Prime Minister Modi has taken up an ambitious target of redeeming Mother Ganga. His intentions are noble but talks to redeem Ganga are not new, around 20 thousand crores has been spent since 1986 under the Ganga action plan but the fate of the river never changed. From a layman’s point of view it looks like reducing the sewerage going to the river and removing the silt from the river basin will solve the problem as it will let the river flow naturally and restore its pristine glory. It is only after a while when we go deep in the problem and realize that ganga lacks one important thing for this plan to work out and that missing element is….WATERR….And once we understand that our approach to the problem begins to change.
Meanwhile A little before 1 month India was facing drought like conditions, and from last few weeks when rain gods started coming down in plenty our cities could not handle those showers and came to grinding halts. This is not new we have been seen this years after year. Droughts if there is no rain and flood like situation the moment it starts to rain. Who can forget the 1000 lives lost in the financial capital Mumbai few years back when Mithi River flooded due to incessant rains? PM Modi has also tapped into the aspirations of young India to build 50 new smart cities. The question is are all the problems or challenges stated below are interlinked or are they separate issues.
- Reviving our rivers
- Building new smart cities
- Making ourselves prepared for uncertainties of monsoon
I feel all the above stated objectives are in a way interrelated to each other. When I tried to explore why did the revival work of Ganga fail I went into a journey where the garbage disposal problems of Bangalore, the floods in Mumbai or flooding of any city after a few hours of rain, the receding underground water levels across India, the floods and landslides in Uttrakhand/Kashmir and the dying ganga or say any other dying river they all seemed to be interlinked.
Reasons for failure – Dams, sewage
The most important reason for failure of Ganga action plan or say any other river cleaning plan must have been the same
- The core of problem lies in unscientific extraction of water from river for irrigation and other purposes.
- By design, dams alter the natural flow regime, and with it virtually every aspect of a river ecosystem, including water quality, sediment transport and deposition, fish migrations and reproduction, and riparian and floodplain habitat and the organisms that rely on this habitat get impacted.
- The other big reason of river decline is the disposal of untreated sewage and industrial waste into the river in much greater quantity then the river can actually take with it. Here too the problem of diverting all the water from rivers results in drastically reduced capacity of river to naturally carry these pollutants.
- As per some data on Ganga and its tributaries there are at least 34 barrages/structures functional in India and Nepal. In India, barrages control all of the tributaries to the Ganges and divert roughly 60% of river flow to large-scale irrigation. There are around 558 dams on the Himalayan Rivers, including those complete, under-construction and still others that are proposed. The river Bhagirathi and its tributaries has 85 projects dotting its flow. Of the other major rivers, Bhilangna has 19 dams, Alaknanda and its tributaries have an astounding 91, Dhauliganga and its tributaries 19, Pindar and its tributaries 23, Gauri and its tributaries have 27 dams.
- The Ganga and the Yamuna, along with their tributaries, have 55 ongoing projects.
- Apart from that the govt sometime back came with the idea of setting up barrages at every 50/100 kms on the Ganga. Just imagine how would a river continue to flow if its water is diverted at every 100 kms .How do we expect to revive the glory of a river without leaving the minimum amount of water in it that which is essential for maintaining the amount of flow to carry out the sediments and then worsening the problems by releasing more sewage in it than it can carry with that current.
However once we identify the problems the question is how can we minimize the requirements of those necessities or is there an option to eliminate it altogether?
Looking Beyond Dams
Pundit Nehru called Dams as the temples of modern India. But as India catches pace in the new millennia a very little is now left of the Nehruvian legacy. Dams will probably be another legacy which needs to be looked into thoroughly. In order to address the question of restoration of river we will have to evaluate the requirements of Dams and how much waste can be disposed of in the river. If we come to the conclusion that dams are essentially at the core of the problem then we need to find out is there an option to remove the dams. The truth is that a large part of the country is getting its irrigation requirements from Dams and therefore removing them altogether is not an option. However across the world this realization that there is a requirement to look beyond Dams and identify ways in which we can reduce our dependence on dams is gaining traction. In a report in “Beyond Dams: Options and Alternatives” done in US it lists out the options on how can we look to alternatives to achieve the same benefits which Dams provide.
Broadly Dams are used for the following purposes
- Flood controls
- Energy/Power generation
While many of these alternatives are not quick fixes, they are real solutions that can be implemented with long-term planning. The following are some alternative approaches to dams for flood management:
- Reducing runoff by Low Impact development
- Riparian & in-river flood management
- Separating the people & the threat
Reducing Runoff by Low Impact Developments (LID): The principle behind runoff reduction measures is to increase the proportion of precipitation that infiltrates the soil and decrease the amount that runs off directly into rivers. On undeveloped land, typically less than 20 percent of the volume of rainfall becomes direct surface runoff that drains into rivers. With development of buildings and paved impermeable surfaces, and the use of conventional piped drainage systems, direct runoff can increase to over 80 percent of the volume of rainfall. By reducing the amount of runoff, the stream flow levels during storm events will be reduced, thereby reducing flood risk and the need for structures such as dams.
