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    Rain Water Harvesting: Jagdambha Collage of Engineering & Technology, Yavatmal

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    Praveen Saksena
    This document discusses a seminar presentation on rainwater harvesting given by Vikram K. Chavhan, a third year civil engineering student. It introduces the topic by discussing India's traditional water harvesting systems and the need to revive these approaches. The presentation defines rainwater harvesting as collecting and storing rainwater for drinking, domestic and irrigation purposes. It describes various components of roof rainwater harvesting systems including catchments, transportation pipes, first flush devices, and filters. Common methods of rainwater harvesting discussed are storage and direct use or recharging groundwater through structures like borewells, dug wells, recharge pits, trenches, soakaways and percolation tanks.

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    Rain Water Harvesting: Jagdambha Collage of Engineering & Technology, Yavatmal

    Uploaded by

    Praveen Saksena
    243 views11 pages
    This document discusses a seminar presentation on rainwater harvesting given by Vikram K. Chavhan, a third year civil engineering student. It introduces the topic by discussing India's traditional water harvesting systems and the need to revive these approaches. The presentation defines rainwater harvesting as collecting and storing rainwater for drinking, domestic and irrigation purposes. It describes various components of roof rainwater harvesting systems including catchments, transportation pipes, first flush devices, and filters. Common methods of rainwater harvesting discussed are storage and direct use or recharging groundwater through structures like borewells, dug wells, recharge pits, trenches, soakaways and percolation tanks.

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    rwh by vikram chavan

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    Vikram Chavhan

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    This document discusses a seminar presentation on rainwater harvesting given by Vikram K. Chavhan, a third year civil engineering student. It introduces the topic by discussing India's traditional water harvesting systems and the need to revive these approaches. The presentation defines rainwater harvesting as collecting and storing rainwater for drinking, domestic and irrigation purposes. It describes various components of roof rainwater harvesting systems including catchments, transportation pipes, first flush devices, and filters. Common methods of rainwater harvesting discussed are storage and direct use or recharging groundwater through structures like borewells, dug wells, recharge pits, trenches, soakaways and percolation tanks.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    243 views11 pages

    Rain Water Harvesting: Jagdambha Collage of Engineering & Technology, Yavatmal

    Uploaded by

    Praveen Saksena
    This document discusses a seminar presentation on rainwater harvesting given by Vikram K. Chavhan, a third year civil engineering student. It introduces the topic by discussing India's traditional water harvesting systems and the need to revive these approaches. The presentation defines rainwater harvesting as collecting and storing rainwater for drinking, domestic and irrigation purposes. It describes various components of roof rainwater harvesting systems including catchments, transportation pipes, first flush devices, and filters. Common methods of rainwater harvesting discussed are storage and direct use or recharging groundwater through structures like borewells, dug wells, recharge pits, trenches, soakaways and percolation tanks.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    of 11

    Civil engg.

    Dept
    rain water harvesting

    JAGDAMBHA COLLAGE OF
    ENGINEERING & TECHNOLOGY,
    YAVATMAL.
    SEMINAR ON,
    RAIN

    WATER HARVESTING
    By,
    VIKRAM K. CHAVHAN
    ( THIRD YEAR CIVIL ENGG. )

    INTRODUCTION:-

    In the present scenario management and distribution of water has become


    centralized. People depend on government system, which has resulted in disruption of
    community participation in water management and collapse of traditional water
    harvesting system.
    As the water crisis continues to become severe, there is a dire need of reform in water
    management system and revival of traditional systems. Scientific and technological
    studies needs to be carried out to assess present status so as to suggest suitable
    mitigative measures for the revival to traditional system/wisdom. Revival process should
    necessarily be backed by people's initiative and active public participation.
    Living creatures of the universe are made of five basic elements, viz., Earth, Water, Fire,
    Air and Sky, Obviously, water is one of the most important elements and no creature
    can survive without it. Despite having a great regard for water, we seem to have failed
    to address this sector seriously. Human being could not save and conserve water and it
    sources, probably because of its availability in abundance. But this irresponsible attitude
    resulted in deterioration of water bodies with respect to quantity and quality both. Now,
    situation has arrived when even a single drop of water matters. However. " better late
    than never", we have not realized the seriousness of this issue and initiated efforts to
    overcome those problems.
    1

    Civil engg. Dept


    rain water harvesting

    GENRAL INFORMATION:System of collection rainwater and conserving for future needs has traditionally been
    practiced in India. The traditional systems were time-tested wisdom of not only
    appropriate technology of Rainwater Harvesting, but also water management
    systems, where conservation of water was the prime concern. Traditional water
    harvesting systems were Bawaries, step wells, jhiries, lakes, tanks etc. These were the
    water storage bodies to domestic and irrigation demands. People were themselves
    responsible for maintenance to water sources and optimal use of water that could fulfill
    their needs

    WHAT IS RAINWATER HARVESTING?


    The term rainwater harvesting is being frequently
    used these days, however, the concept of water harvesting is not new for India. Water
    harvesting techniques had been evolved and developed centuries ago.

