Water Harvesting Final_editd

8/3/2019 Water Harvesting Final_editd

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GROUP 1GROUP 1JOAO ARNALDO SALAMIQUEJOAO ARNALDO SALAMIQUE

DIPANKAR SAIKIADIPANKAR SAIKIA

SHOBHIT VERMASHOBHIT VERMA

TRYAMBAKESH KUMAR SHUKLATRYAMBAKESH KUMAR SHUKLA


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Water is life's mater and matrix, motherand medium. There is no life withoutwater.

(Albert Szent-Gyorgyi, 1937)

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CONTENTS

CH

APTER 1 : PANO.INTRODUCTION

y WATER SCENARIO IN URBAN AREAS 4y SOURCES OF WATER THE HYDROLOGICAL CYCLE 5y NEED OF CONSERVATION OF WATER 6CHAPTER 2 :

CONCEPT OF RAIN WATER HARVESTINGy DEFINITION 7y SCALE OF RAINWATER H ARVESTING y AMOUNT OF WATER CAN BE H ARVESTED CHAPTER 3 :

METHODS OF RAIN WATERHARVESTINGy SOME TRADITIONAL METHODS OF H ARVESTING RAIN WATER 9CHAPTER 4 :

COMPONENTS OF RAIN WATERHARVESTING SYSTEMy CATCHMENTS 11y STORAGE RESERVOIRS 12y CONVEYANCE SYSTEMS 13

ADVANTAGES AND DISADVANTAGES 14CHAPTER 5 :

CASE STUDY : BUILDING LEVEL WATER H ARVESTING 15y

URBAN 16y RURAL 23CHAPTER 6 :

CASE STUDY : AREA LEVEL & CITY LEVELWATER HARVESTING

y JAMIA MILIA ISLAMIA 25y INDORE 34CH

APTER 7 :CONCLUSION 39BIBLIOGRAPHY 40

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INTRODUCTION

URBAN SCENARIOA sufficient, clean drinking water supply is essential to life. Millions of peoplethroughout the world still do not have access to this basic necessity.

Over 70% of the planet's surface is covered by water. Of all the available water on theplanet, only 2.5% is fresh water, the remaining 97.5% is seawater. Of the 2.5% freshwater on the planet, only 0.4% is readily available for human usage with a majorityof the earth's fresh water stored as ice at the poles or as inaccessible ground water.The world has a shortage of potable water for drinking and water for agricultural,irrigation and industrial use.Rainwater harvesting (RWH) is an option that has been adopted in many areas ofthe world where conventional water supply systems have failed to meet peoplesneeds. It is a technique that has been used since antiquity.

Almost all urban areas, consisting of large and medium sized cities, face the twinproblems of floods during monsoon and shortage of fresh water during non-monsoon months.Unlike in the past, present day urbanization has resulted both in shrinking of openspaces and very minimal area remaining unpaved. This has ultimately resulted notonly in flooding of cities but has also caused water scarcity due to groundwaterdepletion in general and saline intrusion in coastal cities.

CHAPTER 1

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SOURCES OF RAINWATER-

THE HYDROLOGICAL CYCLE

All rainwater originates from the oceans from where it is distilled through theprocess of evaporation and about 20 % is carried over the land as clouds byatmospheric winds. Once it falls on land as precipitation(rain, snow, hail or dew) itstarts its journey via glaciers, rivers or groundwater back to the sea. This familiarcycle is known as hydrological cycle. Freshwater for human use is accessible atseveral points in the cycle and even seawater can be used if desalinated.(Rainwater catchment systems: John Gould & E.Nissen-Petersen,1999)

Source : www.wikipedia. com

Fig 1 : The hydrological cycle

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WHY RAIN WATER HARVESTING ?

Rain water harvesting is essential because:y Surface water is inadequate to meet our demands, and we have to

depend on ground water.y Due to rapid urbanization, infiltration of rain water into the sub-

soil has decreased drastically and recharging of ground water hasdiminished.

y Water is one of the most basic human need.y Rain water has to be harvested to conserve and augment the

storage of ground water , to reduce table depletion, to improvequality of ground water and to arrest sea water intrusion in costalareas.

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DEFINITION

RainwaterHarvesting uses a wide range of techniques for concentrating,collecting and storing rainwater and surface runoff for different uses by linking arunoff producing area with a separate runoff-receiving area (Mbilinyi et al., 2005,pg. 2).In this sense, RWH collects rainwater runoff and stores it for future use, be it foragricultural, domestic or drinking purposes. As such, RWH encompasses all WHtechniques that collect and harvest runoff from roofs or ground surfaces (Critchle

and Siegert, 1991).

