Tipaimukh : The Conclusion

I read a good, long but comprehensive account of effects in Bangladesh due to dam in Tipaimukh (Thanks to Zahidul Islam, from University of Alberta, Canada). Although I differ from him in a few aspects of technical matters, I agree to the core of his arguments. The Tipaimukh dam will be an Environmental and Ecological disaster for Bangladesh. I agreed to this several times when I wrote about this earlier.

The purpose of the Tipaimukh dam is to control flood (I argued this also in my earlier article) and all the potential losses are tied to it. But flood itself is a part of ecology. Once flood is controlled, everything associated with it will face the consequences. The typical floodplain ecology consists of seasonal wetlands, alluvial plane and animals dependent on them. On the other hand, floods cause damages too. It disrupts roads, damages human habitat and causes heavy damage to economy.

I found that a large section of lower riparian living in Silchar and surroundings – are actually in favor of the dam. If you cross the international boundary and move to Bangladesh – the supporters would be few and far between. How can you reconcile this information? I agree that political climate in both of these countries do differ. In India, the discussion is much about how would it control floods and in Bangladesh the discussion is more about what possible disasters can it cause. Although, these are flip sides of the same coin – each side of the international boundary will have their own version of effects based on their own knowledge. In Indian side, they know it would control floods but doesn’t even know that it will reduce the fish catch, decrease silt deposits and dry up floodplain wetlands. On the other hand, in Bangladesh people know the latter part of the story and don’t want to believe that it would actually control flooding.

The political awareness alone can not explain the whole phenomenon. There is a huge gap in their effort to develop the country. India is more focusing on pulling people out of Agriculture and engaging them in other productive sectors, i.e. to it’s booming services and industrial sector. Bangladesh is still not have developed any alternatives to agriculture for occupation. The fun part is, officially both countries have approximately 70% population dependent on Agriculture. The difference is still in attitude. Indian would love to develop Silchar as a hub of BPO in North-East – resting on top of high literacy and English speaking skills of North-East India.

Silchar City and Barak river

This attitude is reflected in flood control too. Floods, as I said, are beneficial to fisheries, land fertility and ecosystem on a whole. A modern urban person cares much less about these than a villager. So an agricultural economy would consider flood as an one month problem and eleven month asset. An urban economy would see it as only a liability that must go. For an industrial economy, floods halts production and increases cost of maintenance. For agrarian economy, flood recharges the wetlands, deposits silt and brings more fish with it. All these are flip sides of the same coin – as a part of nature – it helps people who are adapted to it and it opposes people who dislikes the old way and want to unfetter themselves from the indigenous way of living. The former would want to control flood and the latter would prefer to live with the flood. There is no doubt that there are pros and cons in both side of the story. But, the end message is the same – massive efforts of flood control is a result of increased pressure of unplanned urbanization (look at the picture above – how Silchar city is located in the bank of Barak – any flood would affect it).

When I call something unplanned, it forces me to rethink. The urbanization in India (and Bangladesh too) was actually never a planned one. All towns and cities in India were actually villages or conglomeration of highly populated areas. As more fertile land attracts more people – most of Indian cities end up being in high flood prone zones. So in essence, that was reflected in post-independence Indian policy towards erecting dams – flood control was one of the major benefits projected. In Bangladesh, under similar plans, the average normal flood was controlled from 20% of land area to 10% of land area.

At the same time, when Bangladesh took up its own flood control project (also known as FAP), and implemented parts of it, there were protests among a large section of educated people. They opposed plans of unplanned flood control citing the benefits of flooding. The govt of Bangladesh, though, has stuck to its old position of controlling the flood rather than living with it. Even in 2005-2006 budget, Govt allocated 2.3 billion taka for flood control where the total budget is of 64 billion taka. At some point of time, Bangladesh also would need to get rid of agrarian economy. In an industrial world – floods are liability. It would inundate garments factory, disrupt exports to foreign countries and close down the educational institutes. Silt can be good for agro-lands but would anyone love it on concrete roads? Fishing can be fun in flooded urban areas but can it be a source of living for urban people? As population grows, more and more people in Bangladesh would take refuge to urban centers – as they are doing in India and China also. As they integrate themselves with the urban habitat, they will start looking at flood to be a liability.