    Civil engg. Dept


    rain water harvesting

    Ground water resource gets naturally recharged through percolation. But due to
    indiscriminate development and rapid urbainzation, exposed surface for soil has been
    reduced drastically with resultant reduction in percolation of rainwater, thereby depleting
    ground water resource. Rainwater harvesting is the process of augmenting the natural
    filtration of rainwater in to the underground formation by some artificial methods.
    "Conscious collection and storage of rainwater to cater to demands of water, for
    drinking, domestic purpose & irrigation is termed as Rainwater Harvesting."]
    WHY HARVEST RAINWATER ?
    This is perhaps one of the most frequently asked question, as to why one should
    harvest rainwater. There are many reasons but following are some of the important
    ones.

    To arrest ground water decline and augment ground water table.


    To beneficiate water quality in aquifers .
    To conserve surface water runoff during monsoon .
    To reduce soil erosion .
    To inculcate a culture of water conservation .

    How to harvest rainwater:


    Broadly there are two ways of harvesting rainwater:
    (i)
    (ii)

    Surface runoff harvesting


    Roof top rainwater harvesting

    Surface runoff harvesting:


    In urban area rainwater flows away as surface runoff. This runoff could be caught and
    used for recharging aquifers by adopting appropriate methods.

    Roof top rainwater harvesting (RTRWH):


    It is a system of catching rainwater where it falls. In rooftop harvesting, the roof
    becomes the catchments, and the rainwater is collected from the roof of the
    house/building. It can either be stored in a tank or diverted to artificial recharge system.
    This method is less expensive and very effective and if implemented properly helps in
    augmenting the ground water level of the area.

    Civil engg. Dept


    rain water harvesting

    Components of the roof top rainwater harvesting system


    The illustrative design of the basic components of roof top rainwater harvesting
    system is given in the following typical schematic diagram/
    The system mainly constitutes of following sub components:
    Catchment
    Transportation
    First flush
    Filter

    Catchment
    The surface that receives rainfall directly is the catchment of rainwater harvesting
    system. It may be terrace, courtyard, or paved or unpaved open ground. The terrace
    may be flat RCC/stone roof or sloping roof. Therefore the catchment is the area, which
    actually
    contributes
    rainwater
    to
    the
    harvesting
    system.

    Transportation
    Rainwater from rooftop should be carried through down take water pipes or drains
    to storage/harvesting system. Water pipes should be UV resistant (ISI HDPE/PVC
    pipes) of required capacity. Water from sloping roofs could be caught through gutters
    and down take pipe. At terraces, mouth of the each drain should have wire mesh to
    restrict floating material.

    First Flush
    First flush is a device used to flush off the water received in first shower. The first
    shower of rains needs to be flushed-off to avoid contaminating storable/rechargeable
    water by the probable contaminants of the atmosphere and the catchment roof. It will
    also help in cleaning of silt and other material deposited on roof during dry seasons
    Provisions of first rain separator should be made at outlet of each drainpipe
    4

    Civil engg. Dept


    rain water harvesting

    Filter
    There is always some skepticism regarding Roof Top Rainwater
    Harvesting since doubts are raised that rainwater may contaminate groundwater. There
    is remote possibility of this fear coming true if proper filter mechanism is not adopted.
    Secondly all care must be taken to see that underground sewer drains are not
    punctured and no leakage is taking place in close vicinity. Filters are used fro treatment
    of water to effectively remove turbidity, colour and microorganisms. After first flushing of
    rainfall, water should pass through filters. There are different types of filters in practice,
    but basic function is to purify water

    Sand gravel filter:


    These are commonly used filters, constructed by brick masonry and filleted by pebbles,
    gravel, and sand as shown in the figure. Each layer should be separated by wire mesh

    Civil engg. Dept


    rain water harvesting

    Charcoal Filter
    Charcoal filter can be made in-situ or in a drum. Pebbles, gravel, sand and charcoal as
    shown in the figure should fill the drum or chamber. Each layer should be separated by
    wire mesh. Thin layer of charcoal is used to absorb odor if any.

    PVC- Pipe filter


    This filter can be made by PVC pipe of 1 to 1.20 m length; Diameter of pipe depends on
    the area of roof. Six inches dia. pipe is enough for a 1500 Sq. Ft. roof and 8 inches dia.
    pipe should be used for roofs more then 1500 Sq. Ft. Pipe is divided into three
    compartments by wire mesh. Each component should be filled with gravel and sand
    alternatively as shown in the figure. A layer of charcoal could also be inserted between
    two layers. Both ends of filter should have reduce of required size to connect inlet and
    outlet. This filter could be placed horizontally or vertically in the system.

    Sponge Filter
    It is a simple filter made from PVC drum having a layer of sponge in the middle of drum.
    It is the easiest and cheapest form filter, suitable for residential units.