It is these new techniques of Low Impact development that will redefine the way future cities will be planned. It is here I can relate the flooding of Indian cities after an hour of shower. It is because there is no place for water to go anywhere. If the Smart cities project take up these approaches of Low Impact developments they would release much less water into the river around which they are located. It will also help keep the ground water levels at much higher levels.
Restoring meander: Many flood management measures constructed in the past reduced the natural live storage capacity of river channels. When engineers cut off meanders to straighten rivers and increase flow velocities, the storage provided by the longer, meandering river channel is lost. Levees constructed to keep rivers within their channels prevent floodplains from storing and slowly releasing flood flows. As a result, in some cases peak flood flows have increased and caused greater flood risk downstream of highly controlled river reaches. This transferring of the flood creates a feedback loop of escalating flood risk and flood management actions that propagates downstream. By restoring the natural flood-carrying capacity of rivers and/or their riparian buffer regions, the need for a new or existing dam is reduced.
Separating the people & the threat: An important component of floodplain management is controlling the development of floodplains to place people and flood intolerant land uses in areas with relatively lower flood risk (i.e., land at higher elevation or greater distance from the river). Land with greater flood risk is used for more flood tolerant activities, such as agriculture. This type of zoning or resettlement has the biggest impact on the need for an existing or new dam aimed at flood management.
If property and people cannot be located out of flood prone areas, flood proofing or some of the “natural” flood management measures discussed above can prevent floodwaters from reaching areas at risk. While it is not likely that flood proofing alone will lead to the removal of a dam designed for flood management or delay a proposed flood management dam, it can be a useful tool when used in conjunction with the alternatives discussed above. We have seen in Uttrakhand floods last year how unplanned development around river side leaving little or no buffer land resulted in around 10000 lives lost and property worth of billions being just washed away. If we do a cost-benefit analysis of those lives and billions worth of property we will realize that some of the Dams are not giving away so much of benefit.
Energy generation: Across the globe the energy generated by Hydel power is slowing being questioned to be counted as renewal source of energy. Instead the cheapening of solar energy is opening up new ways to harness renewable energy in a more ecologically sustainable way.
Irrigation: In India Dams are a major source of diverting water for irrigation purposes. It is here where the choice lies between the Devil and the deep sea. While the alternatives discussed above do reduce the dependence on Dams, a majority of them would still be required to feed the requirements of a growing economy and increasing population. However new techniques in agriculture using drip irrigation , creating structures to store the monsoon rains and reducing the rain water run-offs in both urban and rural areas have the potential to make a significant impact reducing the requirements of new dams.
The Verdict – Holistic view is the need of time
Where does all this leave us? Are these ideas new? Are the suggestions that are coming up are new? Probably not, they have been discussed and recommended again and again by different committees? So what has changed this time, Modi fought a bitter battle in Gujrat for the sardar sarovar dam, it is therefore quite obvious the direction new govt is likely to take. But the question is has anything changed during last few decades that desires a change in our approach .The answer is Yes , a lot has changed in India. Unlike in past the cost of floods, disasters and lost lives are exponentially going up. Soon we are reaching the level where a big disaster will nullify decades of development gone around in the region. In the age of social media one such disaster can revive the memories of the anti-corruption movement and the govt in New Delhi could be on stake. It is in this light that the new govt has to take up a new approach to solve the problems rather than working to remove the silt in the river bed. In the end if we summarize river restoration has to be a combination of these steps.
- Identify the cities around the banks of all major rivers to be developed as Smart cities, focus on Low impact developments in those cities which in turn may reduce the dependence on any new Dams and will act as model cities for other existing cities
- While the requirements of dams cannot be looked away totally there should be a proper cost – benefit analysis of the long term environmental impacts versus the benefits it brings to the community.
- Restore the river by reducing the number of dams required, maintaining the minimum level of water in the rivers around the year.
- Restore meanders, levees which provide natural protection against floods and helps to increase the storage capacity of the river naturally.
- Work on latest techniques like Infiltration Galleries & Wells, Screened Intake Pipes, Seasonal Dams, and Consolidated Diversions to achieve the same benefits as of Dams. These techniques provide the same benefit as Dams while taking away the negatives out of building large dams.
- Use latest dredging machines to remove the silt from the rivers. It has to be done in multiple phases. Each phase of dredging leaves behind some amount of contaminated sediment. Only after multiple times it gets to the point where it gets restored with the fresh sediment brought down by the river. Proper arrangements have to be done so that the contaminated sediments do not flow back to the river.
- Promote commercial navigation and develop river fronts promoting economic activities around the river
- Develop sufficient sewerage treatment capacity so that the amount of pollutants going into the river get reduced.
In the end all that is suggested sounds extremely challenging. So was it when it was proposed in other parts of the world. However there were about 3000 dams removed in US using these techniques and many rivers have been restored since then using a combination of these techniques. There was a lot of resistance and indifference initially for this approach until they realized that it was not about us it was about the river but ultimately what is good for river today will be good for us in the long term.