SCALE OF WATER HARVESTINGThe principles of water harvesting can be applied for harvesting projects at a scalelarger than individual buildings, i.e. a housing cluster, a residential colony, a sectorof a town as well as large parks, open spaces and recreational areas etc. To a greatextent the design parameters and recharge components remain same but thenetwork becomes larger with the size of the catchments.For a larger scale project the total land needs to be sub-divided into several smallersub-catchments based on man made /natural watershed boundaries like roadembankments, walls, drains etc. and a storm water drainage network (without anyfoul water) with appropriate number and type of recharge components which maybe located within individual premises or common area. However, the totalquantity of rainwater to be used for recharge being high, it calls for water rechargestructures with higher recharge capacity and higher efficiency of recharge. It is

therefore, appropriate to obtain reliable data on sub-soil characteristics, aquiferprofile and select location and capacity of recharge components based onappropriate investigations, if such data is not available.It is also important to incorporate over flow provision so that runoff in excess oftotal recharge capacity of the proposed system is appropriately drained out to anout-fall drain, otherwise there is likely to be water logging conditions created inthe premises.

(Water Harvesting: An Overview- Robert Rutherford)

CONCEPT OFRAINWATER HARVESTING

CHAPTER 2

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AMOUNT OFWATER WHICHCAN BE HARVESTED

The quantity of water (Q) that runs off a roof into gutters, in litres per year, is fairly easy tocalculate using the rough equation

Q = 0.85 R A

where:

R is the total rainfall in millimetres in that year

A is the guttered roof area in square metres

0.85 is a run-off coefficient. It takes into account evaporation from the roof and lossesbetween the roof & any storage tank; its value is around 0.85 for a hard roof in thehumid tropics, where rain is often intense. It would be lower where rain falls as lightdrizzle and much lower for a thatch roof.

The amount of this run-off that can be actually delivered to a user by a RW system is U litresper year, where U is less than the run-off Q because the receiving tank sometimes overflows.

In fact U = E Q

Where E is the storage efficiency (a number never greater than 1) with which we use the

water that reaches the tank.

Example based on a fixed storage efficiency:Suppose rainfall is 1150 mm a year and the guttered-roof area is 4 m x 6 m. Then the expectedroof run-off is 0.85 x 1150 x 4 x 6 = 23,460 litres per year. Assuming a storage efficiency of 70%the water drawn would be 0.7 x 23,460 = 16,420 litres a year. The following examples illustrateuser options household: Employing a small tank, the water would all be used during the wet season of

20 weeks (wet-season RWH). The family could draw about 117 litres a day during that seasonbut nothing for the rest of the year.

By means of a medium-sized tank, the water could be spread over 40 weeks(main source RWH). the family could draw 59 litres per day for those 40 weeks.

By means of a very large tank, the water could be used throughout the year asa sole source. The supply would only be around 45 litres per day for the whole year. (However,with a large tank, storage efficiency would rise above the 70% assumed above, so that 55 litres

per day or more might be obtained).

(Rainwater catchment systems: John Gould & E.Nissen-Petersen,1999)

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TRADITIONAL RAINWATERHARVESTING STRUCTURES

The Indian sub-continent has a long tradition of rain water collection for bothdomestic supply and agriculture( Pakianathan,1989;Ray,1983). Examples of sometraditional rainwater harvesting methods are discussed below:ApataniThis is a wet rice cultivation cum fish farming system practiced by Apatani tribes ofZiro in the lower Subansiri district of Arunachal Pradesh. In Apatani system ,valleys are terraced into plots separated by 0.6 meters high earthen dams supportedby bamboo frames. All plots have inlet and outlet on opposite sides. The inlet of

lowlying plot functions as an outlet of the high lying plot. Deeper channelsconnect the inlet point to outlet point. The terraced plot can be flooded or drainedoff with water by opening and blocking the inlets and outlets as and when required.The stream water is tapped by constructing a wall of 2-4 m high and 1 m thick nearforested hill slopes. This is conveyed to agricultural fields through a channelnetwork.VirdasVirdas are shallow wells dug in low depressions called jheels (tanks). They are found

all over the Banni grasslands, a part of the Great Rann of Kutch in Gujarat. They aresystems built by the nomadic Maldharis, who used to roam these grasslands.SurangamKasaragod district in the northern Malabar region of Kerala is an area whose peoplecannot depend directly on surface water. They depend, therefore on groundwater,and on a special water harvesting structure called surangam;a word derived from aKannada word for tunnel.A surangam is about 0.45-0.70 metres (m) wide and about 1.8-2.0 m high. Thelength varies from 3-300 m. Usually several subsidiary surangams are excavatedinside the main one.Surangams are similar to qanats which once existed in Mesopotamia and Babylonaround 700 BC.1,2 By 714 BC, this technology had spread to Egypt, Persia (nowIran) and India. Traditionally, a surangam was excavated at a very slow pace and wascompleted over generations.

CHAPTER 3

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Katas / Mundas / BandhasThese were the main irrigation sources in the ancient tribal kingdom of the Gonds (now

in Orissa and Madhya Pradesh). Most of these katas were built by the village headmenknown as gountias, who in turn, received the land from the Gond kings. A kata isconstructed north to south, or east to west, of a village. A strong earthen embankment,curved at either end, is built across a drainage line to hold up an irregularly-shaped sheetof water.

