Life originated from water. Water - a primary requirement for sustainability of life on Earth and probably elsewhere too, is the basic necessity for survival. But at times like ours, water is scarce and precious. For seven billion people, affordability of clean and potable water has become a privilege rather than a basic fundamental right. There have been political disputes, decline in agricultural productivity and what not that can impact the existence of Homo sapien. It is predicted that -
“World War III will be fought over water”
But are we really that short of water? If we are, are we managing our water resources well? Is there an answer to all our problems dealing with water scarcity? Yes, sustainable water management is a ray of hope.
Sustainable water management is an activity of planning, developing, distributing and using the water resources. It includes many traditional and modern techniques like rain water harvesting, wetland preservation, drip irrigation etc. It also includes the need to implement certain policies regarding the proper use of water, and the change in habit of using water.
More than 70% of the earth’s surface is covered with water but there is only 0.75% is available for use. Due to change in lifestyle the water used per capita has increased dramatically. Nowadays, an average person uses double the amount of water compared to that of 1950s. Many major aquifers are drying at an alarming rate leading to a drastic decrease in ground water level. Many large fresh water bodies like lakes and rivers are also on the verge of disappearing . Also, industrial revolution and use and discovery of new chemicals has played a destructive role in reducing the amount of clean water rapidly. There are more than 780 million people in the world who don’t have access to clean drinking water. That implies one out of every nine human is struggling to get this basic necessity. This decrease in water availability and inadequate distribution of water among people is now a major reason of stress between communities which is creating political tensions around the world.
There are numerous ways to manage water stress and many of them are carried out since medieval times. These include rain water harvesting, ground water recharge, drip irrigation etc. Also, with the change of technology, many modern ways have been innovated and the trends in water management has changed. New approaches such as sewage treatment plants, development of new varieties of industrial plants which require low water etc have been introduced with respect to modern lifestyle.
Rain water harvesting is one of the oldest and traditional way to conserve water. It is the accumulation and deposition of rainwater for reuse on-site, rather than allowing it to run off. Rainwater can be collected from rivers or roofs, and in many places, the water collected is redirected to a deep pit (well, shaft, or borehole) a reservoir with percolation. It’s uses include water for gardens, livestock, irrigation, domestic use with proper treatment, indoor heating for houses etc. The harvested water can also be used as drinking water, long-term storage, and for other purposes such as groundwater recharge. It provides independent water supply during local water restrictions and ensures water availability. This is a very common practice in drought or flood prone area and it can provide emergency drinking water. It is often used as the supplement to the main water supply in most areas. This is one of the very effective way to curb the water shortage. A case study of Rajasthan as compared to Cherapunji shows the former experiences less acute water shortage only due to proper water management practices. This shows water availability and security depends upon the management practices and is not fully dependent upon the amount of water available.
Drip Irrigation is another method of irrigating the plant directly at their roots and not irrigating the whole land. This saves a lot of water since it tends directly to the plants. Agriculture is one of the most water intensive occupation and this technique helps save million tons of water which was otherwise wasted in irrigating whole plot of land. In India, 70% of the land is used for agricultural purpose and almost none of the fraction have drip irrigation facility. It is also economically sensible to invest in drip irrigation since the nutrients is provided directly to the roots hence, requires less amount of water and nutrients. Also, there is a better control over the concentration of nutrients provided to the crops.
Another approach in water management is groundwater recharge or deep drainage or deep percolation. This is a hydrologic process where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer. Groundwater is the primary source of portable water all over the world. It occurs naturally but due to covering of land and construction with non-percolating material, the water cannot percolate directly into the ground. There is a decline in water table in all of the major aquifers of the world. The wells are now much deeper and often gets dry in summer seasons. Having no central management of water, India has been the largest user of ground water. Statistics show our consumption to be double the amount of China.There is indeed a need to maintain this level of water or else, there can be consequences. Groundwater recharge can be achieved by various methods like through wetlands, depression-focused recharge, soak pits etc and is currently the need of the hour.
