Prepared by; Hameed Khan Niazi 13003101030

Rianwater Harvesting

Definition Rainwater harvesting is the

accumulation and deposition of rainwater for reuse on-site, rather than allowing it to run off. Its uses include water for garden, water for livestock, water for irrigation, water for domestic use with proper treatment,and indoor heating for houses etc.’’

Introduction

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 techniques usually found in Asia and Africa arise from practices employed by ancient civilizations within these regions and still serve as a major source of drinking water supply in rural areas. Commonly used systems are constructed of three principal components; namely, the catchment area, the collection device, and the conveyance system.

Why Rainwater Harvesting..??

Towhat is life without water. If there is no water there is no life. So even a single drop of water is essential for the survival of human beings. Keeping in view the scarcity of water at every level, rainwater harvesting is absolutely necessary. We, in India, should learn the importance of water. We should not spoil or waste water but we should preserve it by harvesting it also.day we can well imagine

Uses Of Rain Water Harvesting

Domestic Use.Agricultural Use. Industrial Use. Increase GroundWater Supplies.

How clean is the water? The rainwater is filtered as it enters the storage tank, to remove particles and other matter. It is kept in the dark and kept oxygenated to discourage algal growth, and properly designed systems are designed with calming inlets, which ensure that any sediment at the bottom of the tank does not get stirred up. The water is not drinking water fit for humans.

Graphical Understanding…

Catchment Areas

Different Techniques

Surface runoff harvesting Roof top rainwater harvesting 1. Surface runoff harvesting In urban area rainwater flows away as surface runoff.

This runoff could be caught and used for recharging aquifers by adopting appropriate methods.

2. Roof Top rainwater 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. 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.

 Components of Rainwater harvesting

The system mainly constitutes of following sub components:§         Catchments§         Transportation§         First flush§         Filter

Components of Rainwater harvesting

1Collection Surface

7 Collection Cistern

2 Collection Gutters 8 Overflow

Port

3Gutter Protection

9

Auto-fill / Automatic Top-up Mechanism

4

Rain Head Inlet Filter

10 Pump

5First-flush Diverter

11 Water Filter

6 Inlet Screen 12

Water Level Indicator

Benefits of Rainwater Harvesting

The collection of rainwater and harvesting it for everyday use has an ample number of exciting benefits. Let’s take a look and discover some of those benefits.

The biggest benefit that you will find is reduced dependency on water storage dams. The reduced dependency means a reduced amount of stress on the dams and the elimination to expand upon them. Since we have such a limited supply of water available and it is very costly and timely to produce water through dams, the benefit found here is sure one that you will appreciate.

Secondly, once you begin using rainwater you will also appreciate a reduced amount of water consumption in the home, thus all of your utility bills will greatly shrink in size. How incredible would it be to slash as much as 50 to 60% off of your water bill each month? No complaints with having additional money in the pocket each and every month.

Thirdly, the collected rainwater can be used for many different purposes around the home. This includes laundry, washing dishes and more. This would prevent groundwater depletion and augment ground water table.

Fourth, rainwater harvesting systems are cost effective, provide high quality water, reduce dependence on wells. The surplus rainwater can also be used to recharge ground water aquifer through artificial recharge techniques.

Lastly, it helps to reduce soil erosion as by capturing rainwater, the flow of storm water is reduced which can also prevent urban flooding.