JackwellsThe shompen tribals here made full use of the topography to harvest water. In lower parts

of the undulating terrain, bunds were made using logs of hard bullet wood, and waterwould collect in the pits so formed. They make extensive use of split bamboos in theirwater harvesting systems. A full length of bamboo is cut longitudinally and placed alonga gentle slope with the lower end leading into a shallow pit. These serve as conduits forrainwater which is collected drop by drop in pits called Jackwells. Often, these splitbamboos are placed under trees to harvest the throughfalls (of rain) through the leaves.

A series of increasingly bigger jackwells is built, connected by split bamboos so thatoverflows from one lead to the other, ultimately leading to the biggest jackwell, with anapproximate diameter of 6 m and depth of 7 m so that overflows from one lead to theother.

JhalarasJhalaras were human-made tanks, found in Rajasthan and Gujarat, essentially meant forcommunity use and for religious rites. Often rectangular in design, jhalaras have steps on

three or four sides. Jhalaras are ground water bodies which are built to ensure easy &regular supply of water to the surrounding areas . The jhalaras are rectangular in shapewith steps on three or even on all the four sides of the tank . The steps are built on aseries of levels .The jhalaras collect subterranean seepage of a talab or a lake located upstream .The water from these jhalaras was not used for drinking but for only community bathingand religious rites . Jhodhpur city has eight jhalaras two of which are inside the town &six are found outside the city .The oldest jhalara is the mahamandir jhalara which dates back to 1660 AD .

SOURCE : WATER ,ASHOK KUMAR JAIN(2007)

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COMPONENTS OF RAINWATERHARVESTING SYSTEM

Commonly used systems are constructed of three principal components;y The catchment area where the rainwater runoff is collected,y The collection device where rainwater is stored until required,y The conveyance system for transporting the water from the catchment area to

the storage reservoir.A) Catchment Areas:

A wide variety of catchment surfaces can be used to collect and concentrate

rainwater runoff. The key requirement for the a catchment surface is that it has tobe impermeable and does not seriously contaminate the water.

These are of three types:y Rooftop catchments: In the most basic form of this technology, rainwater is

collected in simple vessels at the edge of the roof. Variations on this basicapproach include collection of rainwater in gutters which drain to the collectionvessel through down-pipes constructed for this purpose, and/or the diversion of

rainwater from the gutters to containers for settling particulates before beingconveyed to the storage container for the domestic use.As the rooftop is the main catchment area, the amount and quality of rainwatercollected depends on the area and type of roofing material. Reasonably purerainwater can be collected from roofsconstructed with galvanized corrugatediron, aluminium or asbestos cement

sheets, tiles and slates, althoughthatched roofs tied with bamboogutters and laid in proper slopescan produce almost the same amountof runoff less expensively.(Gould, 1992).

Fig 2 :An arrangement ofrooftop catchment system

CHAPTER 4

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y Ground catchments: Rainwater harvesting using ground or land surface catchmentareas is less complex way of collecting rainwater. It involves improving runoff capacityof the land surface through various techniques including collection of runoff with

drain pipes and storage of collected water.C

ompared to rooftop catchmenttechniques, ground catchment techniques provide more opportunity for collectingwater from a larger surface area. This technology can meet water demands during dryperiods.There is a possibility of high rates of water loss due to infiltration into the ground,and, because of the often marginal quality of the water collected, this technique ismainly suitable for storing water for agricultural purposes.Water can be easily contaminated in this system.

y Rock catchments:It is a rainwater catchment area developed from a rock outcrop to catch and

concentrate runoff into a storage structure for later use. Stone gutters are made tocollect the runoff from the rock catchment area, and direct the rainwater into astorage structure. The storage structure can be a tank or reservoir above a dam.

Reservoirs for rock catchments normally consist of a dam wall behind which an openreservoir stores the rainwater. Generally the surface area of the reservoir will be toolarge to make covering it economically feasible, despite the considerable evaporationlosses which may be expected.These can yield large quantities of water. It is capable of providing sufficient water forwhole communities.These system are effected by evaporative loses also, defecation can be done by animalsand humans

Source: (Rainwater catchment systems: John Gould & E.Nissen-Petersen,1999)

Fig 3:Fig 4:

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B) Collection Devices(storage reservoirs):Rainwater storage reservoirs can be subdivided into three distinct categories:y Surface or above ground reservoirs (associated with roof catchment systems): These can

be constructed from a wide range of materials like metal, wood, plastic etc.Water can be extracted simply and easily through a tap from the reservoir. But, it isexpensive.

y Sub-surface reservoirs (associated with ground catchment systems): these areconstructed in excavations with the soil being backfilled around the outside.

It is cheaper than surface tanks. In low space condition this type of reservoirs areappropriate.

But to access the water, some form of pump or other extraction methods are required.

They also suffer risk of contamination and excessive sediment flow.y Dammed reservoirs: these are one of the cheapest and most effective types of rain water

storage systems. Water can normally be piped by gravity to tape stands or storage tanksat the base of the out crops or to nearby villages to improve accessibility.

