runoff water for drinking and for recharging membranes. Early 1960, research programmes in
purposes. water harvesting were also initiated in Israel by Hillal
and at the University of Arizana by Gluff. Hillal’s
2. History of Rain Water Harvesting work related primarily to soil smoothing and runoff
Water harvesting like many techniques in use farming. Cluff has done a considerable amount of
today is not new. It is practiced as early as 4500 work on the use of soil sealing with sodium salt and
B.C. by the people of Ur and also latest by the on ground covered with plastic membranes.
* International Consultant in Water Resources & Irrigation,
No:14, Bharathi park, 4th Cross Road, Coimbatore 641 043
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2. Water harvesting was practiced more than These rainwater are used for all labs, which require
1000 years back in South India, by way of pure and good quality of water. In the same way
construction of irrigation tank, ooranis, temple tanks, the rainwater falling on the terrace in all the building
farm ponds etc, but the research in India on this constructed subsequently are collected and stored
subject is of recent one. Work is taken up at in the underground masonry tanks Even the surface
ICRISAT, Hyderabad, Central arid Zone Research water flowing in the Nalla’s in the campus are also
Institute, Jodhpur, Central Research Institute for diverted by providing obstructions, to the open wells
dryland Agriculture (CRIDA), Hyderabad, State to recharge ground water.
Agricultural Universities and other dry land research Hence Rainwater harvesting is as old as
centers throughout India. civilization and practiced continuously in different
In Pakistan, in the mountainous and dry ways for different purposes in the world The only
province of Balukhistan, bunds are constructed thing is that it has not been done systematically in all
across the slopes to force the runoff to infiltrate. In places. Need has come to harvest the rainwater
China, with its vast population is actively promoting including roof water to solve the water problems
rain and stream water harvesting. One very old but everywhere not only in the arid but also in the humid
still common flood diversion technique is called region.
‘Warping’ (harvesting water as well as sediment).
When water harvesting technique are used 3. Need for Rain Water Harvesting
for runoff farming, the storage reservoir will be soil Water is a becoming a scarce commodity and
itself, but when the water is to be used for livestock, it is considered as a liquid gold in this part of the
supplementary irrigation or human consumption, a country (especially in Coimbatore, Erode, Salem
storage facility of some kind will have to be Districts of Tamil Nadu). The demand of water is
produced. In countries where land is abundant, water also increasing day by day not only for Agriculture,
harvesting involves; harvesting or reaping the entire but also for household and Industrial purposes. It is
rainwater, store it and utilize it for various purposes. estimated that water need for drinking and other
In India, it is not possible to use the land area only to municipal uses will be increased from 3.3 MHm to
harvest water and hence water harvesting means 7.00 MHm in 2020/25. Similarly the demand of water
use the rain water at the place where it falls to the for industries will be increased by 4 fold i.e. from
maximum and the excess water is collected and 3.0 MHm ti 12.00 MHm during this period At the
again reused in the same area. Therefore the same time more area should be brought under
meaning of water harvesting is different in different irrigation to feed the escalating population of the
area/ countries. The methods explained above are country, which also needs more water. But we are
used for both agriculture and to increase the ground not going to get one litre more water than we get at
water availability. present though the demand is alarming.
The water harvesting for household and for The perennial rivers are becoming dry and
recharging purposes are also in existence for long ground water table is depleting in most of the areas.
years in the world. During rainy days, the people in In Coimbatore, the depletion is about 30-50m in the
the villages used to collect the roof water in the last 30-40 years. Country is facing floods and drought
vessels and use the same for household purposes in the same year in many states. This is because, no
including drinking. In South East Asian countries concrete action was taken to conserve, harvest and
people used to collect the roof water ( thatched roof manage the rain water efficiently.
by providing gutters) by placing 4 big earthern drums The rainfall is abundant in the world and also
in 4 corners of their houses. They use this water for in India. But it is not evenly distributed in all places.
all household purposes and if it is exhausted only India being the monsoonic country, the rain falls only
they will go for well water. The main building of the for 3 to 4 months in a year with high intensity, which
Agricultural College at Coimbatore was constructed results more runoff and soil erosion. Total rain occurs
100 years ago and they have collected all the roof only in about 100 hours out of 8760 hours in a year.
water by pipes and stored in a big under ground It also erratic and fails once in 3 or 4 years. This is
masonry storage tanks by the sides of the building. very common in many parts of the country.
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3. The availability of water in the world, in India hard rock in Tamil Nadu. Further the porosity of the
and in Tamil Nadu is given below with rainfall. rock is only about 3%. The natural recharge of
rainwater in this region is only about 8 -12%, which
Places Rainfall Population Availability of is very minimal. Therefore there is an urgent need
in mm Water/Person/Yr to take up the artificial recharge of the rain for which
M 3 /P/Year water harvesting and water conservation structures
World 840 6 Billion 700 are to be build up in large scale. The rainfall in coastal
area is more than 1200 mm (Chennai) still; drinking
India 1150 1.0 Billion 2200 water is a problem in almost every year. This is
Tamil Nadu 925 62.5 Million 750 because the entire rainwater is collected in masonry
drains (from houses, streets/roads etc) are taken to
If the availability of water is 1700 M3/p/y, the sea instead of taking into the ground water
there will be occasional water stress, and if it is less aquifers or in surface reservoirs by pumping if need
than 1000 M3/p/y, it is under water scarcity condition. be. The ground water available can be used during
Though India is not under water stress conditions summer and make the aquifer empty so that the
but Tamil Nadu state is already under water scarcity rainwater can be put into the aquifers during rainy
condition, but there is no need for panic since it is period by suitable water harvesting measures.
possible to manage this condition as in the case of All the above details indicate the need for
Israel where the availability is only about 450 M3/p/ water harvesting measures in urban and rural area
y, by means of water harvesting, water conservation for the use of Agriculture, drinking and other
and water management. purposes.
Water scarcity / stress is not limited to the
arid regions; only but also occurring in high rainfall 4. Methods of Water Harvesting in Rural and
areas also. Chirapunji gets more than 11,000mm of Urban Areas
average annual rainfall but face drinking water There are different / various system of water
problem before monsoon commences whereas in harvesting depending upon the source of water
Ralegoan Siddhi, in Maharastra there is no water supply and places as classified below.
scarcity problem though the annual average rainfall a) In situ Rainwater harvesting
is only about 450mm. Hence to mitigate water • Bunding and terracing.
problem / drought etc, there is an urgent need to • Vegetative / stone contour barriers.
follow our ancestral way of water harvesting and
• Contour trenching.
the latest technologies adopted in Soil and water
conservation measures on watershed basis including • Contour stone walls.
roof water harvesting etc which are described in • Contour farming.
detail below. • Micro catchments.
The Theme paper on Water vision 2050 of • Tie ridging methods
India, prepared by Indian Water Resources • Farm ponds.
Society(IWRS) has indicated that a storage of 60 b) Direct surface runoff harvesting
MHm is necessary to meet tbne demand of water • Roof water collection
for irrigation, drinking and other purposes. But the • Dug out ponds / storage tanks
present live storage of all reservoirs put together is
• Tankas
equivalent of about 17.5 MHm which is less than
10% of the annual flow in the rivers in the country. • Kundis
The projects under contruction (7.5 MHm) and those • Ooranis
contemplated (13 MHm) are added, it comes only • Temple tanks
37.50 MHm and hence we have to go a long way in • Diversion bunds
water harvesting to build up storage structures in • Water spreading
order to store about 60 MHm. c) Stream flow / runoff harvesting
More than 75% of the areas comes under • Nalla bunding
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4. • Gully control structures municipalities / corporation without any difficulty to
• Check dams – Temporary some extent.