Urbanization in Bangladesh

A glimpse of what needs to be done to mitigate flood damage in Bangladesh can be found in the causes of flood damage. As per Prof Khalequzzaman, the contributing factors are – Unplanned urbanization, Riverbed aggradation, Soil erosion, upstream deforestation, local relative sea level rise, inadequate sediment accumulation, compaction of sediments. Among these, the first and the foremost is the unplanned urbanization – all of Bangladesh cities are in natural floodplains and the expand in floodplains too. So, scope for “living with the flood” gets limited as people choose flood-prone areas for settlement. Increased people implies increased pressure on Govt to control flood. In a democracy, people drives country and not the other way around. Similarly, deforestation in Nepal and Indian upstream regions causes river to dump more and more silt on the riverbed. Embankments can provide temporary relief but it also increases sedimentation in the riverbed (Flood distributes silt – lack of flood puts everything in riverbed). The effect is described best at BWDB site about the flash floods in Northwest :

“This floodwater not only carries the water but also carry a huge amount of sediment originated mainly from hill. Over the time this sediment has deposited on the rivers and canals bed and has reduced the conveyance capacity more or less all of the water resources system with in the Haor area. As a result, when flash flood due to sudden heavy rainfall creates pressure on the water resources system, water easily overtopped and creates breaching at several locations on the submersible embankment eventually water quickly enter into the haor. Most of the cases, flood water comes into the haor very early in the monsoon and farmers are not get sufficient time to harvest their standing boro crop.”

Structural efforts are must to reduce harm done by flood. Flood ecosystem is not only controlled by dams and embankments, it also is controlled by forests, habitat and human population density. Once we can’t keep our forests, can’t keep the population at sustainable limit we would require structural intervention to stop natural revenge. Indigenous ways to mitigate flood damage can of course work with methods developed over thousands of years. But those methods were not developed for such high population density, neither those took account of urban culture and modern vehicles. Applying indigenous techniques to solve urban problems could bring disasters. The modern methods to live with the flood have problems too. The early warnings can save lives (so does the helicopter based rescue mission), but can they save property and financial damages?

I would be highly surprised therefore if Bangladesh changes its course from the current track of structural flood control and move to non-structural one. The other industrial and densely populated countries (Japan, the Netherlands) did it, China is doing it. And of course (as I mentioned in my previous article), all of them have taken inherent problems of flood control too. Flood is natural to Japan too. Japan is an island having high mountains in the middle. It’s expected to have heavy floods whenever it rains. They controlled it in order to protect its thriving manufacturing industry. Even today, most of Japanese lives in traditional floodplains and Japan loses 5 billion USD per annum on an average to floods (though it’s only 0.1% of their GDP). Of course, they lost their valuable wetlands too.

It may be argued that India is upper-riparian and hence it is pursuing such position. However, India is also pursuing plans to control floods in Bihar and UP by daming Kosi. India is completely a lower riparian in Kosi – having all floodplains at stake. But it will try to urbanize the area as time goes and hence the emphasize is on controlling floods. As an icing to the cake, dams geneate electricity too. Urban India would get less power cuts as dams come up. So, it’s India’s urbanization that it pushing it towards rampant flood control. Bangladesh is scheduled to join the race, very soon.

Debate : Should we control flood?

I read a string of articles on how to control flood. I also read a lot of articles on benefits of flooding and the ecosystem sustained by it. It seems that a debate is required in the beginning of each and every flood control project to determine the cost-benefit return of the project. The reason is counter-intuitive : Flood has both risks and benefits. I would like to quote from World Commission of Dams report in my article to articulate my position.

Each year flood events result in significant loss of property, life and livelihood in many countries. But on a small scale floods can be beneficial in providing groundwater recharge, silt deposits, floodplain fisheries and so on. Floodplains have played and continue to play an important role in the economies of many countries.

Physical flood protection infrastructure in the form of embankments and storage reservoirs cannot always provide full protection, and their effectiveness change with changes in river morphology and sedimentation. Additional management effort is required involving non-structural interventions such as flood forecasting, land use zoning, flood proofing, disaster preparedness, flood insurance and so on, either in parallel or independently from structural forms of protection.

As developing countries urbanize and industrialize, the financial consequences of flood damage will increase, and the demand for flood protection will intensify, leading to the need to construct more dams. At the same time such investment in flood protection often encourages settlements in floodplains, a rise in property values and pressure to provide more flood protection. Consequently it is likely that there will be a significant increase in flood physical protection structures, particularly dams, in the coming decades, to counteract the effects of climate change as well as to meet the needs of growing urbanization.

Risks of Flood Control

Flood is a part of ecosystem. Controlling flood will remove one part of the ecosystem – causing irreparable damage. To understand the damage, one needs to understand how the floodplain ecosystem works.

