Rain Water Harvesting...rain catchers.

Hitesh M. Majithiya

Email: hmajithiya@gmail.com

Contents

1. Introduction.

2.Need for Rainwater Harvesting.

3. Advantages of RWH

4. Where Rain Water Harvesting ?

5. Methods for Rainwater Harvesting.

6. Water Conservation Tips…

5. Lessons Learnt

Water is unique in our natural resources although it is renewable, it is not replaceable. We have various

substitutes for energy sources, but there is no substitute for water.

Once it is gone or degraded through overuse or pollution, it cannot be substituted.

Amount of drinking water in world

•Water Crises in the world

1. Water stress results from an imbalance between water use and water resources. 2.A United Nations report predicts that access to water may be the single biggest cause of conflict and war in Africa in the next 25 years.3.All three rivers feeding China's Northern Plain are severely polluted, damaging health and limiting irrigation. 4.More than half of Europe's cities are exploiting groundwater at unsustainable rates. Chronic water shortages are already affecting 4.5million people in Catalonia.5. Competition for water from the River Jordan was a major cause of the 1967 war in Middle East.

Per capita consumption – India / World

Liters per person per day

Drinking 3Cooking 4Bathing 20Flushing 40Washing clothes 25Washing utensils 20Gardening 23

Total 135 liters

Rainfall in India

India annualrainfall

is within the top 6 countries

in the world.

“But we do not conserve the Rain Water”

India has TWO disastrous seasons…Flood & Draught

Introduction

What is Rainwater Harvesting (RWH) ?

“Capture rain water, store it & use it…it is as simple as that”

OR“Rain Water harvesting is technique of collection, storage & use of rain water at

surface or sub-surface before it is lost as runoff ”

• Commonly used systems are constructed of three principal components; namely,

• The catchments area.

• The collection device, and

• The conveyance system.

Need for RWH ???

Continues failure of rainfall & consequent deficit of rainfall. Because it cost less to collect rainwater than to exploit ground

water. Increased population α More water demand = Depletion of

ground water table. In some parts Excessive heat waves creates drought condition. So Rain Water Harvesting is need of the hour due to decreasing

trend of GROUND WATER i.e. well, lake, tubewells etc.

Advantages of RWH

•It can complete our present water demand.•It reduces flood hazard.•It reduces the drought effects.•It increases level of ground water table.•It reduces soil erosion.•Underground water storage is ecofriendly.•Rainwater harvesting technologies are simple to install and operate.

Where Rain Water Harvesting is required ?

• Ground water levels are declining on regular basis.• Areas where inadequate amount of water in lean

months.• Where due to rapid urbanization, infiltration of

rain water into subsoil has decreased drastically & recharging of ground water has diminished.

• RWH is essential where ground water get saturated with high Iron & fluoride content.

Methods for Rainwater Harvesting

1. Roof top Rain water Harvesting & storage in tanks.

2. Roof top Rain water Harvesting & and recharging of surface aquifers i.e. dams, lakes etc.

3. Surface runoff harvesting and recharging of sub surface aquifers.

RWH CalculationTo calculate the approximate amount of rainwater you are likely to harvest,

use the following formula:

Roof area in sq. meters x Rainfall in mm x 0.8 (Coefficient factor)

 For e.g.: 100 m2 x 1000 mm rainfall x 0.8 = 80,000 liters

= 80 Cubic meter

Note:-1. Tank size should be 5 % of annual rainfall.

2. Flush first rainfall to clean rooftop.

1. Roof top Rain water Harvesting, storage & Use

a. Rain water collects on roof top.b. This water is guided into overflow pipe.c. These pipes connect to rainwater storage tanks.d. Water can be access through bucket or pumps using filters.

2. Roof top Rain water Harvesting & and recharging of surface aquifers i.e. dams, lakes etc

3. Surface runoff harvesting and recharging of sub surface aquifers.

Water Conservation Tips…

• Install small shower heads to reduce the flow of the water.  At the end of the day if you have water left in your water bottle do not throw it away, pour it over some plants.

• While brushing or other use, do not leave the tap running, open it only when you require it. See that there are no leaking taps.

• Do not leave the taps running while washing dishes and clothes.

• Re-use water as much as possible.

• Change in attitude & habits for water conservation.

• Because every drop counts!!!

• MOST IMPORTANT BEYOND RWH, “PLANT TREES” THIS ONLY CAN BRING RAIN.

Lessons learnt…1. Rainwater can be collected where it falls & reuse it at marginal cost.2. This is the only long term solution to draught proofing places against water scarcity.3. We have management & control over the water not the government.4. RWH must be understood & replicate everywhere in the world where there is acute water shortage.

Still we have time to face this situation…!!!

LET’S TRY TO MAKE WATEREVERYBODY'S BUSINESS.

Thank you!!!