RAINWATERHARVESTING

MANOJ DAS.DCE,3 RD YEAR,ROLL-25

Rain Water Harvesting?. • Rain Water Harvesting RWH- process of

collecting, conveying & storing water from rainfall in an area – for beneficial use. • Storage – in tanks, reservoirs, underground storage- groundwater

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Condensation

Precipitation

Evaporation

Surface Water

Infiltration

Evapotranspiration

Let’s take a look atThe Water

Cycle

Consumption

Surface Runoff

Groundwater

Sea water intrusion

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Why Rainwater Harvesting?

Conserve and supplement existing water resources Available for capture and storage in most global locationsPotentially provide improved quality of waterSupply water at one of the lowest costs possible for a supplemental supply source. Capturing and directing storm water (run-off) and beneficially use itCommitment as a corporate citizen - showcasing environmental concernsPublic Mandate (India)Replenishing local ground water aquifers where lowering of water tables has occured

Surface runoff harvesting

In this method of collecting rainwater for irrigation, water

flowing along the ground during the rains will be collected to a tank

below the surface if the ground

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Percolation PitTo divert rainwater into an aquifer,

The percolation pit is covered with a perforated concrete slab

The pit is filled with gravel/ pebbles followed by river sand for better percolation.

The top layer of sand must be cleaned and replaced at least once in two years to remove settled silt for improving the percolation

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Ground Water Recharge

Under natural conditions it may take days to centuries to recharge ground water by rain water. As we need to replenish the pumped water, Artificial Recharge of Ground water is required at some locations.

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Recharge WellsThe runoff water from rooftops or other

catchments can be channelized into an existing /new well via sand filter to filter turbidity and other pollutants

Abandoned wells can also be usedCost-effective process, which not only

conserves rainwater for immediate use but also helps to enhance the local ground water situation

THANK U ALL