Permanent To sum up the following types of Water
• Silt detension tanks Harvesting System for different uses can be
• Percolation ponds implemented in different parts of the country.
d) Sub surface flow harvesting
• Sub surface dams No. Region Types of Water Use
• Diaphragm dams
e) Micro catchment’s / watershed 1 Arid Artificial catchments Drinking
• Inter terrace / inter plot water harvesting plains to capture rainfall
(tankas or kundis in
• Conservation bench terrace
Rajasthan)
f) Runoff inducement by surface treatment
• Roaded catchments Tanks or talabs in Drinking
• Use of cover materials – Aluminum foils, Rajasthan to capture and
Plastic sheet, bentonite, Rubber, etc surface runoff irrigation
• Using chemicals for water proofing, water
repellent etc. to get more run off water. Embankments / Irrigation
obstructions across water & also
A comprehensive watershed development on drainage / Nalla to for recharging
watershed basisincluding water harvesting structures capture surface runoff
are given in the figure 1.
2 Semi Tanks / Ponds/Eri to Irrigation
Arid capture surface runoff water and
5. Plan of Action for Rainwater Harvesting places and also chains of drinking water
As stated early, rainwater harvesting is as old tanks called cascade. through
as civilization and is practiced in many countries recharge of
including India from time immemorable. But ground water
government and people remember this only when
water is not available even for drinking purposes. 3. Flood Mud embankment Irrigation
There is no use of spending huge sum of money plains which may be water and
breached during the drinking water
when we notice the water scarcity for drinking,
floods. through
industry and agriculture. These activities / structure recharging
should be taken / constructed before the rainy season ground water
so that the rain water which goes as runoff outside
the sub watershed / city limits can be collected and 4 Hill and Diverted stream flows Irrigation
used directly or by recharging into the ground. Mountain Jammu, M.P., water
Government is undertaking the wasteland / region Maharastra
watershed development programs, but not done in a
comprehensive / integrated manner / holistic 6. Case Study In Water Harvesting
saturating the watershed in all water harvesting There are numerous case studies available in
measures. Hence there is a need to take up water harvesting both in Rural and Urban sectors.
watershed development programmes – mainly water In Rural areas it is Soil and Water conservation
harvesting measures in a scientific and systematic measures taken on watershed basis to conserve and
manner. augment ground water. In the urban sector, it is
The government of Tamil Nadu has laid mostly roof water harvesting for direct use and
condition that in any building construction, water recharging the ground water and also collecting of
harvesting work should be included and executed, surface runoff from pavements / roads and
but in practice, it is not perfect. The authorities recharging it into the ground through recharge pits
concerned should monitor the programme so that or using abandoned / existing wells. The following
the drinking water problem can be solved in all are the places where rain water / roof water
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5. harvesting has been implemented in a successful the rain water harvesting to their Industry premises.
manner. If the above measures are implemented in
1. Rural areas Rural and Urban areas, the drought in rural areas
a. Ralegoan Siddhi in Maharastra state and drinking water problem in Urban and Rural
b. Lakshman Nagar and Varisai Nadu inTheni population can be solved to some extent. The people,
Dt., Tamil Nadu. NGO, and Government should joint together and
c. Alankulam Taluk in Tirunelveli Dt., Tamil Nadu. implement the rain water harvesting in a big way in
d. Aravari watershed in Alwar Dt., of Rajasthan. all places in the years to come to solve water scarcity
e. Maheshwaram watershed in Andhra Pradesh. problem in the country.
f. Kapilnalla watershed in Karnataka
7. Conclusions
2. Urban Sectors It is very important to make water everybody’s
Mostly the roof water harvesting measures are taken business. It means a role for everybody with respect
up. to water. Every household and community has to
a. India become involved in the provision of water and in
i. Tamil Nadu Agricultural University, Coimbatore, the protection of water resources. Make water the
all main buildings. subject of a people’s movement. It means the
ii. PRICOL, Periyanaickenpalayam (Industry empowerment of our Urban and Rural community,
Building), Coimbatore i.e., to manage their own affairs with the state playing
iii. TWAD Board / office and PWD office at a critical supportive role.
Chennai. Further involving people will give the people
iv. Numerous Apartment buildings in Chennai. greater ownership over the water project including
v. Sundaram and Clayton Ltd, Padi, Chennai – watershed development, Soil and Water
(Industry buildings) conservation and water harvesting will go a long
vi. TVS training schoool at Vanagaran, Chennai way towards reducing misuse of government funds.
vii. Rastrapathi Bhavan, Delhi. It will also develop the ownership (own water supply
viii. Center of science and environment building at systems), they will also take good care of them. In
Delhi. this way it is possible to solve water problems facing
ix. Institute of economic growth, New Delhi. the county in the 21st century.
b. Foreign Countries References
i. Thailand – Many houses including thatched • Ake Nilsson, Ground water dams for small-scale water
houses in villages. supply, IT publication, 1988.
ii. Japan – office complex. • Center for science and environment. A water-harvesting
manual, Delhi 2001.
iii. Germany – office buildings. • Center for Science and Environment – Making water
iv. Singapore – office buildings. everybody’s business, New Delhi, 2001.
• Chitale M.A., A blue revolution, Bhavans Book
Rules and regulations have been framed for University, Pune 2000.
Rain Water Harvesting in all corporation, • CII, Rainwter harvesting – A guide, New Delhi 2000.
municipalities and panchayat unions in Tamil Nadu. • Rajiv Gandhi, National Drinking water missions
The Gujarat government has issued a general Handbook on Rainwater harvesting, Government of India,
New Delhi, 1998.
resolution for the effort that no new construction • Sivanappan, R.K., Soil and Water Conservation and
would be allowed if it does not have provision for Water harvesting, Tamil Nadu Afforestation project,
roof top rainwater harvesting. This would be valid Chennai, 1999.
in all 143 municipalities and 6 urban development • Sivanappan, R.K. Water harvesting, ICCI, Coimbatore
authorities in the state. It is heartening to note that 2001.
Confederation of Indian Industries (CII) and • Stockholm water Symposium – ‘Water harvesting’
Stockholm, Aug 1998.
Federation of Indian Chambers of Commerce and
• Verma HN & Tiwan KN current status and Prospects of
Industries (FICCI) have taken action to implement Rain Water Harvesting, NIH, Roorkee, 1995.
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6. National Seminar on Rainwater Harvesting and Water Management 11-12 Nov. 2006, Nagpur
2. Water Issues and Related Concerns
* Prof. (Mrs.) Vijaya Agarwal ** Prof. (Dr.) J. H. Agarwal
ABSTRACT
By 2025, world population will be 8 billion – water will become scarcer. Global
farming accounts for 70% of water use, while only 17% of farmland is irrigated and
it provides only 40% (estimated) of world’s food. Water application losses in irrigation
are quite high – almost 40 % of the total irrigation water is lost. Per capita irrigated
agricultural land is declining – main reason shortage of water. Water table is falling
steadily in intensive farming regions. People and ecosystems are under threat from
persistent chemicals like pesticides, fertilizers and heavy metals in waters. There are
no serious efforts to gain water by practices like rainwater harvesting, watersheds
and mini-ponds, reuse and recycling of waste water. It is said there is enough freshwater
in world – however, it is not always available in the right place or right form. The
problem is mainly of access, distribution, and optimum utilization.
The paper discusses related concerns and outlines what need to be done.
Key words : Fresh water, harvesting and conservation of water, water reuse, water
management in agro-ecosystems, electronics and IT based devices.
1.0 WHAT NEED TO BE DONE? – Some • Water conservation and higher efficiencies for
suggestions water-conveyance, water-application and
water-use. Scientific management of water by
1.1 Ground Water Recharge, Reuse, and making use of electronics and IT based aids
Efficient Systems like soil-moisture measurements.