Floodplain Ecosystem

Floodplain rivers in their natural form are in a constant state of change, roaming about across unrestricted floodplains, creating and destroying side channels, backwaters, oxbow lakes, and a variety of other habitats. In this process, over long time periods, rivers maintain a relative balance between these various habitats a situation called “Dynamic Equilibrium”. The floodplain serves as an important part of the river itself, acting as a check valve to absorb high flows or flood pulses, as a kidney to cleanse runoff waters, as a mechanism of energy exchange, and as temporary and seasonal habitats for its biological components. In fact the presence of a periodic flood pulse is a key factor in maintaining a healthy river ecosystem.

The typical damages done once flood is artificially controlled -

• Damage to shallow floodplain aquifers and subsequent damage to plants and animals dependent on it
• Impact on migratory species
• Loss to direct silt and nutrient replenishment leading to gradual loss of fertility

Mitigation : Managed Floods

The WCD Knowledge Base includes a number of cases where artificial floods have been released from large dams to regenerate the natural resource base of downstream floodplains for local livelihoods (for example Manantali dam in Mali and Senegal and the Pongolapoort dam in South Africa). Managed floods generate economic benefits when downstream communities depend on natural, flood-maintained resources such as grazing, flood-recession agriculture and fishing (see Chapter 4). For example, on the Tana River, Kenya, a released flood from the planned Grand Falls scheme would have a net present value of at least $50 million for the downstream floodplain economy. Managed floods also entail an opportunity cost which may be greater or lesser depending on the value of the released flood waters to the dam for irrigation, hydro-power or other uses. A set of preliminary studies show that in some cases there are clear net economic benefits to these releases and in other cases the opportunity costs exceed the
value of downstream benefits that were identified, quantified and valued in economic terms. The potential for managed floods is often constrained by the design of the sluice-gates, sedimentation in the reservoir and in downstream
channels and the development of infrastructure on areas previously prone to flooding. Another constraint may be the political will to support traditional means of livelihood at the expense of benefits from the dam.

How to Manage Flood

Reducing the scale of floods  - It includes better catchment management (afforestation), Controlling runoff (by creating reservoirs), Detention basins (to bypass excess water), Dams (to control flow), Protecting wetlands.  Example – Large dams in Japan have dramatically reduced the sudden arrival of floods in populated areas where the rivers are exceptionally steep and short, and susceptible to flash floods.

Isolating the threat of floods - It includes Flood embankments (dykes and other structures to enable better drainage), Flood proofing (waterproofing walls; fitting openings with permanent or temporary doors, gates, or other closure devices; fitting one-way valves on sewer lines), limiting floodplain development (not to build any major infrastructures in floodplains).

Increasing people’s coping capacities - Emergency planning, Forecasting, Warnings, Evacuation, Compensation, Insurance. The last option is really interesting one as it avoids most of the observed shortcomings of the earlier ones. It includes :

• integrated catchment and coastal zone management, and wise planning and use of floodplains and coastal zones;
• empowering local communities to make choices about land development and flood alleviation;
• reducing the impacts of humans on the environment by promoting flood disaster resilience;
• valuing and preserving the best of indigenous adaptations and improving local capacities to respond;
• addressing problems of equity (for example alleviating poverty and lack of access to resources as a means of addressing
• flood vulnerability)

Emergency planning and management has three phases: preparedness, response and recovery. The capacity of individuals, households, groups, and communities to cope with flooding depends upon

• their knowledge, resources, organization and power
• their knowledge about how to identify that a flood threatens, how to mitigate effects of floods, what to do before, during and after a flood, the causes of flooding and appropriate mitigation measures;
• the resources at their command, including their skills and physical assets, and the support of others that they can call upon;
• the extent of their organization, including within households, within neighborhood groups, and within whole communities, as a way of pooling knowledge, skills, resources, and planning and coordinating activities to achieve optimum use and power in relation to other groups in society.

A flood management strategy will need to cover flood warnings, flood mitigation, any necessary evacuation and post-flood recovery. A clear commitment by national or federal governments to the emergency planning and management process will enhance its effectiveness.

Conclusion

Flood Damage Cycle

If we compare between method 1,2 and 3 for managing (the third one does not actually ‘control’ but let flood to occur) flood the third one has almost no impact on the environment and ecosystem since flood is not stemmed. It is the most eco-friendly approach towards managing flood. So, why don’t people adopt it always?

The answer to it could be obtained by the countries those successfully adopted first two options. The Netherlands and Japan built their flood management system broadly based on structural measures – the Netherlands built dams, embankments and artificial drainage, while Japan built a series of reservoir dams to stem the flash flood. They both sacrificed a significant amount of bio-diversity and ecosystem to build up their industrial infrastructure. The third option to let the flood continue can not work with modern day infrastructures. That is the biggest drawback of that method.

