Rooftop rainwater harvesting, a technique of capturing rainwater from roof catchments and storing them in reservoirs, is carried out to conserve fresh water resources. The water accumulated can be saved in containers or sub-surface ground water reservoir through artificial recharging techniques and reused for domestic and other purposes.

1. TGS
Guide Rain Water
Harvesting
Roof Water Collection

2. Rain water is a
bliss to our nature.
Every year a large
volume of
rainwater gets
wasted, which
could have been
utilized in our
day-to-day use,
through proper
accumulation &
storage.
Lack of systematic
set-ups in our roof
also leads to loss
of bulk volume of
Rain Water !!
HERE IS HOW !!............

3. PROBLEMS

4. SOLUTION

5. • In
containers
Collect
• Filters
• Sprinklers
Store
• Household
• Gardening
Use
PURPOSE

6. 1. Rain water collected from the roof is
channelized through the pipe that drains
it into the De-siltation Tanks.
2. The water accumulated, seeps into the
Ferro-Cement Tank from the De-siltation
Tanks.
3. Percolation Pits are one of the easiest
and most effective means of harvesting
rainwater, measuring not more than
60 x 60 x 60 cm.They are usually filled with
pebbles or brick jelly and river sand,
covered with perforated concrete slabs.
4. Water can be withdrawn via outlets like
tap attached to the De-siltation tanks or
Tube Wells pumping out fresh water from
the Ferro-Cement Tanks.

7. To make the collected rain water re-usable for domestic or other purposes, effective
filtration is must. A filter has to be designed to purify the incoming water-flow from
the roof.
 Water from the roof hits a cement slab after getting discharged through a pipe outlet
 As a result, it gets sprinkled on the under-lying sand bed – 1st step of filtration happens
 The water next percolates through the below layer of pebbles – 2nd step of filtration
takes place
 Water then seeps in a PVC (Poly-VinylChloride) pipe of 200 mm diameter, which leads to a
150 mm pipe, which in turn channels the water into Bore Well.
 The entire unit is 0.75 to 1.2 m high, with diameter 0.6 to 1.2 m. It is also assisted with a
air ventilator

8. Rainwater harvesting systems
installed in Multistoried buildings
can suffice for daily water usage
by the building residents :
 Rainwater collected in the roof
flows down the pipes running
down the length of building, into
Service Wells or Percolation Pits
 Water trickles down the layer of
Pebbles and Boulders designed
for underground filtration
 Filtered water flows into either
Recharge Well or the Collection
Chambers
 With this setup, the building can
draw water readily from its
water table in the basement,
without any shortage in supply

9. Roof Water Harvesting …….. a quick summary
 Rooftop RainWater Harvesting – Capturing of rain from roof catchments
and storing it in containers or sub-surface
ground water reservoirs
 ADVANTAGES:
1. Reduced ‘ground-water pumping’ cost
2. High quality water, low in mineral content
3. Reduced soil erosion rates in urban areas
4. Less expensive and easy to construct, operate & maintain
 PRECAUTIONS:
1. Filters should be provided to avoid silting of
hand-pumps and tube-wells.
2. Storage tanks should not be close to sources of
contamination (eg. Septic tank)
3. Setup should be regularly cleaned & disinfected
4. Speed breaker plate should be provided below inlet
pipe so as to not disturb the filter material.

10. Our Civilization Needs Water To Sustain
Let Us Save It Together !!