• Watersheds, Check dams, Roof water • Participation of women in conservation of
harvesting (should be made compulsory and water.
mandatory), India uses around 15% of rain • Competent, knowledgeable and experienced
water while Israel almost 100% (see personnel to be involved in management of
Appendix). water related activities and balanced
• Efficient irrigation systems: Sprinkler, drip, distribution of water.
trickle (macro and micro irrigation). Drip
irrigation cuts water use by between 30% and 1.2 Water needs of plants
70% , increases crop yield by between 20% Agriculture accounts for 70% of fresh water
and 90%, compared with traditional irrigation. use. It requires as much as 2000 litres of water to
• Sequential water use : Reuse, recovery and grow 1 kg of rice. Water (with elements H + O) is
recycling of waste waters. a vital component for crop growth. Plants need
• Switching to less water-dependent crops. water for:
* Selection Grade Assistant Professor (Electrical Engineering), Department of Agricultural Structures and
Environmental Engineering, College of Agricultural Engineering, Jawaharlal Nehru Agricultural University,
Krishi Nagar, Adhartal P.O., Jabalpur 482 004, Email : vijaya_agarwal@gmail.com Phone : 0761 – 2681820
** Retired Director Instrumentation & Project Coordinator UNDP-GOI-MAEP, JNAU, G-83 Krishi Nagar,
Adhartal P.O., Jabalpur 482 004 Email : jhagarwal@sancharnet.in Phone : 0761 – 2680400
6

7. • Temperature regulation, web site: www.irrometer.com).
• Photosynthesis, • Tensiometric principle, indicates the amount of
• Transport of nutrients from soil to plant, and moisture available to plants.
• Transport of assimilates from plant parts to the • Direct display of moisture.
produce location. • Automatic control of irrigation systems.
1.3 Excess water harmful 4. Watermark Soil Moisture Sensor – 200SS
Excess water to crop is harmful. It causes/ (Irrometer Company, USA,
results in : web site : www.irrometer.com ).
• Spoilage of soil-health, salinity built up. • Solid state, electrical resistance type.
• Loss of nutrients due to excessive leaching. • Available with meter, electronic control unit.
• Contamination of surface and ground water. • Low cost.
• No proportionate increase in yield, and wastage
of water and energy. 5. Sentek Soil Moisture Probes – EnviroSCAN,
EnviroSMART, EasyAG and Diviner 2000
2.0 SOIL-MOISTURE MEASUREMENT (Sentek, Australia,
SYSTEMS web site : www.sentek.com.au ).
A variety of electronics and microprocessor- • Electrical capacitance principle, continuous
based devices for soil-moisture measurement are measurement of soil moisture over multiple
available for scientific water management in agro- depths in root-zone.
ecosystems. Some of the devices are based on • Easy installation, data download options for
electrical impedance, infrared thermometry and retrieving data in the field or remotely.
time-domain reflectometry. Salient features of five • Provides information on crop water use and
such devices are given below: water management in root-zone, facilitates
1. Gro-Point GP-ERS Moisture Sensor and decisions on how much and when to irrigate.
Irrigation Management System (ESI
Environment Sensors Inc., Canada, These devices should be used for scientific
web site : www.esica.com ). management of water in agro-ecosystems to make
• Soil moisture range: 5 – 50 % (volumetric) +/- efficient use of water and to minimize problems like
1%. water logging, salinity built up, non-point
• Rechargeable battery or mains operated. contamination (see Appendix , Fig. 2 (a), (b), (c)
• Available with hand-held display or with data and (d) for photographs of some soil-moisture
logger. devices).
• Intelligent Irrigation System, with a set of
sensors, computer, 3.0 IT ENABLED SUPPORT SYSTEMS
software and irrigation controller. FOR OPTIMUM UTILIZATION
Use of Crop Simulation Models, Weather
2. Moisture-Point, Multi-Probe Sensor MP-917 data and Knowledge Base(s):
(ESI Environment Sensors Inc., Canada, • To select appropriate crop and crop variety
web site: www.esica.com ). suitable to agro-climatic pattern, and switch to
• Soil moisture range : 0 – 50 % (volumetric) +/- less water-dependent crops.
1.5%. • To decide about the date of sowing, duration of
• A single probe gives moisture profile. crop.
• Rechargeable battery or mains operated. • To decide about the irrigation inputs to crop by
• LCD display or datalogger or RS-232 with monitoring soil-moisture and crop-water stress,
PC. to decide when and how much to irrigate, and
to optimize utilization of water by using
3. Irrometer-Tensiometer Probe (Irrometer efficient systems like sprinkler, drip and trickle
Company, USA, irrigation.
7

8. • To apply fertilizer to crops through irrigation Population Reports, Series M, No. 14.
water by computer-controlled fertigation Population Information Program, Johns Hopkins
techniques. School of Public Health, Baltimore, December
• To adopt controlled environment farming 1997.
wherever easily feasible: This provides • United States Department of Agriculture. ARS
monitoring and control of lighting, humidity, National Program # 201 on Water Quality and
temperature, CO2 level, irrigation, nutrients Management : Component I – Agricultural
supply, chemical treatments, etc. watershed management, Component II –
• To adopt a GIS coupled soil-water-balance Irrigation and drainage management,
computation system to calculate the available Component III – Water quality protection and
residual soil-moisture for its better utilization. management, 1998 – ongoing. <
www.nps.ars.usda.gov >
4.0 CONCLUDING REMARKS • Li, F., S. Cook, G. T. Geballe and W. R.
Water is a very valuable resource. There are Burch. Rainwater Harvesting Agriculture: An
no serious efforts to gain water by practices like integrated system for water management on
rainwater harvesting, watersheds and mini-ponds. rainfed land in China’s semiarid areas, AMBIO
Rainwater harvesting should be made mandatory. – Journal of Human Environment, Vol. 29, Issue
Sequential water use (reuse, recovery and recycling 8, December 2000, pp. 477-483.
of waste waters) should be planned wherever • Gleick, P. H. The World’s Water 2000 - 2001:
possible so that the load on fresh water can be The Biennial Report on Freshwater Resources.
reduced. Water’s presence in agro-ecosystems Island Press, Washington, DC, 2000.
should be treated on a holistic approach, and by • Rijsberman, F. and D. Molden. Balancing water
employing scientific management tools it should be uses: water for food and water for nature
judiciously used. For agriculture, an integrated (Thematic background paper), International
water management practice consisting of three main Conference on Freshwater, Bonn, Germany, 3-
components – rain water harvesting, water-saving 7 December 2001.
micro-irrigation, and highly efficient crop • Smajstrla, A.G., B.J. Boman, D.Z. Haman, F.T.
production – should be adopted. Conservation of Izuno, D.J. Pitts and F.S. Zazueta. Basic
water should be taken as a way of life and widely irrigation scheduling in Florida < http://
adopted. edis.ifas.ufl.edu/AE111 > Bulletin # 249,
Agricultural and Biological Engineering
SELECTED READING Department, Cooperative Extension Service,
• Goodchild, M.F., B.O. Parks and L.T. Steyaert Institute of Food and Agricultural Sciences,
(Eds.). Environmental Modelling with GIS. University of Florida, Gainesville, 2002.
Oxford University Press, New York, 1993. • Fahimi, F.R., L. Creel and R.M. De Souza.
• Berkhoff, J. A Strategy for Managing Water in Finding The Balance: Population and Water
the Middle East and North Africa. World Bank, Scarcity in the Middle East and North Africa.
Washington, DC, 1994. Population Reference Bureau, Washington, DC,
• Bian, F., Z. Sha and W. Hong. An integrated 2002.
GIS and knowledge-based decision support • Simonne, E. and G. Hochmuth. Irrigation
system in assisting farm-level agronomic scheduling as a means of applying the right
decision-making. J. Geogr. Syst., 1995, 3, pp. water amount and monitoring soil moisture for
49-67. vegetable crops grown in Florida in the BMP
• Soil-Moisture Systems. ESI – Canada < era. Document # HS909, Horticultural Sciences
www.esica.com > , Irrometer – USA Department, Cooperative Extension Service,
< www.irrometer.com > , Sentek – Australia < Institute of Food and Agricultural Sciences,
www.sentek.com.au > . University of Florida, Gainesville, 2003 < http:/
• Hinrichsen, D., B. Robey and U. D. /edis.ifas.ufl.edu/HS166 >
Upadhyay. Solutions for a Water-Short World. • Rijsberman, F. Sanitation and Water, In: Global
8

9. crises, global solutions (Ed. - B. Lomborg), 2. Soil-Moisture Probes :
Cambridge University Press, Cambridge, 2004,
670 p.