Water reuse or recycling is one of the methods that can be used to save a large chunk of water. It can be practiced by both an individual and a community. The simple water reuse techniques involve usage of water from one process for another process i.e. water of swimming pool could be used for gardening purposes. For use of larger fraction, the water could be recycled and then reused. Reuse may include irrigation of gardens and agricultural fields or replenishing surface water and groundwater (i.e., groundwater recharge). Reused water may also be directed toward fulfilling certain needs in residences (e.g. toilet flushing), business or industry, and could even be treated to reach drinking water standards. Reclaiming water for reuse applications instead of using freshwater supplies can be a water-saving measure. When used, water is eventually discharged back into natural water sources. It can still provide benefits to ecosystems, improving stream flow, nourishing plant life and recharging aquifers, as part of the natural water cycle. Wastewater reuse is a long-established practice used for irrigation, especially in arid countries. Reusing wastewater as part of sustainable water management allows water to remain as an alternative water source for human activities. This can reduce demand and alleviate pressures on groundwater and other natural water bodies.
Another important introduction in sustainable water management is sewage treatment which mainly deals with the quality of water that goes back to the natural resource or natural origin of water. One of the major issue related to health nowadays comes from pollution of natural water resources. The main reason behind this is the indiscriminate flow of chemical and waste from home and industries to the water bodies. It is affecting the aquatic life and ecosystem and the degraded quality of water also harbours for a number of diseases. Sewage treatment involves cleaning and monitoring of the flow going into the water bodies from municipality and industry. It includes physical, chemical and biological processes to remove these contaminants and produce environmentally safer and treated wastewater (or treated effluent). A by-product of sewage treatment is usually a semi-solid waste or slurry, called sewage sludge, that has to undergo further treatment before being suitable for disposal for land application.
Water reservoirs are also a great method to store large quantity of water which can be used as per need. Reservoirs can be created by controlling a stream that drains an existing body of water. They can also be constructed in river valleys using a dam. Alternately, a reservoir can be built by excavating a flat ground or constructing retaining walls and levees. These reservoirs are very useful for daily lives. Many dammed river reservoirs and most bank-side reservoirs are used to provide the raw water feed to a water treatment plant which delivers drinking water through water mains. They are also used for hydroelectricity, downstream water supply, irrigation, flood control, construction of canals, and for recreational purposes.
Water redistribution is a way to allocate the water resource suitably among the people. It is always observed in a region with economic difference that the water distribution creates much problem among the communities. When provided with ample supply of water, people tend to over exploit the resource as seen in case of Delhi - where acute water scarcity is a severe problem. When 24X7 water is provided in some posh area, people promptly switch to washing their cars thrice a day. There is a need to redefine the policies for water distribution and provide the water as basic necessity to each and every one.
There are many similar practices that could be done in order to manage the water resources which is the need of the hour. But at the ground level, there are many difficulties. One of the most common obstacle is of initial cost investments. There is an investment needed to establishe such facilities i.e. the rainwater harvesting system and ground water recharge without any apparent return in near future, the government shall have to take steps in this regard. There have to be some incentive or penalty or initial support from the government which prompts people to take action and initiatives in this regard. In case of reserving the water in large reservoir, the land requirement is very high which is more difficult to find due to a fast growing population. Also making a dam on rivers disrupts the river ecosystem. There are many other specific problems with different methods as well which can be implemented to deal with water shortage.
We need more people to actively associate in the field of water management. There are possibilities and need of more efficient innovation in this field. This sector is suffering from lack of people with technical expertise, who can handle the large water management plants when needed. Also there is a need for much more investment in this sector and they need to be maintained properly, i.e. a very small fraction of sewage treatment plant has been established than the actual requirement. And out of those few, only a handful meet the international standards.
There are many existing technologies that could be implemented for the management of water. The need of the hour is a collective consciousness and awareness about the severity of the problem. The initiative like “Rally for Rivers” and Clean India gives hope for a better future. Ultimately, best management is to know that water is important to us more than a political crisis. Water is life.
“Thousands have lived without love, not one without water.” - W. H. Auden