Solution to river bank erosion in lower stream of Ganga?

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Ganga river bank erosion is one of the burning issues in the lower stream of Ganga. That causes displacement of thousands of inhabitants each year. Till date, various steps have been taken up for erosion control but the erosion and degradation still continues. 

Experts suggested that the only permanent solution under the existing river flow condition is to decrease water pressure from the left bank to divert flow from eroding channel.

I would like to ask experts from this community, are there any other solutions for reducing the river bank erosion? Has anyone worked on this issue? 

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26 Answers

  1. We are in early R&D on ConstruKs(dot com). It has several potential uses - perhaps some opportunities in this area(?)

  2. I think we ​should follow ​the integrated ​approach for ​river bank ​erosion ​mitigation like ​rejuvenation of ​natural stream ​of the river ​catchment, ​afforestation, ​redevelopment ​of degraded ​slope etc.

  3. The best way to reduce erosion is to allow nature ecosystem to function without hindrance but with the growth of the population it's challenging. But we can at least follow the agro-climatic zone boundaries and crop selection. Agro-climatic zone is defined by climatic condition, soil and bio diversity. All are inter linked and work as family to protect ecosystem. Erosion can be minimised by adopting the above.

     

    1 Comment

  4. Silt deposited at Ghats and River banks by receding floods in Ganges is made to flow back into the river by high pressure water jet cleaning of banks and allowed to flow into the ocean depths. I think that putting such silt and clayey deposits to better use should also be planned.

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  5. Possible actions can be summarized from all the discussions we had till date -

    • Preventive actions (to stop recurrence of erosion) -

    - Ecosystem based control measure i.e. Vetiver grass plantation could be the most useful control measure to tackle Ganga river bank erosion. This control measure can be used as a preventive action to protect unaffected and partly affected river banks from further erosion.

    - Any other vegetative (alternative to Vetiver grass) shield can be used. In case of vegetative cover, it needs to be remembered that the vegetative cover should not work as invasive to the local ecosystem.

    - Control of animal movement in river banks, especially where vegetative cover will be grown.

    - Detailed morphological analysis at planning and design stage, especially erosion and sediment modeling.

    - Analysis of river oscillation with the help of satellite imagery

    - Development of emergency preparedness and response guideline to monitor and control emergency situations towards river bank erosion in future.

     

    • Corrective actions (to take immediate action) –

    -   Construction of revetments (e.g. stone) or constriction of bed bars to safeguard the bank already under erosion.

    -    Directing the flow longitudinally to the central channel with scientifically designed river training works.

    -     Deepening of channel. Selective dredging for channelization will be required in this case.

    - Depth of flow is needed to be maintained.

    - Groynes can be used where the river is not wide enough.

    Further inputs in this context are always welcome.

     

    Two more open questions in this context-

    • How to develop a comprehensive standard or Standard Operation Procedure (SOP) which will work as a structured guideline to combat river bank erosion in Ganga by employing best practices to achieve a balance among environment, society and economy?
    • Is it possible to restore lands lost in Ganga due to river bank erosion?

    1 Comment

  6. It is a very NICE IDEA to plant SEA WEED S(Kandal Kad) along the sides of,BANKS of GANGA and all rivers all making erosion.A team within the control of GRAMA PANCHAYATH will make a CHANGE.THIS will give protection to Banks and Protection to People  by way of PROTECTING

  7. Few of the reason of SOIL EROSION at banks of river is:

    1. Increased activity in Flood plains which are diminishing and ecological balance is getting disturbed.. especially the reduced shrubs and tress.

    2.Unabashed discharge of Drains of storm water illegally bringing lot of influents -sewage, effluents round the clock

    3.No River Training and in HFL situation, lot of area gets flooded with accumulated waters receding equally fast as per level of water in Ganges, there by eroding the banks and also depositing a lot of silt and muck including plastic wastes.

     

    1 Comment

  8. Yes, Mangrove forest works as the shield against Tsunami in coastal areas. A very big mangrove forest exists in Sunderbans (one of the largest of such forests in the world) area near the estuary of Ganga. However, Mangrove forest has its own ecosystem. Concern is whether this Mangrove ecosystem may work as an invasive ecosystem to the existing ecosystem if it can be planted in upper stream of estuary.

    Channel deepening will really be benefitial  in this case. However, diversion of channel may not be possible. Let alone other reasons, getting extra land for diverting channel in this region will give rise to a number of legal issues.