(C)Runoff delivery systems:In order to convey rain water runoff from the catchment surface to the storage reservoirs,

some sort of delivery system is normally required.y Roof catchment delivery systems: It consists of gutters, suspended from the eaves sloping

towards a down pipe and tank.y Ground catchment delivery systems: For the small systems the floor normally slopes to a

single tank. For larger systems a network of drains and channels is required.,It includes coarse stone filter to prevent sticks, leaves and other debris from entering the

storage tanks. it also includes a sedimentation chamber for the removal of dust, fine siltand other dirt.

y

Rock catchment delivery systems: Large flat stones are placed upright and cemented inlines to form stone gutters. These stone gutters can be extend for several hundredmeters.

SOURCE : Rainwater catchment systems: John Gould & E.Nissen-Petersen,1999

Fig 5: A surface rainwater harvestingtank at a school in Kenya Fig 6: A dammed reservoir

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Advantages:y Rainwater harvesting technologies are simple to install and operate. Local

people can be easily trained to implement such technologies, andconstruction materials are also readily available.y It provides water at the point of consumption, and family members have full

control of their own systems, which greatly reduces operation andmaintenance problems.

y Running costs, also, are almost negligible. Water collected from roofcatchments usually is of acceptable quality for domestic purposes. As it iscollected using existing structures not specially constructed for the purpose,rainwater harvesting has few negative environmental impacts compared toother water supply project technologies. Although regional or other localfactors can modify the local climatic conditions, rainwater can be acontinuous source of water supply for both the rural and poor.

y Depending upon household capacity and needs, both the water collectionand storage capacity may be increased as needed within the availablecatchment area.

Disadvantages:y Disadvantages of rainwater harvesting technologies are mainly due to the

limited supply and uncertainty of rainfall. Adoption of this technologyrequires a *bottom up* approach rather than the more usual *top down*approach employed in other water resources development projects. This maymake rainwater harvesting less attractive to some governmental agenciestasked with providing water supplies in developing countries, but themobilization of local government and NGO resources can serve the samebasic role in the development of rainwater-based schemes as water resourcesdevelopment agencies in the larger, more traditional public water supplyschemes.

y The prime disadvantage is cost. Storage tanks, as has been seen, are expensiveto build so the initial capital outlay is large.

y Another disadvantage with rock and ground catchment schemes is that the

water may require treatment before it can safely be drunk.

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RAIN WATER HARVESTINGAT BUILDING LEVEL

There are basically two models associated with Rainwater harvesting: Urban model Rural modelUrban model: this method mainly insists on directly harvesting waterfrom roof tops. The schematic diagram is as follows :

URBAN METHODS.In domestic Rooftop Rainwater Harvesting Systems rainwater from the house roof iscollected in a storage vessel or tank for use during the periods of scarcity. Usuallythese systems are designed to support the drinking and cooking needs of thefamily at the doorstep. Such a system usually comprises a roof, a storage tank andguttering to transport the water from the roof to the storage tank. In addition, afirst flush system to divert the dirty water which contains roof debris collected onthe roof during non-rainy periods and a filter unit to remove debris and

contaminants before water enters the storage tank are also provided.

CHAPTER 5

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Fig 7: Components of urban rwh model


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CASE STUDY( LOCATED 17 KM NORTH OFCITY IN A SUBURB VIDYARANYAPURA

Roof catchment Gutters Down pipe and first flush pipe Filter unit Storage tank Collection pit

RoofC

atchment:The roof of the house is used as the catchment for collecting the rainwater.Roofs made of corrugated iron sheet, asbestos sheet, tiles or concrete canbe utilized as such for harvesting the rainwater. But thatched roofs are notsuitable as it gives some colour to water and also the water carries piecesof roof material (such as palm leaves).

Gutters:Gutters are channels fixed to the edges of roof all around to collect andtransport the rainwater from the roof to the storage tank. Gutters can beLocally available material such as plain galvanized iron sheet can be easilyfolded to required shapes to prepare semi-circular and rectangular gutters.Semi-circular gutters of PVC material can be readily prepared by cutting the

PVC

pipes into two equal semi-circular channels. Bamboo poles can also be used.

Downpipe:Down pipe is the pipe, which carries the rainwater from the gutters to thestorage tank. Down pipe is joined with the gutters at one end, and the otherend is connected to the filter unit of the storage tank as shown in figure

below. PVC or GI pipes of diameter 50 mm to 75 mm (2 inch to 3 inch) arecommonly used for down-pipe.

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First Flush Pipe:Debris, dirt and dust collect on the roofs during non-rainy periods. When thefirst rains arrive, this unwanted material will be washed into the storage tank.This causes contamination of water collected in the storage tank therebyrendering it unfit for drinking and cooking purposes. Therefore, a first flushsystem is incorporated to dispose off the water from first rain so that it does

not enter the tank. There are two such simple systems. One is based on a simplemanually operated arrangement, where by, the down pipe is moved away fromthe tank inlet and replaced again once the first flush water has been disposed. Inanother simple and semi-automatic system, a separate vertical pipe is fixed tothe down pipe with a valve provided below the "T" junction. After the first rainis washed out through first flush pipe, the valve is closed to allow the water toenter the down pipe and reach the storage tank.

