1. By : Sanjay Singh Rain Water Harvesting : An alternate
Source of Water Mentor: WIKIPEDIA CIVIL ENGINEERING
2. INTRODUCTION The total amount of water on earth remains
constant. The rapid growth in population together with the
extension of irrigated agriculture and industrial development, are
putting stress on the natural ecosystems. In the face of growing
problems, society has begun to realize that it can no longer
subscribe to a use and discard philosophy with any natural
resource. One such resource is WATER. To deal with it, a technique
called RAIN WATER HARVESTING was introduced where rain water is
used to
3. WHAT IS RAINWATER HARVESTING Rainwater harvesting is the
accumulating and storing, of rainwater. It has been used to provide
drinking water, water for livestock, water for irrigation or to
refill aquifers in a process called ground water recharge. The
principle of collecting and using precipitation from a catchments
surface. Rain water harvesting means to make optimum use of rain
water at the place where it falls i.e. conserve it and not allow
draining away and causing floods elsewhere.
4. Need of Rainwater Harvesting Water is becoming scarce.
Surface water is inadequate to meet our demand. We have to depend
on ground water. To reduce soil erosion. Groundwater is getting
depleted and polluted. Improves the ground water quality.
Increasing population of India. Of the total water on earth, only
3% constitutes freshwater. Rest is saline water in the oceans. 11%
of the total fresh water on earth is groundwater available upto a
depth of 800m which can be extracted for use
6. Roof Top Rain Water Harvesting 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.
7. How to Harvest Rainwater Collect water from the rooftop.
Draw it down from pipes. Filter the water. Store in a sump or tank
for later use. Charge the groundwater through a soak pit. Lead the
water into a well to increase ground water content.
8. Elements of Rooftop Rainwater Harvesting CATCHMENT COUNDITS
FILTERS STORAGE FACILITY
9. 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
rainwater for irrigation, water flowing along the ground during the
rains will be collected to a tank
10. TRADITIONAL RWH STRUCTURE BAWODI: Traditional step wells
are called vavadi in Gujarat, or baoris or bavadis in Rajasthan and
northern India. They were secular structures from which everyone
could draw water. Most of them are defunct today.
11. Kunds or Kundis Covered underground tank, developed
primarily for tackling drinking water problems. Usually constructed
with local materials or cement, kunds were more prevalent in
regions where groundwater is saline. Before the onset of rains
every year, meticulous care was taken to clean up the catchment of
the kunds. The proximity of a kund to the house or village saved
time and effort in searching for drinking water.
12. Ooranis Designed to harvest and store rainwater to meet the
drinking needs of a community. Created by excavating the soil which
is then used to form bunds around the area. More than 39000 ooranis
in Tamilnadu state alone
13. Paar System The rainwater flows from the agar (catchment
area) and in the process percolates into the sandy soil. Kuis or
beris are dug 5 to 12 m deep to access the water. Rainwater
harvested through the paar technique is known as patali paani.
14. Advantages of RWH RWH is the ideal 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
15. Disadvantages of RWH Seasonal nature and uncertainty of
rainwater supply depending on the region in the world. Capital
costs . Regular maintenance and cleaning is essential for
successful operation.
16. Summary On 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.
Harvested 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 an important resource we should be very careful while
dealing with it.