• IWMI. Beyond more crop per drop (Note
prepared by F. Rijsberman and D. Molden for
the 4 th World Water Forum, Mexico, 16-22
March 2006), International Water Management
Institute, Sri Lanka, Press release, 17 March
2006.
APPENDIX
1. Rainfall Facts : Percentage of Rainfall (a) Soil-Moisture Probe for moisture measurements in the
consumed to support direct and indirect human root zone of a crop (Sensors are mounted on a screwable
insert )
uses of water (Source: IWMI, Sri Lanka)
System / Uses % of Rainfall
Food – irrigation 2
Food – rainfed 4
Domestic & industry 1
In-stream ecology 8
Flood runoff 27
Permanent grazing 18
Grasslands 11
Forests & woodlands 17
Arid lands 5
All others 7
Total 100
(b) Tensiometer type soil-moisture probe.
(d) Soil-Moisture Probe working on impedance
principle.
[Note : Photographs of the probes from websites / product
(c) Sentek Soil-Moisture Probe working on literature. Disclaimer: No preference to any particular firm
capacitance principle. by the authors].
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10. National Seminar on Rainwater Harvesting and Water Management 11-12 Nov. 2006, Nagpur
3. Rainwater Harvesting Techniques
* Dr. K. A. Patil ** G. K. Patil
ABSTRACT
Water is our most precious natural resource and something that most of us take for
granted. We are now increasingly becoming aware of the importance of water to our survival
and its limited supply. The human beings require water for various purposes. The most part
of the earth surface i.e. about 71 % is covered by water. Out of total volume of water
available on the surface of the earth 97 % is saline water, 2 % water is in the form of ice
and glaciers and only 1 % is fresh and potable water. India is well endowed nations in the
world in terms of average annual rainfall. It is unbelievable but it is true that Cherapunji
which gets 11000 mm annual rainfall still suffers from serious drinking water shortage.
Though India’s average annual rainfall is 1170 mm; in the deserts of western India it is as
low as about 100 mm. Hence, it is necessary to opt for rainwater harvesting measures for
fulfillment of water requirement.
INTRODUCTION harvesting can play important role for solving the
India is one of the developing countries. Due water problems.
to faster industrialization and urbanization and
increase in population water demand is increasing WHY RAINWATER HARVESTING?
day by day. Rainfall in India is highly irregular. Most Rainwater harvesting means the activity of
of it is concentrated during a few months of the year direct collection of rain water which can be
and maximum amount flows away resulting in poor recharged in to the ground water to prevent fall of
recharge of ground water. There is significant spatial ground water level or storing in surface or
imbalance in water resource available and water underground water tank. It is most suited in today’s
demand. Therefore, it is becoming necessary to context due to following reasons.
bring water from distant places increasing the cost 1. It is the most scientific and cost effective way
of conveyance. It is also a common observation that of recharging the ground water and reviving the
underground water table is depleting due to water table.
uncontrolled extraction of water. The state of 2. It offers advantage in water quality for both
Maharashtra covers an area of 307,713 square km irrigation and domestic use.
and supports a population of 82 million. Over half 3. It provides naturally soft water and contains
of this population is in rural area which faces almost no dissolved minerals or salts, arsenic
problems related to water. Conventional sources like and other heavy metals.
open well, bore well and piped water supplies have 4. It can be done at individual as well as in a
failed due to depleting water tables, poor water community level. This way we can be self
quality and high cost involved in operation and sufficient in terms of domestic water
maintenance. Every year a great amount of water requirements and not just dependent on the
is being lost that falls on terraces, all of which finds actions initiated by government or any other
its way to the storm water drains. Rain water local body.
* Lecturers in Civil Engineering Dept; Govt. College of Engineering, Aurangabad (M.S.) 431 005
10

11. Collecting rainwater as it falls from the sky 2. Utilization of Rainwater for Recharging Pit
seems immensely sensible in areas struggling to Where there is no well or bore well in the
cope with potable water needs. Rainwater is one of house, total rainwater falling on the open plot can
the purest sources of water available as it contains be recharged by making recharge pit. Water flowing
very low impurities. Rain water harvesting systems out of the plot can be directed to this pit. This pit
can be adopted where conventional water supply may get filled 10 to 15 times in one monsoon and
systems have failed to meet people’s needs. can recharge water up to 200 m3. This method is
effective in the area where permeability of soil is
COMPONENTS OF RAINWATER more. The capacity of the pit may be taken up to 10
HARVESTING STRUCTURE m3. The percolation of water through this pit of the
All rainwater harvesting structures will have three order of 200 m3 per annum is possible. The cost of
basic components: this structure may come about Rs 7000.
1. Catchment area i.e. the surface area utilized for
capturing the rainwater. 3. Utilization of Rainwater for Well Recharging
2. Collection device, like tanks or cisterns or Rainwater flowing in the farm is diverted to
percolation pits used for collecting or holding a water collecting tank of size 6 m x 6 m x 1.5 m
the water. near well and a small filter pit of size 1.5 m x 1.5 m
3. Conveyance system i.e. the system of pipes or x 0.6m is made at the bottom of large pit. Otherwise
percolation pits through which water is suitable pit may be excavated depending upon the
transported from the catchment area to the availability of space near well. Fig.2 shows details
collection device. regarding recharge of open well by runoff from farm.
Filter pit is filled with sand, pebbles larger than 20
METHODS OF RAINWATER HARVESTING mm and pebbles/boulders larger than 75mm pebbles
There are different ways by which rain water is filled in three equal layers and connected to the
harvesting is carried out. Some of the important well by 150 mm diameter PVC pipe and this pipe
methods are discussed one by one as discussed in projects 0.5 to 1.0 m inside the well. The capacity
coming paragraphs. of the water tank may be taken about 50 m3. The
percolation of water 400 to 1000 m3 per year is
1. Utilizing Rainwater for Dewas Roof Water possible through this structure.
Filter
Dewas is the name of the city located in 4. Utilizing of Rainwater for Bore well
Madhya Pradesh. This roof water filter is first Recharging
practiced at Dewas and hence the name Dewas roof Arrangement of bore well recharging is as
water filter. Fig.1 shows details of Dewar roof water shown in fig. 3. A six metre diameter collecting pit
filter. It can be made easily using sand pebbles of of 1.5 m depth is excavated around the bore well
different sizes. In this two caps are provided as T1 casing pipe. Another small pit of 1.5 m x 1.5 m x
and T2. Keep the cap T1 and T2 always closed. The 0.6 m depth is made at the bottom of large pit and
T2 is used for periodical back washing of filter and filled with filter media. A 75 mm diameter PVC pipe
cap T1 is used for backwash drainage. Small pebbles is connected to the bore well casing pipe after first
of size 6 mm are on entry side of rainwater. Use of layer of 75 mm pebbles. An inverted elbow is
medicine for water purification is made through cap connected to the pipe.
T2. Do not recharge rainwater for first two days in
rainy season. Keep the roof always clean, especially 5. Utilizing Roof Water to Recharge Trench
in rainy season so that quality of rain water falling The roof water collected can be recharged
on roof is not deteriorated. The cost of this roof through recharge trench. Water can be recharged
filter excluding connecting pipe is about Rs 800. throughout the year either by using used water or
For average condition in Maharashtra, from 100 rainwater. This recharge trench may get filled many
square metres roof area about 50 m3 of water can times as per availability of used or rain water. This
be percolated through this filter. method is effective in the area where permeability
11

12. of soil is more. The capacity of the trench may be second sand filter surrounding the slotted section of
taken up to 20 m3. The percolation of water through the well at the top prevents the remaining suspended
this pit of the order of 100 to 200 m3 per annum is material entering the well. Beyond this is a coir
possible. The cost of this structure may come about wrapping as a final protective filter before water
Rs 5000. enters the well. The rate gradually decreases due to
setting of slit at the top. Every year, after the rainy
6. Utilizing Surface Rainwater to Recharge Tube season about one meter of the sand at the filter bed
well has to be replaced. Every year the well is developed
Depleted aquifers are directly fed with surface with a compressor once immediately after the
rainwater by using a recharge tube well so that storage structures become empty because the water
recharge is fast and evaporation and transit losses level is shallow immediately after the monsoon and
are zero. development is effective.