I believe all these three could be used together with an appropriate mix to obtain the best result. To decide on the ration in the mix the floodplain ecosystem needs to be studied, the losses need to be appropriated and corresponding benefits should be evaluated. A debate on cost-benefit will help all of the interested parties to come to a correct conclusion.

Source

1. World Commission of Dams report – chapter 2, 3 and 5

2. Flood plain ecosystem by Jerry L. Rasmussen, U.S. Fish & Wildlife Service

Further Studies

1. Rhine river ecosystem restoration (The Netherlands, Germany, France)

“stretches of the originally freely flowing Rhine and its numerous tributaries, such as the Mosel, Main and Neckar, have been turned into a series of impoundments. Numerous engineering measures along the main channel of the Rhine and of almost all its tributaries have fundamentally changed the hydrological and morphological conditions. More than 85 percent of the floodplains have been cut off from the Upper and Lower Rhine leading to a considerable loss of habitat and of animal and plant species typical of the river.”

2. The Land Reclamation in the Netherlands – the other face of the story

The loss of estuarine environments in the deltas of the Rhine, Meuse and Scheldt is a good example of the effects of excluding natural environments in decision making processes (Saeijs, 1999). Of the original 8,660 km2 of estuaries in this delta in 1900, there remain only 3,930 km2 in 2000: more than 54% of estuarine environment (4,730 km²) has disappeared within one century. When Costanza’s key figures (1997) are applied to these estuaries and the new systems, the Gross National Nature Product of the estuaries in 1900 is estimated to have been ca. $4 16 billion per-annum. These water-systems would presently represent a capital value of ca. $ 336 billion. Of course, the figures are not absolute, but indicative. However, the message the figures convey is clear. Taking in account the gains of the new land and lakes, the loss in national nature product amounts to $ 8.8 billion per-annum while the net production loss can be estimated at $ 6.6 billion. The net loss in capital is estimated $ 138 billion. These costs of estuarine destruction have never been included in decision making tools like cost-benefit analyzes during projects like the so-called Zuyderzee project and the Delta project. …….. For example, the cause of ever increasing water levels in The Netherlands is a result of 500 years of land reclamation in the floodplain and un-sustainable use of the rivers’ resources.

3. How Japan damaged their ecosystem and how they are trying to recover

“Human impacts such as river engineering, agricultural development, invasion by nonnative species, and urban development have degraded aquatic ecosystems throughout Japan (Yoshimura et al. 2005). Since 1868, wetland area has decreased by approximately 60% (GSI 2001). Recently, the appearance of once common species such as medaka (Oryzias latipes, or Japanese rice fish) in the Red Data Book of Japan has shocked the public (MOE 2003). Today the conservation of aquatic ecosystems is of great importance in Japan, and many countermeasures have been implemented to slow or reverse the degradation of river habitat (MLIT 2001, ESJ 2002). In 2004, for example, the Invasive Alien Species Act was implemented to eradicate certain invasive species and to regulate their import, dispersal, and spread.”

4. Environmental Aspects of Integrated Flood Management

5. Bigger, Better, Bolder (Netherlands land reclaimation)

“Marsh areas that depended on the right balance of salt and fresh water are slowly dying as fresh water takes over. Where shrimp, mussels and oysters once thrived, invasive freshwater zebra mussels the same species that plague U.S. waterways have taken up residence. … Scientists are hoping to try this approach on a larger scale. The new philosophy calls for reversing the whole trend line of Dutch history: Giving up some reclaimed land and letting water reclaim it. The general idea is that if water has more space, it is less likely to flood inhabited areas.”

6. The Eastern Scheldt barrier: Environmentally friendly engineering? by HUIB DE VRIEND

7. Fisheries was destroyed in Isahaya Bay, Japan by Stanley

“Moreover, other economic consequences are making themselves apparent. Tairagi (pen shell in English) is another species symbolic of the Ariake Sea, and since the closure of the dike, the number harvested has plummeted and catches of various species of fish off the Shimabara peninsula are dropping. It seems that the sacrificed tideland was a nursery for the young of various species and the smaller creatures that make up the base of the Ariake’s food chain. The cosmetic compromise of opening the narrow gates for a limited period of time cannot restore the intricate mosaic of life in Isahaya Bay or the Ariake Sea as a whole. We are witnesses to the death of a wetland of vast importance.”

8. How Fisheries were affected by Dutch Delta-works

“The salmon case clearly shows that one-sided promotion of navigation and hydropower interests harmed the ecosystem and fishery interest despite a treaty on salmon preservation.”

Salmon Catch over years in Rhine