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Fig 8: the catchment area


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Filter Unit:The filter unit is a container or chamber filled with filter media such as coarsesand, charcoal, coconut fiber, pebbles and gravels to remove the debris and dirtfrom water that enters the tank. The container is provided with a perforatedbottom to allow the passage of water. The filter unit is placed over the storage

tank. Commonly used filters are of two types. One is a ferro-cement filter unit,which is comparatively heavy and the other is made of either aluminium orplastic bucket. The latter is readily available in market and has the advantage ofease in removing, cleaning and replacing.Another simple way of filtering the debris and dust particles that came fromthe roof along with rainwater is to use a fine cloth as filter media. The cloth,in 2 or 3 layers, can be tied to the top of a bucket or vessel with perforations at

the bottom.

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Fig9 & 10: flush pipes


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Storage Tank:Storage tank is used to store the water that is collected form the Rooftops.Common vessels used for small scale water storage are plastic bowls,buckets, jerry cans, clay or ceramic jars, cement jars, old oil drums etc. Forstoring larger quantities of water the system will usually require a bigger tankwith sufficient strength and durability.

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Fig 11 & 12: storage tanks


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(Capacity from 1,000 lt. to 15,000 lt. or even higher) and the material of

construction (brickwork, stonework, cement bricks, ferrocement, plain

cement concrete and reinforced cement concrete). For domestic water

needs, taking the economy and durability of tanks into consideration,ferrocement tanks of cylindrical shape in capacities ranging between 4,000

lt. and 15,000 lt. are most suitable. Plain cement concrete and reinforced

cement concrete are used for tank capacities usually more than 50,000 lt.

Brick, stone, cement brick may be used for capacities ranging between

15,000 lt. to 50,000 lt.

The ferrocement tanks are usually constructed above ground level because

of the following advantages :

a) ease in finding structural problems/leaks,b) easy to maintain and clean and

c) easy to draw water.

It is difficult to detect the leaks and take corrective measures in case ofUnderground tanks. Water from underground tanks cannot be drawn bygravity. Some kind of manual or power lifting devices need to be used for

drawing the water. Further, in coastal areas, under ground tanks are proneto water contamination due to fluctuation in groundwater table and leakageof stored water.

The storage tank is provided with a cover on the top to avoid thecontamination of water from external sources. The cover will be in domeshape having a raise of about 20-30 cm. in the middle. The dome isprovided with two circular openings, one for manhole and another for

accommodating the filter. A lid covers the manhole avoiding exposure ofstored water to the outside environment. The storage tank is provided withpipe fixtures at appropriate places to draw the water, to clean the tank andto dispose of the excess water. They are named tap or outlet, drainpipe and overflow pipe respectively. PVC or GI pipes of diameter 20 mm to 25 mm ( inchto 1 inch) are generally used for this purpose.

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Collection Pit:

A small pit is dug in the ground, beneath the tap of the storage tank andconstructed in brick masonry to make a chamber, so that a vessel could beconveniently placed beneath the tap for collecting water from the storagetank. A small hole is left at the bottom of the chamber, to allow the excesswater to drain-out without stagnation. Size of collection pit shall be 60 cm x60 cm x 60 cm.

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Fig 13: the whole framework


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RURAL MODEL : ZURA VILLAGEOF KUTCH DISTRICT OF GUJARAT

It is quite similar to urban model but has few more methods used to store watereither for agricultural purpose or for domestic use. In rural areas, houses haveusually inclined roof made up of asbestos sheets, bricks or cemented sheets. Thuswater from the roof comes to the edges easily and is collected using channelsfitted and is brought to storage tank through PVC pipes. The storage tank ismade up of ferrocement. Cloth is the material used as filter to clean out the

water from the roof. This type of tank stores enough water for drinking needs ofa five member family for a month.

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Fig 14: initial stage

Fig 15: middle stage

Fig 16: final stage


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EXPECTED BENEFITS1. Prevents water wastage by arresting run off.2. Prevents soil erosion and mitigates flood.3. Sustains and safeguards existing water table through recharge.4. Increases water availability and improves water quality.5. Arrests sea-water intrusion and prevents salination of ground water.C

OLLEC

TION OF RAIN WATER :The quantity of rainwater that can be harvested from a roof area of1000 sq. ft for 100 mm of average annual rainfall and with a surfacerun off coefficient of 0.6 would be :0.1 x 100 x 0.6 x 0.9295 = 5.577 m or 5570 litres /annum.100 mm of rain falling on 1 hectare of land means 1 million litres ofwater. Even if 50 % of this water is collected, it can provide 15 litres of

water/day to 91 persons for a whole year.

