India is among 17 extremely water stressed nations in the world but has no business to be in this unenviable list as all the others except Pakistan are desert nations in the Middle East and North Africa.

India is endowed with bountiful rain (India’s average rainfall is 1170 mm against the world average of 1000 mm) and many perennial rivers that criss-cross the country, yet, sadly because of nature-abusive practices we find ourself in a calamitous predicament, wherein 256 out of 700 districts are ‘over-exploited’ and 21 major cities including Delhi, Chennai would run out of groundwater by 2030.

Even under these challenging circumstances, we are only reactive and do not address the root causes in a holistic manner integrating soil, water, air and vegetation.

The inter-dependency

There is an inter-dependency amongst water, soil and plants and each is equally important.

Unfortunately, human beings tend to respect food (and therefore plants) and water but do not realise its importance as a life-giver — soil is the largest reservoir of fresh water on earth holding 6-8 times the combined capacity of all river basins put together; and 95 per cent of food is directly or indirectly produced in soil.

Besides it is a veritable ‘living being’ containing millions of micro-organisms that fix nitrogen and decompose organic matter; and armies of microscopic animals act as plant nutrients providing nourishment.

Soil water is the medium from which all plant nutrients are assimilated by plants. On an average, a unit of soil contains 50 per cent soil particles, 25 per cent moisture and 25 per cent voids. For survival of the planet, soil needs to be fed with moisture/rain water in a well distributed manner.

This loss of vegetation potential in turn limits the greenhouse gas absorption capacity of the atmosphere leading to higher air pollution and adverse impact on climate. Ideally, the soil organic matter content should be about 2.5 per cent to 3.0 per cent by weight in the root zone (top 20 cm) for it to be healthy. If soil is dead and lacks important organic ingredients it will actually repel water, rather than soaking it when it rains.

Practical solutions

Customised Terrain friendly Rainwater harvesting (RWH): It involves (i) terrain-friendly groundwater recharge measures, — use of graded gravel pits, wells, recharge wells, ponds, water bodies, lakes and conservation of wetlands and (ii) collection of roof-water into storage tanks for direct use.

Stormwater drains with micro-graded gravel pits are an effective method of distributed RWH. In the natural scheme of things, in urban areas, stormwater (excess stagnant rainfall that cannot penetrate the ground) may (i) infiltrate soil, (ii) discharge directly into streams, water bodies, drain inlets, or (iii) evaporate into the atmosphere. The present system of drains is designed to carry stormwater to rivers, seas, water bodies which vitiates the objective of maximising water recharge to soil. Thus, soil gets depleted of moisture leading to slow death.

To combat this, if the theme of shallow aquifer recharge using graded gravel rainwater harvesting (RWH) pits can be adopted inside drains, water will find its own way through available pores and ingress the soil. One of the arguments of city planners against this is that pollutants (especially in industrial areas) “hitch a ride” with stormwater and flow unhindered into the drains.

Granted, that pollution of pure rainwater should not happen at source, at least in the non-industrial zone (which will cover a large area), distributed RWH pits can be put up in stormwater drains which is highly cost-effective, easily implementable and scalable.

Urban water management including water logging has been a problem world over and countries like the US, UK, Australia, New Zealand and China have developed customised solutions. Our forefathers practised the ‘Sponge village’ concept which is currently making waves in the form of ‘Sponge city’.

Essentially it involves mechanisms for (i) water infiltration in soil through RWH, (ii) retention, (iii) storage, (iv) purification, (v) utilisation and (vi) delivery to urban consumers. This ensures elimination of waterlogging, enhanced water storage and discharge capacity, improved water quality, largely through nature-based solutions- examples include green roofs, sunken green areas, rain gardens, wells, ponds.

Nature has enjoined that the air in the atmosphere, soil in the geosphere, water in the hydrosphere, and human beings, animals and other living creatures in the biosphere are so interdependent that each cannot live without the other.

The indifference and arrogance of citizens has upset this delicate balance resulting in soil decay and water scarcity in India. Under the aegis of the National Water mission that is propagating RWH, the government should mandate every town/city to develop customised terrain friendly solutions based on RWH, distributed RWH pits in storm water drains and the Sponge city concepts. The Life Giver of our planet is soil which has been hitherto neglected.

Let us nurture the soil by feeding it with pure rainwater which nature gives us in abundance, in a distributed manner, so that Mother Earth would take care of our water needs for generations to come.

With appropriate action on the above lines to accelerate change in conformity with the theme of the World Water Day 2023, we can be ‘Water Rich’ for generations.

Mony is Advisor, Rajagiri Vidyapeeth, and SCMS Kochi; Ramkumar is Former Executive Director, IOC, and Rainwater Harvesting Expert. Both are members of the ‘IIT Madras Alumni Association – Societal Impact Action Group’.

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