Watering Concrete or Concreting Water?

Analysis, Climate Change Adaptation, Field Notes, News & Events, Sustainable Development, Uncategorized

June, 2019

Watering Concrete or Concreting Water?

By Nitesh Rikame

Pune is the second-largest city in Maharashtra and the ninth largest city in India, with a population of 64.5 lakh people. Pune ranked first in the Mercer’s Quality of Living Ranking 2019 as the best city to live in India. It is also one of the fastest growing cities in the country. The ongoing construction of roads, flyovers, information technology & Industrial Parks and projects like the upcoming Pune metro rail project, are a testament to the city’s dynamism and progress. However, Pune is also facing the issue of groundwater depletion. In this article, I will take a look at this issue, both in Pune and other Indian cities.

Other cities

According to a World Bank report, at least 21 Indian cities are moving towards zero groundwater level by 2020, which has already set the alarm bells ringing for policymakers and urban planners. Many large cities like Banglore, Gurgaon, Hyderabad, Chennai, Coimbatore, Vijayawada, Amravati, Solapur, Shimla, Kochi are moving towards an acute water crisis. Climate change, early summer, deficit rainfall, depleting water level, rising population and lack of a proper water management policy is making it difficult for the urban local bodies to meet the increasing demand for water.

What about Pune?

Though Pune is not part of the list yet in the above report, the city could be soon heading in that direction. We need to understand how Pune meets its water needs currently. At present, Punekars use the waters of the Mutha from the Khadakwasla reservoir. Dams at Panshet, Warasgaon, and Temghar supplement the storage capacity of Khadakwasla. PMC buys water from the Irrigation Department and treats and supplies it to the city residents. Many private residential complexes and industrial parks have their independent bore wells to fulfill the domestic and commercial need of water. Besides this, tankers supply water from community wells. All this means that there is considerable pressure on the groundwater resources of Pune.

Today, enormous municipal and private construction projects are covering the roads, pavements, land surrounding the trees and private land with concrete. The concrete in many public locations is occupying the land to such an extent that only the tree trunk can be seen with no space around it. The area surrounding the private apartments, complexes and houses are also done up with concrete. These trees in the public localities depend on groundwater for their water intake. The groundwater under the surface is available from the percolation of rainwater during the rainy season. The larger the surface area, the higher will be the percolation of water in the ground. With the concrete spreading over the surface of the city, the surface area available for water percolation is decreasing day by day. Hence, the surface runoff will increase and dispersal of the water outside the city, thus leading to further depletion of the groundwater levels.

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An example of trees with concretized bases, in Pune. Such bases choke tree roots access to water. Photo:  Nitesh Rikame

The trees are not the only ones to get affected by this development. The groundwater in the city is also the source for domestic and industrial use in many public societies, industries, and IT Parks. The depleting groundwater table will create a shortage of water supply to these entities and ultimately to the residents of the city.

Roads construction

From the example of trees, let us shift to that of roads. Generally, roads are constructed in such a way that, water is discharged to drainage or water collection system and should not stay on the surface. A camber (rise at center) is in the road, providing a slope to drain the water towards roadsides.

Also, the roads are made up of impervious material so any water retained on the road surface won’t get through those impervious layers. Some roads are WBM (water bound macadam roads) roads, which are highly water absorbent and super porous, which gives good intermittent flow and joins groundwater. But, in the case of concrete roads, they have a poor void ratio. The road will saturate if there is a considerable water quantity. Further water will stagnate on the road without any percolation.

Nitesh Blog Photo
An example of concrete pavement in Pune. Such pavements are becoming increasingly common in Indian cities. Photo: Nitesh Rikame
Perviousness 

Considering the problems of waterlogging and groundwater recharge, it is recommended that water should be allowed to percolate into the ground. However, the methods or ways to provide perviousness to road surface are quite expensive (These methods include pervious concrete, permeable pavement system, previous asphalt road). Also, these methods have large maintenance costs and low stability for high loading vehicles.

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An example of a concrete road in Pune. Photo: Nitesh Rikame

For now, it’s impossible for governments in India to make such an expensive investment in roads. The permeable pavement system is used in India for groundwater recharge in the parking areas and other private area sections (like hotel lobbies, home lobbies and so on).

Other issues

In this blog, I have only emphasized on one issue: concrete roads, pavements, and commercial spaces. There are many other issues in the country that are affecting groundwater depletion. For example, landfilling of lakes by land mafias in different cities. To take two examples, in Chennai, 30,000 lakes have been filled up while 12,000 lakes have been filled in Patna, Bihar. (https://www.youtube.com/watch?v=FdV7btCRXfU)

The AIIMS in Patna has been constructed on a lake spread over 35 acres, according to the above report. Other major problems are that water and tanker mafia extract water illegally from wherever possible, submersible pumps are replacing hand pumps and exploiting even greater groundwater resources (boring and installing submersible pumps has become a big business in the northern cities of India). Infrastructure projects that occupy flood basins is also a major issue. A case in point is the airport, that has been constructed on a flood basin. ( https://www.thehindu.com/opinion/op-ed/preparing-for-the-floods/article24988789.ece) 

It is quite clear that concreting roads, pavements, and commercial spaces is a major issue in Indian cities, as it has led to declining groundwater levels. In this context, it is pertinent to note June 20, 2019, NDTV PrimeTime report by Ravish Kumar, which goes into this issue (https://www.youtube.com/watch?v=FdV7btCRXfU). However, it is beyond the scope of this blog to go deep into those issues here.

In light of all this, I believe that Pune, like other cities, will sooner or later face a water crisis. (Pune among cities that overuse water: Madhav Chitale). The fast-growing population, the growing residential complexes, and the IT and industrial parks will have to rely on external sources of water, thus increasing the cost of living and working in the city (Finding the Right Price for Water.). Thus, the city will no longer be the best one to live in.

Conclusion

There are a plethora of articles, like this one, about falling groundwater levels, and how concreting is contributing to it. However, the real question is, what are the solutions to this issue? From WOTR’s perspective, some solutions can be found in the area of water management. At WOTR, we are currently implementing the Water Stewardship Initiative, in 113 villages of Maharashtra and Telangana. This program aims at the efficient and effective management of water resources, in an equitable and environment-friendly manner. Though this program is in rural areas, it could hold lessons for the urban areas too.

Thus, the need of the hour is to have a collective dialogue about the management of groundwater resources in urban areas and chalk out a vision for the future.

(Edited by Vikas Prakash Joshi)

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