SOME OF THE METHOD USED IN THE VILLAGES FOR RUNOFF AS WELL AS WELLRAIN WATERHARVESTING. (SEE FIG 17 & 18)

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Fig 17: method Fig 18: method


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DESCRIPTION OF STUDY SITE

Kutch district falls in the arid tracts of the country and has a unique arid-coastalclimate. It forms the north western region of Gujarat state and stretches between22o 41' 11' to 24o 41' 47' north latitude and 68o 09' 46' to 71o 54' 47' eastlongitude.It experiences extremes of weather condition. The winter season lasts usuallyfrom the middle of November to the end of February with January being the

coldest month having an average minimum temperature of 4.6 oC

.H

owever,mercury drops down below the freezing point. Summer starts from March andcontinues till June end, with the maximum temperature ranging between 39-45oC.The monsoon commences with the onset of southwest monsoon and continuesbetween July and September. The district is characterized by the scanty rainfallwith the mean annual 332 mm (1980-2002). The rainfalls are highly erratic andthe average number of rainy days in a year is only 14. Winds are generallymoderate to high with an annual average speed of 11.3 km/h experienced duringmost of the year. In July, the average wind speed goes up to 36 km/ h. Due to

high temperature and wind speed; the evapo-transpiration rates are very high(Gujarat Institute of Desert Ecology, GEC-Report on Kutch, 1999).Zura village was highly rich in ground water as well as surface water. Due to overexploitation of ground water for the irrigation as well as domestic purpose thefresh water resources depleted. Due to lack of community management, theponds of the village under gone heavy siltation, and densely as well as sparselycovered by the ganda bawal (Prosopis juliflora). The village has 5-6 open well, 2-3 small & large ponds and also a seasonal river, which has water during the rainyseasons only. An extensive water resource survey of the village reveals that the

local water sources is not available. So, for domestic requirement they dependonly on regional water supply scheme. Survey on seasonal migration from thevillage shows that water is a limiting factor and play very vital role on the villageeconomy. About 34% of total human population of Zura migrated to otherplaces due to water scarcity (UNICEF/ IRMA, 2000).

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AREA LEVEL CASE STUDIESCHAPTER 6


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JAMIA MILLIA ISLAMIA UNIVERSITYJamia Millia Islamia is located in the Mehrauli in Delhi. Here, the groundwater is

fresh in the alluvium up to the depth of 30-60 metres Below ground level. Furtherdown salinity increases with depth.

Total Area : 205 (829942.5 sq. m.)Covered Space : 15%Open space : 85%

Depending upon the area of sub-campuses the campus of JamiaMillia Islamia has been dividedinto ten zones.

The rainwater harvestingstructures were installed atthe campus and theanalyses of the impact of rainwater recharge ongroundwater quality was

done.

AREA LEVEL CASE STUDIES

ON WATER HARVESTINGCHAPTER 6

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Fig 19: location map

Fig 20: different zones


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SCOPE OF THE STUDY

The rainwater harvesting structures were installed at Engineering faculty, Gaddha

Colony, department of Fine Arts, University Polytechnic and AdministrativeBlock and the scope of the project is impact of rainwater harvesting ongroundwater quality, the following steps are followed:

The groundwater quality analysis data at pre-installation period of the rainwaterharvesting structures at the JMI.To collect the groundwater samples in the Post-Monsoon period covering theentire JMI campus area in order to analyse the impact of rainwater harvesting ongroundwater quality.Collection of groundwater samples after few months to know the changes in thegroundwater quality since the post-monsoon times.Comparative Study of quantity all the three-groundwater quality test resultsin order to ascertain the overall impact of Rainwater Harvesting ongroundwater quality and quantity of the campus area.

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ANALYSIS OF RAIN WATER HARVESTING ATJAMIA MILIA ISLAMIA UNIVERSITY

Jun Jul Aug Sept

38.8 191.6 197.4 105.3

AVERAGE ANNUAL RAINFALL : 611mm

ROOFTOP RAINWATER POTENTIAL

TOTAL ROOFTOP AREA = 74729.38 SQ. M.

TOTAL ROOFTOP RAINWATER POTENTIAL AT JMI(AT RATE OF 16 CM ANNUAL RAINFALL) = 42698.96 CU.M.

TOTAL ROOFTOP RAINWATER POTENTIAL AT JMI(AT2.5CM/15MIN.FOR DESIGN PURPOSE) = 1588.01 CU.M.

Table 1: Rainfall measurement at jamia milia

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Fig 21: SITE LOCATION OF INJECTION WELL S AND

MONITORING SYSTEM

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TECHNIQUES APPLIED FORRAINWATERHARVESTING AT JMI

Fig22: CIRCULAR RECHARGINGAND DISTILLING CHAMBER

Fig 23: RECHARGINGABANDONED WELL

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ADVANTAGES OF RAIN WATER HARVESTING AT JMI

Before the rain water harvesting the water table at the JMI campus was below8m to 12 m.