  9. The Bank erosion can reduce by the strength of FLOW.It can be done by deepening the Channals before the erosion area.We can divert the Flow by constructing CANALs and flow water in needs.Vegetation is a very GOOD idea.This will benefit to strengthen the Banks.In sea sides  where the Plants there the SUNAMI is not effected Much .The KANDAL forest has big ROOT SYSTEM and it Protect River sides ,Banks EFFECTIEVELY.We can start this and try to effect immediately.

  10. Thank you Editor for inviting  me.

    Reason for River Ganga bank erosion

    1. Animal trampling can remove vegetable layer and make an erosion.
    2. Steep slope river or high velocities of the flow.
    3. Decreasing the slope of the bank.

     

    Following are the protection

    1. One of the most common soil erosion prevention methods is vegetation. It is the simplest and most natural way to prevent erosion control through planting vegetation Plants establish root systems, which in turn, stabilizes the soil, preventing erosion.
    2. Increasing the resistance of the bank, (riprap, concrete blocks, stones , plantation …)
      Decreasing the slope of the bank Enlargement of the river bed Using the epis.
    3. Control of animal on river bank.
    4. Tree planting or Heggerow
    5. Another common option for erosion control is one of our erosion control mats. These soil erosion mats are typically made from either a coconut coir fiber, straw, or wood fiber material that helps to stabilize the soil while naturally biodegrading over time.

    Regards,

    Prem Baboo
     

    1 Comment

  11. I hope this issue can be reduced by INTERLINKING RIVERS.The Erosion of River Banks costs a LOT.The people LOOSE every thing including Small towns,villages.An early Solution is needed.The eyes of all stake HOLDERS to Open.

    2 Comments

    1. Saying about interlinking of rivers, there is still no scientific basis to arrive at the conclusion that whether any river basin in India is 'surplus' or 'deficit' which was considered as the foundation on which  interlinking of rivers was said to be done. A full assessment of that study will take another 15 years.   

      In addition to that, interlinking of rivers without looking at the ecological impact may be very harmful for  environment. Scientists are still doubtful that river diversion may bring significant changes in the physical and chemical compositions of the river morphology, sediment load and the shape of the delta formed at the river basin. 

      1 Comment reply

  12. The Norfolk Broads UK river erosion problems were a lot to do with boats pushing water into the banks but also deterioration of the reed borders and not enough barrier protection at the most affected places. Please check this with Google.

  13. Is it a new phenomena, or was it always the case ?

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  14. I think that one can try Concrete revetment on the bank facing most severe conditions where River takes relatively sharp curvature besides having higher velocities. If it convinces that even nominal concrete revetment can be the cost effective and long term solution, then why not attempt it in most sections.. One can leave some patches to allow flood waters access flood plains where they exist and such untrained sections can have Bio Remedial measures.

    2 Comments

    2. As Per experiences the small rivers where concrete REVETMENT is a great Failure.Then thinking of RIVER GANGA will be a Total Failure.The cost is very high and the failure will make more Problems .The concrete BLOCKS  will become problems in future.

  15. I think that one can try Concrete revetment on the bank facing most severe conditions where River takes relatively sharp curvature besides having higher velocities. If it convinces that even nominal concrete revetment can be the cost effective and long term solution, then why not attempt it in most sections.. One can leave some patches to allow flood waters access flood plains where they exist and such untrained sections can have Bio Remedial measures.

  16. My thought on this topic is to construct a series of Islands and or groynes using waste tires, dirt and vetiver or other suitable plants. The tires would be fashioned into 'chain mail' using either the tires themselves and or rot -resistant connectors/bindings/fasteners. Waste tires are available from all over the world and some places may pay you to take them. Some of the tires can be cut and interlinked with whole tires and then bolted back together. The tires could also be bolted together with fasteners. The chain mail of tires forms the skeleton of the barrier island or groyne. The tire skeleton is filled in with rubble and dirt to build a mound high enough to be above water during floods to provide refuge for people and livestock.  Tires can be rolled into place by hand, They can be cut and drilled with simple tools by hand. They can be assembled into a chain mail structure by hand. They can be filled with dirt or river dredging spoils by hand if no heavy equipment is available. Planted with vetiver or other similar plant, the barrier may be strong enough to resist disintegration during a flood.  A 90 pound person can roll a 30 pound tire a long way on flat ground without fatigue.