A typical recharge tube well is designed as During pumping when the water is clear, it
follows : may be allowed on the filtered bed so that it takes
1. A borehole of 50 cm diameter is drilled to the down the slit accumulated in the filter bed into the
desired depth. well which is being developed. Through this method
2. A 20 cm diameter casing i.e. outer pipe of the the entire filter bed also gets cleared of the silt during
bore well is designed by providing slotted the time of infiltration.
perforated sections against aquifers.
3. The depth of the recharge tube well should be 7. Utilizing Roof Water to Collect into the Storage
about 30 metre below the water table in the area. Tanks
4. The annular space between the borehole and Rainwater from the roof surface is drained
the pipe is filled with good gravel and developed through gutters into storage tanks. To prevent
with a compressor till it gives clear water. To contamination and dust to flow into the storage tanks
stop the suspended solids from entering the there is a provision of a hand movable gutter
recharge tube well, a filter mechanism is connection which can be manually moved to divert
provided at the top. the water out. The rooftop is used as the collection
5. A pit of dimensions 6 m x 6 m x 6 m is dug with device. Guttering generally made of PVC is used to
the tube well at the center. transport the rainwater from the roof top to the
6. This pit is filled with small rounded boulders, storage tanks. Storage tanks may be either above or
stone chips and sand in layers with boulders at below the ground and should be properly covered.
the bottom and sand at the top. In apartments more than one storage tanks can be
7. The top one metre of the casing assembly in used and they can be interconnected through
this pit is filled with sand. The top of the casing connecting pipes. The storage tanks should have
pipe is provided with a cap which is about 600 provision of an adequate enclosure to minimize
mm below the sand bed to prevent suspended contamination from human, animal or other
material from entering the well. environmental contaminants. The end of the gutter,
8. In order to release the air present in the casing which connects the storage tank, should be attached
assembly during the percolation process of with a filter to prevent any contaminants to get into
floodwater, the air vent is provided through a the storage tank. It is also advisable to drain the
75 mm diameter pipe connected to the first flow to get rid of the dust and contaminants
recharging tube well within the top 600 mm from the roof top.
through a reducer tee of dimensions 200 mm x
75 mm. The air releasing pipe is then extended CASE STUDY OF RAIN WATER
to one of the banks where the vent is HARVESTING FOR BUILDING IN URBAN
constructed. AND VILLAGE AREA
Rain water harvesting system for annexure
When flood water filters through the sand, building of Govt. College of Engineering,
most of the suspended materials are filtered out. The Aurangabad is being considered for study purpose.
12

13. The Government Engineering College is located in III) Plumbing cost
Marathwada region of Maharashtra State. The a. PVC pipe 6" size total length 200 m @ Rs
average annual rainfall of Aurangabad town is 100/- per m = Rs.20000/-
around 700 mm/year. The population of the city is b. PVC pipe 4" size total length 120 m @Rs 85/-
more than 10 lakh. Presently the water is supplied per m = Rs 10200/-
to the town by Municipal Corporation, Aurangabad. c. Labour charges (Lump sum)
Considering the capacity of water treatment plant, = Rs 20000/-
the water is supplied to town on alternate day. d. PVC pipe accessories = Rs 10000/-
The institute needs water about 350 m3 per
day. In last few years it is observed that the ground IV) Tube Well 100 m deep and 2 H.P. pump
water level of the town is being depleted. It is = Rs.30000/-
essential to conserve the rainwater not only in the Total Expenditure = Rs142680 /-
city itself but also in areas surrounding to The total cost of rain water harvesting system
Aurangabad. No one can neglect the importance of project is Rs.142680/-
rainwater harvesting. According it is proposed to
collect roof water from at least ten hoses from each Rain water harvesting system for village
village. It is also proposed to collect rainwater from community
roof of Annex building of this institute. If this roof This system is designed for the village
top rain water harvesting scheme is implemented community situated in locality where there is
all civil engineering students from this institute will scarcity of water. The annual rainfall is 650 mm per
have a role model. These students will see the system year. The water is supplied by panchayat/local
and in future they will be motivated to implement authority alternate day. Incase of summer season
roof water harvesting system elsewhere. The the water is supplied by tankers. So it is proposed
tentative estimate is as given below. to conserve the rain water by allowing it to percolate
so as to meet underground water. It is proposed to
Estimate for rain water harvesting system for conserve rain water collected on top of every house
annex building and common rain water harvesting system is
Area of building : 2159.78 m2 designed for group of 10 houses having approximate
Perimeter of building : 335.45 m area of 70 m2 each
Average annual rainfall at Aurangabad : 700 mm
Coefficient of runoff : 0.8 Estimate for rain water harvesting system for
Quantity of water to be harvested per year : village community
1209.47 m3 Area of group of houses : 700 m2
Requirement of soak pit : 6 m x 6 m x 1.5 m (Two Perimeter: 340 m
numbers) Average annual rainfall: 650 mm
Coefficient of runoff: 0.8
I ) Cost of excavation : 2 x 54 m3 x Rs.60/- Quantity of water to be harvested per year: 364 m3
= Rs. 6480/- Requirement of soak pit: 3 m x 3 m x 2 m
II) Cost of material for filling of soak pit I) Cost of excavation : 18 m3 x Rs.60/-
a. 75 mm to 100 mm size aggregate = Rs. 1080/-
= Rs. 12000/-
b. 15 mm to 25 mm size aggregate II) Cost of material for filling of soak pit
= Rs. 12000/- a. 75 mm to 100 mm size aggregate
c. Sand = Rs. 8000/- = Rs. 2500/-
d. Protection wall with perforation b. 15 mm to 25 mm size aggregate
= Rs 8000/- = Rs. 2500/-
e. Labour cost for filling material ( Lump sum) c. Sand = Rs. 2000/-
= Rs. 6000/-
13

14. d. Protection wall with perforations failing on his roof, plot, and farm and recharges it
= Rs 2000/- under ground. Two cases of roof top water
e. Labour cost for filling material harvesting for urban and rural area have been
= Rs. 5000/- considered in the present study. Similarly for other
building roof top rain water harvesting can be
III) Plumbing cost implemented. In fact there is no village and
a. PVC pipe 4" size total length 200 m @Rs 85/- habitation in India that cannot meet its basic drinking
per m = Rs.17000/- and cooking needs through rainwater harvesting
b. Labour charges (Lump sum) techniques.
= Rs 8000/-
c. PVC pipe accessories = Rs 6000/- REFERENCES
Expenditure for one unit of ten houses 1. Gawai A.A. and Aswar D.S. (2006) “Towards
= Rs 46080/- Self reliance for Water Needs through Rain
Water Harvesting” Conference on ‘Engineering
CONCLUSION Technology for Efficient Rain Water Harvesting
Water is essential element of life. Everyone and Soil Conservation’, S.G.G.Nanded, 29-30
knows that, if we do not harness available sources May 2006.pp. 1-7
of water and use them judiciously with proper care 2. Kaushal Kishore (2004) “Rain Water
the problem of water scarcity is going to be serious. Harvesting”, Journal of Civil Engineering and
Irrespective of fast development in all fields of Construction Review, May 2004, pp.42-48
science there can be no substitute to water. Hence, Magar R.B. and Waghmare S.T. . (2006) “Rain
it is necessary to opt for various water harvesting Water Harvesting” Conference on ‘Engineering
measures. It is the responsibility of government Technology for Efficient Rain Water Harvesting
organization as well as individual to harvest each and Soil Conservation’, S.G.G.Nanded, 29-30
drop of water falling on earth surface. For this, it is May 2006.pp. 44-51
necessary that each person collect the raindrops
14

15. 15

16. National Seminar on Rainwater Harvesting and Water Management 11-12 Nov. 2006, Nagpur
4. Harvested Rainwater for Drinking
*Dr. N. Balasubramanya
Abstract
It is clear from the World water quantity that out of total available water, only 0.3%
is available for human consumption. But today even this is getting polluted due to human
activities like mining, industrialization has created acute shortage of potable drinking water.
