Rain Water Harvesting (RWH)

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Rain Water Harvesting (RWH)

The collected rainwater may be stored, utilised in different ways or directly used for recharge purposes. With depleting groundwater levels and fluctuating climate conditions, RWH can go a long way to help mitigate these effects. Capturing the rainwater can help recharge local aquifers, reduce urban flooding and most importantly ensure water availability in water-scarce zones.

History

  • Rainwater has been harvested in India since antiquity, with our ancestors perfecting the art of water management.
  • Around the third century BC, the farming communities in Balochistan (now located in Pakistan, Afghanistan and Iran), and Kutch, India used rainwater harvesting for irrigation
  • In ancient Tamil Nadu, rainwater harvesting was done in Chola kings.
  • Rainwater from the Brihadeeswara temple (located in Balaganapathy Nagar, Thanjavur) was collected in Shivaganga tank.
  • Rainwater harvesting structures and water conveyance systems specific to eco-regions and culture has been developed.

What is Rainwater Harvesting ?

Rainwater harvesting is the storing of rainwater during the monsoon season for the purpose of using it during periods of water scarcity.

Generally speaking, it is a process used for collecting and storing rainwater for human use. Rainwater harvesting is best described as the technique by which rain water is accumulated and stored with the intention of reusing it during the dry season or when there is a drought. With rapid climatic changes, increase in global temperature and population growth, there is a scarcity of potable water in many countries across the world. The gradual falling of water levels, are a cause of serious concern not only because it leads to shortage of usable water but also because in coastal areas it causes imbalance in salinity of the area.

The importance of rainwater harvesting lies in the fact that it can be stored for future use. Just as it can be used directly so also the stored water can be utilized to revitalize the ground level water and improve its quality. This also helps to raise the level of ground water which then can be easily accessible.

The accumulation of water from rain is known as Water harvesting. One of the significant aims of rainwater harvesting is to construct primary resources of land and water to generate secondary sources. Moreover, during the summer season, some of the parts of India such as Rajasthan face a scarcity of water.

Rain water harvesting is a technique of collection and storage of rainwater into natural reservoirs or tanks, or the infiltration of surface water into subsurface aquifers (before it is lost as surface runoff)

Why Rainwater Harvesting?

Groundwater has minimum scope for evaporation or pollution which means more reliable water for daily consumption. Rainwater harvesting and groundwater recharge also minimizes the chances of flood like situations and water logging at various locations.

The importance of rainwater harvesting lies in the fact that it can be stored for future use. Just as it can be used directly so also the stored water can be utilized to revitalize the ground level water and improve its quality. ... Harvesting rainwater checks surface run off of water and reduces soil erosion.

The benefits of collecting rainwater are numerous. It reduces the demand on the municipal water supply. It allows for storage of seasonal rains for use in off-peak times. Harvesting systems reduce erosion, property flooding, and contamination by reducing the majority of runoff from businesses and homes.

  • Fresh water sources are being heavily exploited to meet the ever increasing demand.
  • The rapid rate of urbananisation has reduced the availability of open surfaces for natural recharge of ground water
  • Indiscriminate extraction of groundwater has resulted in the depletion of water level resulting in the drying of wells.
  • Dependence on ground water increases during periods of low rainfall.
  • Enhancing the the storage of ground water through conservation, to reduce the water level depletion.
  • Improving the quality of ground water & arresting sea water intrusion in coastal area.

How Rainwater Harvesting ?

Rainwater harvesting is collecting the run-off from a structure or other impervious surface in order to store it for later use. Traditionally, this involves harvesting the rain from a roof. The rain will collect in gutters that channel the water into downspouts and then into some sort of storage vessel.

The two major types of rainwater harvesting include roof based and land-based rainwater harvesting. Rain harvested water can be used for watering livestock, laundry, flushing toilets, etc.

Rain water harvesting is one of the most effective methods of water management and water conservation. ... It involves collection and storage of rain water at surface or in sub-surface aquifer, before it is lost as surface run off.

Rainwater harvesting helps manage storm water runoff to prevent erosion, flooding, and poor water quality in our lakes and streams. ... Rainwater systems counteract storm water run off and thereby reduce flooding, erosion, and ground water contamination.

Rooftop Rainwater Harvesting

Rain water from the roof is collected through the gutters in the roof. The collected water is filtered through a filter. The filtered water is collected either in a storage tank or existing sump.

 

Rainwater Harvesting for Groundwater Recharge

Rain water from the roof is collected through the gutters in the roof. The collected water is filtered through a filter. The filtered water is collected either in a storage tank or existing sump.