    Civil engg. Dept


    rain water harvesting

    METHOD OF ROOF TOP RAIWATER HARVESTING:-

    Storage of Direct use


    In this method rain water collected from the roof of the building is diverted to a storage
    tank. The storage tank has to be designed according to the water requirements, rainfall
    and catchment availability. Each drainpipe should have mesh filter at mouth and first
    flush device followed by filtration system before connecting to the storage tank. It is
    advisable that each tank should have excess water over flow system.
    Excess water could be diverted to recharge system. Water from storage tank can be
    used for secondary purposes such as washing and gardening etc. This is the most cost
    effective way of rainwater harvesting. The main advantage of collecting and using the
    rainwater during rainy season is not only to save water from conventional sources, but
    also to save energy incurred on transportation and distribution of water at the doorstep.
    This also conserve groundwater, if it is being extracted to meet the demand when rains
    are on.

    Recharging ground water aquifers


    Ground water aquifers can be recharged by various kinds of structures to ensure
    percolation of rainwater in the ground instead of draining away from the surface.
    Commonly used recharging methods are:a)
    b)
    c)
    d)
    e)
    f)

    Recharging of bore wells


    Recharging of dug wells.
    Recharge pits
    Recharge Trenches
    Soak ways or Recharge Shafts
    Percolation Tanks

    Recharging of bore wells


    Rainwater collected from rooftop of the building is diverted through drainpipes to
    settlement or filtration tank. After settlement filtered water is diverted to bore wells to
    recharge deep aquifers. Abandoned bore wells can also be used for recharge.
    Optimum capacity of settlement tank/filtration tank can be designed on the basis of area
    of catchement, intensity of rainfall and recharge rate as discussed in design
    parameters. While recharging, entry of floating matter and silt should be restricted
    because it may clog the recharge structure. "first one or two shower should be flushed
    out through rain separator to avoid contamination. This is very important, and all care
    should be taken to ensure that this has been done."
    7

    Civil engg. Dept


    rain water harvesting

    Recharge Pits
    Recharge pits are small pits of any shape rectangular, square or circular, contracted
    with brick or stone masonry wall with weep hole at regular intervals. to of pit can be
    covered with perforated covers. Bottom of pit should be filled with filter media.
    The capacity of the pit can be designed on the basis of catchment area, rainfall intensity
    and recharge rate of soil. Usually the dimensions of the pit may be of 1 to 2 m width and
    2 to 3 m deep depending on the depth of pervious strata. These pits are suitable for
    recharging of shallow aquifers, and small houses.

    Soak away or Recharge Shafts


    Soak away or recharge shafts are provided where upper layer of soil is alluvial or less
    pervious. These are bored hole of 30 cm dia. up to 10 to 15 m deep, depending on
    depth of pervious layer. Bore should be lined with slotted/perforated PVC/MS pipe to
    prevent collapse of the vertical sides. At the top of soak away required size sump is
    constructed to retain runoff before the filters through soak away. Sump should be filled
    with filter media.

    Recharging of dug wells


    Dug well can be used as recharge structure. Rainwater from the rooftop is diverted to
    dug wells after passing it through filtration bed. Cleaning and desalting of dug well
    should be done regularly to enhance the recharge rate. The filtration method suggested
    for bore well recharging could be used.

    Civil engg. Dept


    rain water harvesting

    Recharge Trenches
    Recharge trench in provided where upper impervious layer of soil is shallow. It is a
    trench excavated on the ground and refilled with porous media like pebbles, boulder or
    brickbats. it is usually made for harvesting the surface runoff. Bore wells can also be
    provided inside the trench as recharge shafts to enhance percolation. The length of the
    trench is decided as per the amount of runoff expected. This method is suitable for small
    houses, playgrounds, parks and roadside drains. The recharge trench can be of size
    0.50 to 1.0 m wide and 1.0 to 1.5 m deep.

    Percolation tanks
    Percolation tanks are artificially created surface water bodies, submerging a land area
    with adequate permeability to facilitate sufficient percolation to recharge the ground
    water. These can be built in big campuses where land is available and topography is
    suitable.
    Surface run-off and roof top water can be diverted to this tank. Water accumulating in
    the tank percolates in the solid to augment the ground water. The stored water can be
    used directly for gardening and raw use. Percolation tanks should be built in gardens,
    open spaces and roadside green belts of urban area.

    ADVANTAGES:It is the most advantageous system .


    - It is most beneficial to improve the ground water table.
    - Increase the level of natural sources of water.
    - It is useful to reduce the problem of famine.
    - It also useful to maintained the same inviroment for future.
    - To reduce the future water problem.
    APLICATION:Generally maximum people have a knowledge about that, but minimum people
    are apply this system to improve the ground water table. In that paper I just tell the
    importance of rain water harvesting and benefits of that.
    It is possible to aply the following points,
    -where the maximum runoff occur.

    Civil engg. Dept


    rain water harvesting

    -and big building structure where the maximum area of slab present and as possible
    as we collect the more water to percolate into the ground.

    CONCLUSION:Lastly I conclude about that,


    It is very beneficial to maintain the proper level of water for future and also
    increase the level of ground water table. it helps to the economic development of
    our contry. And now the govt. do the same policies for that means if we are going
    to sanctioning the residential bluildng plan it must be show the rainwater
    harvesting plant if we do not show this our plan will not be sanctioned.
    On that point we know the govt. are now aware from that.

    10

    Civil engg. Dept


    rain water harvesting

    11

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