Rain water harvesting is one of the most ancient and easy methods that can be adopted at
urban and rural level efficiently.
The aim of this study is to investigate the possibility of using harvested rainwater as
a source of drinking water without causing any health risk. This can be achieved by adopting
suitable storage technique efficient and economical treatment methods.
Roof harvested rainwater samples were collected from five different places of
Bangalore during October 2005. The water samples were collected and stored in good
grade plastic containers and were subjected to periodical treatments (like chlorination,
solar disinfections and use of silver nitrate) and tests fro and use of silver nitrate and tests
for physical chemical and Biological parameters up to May 2006 as per IS 10500:1991.
All the above treatment methods suggested proved to be highly effective in reducing
the colonies fro an initial value of around 300 to zero.
Introduction increases due to increase in the population. Hence,
For centuries world has relied upon rainwater the most effective way to obtain fresh drinking water
harvesting to supply water. Rainwater harvesting is to harvest rainwater. Rainwater harvesting system
promotes self sufficiency and fosters an appreciation is inherently simple in form, and can often be
for water as a resource. It saves money, saves other assembled with readily available materials by
resources of water, reduces erosion and storm water owners, builders with a basic understanding of the
runoff and increases water quality. plumbing and construction skills.
Rainwater can provide clean, safe and reliable The present investigations was proposed with
water for drinking so long as the collection system a vision to overcome the scarcity of drinking water
is properly constructed and maintained and treated during the non – rainy seasons such that it gives
appropriately for its intended use. easy and economical solution that can be adopted
Rainwater harvesting means capturing rain both in urban and rural areas.
where it falls or capturing the runoff in a village or
town and taking all precautions to keep it unpolluted. Sample Collection and Storage
One third of world’s population will Rainwater samples were collected from five
experience severe water scarcity by the end of this different places of Bangalore during October 2005.
century. In rural areas, the water may not be fit for The samples were stored in good grade plastic cans.
drinking due to the polluted water bodies, due to The above samples were tested for physical,
contaminated ground water and also due to acute chemical and microbiological parameters. Table 1
water scarcity. In urban areas, water demand gives the experimental finding.
* Professor, Dept. of Civil Engineering, M.S.Ramaiah Institute of Technology, Bangalore – 54
16

17. Table 1 : Experimental Results of Physical, Chemical & Biological Parameters
Sample Date of Expt Turbidity pH Do Hardness Chloride Alkalinity Acidity
NTU mg/l of mg/l mg/l mg/l of mg/l of
CaCO3 CaCO3
1. Banashankari 14/08/05 4.6 7 7.8 56 13.96 86 06
2. MSRIT 17/01/06 6.3 8.4 7.7 22 16 30 08
3. Shivajinagar 21/11/05 8.3 8.11 8 58 13.2 40 06
4. Vijayanagar 18/01/06 11.9 7 7.7 58 21.3 46 12
5. Vidyaranyapura 12/12/05 7.3 8 8.1 46 12 18 14
A detailed study of Table 1 reveals that both sis hours. Such an exposure increases the
the physical& chemical parameters are very much temperature of water and also gives an extended
within the limits for drinking water standards dose of solar radiation killing the microbes.
specified by WHO (1984) and IS 10500:1991.
However, the colony counts were quite significant Chlorination
in all the five samples. Chlorination is one of the most reliable
Therefore, it was decided to emphasize more methods of disinfecting drinking water. In this
on the microbiological contaminations and suitable method the calculated amount of chlorine is added
treatment methods to make the rainwater fit for to one litre of water sample for a specified tune and
drinking. thereafter tested for the coliform counts.
Treatment methods and Results Silver Nitrate
All the five rain water samples were subjected Silver nitrate is very small doses of 0.05 to
to the following treatments. 0.1 mg/l helps in disinfecting the drinking water.
• Solar disinfection Silver nitrate in smaller doses does not impart any
• Chlorination taste, odour or produces any harmful effect on
• Using Silver nitrate human body.
• Combination of the above method.
Combination of the above methods
Solar Disinfection In order to investigate the effectiveness of the
Solar disinfection is a process where in treatment methods following combinations were
microbes are destroyed through temperature and tried.
ultra violet radiation provided by the fun. a) Chlorine + Solar disinfection
Water is filled either in a clean transparent or b) Silver nitrate + Solar disinfection.
painted (Black) bottle oxygenated by shaking,
followed by topping up. It is placed in the horizontal Tables 2,3 & 4 presents the details of coliform
portion on tope exposed to direct sunlight for about counts of the above specified treatments.
Table 2: Coliform Count (At room temperature)
Sample Date of Collection Date of experiment Coliform Count/100ml (Average of 3 tests)
Chlorination Silver Nitrate
1. Banashankari 20/10/05 17/05/06 0 0
2. MSRIT 25/10/05 17/05/06 0 0
3. Shivajinagar 25/10/05 17/05/06 0 0
4. Vijayanagar 25/10/05 17/05/06 0 0
5. Vidyaranyapura 28/10/05 17/05/06 0 0
17

18. Table 3 : Coliform Count (Solar disinfection using transparent bottle)
Sample Date of Date of Expt Coliform count / 100ml
Collection Transparent Bottle Chlorination Silver nitrate
(Average of 3 tests)
1. Banashankari 20/10/05 17/03/06 40 0 0
2. MSRIT 25/10/05 24/03/06 38 0 0
3. Shivajinagar 25/10/05 02/04/06 40 0 0
4. Vijayanagar 25/10/05 15/04/06 35 0 0
5. Vidyaranyapura 25/10/05 21/04/06 28 0 0
Table 4 : Coliform Count (Solar Disinfection using black painted bottle)
Sample Date of Date of Expt. Coliform Count / 100 ml (Average of 3 tests)
Collection Black Bottle Chlorination
1. Banashankari 20/10/05 17/03/06 2 0
2. MSRIT 25/10/05 24/03/06 2 0
3. Shivajinagar 25/10/05 02/04/06 3 0
4. Vijayanagar 25/10/05 15/04/06 2 0
5. Vidyaranyapura 28/10/05 21/04/06 0 0
Careful study of Table 2 depicts that Conclusions
chlorination and Silver nitrate in very small dosages Rainwater collection is easy and economical
are very effective even at room conditions, justifying both in rural and urban areas.
their selection. Rainwater harvested during Oct 2005, tested till
Detailed study of Table 3 indicates that solar May 2006 without much changes in physical
disinfection using a transparent bottle is not very properties like colour, odour & turbidity, inspite
effective in reducing the coliform counts. However, of the fact that they were from various sources
addition of chlorine and silver nitrate have proved and stored in normal food grade plastic
to be highly effective, further strengthening their containers.
selection as disinfectants. All the treatment methods suggested are highly
Finally from Table 4, it can be seen that solar effective in reducing the microbiological
disinfection using a black painted bottle has yielded contamination and also viable both at rural and
in a more effective disinfection, the coliform counts urban levels.
have very significant, reduced. The reason being Rainwater harvesting and its treatment is
that a black bottle or body absorbs more heat, which affordable by individuals and will be highly
enables in destroying the bacteria. In the present useful in drought prone areas.
investigations is was observed that the water
temperature in the bottles recorded a temperature Future
around 500 C. It is suggested that similar investigations are
It is also very interesting of disinfection to made on a number of samples collected from
note that the chlorination method has established different places, stored under different conditions.
its supremacy.
