**2.2 Drivers for RWHS**

Rainwater Harvesting System has been used in the water supply system for many years, and has been around for this reason:

1.Water Scarcity

Water scarcity may be due to a lack of adequate surface area and improper control of groundwater resources, polluted land, and groundwater resources and insufficient support for programs to harness and distribute water.

*Smart Rainwater Harvesting System for Sustainable Agricultural Irrigation and Drainage System DOI: http://dx.doi.org/10.5772/intechopen.104442*

#### 2.Reduce flooding and erosion

This system can help reduce erosion around downspouts and in the garden. It controls the stormwater run-off.

3.Reduce water bills

The use of rainwater can substantially reduce the cost to supply main water services. When needed, the rainwater acts as a substitute for a backup source.

4.For sustainable agriculture

The collection of rainwater can be used to boost plants and gardens too. The salt accumulation can be flushed from plants and soil using collected water. Harvested rainwater is usually free of different forms of pollutants and man-made toxins. Rain is also chlorine-free.

#### **2.3 Benefits of the rainwater harvesting system**

The harvesting of rainwater is the element of sustainable agriculture and tends to bring a variety of value not just for users but also environment and government (**Table 1**).

## **2.4 Working principle of the rainwater harvesting system**

Nowadays, the rainwater harvesting system is well known to the public regarding its function and benefits. However, the working process still has the same basic method and component. There are six basic components for a domestic rainwater harvesting system:

• The catchment surface: Surface allowing water to collect from the rain, such as a rooftop. The size of the catchment area determines how much rainwater is harvested.


#### **Table 1.**

*Benefits of the rainwater harvesting system.*

