Usually, plants need more water than what can be provided in the form of rain. When it is needed, people usually run to the faucet and use that to water their yards. However, when there is a shortage of water, more people look for other ways to get water to their plants. One of those is to use gray water from inside the house to water plants and lawns.
What is gray water
Gray water is water that has been previously used in the home from bathroom sinks, tubs or showers, kitchen sinks, dishwashers and washing machines. Water from toilets is not acceptable to use because it contains fecal matter which could contain hazardous bacterial organisms. Gray water does not need chemicals or any special treatments to be used in the garden or for lawns.
Soaps and plants
The soaps and detergents will not damage plants unless they are used over long periods of time. Even then, this can be remedied by adding fertilizers like calcium sulfate to the soil. This will help to keep the soil at a pH level that is more acidic then alkaline. When purchasing soaps and detergents, look for ones that state they are biodegradable. These soaps usually are designed to break down easier in the environment then regular detergents. Bleach also should be kept to a minimum or not used at all if the water is going to be used for plants.
Danger of disease
There is some chance of organisms coming from water from bathroom sinks, showers and washing machines. Although, it is usually in small amounts and dies off rather quickly so it won't affect the use of edible plants. Water from the kitchen sink and the dishwasher has grease and food particles and should only be used for trees and shrubs. For those that are concerned about the safety of the water, it could be used just to water ornamental plants and trees. Then, there would be more water from the faucet available for the garden plants.
Transferring the water
The easiest and cheapest way to get the water from the house to the plants is in five gallon buckets. The other way would be to use hoses with pumps and pump the water out to the yard. The pipes from the house can also be altered to allow the water to run to hoses outside directed onto plants.
The use of gray water is a very good source for water that would otherwise have to go to a sewage plant to be recycled. Cities pay a lot and have to add a lot of chemicals to make it reusable. Using the gray water directly saves sending it through the recycling process and coming back to the consumer. Another benefit to using gray water would be for those that have septic tanks. It would slow down the filling of the tank with excess water and allow the bacteria in the septic tank to grow better. A major consideration when deciding whether or not to use gray water is to check with local laws and make sure using gray water is permitted, and to what extent.

Comments
I used to manually recycle household grey water by watering the garden plants with the bath water when it was finished with. Not having pipes to transfer it, this meant carrying it down there in buckets.
great idea sir, such measures could resolve the problem to an extent. rain water harvesting is also a good idea.
very informative and need of the day. thanks for sharing.
It is a great idea to recycle water and use 'grey' water for garden irrigation. In areas where there is water scarcity, it should be highly recommended.
It will help a lot for cultivating.