    One major financial constraint is that this suggestion will not make as much money for engineering companies as an expensive, government supported, and highly engineered solution that required their expertise. You know, like the LA River. I do not know if my suggestion is the right one for this region or at all but I do suspect that engineering companies may use their 'expertise' and position to do what they can to prevent any low cost solutions because low cost solutions are not in their interest. Their financial interest is in nurturing real problems toward solutions they control so they can deposit money in their bank. Those of you interested in effecting an innovative workable solution in a reasonable time frame should be vigilant of this. My view here is not cynical, it is practical and based on verifiable fact. Simply go to www.uspto.gov and go to patent quick search put in your favorite engineering company as the assignee and search and see what you get. Then compare that with other kinds of companies with similar numbers of engineers. Compare CH2M with Lockheed for instance. Clearly, the engineering companies do not 'do' innovation as part of their business. So if existing technology is too costly or unavailable and innovation is needed - such innovation will, by definition, be at least partially outside their expertise and comfort zone. (both technically and financially.)  So be vigilant of this as you consider the opinions of 'experts' who evaluate potential solutions. Where are they coming from and what is their proposal?

  17. We all have PROBLEMS but we are not thinking or Practicing for a Concrete solution.All are trying for temperarly solution which is loosing thousands of  Millions. and gaining for the stake holders..Here all have to start for a CHANGE.The actual LOSSES and damages for th human beings,Animals and wealth shall be calculated.We can try for a Change.

  18. I would like to thank all of you for your valuable inputs. However, I have some words to say about Groynes and use of Vetiver grass as tools of erosion control. Erosion control of river Ganga requires both the application of mechanical/civil  engineering and ecosystem management. Hence, both application of Groynes and Vetiver system shall be required.

    In the case of Ganga, considering current situation, control measures can be divided into two categories- corrective measure (i.e. in immediate need to control the erosion) and preventive measure (which will provide preventive control measure to protect both the river banks from erosion in future). The mechanical engineering solution (e.g. Groynes) shall fit in this corrective control measure category whereas the ecosystem based river management (e.g. Vetiver system) may fit into the preventive measure category.

    Sharing some facts about lower stream of Ganga- the breadth of the river is approximately 25km at estuary and decreases to 6 km to the head end, with innumerable tidal bars, tidal island, mudflats, sandflats, coastal dunes, creeks, inlets and existence of mangrove forests at the estuary. Semi-diurnal tides are seen in this river and influence of tidal flows are felt up to 300km upwards from estuary. Tidal waves are so strong that they destroy even smaller boats. Tidal currents are relatively uniform while residual currents varies from 0.1 to 0.4 m/s. Annual sediment load is about 20 x 106 t (Mukhopadhyay,2007). Now the concern is whether Groynes system can work effectively in the lower stream of Ganga.

    Use of Vetiver grass ( Chrysopogon zizanioid es) shall result into an effective solution for sure. Also, being an Indian species there is no fear of invasive species. Also Vetiver based river management has similarity to the Ganga management system (discussed in the discussion page). This system will work for sure but in the beginning a mechanical/civil engineering solution may be in need keeping in mind of urban structures and population pressure at the Ganga river banks.

    Farakka barriage is one of the causes of sediment load in river Ganga. But the barrage cannot be dismantled because it will cause drying up of entire south Bengal including the megacity Calcutta (Kolkata).

    A detailed modelling for erosion management  is very much required. Infact, what was discussed  in Ganga Management System (see discussion page), a detail streamwise (upper, middle, lower) aspect-impact analysis is required in the beginning.  

     

    2 Comments

    1. we all agree it is a Complicated  Problem.In 2000 I saw the Bhramaputhra is flowing about one Km. width in Arunanchalpradesh but the next year the river is following in another way .The people are suffering Like this the erosion will change the ROUTE of River Ganga. Here one easy way is to INTERLINKING THE RIVER GANGA to other rivers and reduce the STRENGTH of FLOW in all times in summer and Rainy season this will give FERTILE to 98 Districts of DROUGHT DISTRICTS of INDIA.The river banks can be protected any way we have to safe guard the FLOW of River GANGA.If it Changes the route every thing is in waste .SO years study and How many times it Changed and where the EROSION is happening more CONDUCT study,Research and ONLY start For a solution.

      The Dredging to deepen the river,Making islands, cultivating VETIVER grass ,Steel guarding to Banks are depending upon the FLOW OF RIVER.An apt decision to Protect the Life valuables of Human beings is needed.

    2. I agree, it is really complicated to find one solution for a river with 25 km width. It has to be multiple solutions. It is possible to have one solution per location. There are many measures used before and now as mentioned here asap. In my mine this the steps which  might be considered:

      Modelling of the hydrodynamic and morphodynamic behaviour of this river.