18

19. Acknowledgement Proe. 23rd WEDC Conf. Sep 1-5 1997, Durban
The author wishes to thank the management S.Africa.
of M.S.Ramaiah Institute of Technology, Bangalore 6. Sharma S.K. and Jain S.K, Proceedings of the
560054 for all the encouragements & inspiration International Conference on Management of
provided for the study. Also many thanks are due to Drinking water resources – central leather
Mr.Sunil Hegde, Mr.Anantha Padmanabha & Research Institute. Anna University & Tamil
Mr.Vinay Final Year B.E. Students for their help Nadu Water supply & Drainage, Board,
during the course of the experimental investigations. Chennai, 1997, pp129-138.
7. Wegelin M & Sommer B, Solar water
References : disinfections (SODIS) – Destines for world
1. Bell, F.A.Jr, D.L.Jerry, J.K.Smoth, and wide use. Water lines, Vol 16, No.3, IT
S.C.Lynch, Studies on home water treatment Publications, London 1998.
systems. Jr.Am water works Assoc. 75:104-107- 8. Winter bottom, Daniel “Rainwater Harvesting,
1984. An ancient technology – cisterns in
2. Davies C.M., and Evison L M “Sunlight & the reconsidered, Landscape Architecture”, April
survival of entropic bacteria in natural water .2000 pp 42-46.
Journal of applied Bacteriology 7, 265-274- 9. White G.C, Hand Book of chlorination &
1991. Alternative Disinfectants, Johns Wiley & Sons,
3. Drinking water standards, www.epa.gov/safe Inc, New York 1999.
water/md.html. 10. Wolfe R.L., 1990, “Ultraviolet Disinfection of
4. I.S. 10500:1991 “Drinking Water Standards”. Possible water” Env.Sci and Technology 24(6),
5. Jalbottt R “Rural water supply and Sanitation 768-773, 1990.
program in India – Goals, roles & innovation.
19

20. National Seminar on Rainwater Harvesting and Water Management 11-12 Nov. 2006, Nagpur
5. Rain Water Harvesting and Ground Water Recharge
*Madhaorao Bajirao Deshmukh
1.1 Water is an essential natural resource for By adopting water harvesting, an additional 160
sustaining life and environment. The available water BCM shall be available for use.
resources are under pressure due to increasing
demands and the time is not far when water, which 3.2 Ground water level in some areas are falling at
we have always thought to be available in abundance the rate of one meter per year and rising in some
and free gift of nature, will become a scarce other areas at the same rate.
commodity. Conservation and preservation of water You can capture and recharge 650000 liters of
resources is urgently required to be done. Water rainwater from a 100-sq. meters size rooftop and
management has always been practiced in our meet drinking and domestic water requirement of
communities since ancient times, but today this has family of four for 160 days.
to be done on priority basis. The number of wells and borewells for
irrigation in the country has increased five fold to
1.2 India’s population has recently crossed the one 175 lacks during past fifty years.
billion mark, with an ever-increasing population, our There are 25 to 30 lack wells and borewells for
country faces a serious threat to the management of drinking, domestic and industrial uses.
her water resources as the gap between demand and More than 80% of rural and 50% of urban, industrial
supply widens. and irrigation water requirement in the country are
met from ground water.
2.1 In our villages and cities, down the ages, people
have developed a wide array of techniques to harvest 3.3 Causes Of Fall In Ground Water Levels
rainwater, which are simple, efficient and cost • Over exploitation or excessive pumpage either
effective. There is a tendency to ignore these locally or over large areas to meet increasing water
traditional water-harvesting systems. We should demands.
draw upon the wisdom of our ancient life sustaining • Non-availability of other sources of water.
systems and through better management, conserve Therefore, sole dependence is on ground water.
our precious water resources. • Unreliability of municipal water supplies both
in terms of quantity and timings, driving people to
2.2 Harvesting of rainwater is of utmost important there own sources.
and the ministry of water resources is embarking on • Disuse of ancient means of water conservation
such programme. A judicious mix of ancient like village ponds, baolis, percolation tanks and
knowledge, modern technology, public and private therefore, higher pressure on ground water
investment and above all, people’s participation will development.
go a long way in reviving and strengthening water
harvesting practices through out the country. 3.4 Effects Of Over Exploitation Of Ground
Water Resources
3.1 Ground Water Resources: - Annually • Drastic fall in water levels in some area
replenishable resources are assessed as 432 billion • Drying up wells/ borewells
cubic meters (BCM) • Enhanced use of energy
*B.Sc., B.E. (Hon), AMICE (USA), Ex- Superintending Engineer, 54, Tatya Tope Nagar, Nagpur
20

21. • Deterioration in ground water quality • Benefiting in the water quality
• Ingress of sea water in coastal areas. • Arresting sea water ingress
• Assuring sustainability of the ground water
4.0 Method And Techniques Of Rain Water abstraction sources and consequently the village and
Harvesting town water supply system
• Roof – top rain water harvesting and its • Mitigating the effect of droughts and achieving
recharge to underground through existing wells and drought proofing
borewells or by constructing new wells, borewells, • Reviving the dying traditional water harvesting
shafts etc. structures and their rehabilitation as recharge
• Capturing and recharging city storm water run structures.
off through wells, shafts, storm water drains. • Effective use of lack of defunct wells and
• Harnessing run off in the catchment by tubwells as recharge structure
constructing structures such as gabions, check dams, • Up gradation of social and environmental status
bhandaras, percolation trenches, sub-surface dykes etc.
etc.
• Recharging treated and industrial affluent 7.0 Proposed Policy Measures For Rain Water
underground by using it for direct irrigation or Harvesting
through ponds, basins or wells etc. • Provides at least one roof-top rain water
harvesting structure for every 200sq. meters plot in
5.0 Objective Of Rain Water Harvesting urban areas.
• Restore supplies from the aquifers depleted due • Revive/ rehabilitation all village ponds
to over exploitation • Subject to technical feasibility, provides at least
• Improve supplies from aquifers lacking one check dam / KT weir / Sub- surface dyke in
adequate recharge. each streamlet with catchments of 1 to 3 sq. km.
• Store excess water for use at subsequent times. • Provide all drinking water wells with a recharge
• Improve physical and chemical quality of structure
ground water • Ban construction of irrigation wells / tubewells
• Reduced storm water run off and soil erosion within a distance of 200 m or less (depending on
• Prevent salinity ingress in coastal areas. scientific criteria) of the drinking water supply well.
• Increase hydrostatic pressure to prevent/ stop
land subsidence. 8.0 Success Stories Of MAHARASHTRA
• Recycle urban and industrial wastewater etc. • In Yaval taluka, Jalgaon District, Six
• Rehabilitate the existing traditional water percolation tanks, two recharge shafts and one
harvesting structure like village ponds, percolation injection well were constructed- A total of about 546
tanks, baolis, tanks, etc ha area benefited
• With minor scientific modifications and • In Amravati District, three percolation tanks
redesigning, convert the traditional water harvesting and ten cement plugs benefiting an area of 280 ha
structure into ground water recharge facilities. and 100 ha respectively have been constructed- rise
• Use the existing defunct wells and borewells in water level up to 10 meters recorded.
after cleaning and also the operational wells as • Experiments of catchments treatment carried
recharge structures. out at Adgaon and Palaswadi in Aurangabad,
Ralegaon Siddhi in Ahmednagar and Naigaon in
6.0 Benefits Of Rain Water Harvesting Pune by Shri Anna Hazare - effort have led to revival
• Rise in ground water levels in water of streamlets and enhanced availability of ground
• Increased availability of water from wells water in the water shed.
• Prevent decline in water levels
• Reduction in the use of energy for pumping 9.0 Proposed Strategy
water and consequently the costs. • Organize Mass Awareness Programmes
• Reduction in flood hazard and soil erosion involving district administration and NGOs to
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22. educate in different sections of users and to make industrial houses to be invited to participate in the
the programme demand oriented. work and adopt towns and villages and provide
• Roof-Top rain water harvesting and its recharge financial support.
underground through more than two lack existing • Government organizations to act as facilitators
but defunct drinking water and irrigation wells, or and provide technical and financial support for
by constructing new wells, borewells, Shafts, creating the demonstration facilities etc.
spreading basins etc.
