Importance of Water
- Water is life. It is a precious natural resource so vital for sustaining life on the earth
- Mankind has been using water since its appearance on earth. Civilizations grew in the proximity of water.
Distribution of Water
- 70% of the earth is covered with water
- Of the water available, about 97.30% is saline and only 2.70% is Fresh water .
- Of the small quantum of fresh water which is available, 77.20% is stored as ice caps and glaciers, 22.40% as ground water and soil moisture, 0.35% in lakes and swamps, 0.04% in atmosphere and less than 0.01% in streams.
- This emphasizes the importance of the water
Uses of Water
- Domestic water supply
- Other requirements/uses
Unlike other parts of the country, State of Goa being located on the west coast of the country receives copious rainfall by the South West Monsoons. Rainfall pattern is heaviest at the mountain ranges and on its western slopes, which gradually reduces towards the coastal plains. The entire precipitation is however limited to the monsoon period of just four months from June to September.
In scientific terms, water harvesting refers to collection and storage of rainwater and also other activities aimed at harvesting surface and groundwater, prevention of losses through evaporation and seepage and all hydrological studies and engineering inventions, aimed at conservation and efficient utilization of the limited water endowment of physiographic unit such as watershed. Rain is the first form of water that we know in the hydrological cycle, hence is a primary source of water for us. Rivers, lakes and groundwater are all secondary sources of water. Hence Rainwater harvesting is the activity of direct collection of rainwater that can either be stored for direct use or can be recharged into the ground water. Rainwater harvesting means to understand the value of rain and to make optimum use of rainwater at the place where it falls.
How to harvest water
Broadly, rainwater can be harvested for two purposes.
- For storage for ready use in containers above the ground or below the ground
- For recharging into the soil for withdrawal later .