2. Contents
Introduction
Objectives Of Rain Water Harvesting
Why Is This Required?
Rain Water Harvesting Techniques
Uses Of Rain Water Harvesting
Advantages and Disadvantages
Summary
3. What Is Harvesting?
• Rainwater harvesting is the accumulating and storing of rainwater by artificial
methods for further utilization.
• Rainwater harvesting is a technology used for collecting and storing rainwater
from rooftops, the land surface or rock catchments using simple techniques
such as jars and pots as well as more complex techniques such as underground
check dams.
• The principle of collecting and using precipitation from a catchments surface.
• Mostly done by rooftop harvesting and is used for domestic and agricultural
purposes.
4. Objectives Of Rain Water Harvesting
• To conserve surface run-off during monsoons.
• To recharge aquifer and increase availability of groundwater.
• To overcome the problem of flooding and stagnation of water during monsoon
season.
• To arrest ground water decline and augment ground water table
• Domestic and livestock consumption.
• Irrigation of annual crops pastures and trees.
• To reduce soil erosion.
5. Why Is This Required?
• Surface water is inadequate to meet our demand and we have to depend on ground
water.
• Water scarcity-a serious problem throughout the world for urban and rural communities.
• Urbanization has led to overexploitation of groundwater reserves & the quantity of
rainfall is not certain anytime.
• In some places , excessive heat waves during summer create a situation similar to
drought.
• Out of 8760 hours in a year , most of the rain in India falls in just 100 hours.
6. Rain Water Harvesting Techniques
Roof Top Rain Water Harvesting:
• 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. This method is less expensive and very effective.
Surface Runoff Harvesting:
• Harvesting of surface runoff and storage of the same into reservoirs such as
water pans makes it available for use when required.
• In this method of collecting rain water for irrigation, water flowing along the
ground during the rain will be collected to a tank.
7. Uses Of Rain Water Harvesting
• Domestic use
• Agricultural use
• Industrial and commercial use
• Increase groundwater supplies
8. Advantages Of Rain Water Harvesting
• Rain water harvesting is the ideals solution for all water requirements.
• Increase in ground water level.
• Reduces flooding of roads.
• Reduced soil erosion.
• Improves the ground water quality.
• Low cost and easy to maintain.
• Reduces water and electricity bills.
9. Disadvantages Of Rain Water Harvesting
• Seasonal nature and uncertainty of rainwater supply depending on the region in
the world.
• Regular maintenance and cleaning is essential for successful operation.
• Vulnerable water quality.
• Storage capacity limits.
• Capital costs.
10. Summary
• One of the best way to solve the world burning facing issue: water scarcity.
• Helps in raising ground water level.
• Saving of energy per lifting of well and saving of water bills.
• Harvesting water can be used for daily household needs.
• It is economical.
• Its not a permanent solution as water is not available throughout the year but it
can be utilized to its maximum extent.
• Water is important resources we should be very careful while dealing with it.
