Water makes for 70% of our bodies. We consume it in different forms and have put it to use in ingenious ways to make our lives better and easier. Since the beginning of agriculture, water has been the most decisive factor in the success of civilisations (all of which have flourished on the banks of rivers). Although, while growing up, I never really knew where the water in our house came from and why sometimes the taps went dry. To be in this age when we seek and share all sorts of information and not know about our source of water (or source of food for that matter), is an affirmation of our misplaced priorities.
It is estimated that out of all the water on this planet, only less than 0.1% is available to us as freshwater in rivers and lakes.
(96.5% is saline- in the oceans, 1.7% is locked up as ice, glaciers and permanent snow and another 1.7% is in the ground)
This 0.1 % is the water that we use for drinking, to grow food, to run our industries and also generate some electricity. The same 0.1% is also the water that we use to flush our toilets and into which we dump all our biological and chemical waste.
All of this 0.1% is also not for humans alone. We share this with all the other flora and fauna on this earth.
The water is in constant motion from the oceans to the atmosphere to the land and below it. While on this journey, it changes its energy and form several times. It flows with gravity, moves with wind and sometimes sits still as ice, but the entire water behaves as a single body. The parts of this body keep changing places with each other based on factors such as temperature etc.
The water that will fall today as rain or snow, has probably fallen on this land before and will do again in the future.
The various stages of the movement of water:
Due to heat, water from the land, oceans, rivers, lakes, ponds etc. changes from liquid to vapour, becomes lighter and rises (evaporation). A significant amount of water is also lost as vapour from the plants (transpiration, evaporation from leaves).
As the water vapours rise in the atmosphere, the temperature decreases and they start condensing around dust particles to form clouds, mist, fog and dew (condensation).
(Water always need a surface to condense on.)
The vapours join with each other and become heavier. If the temperatures drop further or the winds carry these condensed vapour to a colder region, the vapours turn into tiny ice crystals (deposition). As the water droplets or ice crystals keep on joining with each other, they become heavy and eventually fall down as rain/hail/snow. Depending on the conditions below the cloud, rain can freeze to fall as ice pallets (sleet/hail) or snow can melt to fall as rain or even evaporate due to high pressure winds (sublimation). Sometimes the rain drops evaporate before reaching the surface of the earth (virga). Some of the rainwater falling on the land evaporates and forms another cloud, part runs off to another area or a water body and a part is absorbed by the land.
The part of the precipitation that flows off the land surface (run off), causes erosion of the soil if its is not covered and carries the nutrient rich sediments in rivers, oceans, lakes etc. causing of degradation of the land fertility and creating a nutrient imbalance in the water bodies affecting the aquatic life.
Some part of the water running off also infiltrates in the ground.
(Infiltration can be increased by slowing down the course of the water)
About 50% of soil is made up of pores or empty spaces. The existence and size of the pores depends on the size of the soil particles. When water falls on the soil, it flows down the surface through these pores in the soil layer and cracks in underground stones until it hits hard rock. As the water starts filling these pores, it starts rising in the ground. This water stored in the deep pores of the soil is the groundwater. When water fills all these pores in the soil, the soil is considered as saturated. The level of saturated soil in the deep soil profile is indicative of the ground water table.
On its downward journey, water might hit an impermeable layer that it cannot travel through. It then starts moving horizontally across these layers and emerges from the ground as spring or flowing into lakes, streams and ocean. From these water bodies, evaporation carries the water to the clouds and it again falls back as rain.
Some of the groundwater will evaporate again and some will be preserved deep inside for ages (until we bore it out).
These processes work simultaneously and in tandem and keep cycling water from one phase to another and one place to another. The water that we dump as waste will become a source at some point, wether we are around till then or not. The availability and quality of water has and will influence our existence and sustenance its sacred nature needs to be acknowledged.