• Make roof-top rain water harvesting and 10.0 Future Action Plans
recharge mandatory in all urban dwellings. • Prepare national and state level water
• Capturing city storm water run- off and harvesting perspective plans.
recharging it through wells, shafts, spreading basins, • Develop plans and implement roof-top rain
storms and water drains etc. water harvesting measures using 1,00,000 wells
• Harnessing run off in catchments by (existing, defunct and or operative wells to be used
constructing structures such as gabions, check dams, in the first instance)
bhandaras, percolation trenches, bus-surface dykes • Provide rural drinking water wells with
etc. recharge facilities- cover 1,00,000 wells
• Impounding surface run from village • Harvest and recharge city storm water in 100
catchments and water shed(s) in village ponds and towns
percolation tanks. • Revive and rehabilitate 1, 000 dying village
• Rehabilitation all ancient rain water harvesting ponds.
structures. • Design and construct 200 percolation tanks,
• Invoke legal provision, if and when required, 5000 check dams/ bhandaras and 1,000 sub surface
to regulate indiscriminate boring of wells and to dykes.
make the installation of recharge facilities mandatory • Recycle secondary treated urban waste water
• Constitute water user Association (WUA) or through aquifers at five centers.
village Beneficiary Groups (VBG) NGOs to • Identify potential aquifers in drought prone
organize the constitution of these bodies. The WUA/ areas and declare these apart as “Ground Water
VBG and NGOs to be associated with the project Sanctuaries”
right from the concept to completion stages.
• For expanding further scope of work, the Ref: - CENTRAL GROUND WATER BOARD-
MINISTRY OF WATER RESOURCES.
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23. National Seminar on Rainwater Harvesting and Water Management 11-12 Nov. 2006, Nagpur
6. Rain Water Harvesting Tanks for Supplementing Minor Irrigation
Tanks during Drought
* Mohd. Mahboob Hussain
Introduction : development etc. Rainwater harvesting is usually
India’s total land area is 3287263 Sqkm. The classified into two types (i) harvesting for
cultivated land is 55.7% i.e., 183.09 million hectors. agriculture (irrigation) needs and (ii) harvesting for
Average annual rainfall is 117 Cm; average monsoon domestic and other needs. For irrigation needs the
rainfall is 55 Cm. The occupation of about 70% of rainwater can be harvested during rainy season by
people in India is agriculture. The population of constructing any of the following structures.
India is fed on the food production of the country. 1. Major storage reservoir
Main source of water in this country is rainfall 2. Medium storage reservoir
during monsoon season. The rainfall mainly 3. Minor storage tanks
confined in the months from June to September. But 4. Watershed development Structures, like
it is not regular and erratic with respect to both time Check dams, percolation tanks, Sunken gully pits
and place. Now a days drought and floods are the etc.,
sever hazards in different parts of our country. The Looking in to the rainfall trends in past forty
requirement of agricultural produce is expected to years it is felt that rain water above 75% P.L. should
rise steeply by 2025.Hence India must concentrate be stored for beneficial use during droughts / low
on increasing area under irrigation and improving rainfall year. In this paper it is proposed to construct
the productivity of both land and water to meet the Rain Water Harvesting Tanks for the beneficial use
needs of the population. The demand of water of water for supplementing minor irrigation tanks
increasing due to several factors such as increase in during drought years. Rain Water Harvesting is
population growth, which has led to a situation in being promoted extensively in India, particularly
which water has become a scarce resource. Hence in the Southern States.
it is very essential to harvest rainwater during rainy
season. Rainwater harvesting is the intentional Need for Rain Water Harvesting Tanks :
collection of rain water from a surface and its Since rivers occasionally swells, hence some
subsequent storage in order to supply water during countries have built oversized capacity reservoirs
the time of demand. Rain water harvesting is to store surplus water which will other wise be
essential in view of the fact that rainfall, which is a wasted in to sea. For example, Egypt had built
source of fresh water, occurs in very short spells Oswan Dam to store water about five times the yield
and runs off as a waste unless arrangements are available in Nile River. During droughts they are
made for its storing. successfully irrigating lands so that the country is
Main source of irrigation development are not vulnerable by famine. In most of the areas of
dams and canals. Other option are water harvesting semi-arid region yearly rainfall is below the normal
structure such as for ground water development, for continuous two to three years followed by a
surface minor irrigation systems, watershed normal rainfall year. The year wise monsoon rainfall
* Deputy Executive Engineer, Medium Irrigation, I & C.A.D.Department, Govt. of A.P., Hyderabad
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24. for some of the rain-gauge stations of Ranga Reddy natural resource. Hence all water over and above
District in Andhra Pradesh are shown in annexure- 75% dependable yield is wasted in to sea. Since
I and graph enclosed showing rainfall variation for rainfall is a natural phenomenon, we do not know
last 40 years indicates that lot of water above 75% when and in which year rainfall will be above 75%
P.L .is wasted. More over from rainfall graphs it P.L., hence it is the need of the hour to harvest Rain
can be seen that there are number of years when water above 75% P.L. also and to utilize during the
there is rainfall more than 75 % P.L followed by a drought / low rainfall year. It is proposed to construct
low rainfall year. From graph of Monsoon rainfall Rain Water Harvesting Tanks without any canal
versus year for Medchal R.G.S, the following system with a sluice to letdown water in the down
conclusions are drawn. stream for existing minor irrigation tanks.
For one R.G.S (i.e., TANDUR) the year wise
(i) In the year 1967 there is excess rainfall over total yield available for one of the subgroup having
75% P.L. followed by a normal rainfall year 20 Sq.Miles for 40 years have been calculated. The
1968 and a low rainfall year in 1969. yield available @ 75 % PL also has been calculated
(ii) In the year 1971 the rainfall is much higher using strange’s table which works out to 255.64
than 75% P.L. followed by low rainfall year Mcft. The surplus yield available after deducting
of 1972. the yield @ 75 % PL from the total yield is also
(iii) In the year 1974 the rainfall is much higher calculated year wise. Statement showing the above
than 75% P.L. followed by low rainfall year values year wise are presented in annexure- II
of 1975. enclosed. From the statement it is observed that for
(iv) In the year 1976 the rainfall is much higher 30 years there is surplus yield available. The
than 75% P.L. followed by low rainfall year maximum surplus yield is 801.20 MCft. The
of 1977. average of surplus yield for 30 years is 267.495
(v) In the year 1978 the rainfall is much higher Mcft, but where as the 75% dependable yield is
than 75% P.L. followed by low rainfall year 255.64 Mcft. The average of surplus yield is slightly
of 1979. higher than the yield available at 75% dependability.
(vi) In the year 1983 there is flood followed by a Since every year the surplus yield may not be
normal rainfall year of 1984 and a low rainfall available so much, hence it is proposed to utilize at
year of 1985. least 50% of the yield available at 75%
(vii) In the year 1990 the rainfall is much higher dependability duly constructing Rain Water
than 75% P.L. followed by low rainfall year Harvesting Tanks. In the statement minus values
of 1991. indicates that the yield available is below the 75%
(viii) In the year 1996 the rainfall is much higher PL yield for ten years out of 40 years. Hence there
than 75% P.L. followed by low rainfall year is scope for storing this surplus yield in the proposed
of 1997. Rain Water Harvesting Tanks.
(ix) In the year 2000 the rainfall is much higher More over sometimes heavy rainfall occurs
than 75% P.L. followed by low rainfall year in one single month followed by a dry spell of 20 to
of 2001. 30 days. In such case also this excess water due to
heavy rainfall can be stored in Rain Water
From the above it can be stated that the water Harvesting Tanks and released for existing minor
above 75% P.L. can be stored in the proposed Rain irrigation tanks during dry spell so that crops can
Water Harvesting Tanks and used in the low rainfall be grown successfully.
years. Presently any irrigation project is design to The World Banks has published a report
utilize water out of the available 75% dependable “India’s Water Economy: Bracing for a turbulent
yield. Water has to be harvested, preserved and future”. In this report it is highlighted that India’s
utilized for beneficial used, as it is becoming a scarce storage capacity of 200m3 per person is too little, as
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