After the rain water harvesting , the water table has been raised by 0.75 metersin the areas.In the engineering department it has been found that the water table raised from9.65m 10.4m.In the fine arts department and the administrative block, the water table hasbeen raised from 10.45m 11.2m.

IMPACT OF RAINWATER HARVESTING ON GROUND WATER QUANTITY

Total Space Potential(at the average annual rainfall of 611mm) : 1,79,665.26 cu.m.

At the rate of rainfall of 748 mm in 2003 : 2,67,823.71cu.m.Hence, the recharge from the area : 2,67,823.71cu.m.

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CENTRE FOR SCIENCE


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CITY BACKGROUND

The city of Delhi is in a group of water crisis.. The average water consumption inDelhi is estimated at 3324 liters per day but the supply is only 2634 liters perday. The gap between supply and demand has led to serious problems with bothquantity and quality of ground water.

Delhi has annual rainfall of approximately 600mm. However, recharge to

ground water is limited because of decreasing availability of permeable soilsurface. As a result of poor recharge and heavy extraction of groundwater, thegroundwater level in Delhi has declined by 8m in the past decade.

CASE BACKGROUND

The total area of the Centre for Science and Environment building is 1.000 sq.m. The office gets most of its water supply from groundwater through its bore

well. The water harvesting system was installed in the building in June 1999.

CENTRE FOR SCIENCEAND ENVIRONMENT, NEW DELHI

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RECHARGING OF ABANDONED BOREWELL

Rainwater from the rearPortion of the terrace isled through a verticaldrainpipe to the 45mdeep abandoned borewell. An aluminumGrating preventsdebris from enteringthe bore well. The borewell and the sump onthe top are filledwith filter media ofbrickbats to trap debris.

SOAKWAYSThirteen soak ways have been constructed around the building. A soakway is avertical shaft of 150mm diameter bored into the ground to a depth of 30 feetand case with a pvc pipe. The mouth of the shaft is covered with an earthen potwith a small hole to prevent the entry of debris into the shaft.

Fig 24: showing drainage of rain water

Fig 25:showing detailed

of abandoned soakway

MEASURES TAKEN FOR WATERHARVESTING

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RAINWATER STORAGE TANK

The rainwater drainpipes from all terraces are connected in series so that therunoff from these terraces falls into the pond in front of the building. When

the pond overflows, water flows to the underground tank of 8,500 litercapacity. Water from this rainwater storage tank is used for low quality useslike gardening.

RECHARGE TROUGH

Three soak ways have been constructed in the trough under the entrance gate,which is covered with an iron grill. The runoff flowing out through the

entrance is collected in this trough and gets recharged through the soakways.

RAISING OF STORMWATER DRAINS

Openings of the municipal storm water drains within the campus area havebeen raised slightly above the ground level, so rainwater does not drain away.

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CITY LEVEL CASE STUDY ON


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INDOREC

ITY

Indore, the premier city of Madhya Pradesh is located almost centrally in themalwa plateau, defined by 220 43 N longitude and 760 42 E latitude. It is atan altitude of 550metres above the sea level. The study area boundary iscontiguous with the planning area of Development Plan of Indore.

Indore recieves an annual rainfall of 930mm. There is no perennial water source

near Indore. Narmada if used as a source of potable water requires long distancetransmission of water which is an expensive process. There is a shortage of 60million litres per day in the municipal water supply as per the data of 1991 and itis estimated to reach 200 litres per person per day by 2010 if the situationremains the same.

Although the government of Indore has taken some initiatives to conserve thecatchments of water bodies through surrounding them with recreational open

spaces and to locate industries away from existing water bodies.

CITY LEVEL CASE STUDY ONWATER HARVESTING

POTENTIAL OF RAIN WATER HARVESTING

Indore slopes south to north with numerous streams running along the slope. Theslope in the city is gentle apart from the centre where a depression may be seen. Theslope varies from 0.1% - 0.035% with an average slope of 0.03%. (1 in 300). Thegentle slope implies that keeping water stagnant and allowing recharge maybe a

feasible proposition but considering the presence of rocky soil and black cottonsoil, this is not possible.

The groundwater levels are lowest in the central parts of the city, ranging from120m to 160 m below ground level. This is because e areas also have e the highestresidential density. In addition to these being the oldest areas of the city, theresidents have been exploiting the ground water for a long time.

The ground water levels are the worse in the East and South of Indore but are thehighest in the north and west of the city.

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INITIATIVES FOR RAIN WATER


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INDORE MUNICIPAL CORPORATION

The IMC has initiated a water harvesting and recharging cell as a part of itsrainwater harvesting initiative. It spreads awareness through exhibitions andcampaigns. It takes up workshops and seminars for plumbers to qualify them inwater harvesting works.

The IMC offers a 6% rebate on the property tax for all the people incorporating

rainwater harvesting on their sites.

PUBLIC HEALTH ENGINEERING DEPARTMENT

The PHED has mainly associated with Narmada water supply project and has notmuch role towards the rainwater harvesting directly. However, it has executed apilot project for rainwater harvesting on its site at Musakheri in Indore.