      Classify the erodible locations in the river. For instance the hydrodynamic conditions and the soil characteristics.

      Apply all the possible measures to see their effects. Measures like groynes, fixed layer, sediment nourishment, and sediment dredging and bank revetment. It is important to know how to design the measure like the length and the angle of a groyne for instance at a certain location.

      Evaluate the measures per location socially, economically and environmentally

      The non-structural measures have to follow the same track.

      Eventually, you may mitigate the bank erosion in some locations, eliminate it from other locations and makes the bank erosion in totally new locations. The cycle is on and on…sustainability. And definitely the situation will be better than now and proactive approach “early warning system of bank erosion” will be under operation .

      But they need to start, the journey towards sustainable river management starts from  a comprehensive study and well knowledge to the system

  19. Hi. This problem is complex and will involve a detailed morphological modelling for erosion and sediment management. The engineering psolutions consist of directing the flow to the central channel with scientifically designed river training works, selective dredging for channelzation etc.  In addition from engineering point. Of view there seems to be an urgent need to consider the impact of proposed structures like bridges on the river regime at thei planning and design stage supported by numerical modelling, instead of just considering the hydraulic aspects and neglecting morphological aspects as is being done at present. Further any engineering measures  will be insufficient without proper regulatatory measures such as locations where sand mining is to be permitted, a more professional and multidisciplinary institutional set up etc.

     

  20. Hi. This problem is complex and will involve a detailed morphological modelling for erosion and sediment management. The engineering psolutions consist of directing the flow to the central channel with scientifically designed river training works, selective dredging for channelzation etc.  In addition from engineering point. Of view there seems to be an urgent need to consider the impact of proposed structures like bridges on the river regime at thei planning and design stage supported by numerical modelling, instead of just considering the hydraulic aspects and neglecting morphological aspects as is being done at present. Further any engineering measures  will be insufficient without proper regulatatory measures such as locations where sand mining is to be permitted, a more professional and multidisciplinary institutional set up etc.

     

  21. I consider it lack of vision on part of the Governments for not putting proven technologies to work to arrest the erosion of soil and free passage allowed to river waters take away soils and dump the same into sea/oceans.

    A. Without having to stop flows in rivers, CONCRETE REVETMENT of design thickness and the design heights along the river embankments is easily possible to train the rivers.

    B. If the real value of SOIL and MINERALS  carried by flows of river is understood and if it is logical that this precious soil serves as top cover in fields across the flood plains or is even transported to areas where required to support better cultivation, it is technologically possible.

    Projects have to be designed at appropriate locations where manmade widening of river flow is attempted to reduce the velocity of flows so that suspended solids settle down on river bed and are pumped out by dredgers or is excavated during lean seasons and transported to designated areas. It can also be utilised to raise the embankments of reservoirs.

     

     

  22. combnation of vetivier and a forest zone might be a solution. but it has to be considered that the main stream of a river is difficult to steer, Flooding can be reduced. Vetivier and forest are building up their own height by sedimentation. a wide enough buffer zone from the river is needed to allow the needed discharge  

  23. I like to support the information from Florence Cattin about the Vetiver System for river bank protecion! Here in Latin America in countries like Columbia, Brasil, Peru, etc.. we have good results with the Vetiver System. Here an information in Spanish from Peru - www.vetiverperu.org 

  24. Greetings, yes there is a solution, planting the banks with Vetiver zizanoides, very cheap and effective. Is being increasingly used along freeways also and other public works as works much better than concrete walls for example.

    The only tricky thing is that because it's such a great weaving material it may get stolen a lot, but that could be prevented by different means. For the Vetiver see: http://www.vetiver.org/

  25. River training to maintain the longitudinal profile through out the channel will really address the issue. Simply focusing at the location with groynes will put pressure on other side of the river bank. This process will lead to more oscillation of sediment laden flow resulting in more unstable banks of the river. Non-structural methods of maintaining depth of flow will be really fruitful.

    Prof. Vijay K. Dwivedi

    National Institute of Technology Durgapur,

    Durgapur, West Bengal, India

  26. Hi Abir, The Department of Agriculture in the Western Cape (South Africa) use groynes as a river training structure rather than longitudinal structure for reasons given in the paper attached (focusing of high flow velocity channel away from bank, creating spaces between structures which are re-vegetated to enhance bio-diversity and improve sustainability of solution)

    1 Comment

    1. I think we should follow the integrated approach for river bank erosion mitigation like rejuvenation of natural stream of the river catchment, afforestation, redevelopment of degraded slope etc.