SGS INSTITUTE OF TECHNOLOGYAND SCIENCE

As an academic institution SGSITS has done a lot of research on rainwaterharvesting and initiated a project of Rs. 8 crore for rain water harvesting inIndore city.

HARVESTING IN INDORE

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RAIN WATER HARVESTING


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RAIN WATER HARVESTINGENACTED IN HUDA NOTIFICATION

1. Arrangement of roof top rain water harvesting will have to be made by theplot owner, constructing the building on the plot allotted by Haryana UrbanDevelopment Authority where the area of the roof is 100 Sq.m. or more.

2. The system of collection, conveyance and dispersion of rain water forharvesting shall be made in such a manner that only clear water is able toenter. No contaminated/ waste water from the building or surrounding area

should find its way in this system.3. The entry points of the rain water for harvesting shall be designed in such a

manner that in normal days, these remain covered. Arrangement of segregation of the rain water from first shower (containing wash water) shallalso be there.

4. The arrangement of quick filtration of rain water also be made in the rainwater harvesting well/ tube-well so that rain water does not pollute or choke

the strata.5. The complete system of rain water harvesting will be constructed within the

plot area allotted to the allottee as per allotment letter.

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6 The recharge well shall be located at a distance of not less than 10 meters away


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6. The recharge well shall be located at a distance of not less than 10 meters awayfrom any structure handling sewage or industrial waste water (such as septictank or effluent plant etc.). This minimum distance of 10 meters will not beapplicable to manholes or sewer lines although it will be ensured that theyare leak proof.

7. The detail proposal of the system comprising of collections, conveyance anddispersion of rain water from the roof top to rain water harvesting well/tube-well will have to be shown on the building plan submitted for approvalto the building plan approval committee. The committee after scrutiny willapprove the drawing for implementation at site.

8. Any engineer not below the rank of Executive Engineer, HUDA so authorisedby Chief Administrator, HUDA / Director Town & Country Planning,Haryana will have the powers to inspect the system whenever considerednecessary and direct the owner of the building to affect any changes/improvement as deemed necessary and the owner of the building will ensurecompliance.

9. Haryana Urban Development Authority shall notify the area where such rain

water harvesting system is to be provided. Broad guidelines about theapproximate depth of the recharge well and the sample strata chart will alsobe made available.

10 The water (Prevention and Control Pollution) Act, 1974, (Act 6 of 1974) withall amendments made from time to time shall be applicable.

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RAIN WATER HARVESTING THROUGHOPEN SPACE

1. Planning of open space at different level Housing area, Housing cluster.

2. Hierarchy of open spaces and their linkages for better recharging capacity andnetworking

3. Design of open space for charging , storage charging, storage.

4. Sloping of open space for water accumulation

5. Open space in educational institutions to have ground water charging

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CHAPTER 7


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CONCLUSION

Rainwater harvesting would be one of the most promising alternatives fordrinking and irrigation water supply in severely safe water shortage areas,especially for south Asian countries and offshore islands in other parts of theworld as well. Most of the harvested and stored rainwater reports showed thatthe chemical quality parameters were quite satisfactory with noparameter being detected above the corresponding maximum allowableconcentration for drinking purposes. However, microorganisms were foundmost of the samples, though they were at low numbers.Rainwater harvesting is not widespread in south Asian countries due to lack ofpublic awareness about the system. Government should take initiatives such as

offering soft lone, and pass legislation to install RWH system in all newgovernment and private buildings to promote RWH system this region. Thenatural hydrological cycle could be rehabilitated through rainwatermanagement especially in severely water shortage areas, which is of greatimportance for sustainable development of our environment.Rainwater harvesting would not be a single solution of drinking or irrigationpurposes, but a series of different approaches which combined increases thesustainability for rainwater management, especially in areas of water scarcity.Thus collect the natural resource, rainwater before entering the drains.

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BIBLIOGRAPHYBOOKS:y RAINWATER CATCHMENT SYSTEMS : JOHN GOULD AND NISSEN

PETERSEN,1999y WATER : A MANUAL FOR ENGINEERS,ARCHITECTS,PLANNERS AD

MANAGERS:ASHOK KUMAR JAIN,2007

y WATER IN INDIA : G.K. GHOSH ,2005THESIS:y ENABLING RAINWATERHARVESTING THROUGH PLANNING INTERVENTIONS,

CASE STUDY : INDORE, 2001y RAIN WATERHARVESTING , JAMIA MILIA ISLAMIAJOURNAL:y ROOF-TOP RAINWATERHARVESTING IN URBAN AREA : Dr. S.K. SHARMA,2007y STUDYOF RAIN WATERHARVESTING OF ZURA VILLAGE , GUJARAT: A. K

TRIPATHI AND UMAKANT PANDEY, 2005OTHERS:y INTERNETy CD : SEMINAR ON WATER HARVESTING,SPA

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