Climate Change and Water Resources in South Asia - Chapter 9 docx

The major water related problems of the country are - floods, droughts, river erosion,land degradation, arsenic contamination in ground water, river sedimentation, low flow inrivers, cyc

mean sea level (MSL) One-third of Bangladesh is under tidal influence.

Generally Bangladesh is blessed with a sub-tropical monsoon climate There are threeprominent seasons in a year namely winter, summer (pre-monsoon) and monsoon Winter,which is quite pleasant, begins in November and ends in February Usually in winter there

is not much fluctuation in temperature The normal winter temperature ranges from aminimum of 7°C to a maximum of 31°C The winter season receives a negligible amount

of rainfall and is characterized by low temperature, low humidity and high solar radiation.The summer begins from March through May, with a mean temperature of about 30°Cand occasionally a rise above 40°C The hot summer (pre-monsoon) season receives somerainfall in occasional heavy thunderstorms and hailstorms The summer is characterized byits highest temperature and evaporation rates The monsoon (rainy) season begins in June

HOSSAIN SHAHID MOZADDAD FARUQUE1

and continues up to October with maximum temperature usually around 30°C with highhumidity and low solar radiation Mean annual temperature throughout the country isabout 26°C but extreme temperatures range from about 5°C to about 43°C (BangladeshNational Committee of the International Commission on Irrigation and Drainage, 1995).The average overall annual rainfall is about 2,300 mm About 81% of the rainfall inBangladesh occurs in the wet monsoon period (June-September) (BANCID, 1995).

Fig 9.1 Location and major river basins of Bangladesh.

The major water related problems of the country are - floods, droughts, river erosion,land degradation, arsenic contamination in ground water, river sedimentation, low flow inrivers, cyclone, storm-surges, river pollution, etc To support its agro-economy Bangladesh,ensuring people’s safety and mitigating economic damage, in the past water resourcesdevelopment was focused on flood control, drainage and irrigation activities

Almost every year floods occur in Bangladesh But the intensity and the magnitude of thefloods vary from year to year In some years, floods occur locally and in others itencompasses vast areas of the country Floods of 1987, 1988 and 1998 were extensive in

a real extent and colossal in terms of destruction (Mirza, 2003) As much as three-fourths

of the country was affected in 1998 Floods cause enormous economic loss to the countrydestroying its infrastructures, standing crops, livestock and also human lives

Natural floods: About one-fifth to one-third of the country is flooded to varyingdegrees each year during June through September when about two-thirds of the food grain(mainly rice) are produced The following natural floods are encountered:

Table 9.1 shows the flooded area of Bangladesh for different return periods.

The available flood damage information is not always complete Flood damageassessments are generally prepared by various organizations, which are often notsystematic and well coordinated There is a need for a unified and consistent method ofcollecting data One of the best available sources of flood damage information is theMinistry of Disaster Management and Relief The assessments by various institutions arecompiled together into an overall flood damage assessment The flood controlembankment itself suffers substantial damage Flood damage to embankment has a strongcorrelation with the magnitude of flood The properties and infrastructure suffersubstantial damage during large and medium floods It is noted that in addition todamages, there are consequential effects such as reduced employment, industrialproduction loss, reduced consumer demand, reduced economic activities due to disruption

to daily life of poor people, etc When converted into monetary term, it is found that flooddamage to infrastructure and property outweighs the damage to crops But the misery ofthe people however cannot be translated into economic indices

The 1988 flood caused over 1,517 deaths and damages variously estimated at about

$1,200 million The lower death toll in the 1998 flood of less than 1,000 and a considerablereduction in livestock deaths (down from 350,000 in 1988 to 26,564 in 1998) reflectimprovements in flood preparedness over the intervening period The 1998 flood forcedover a million people out of their homes, damaged 16,000 km of roads and 4,500 km ofembankment, and destroyed crops of over 500,000 ha of land

Morphological behavior of the Bangladesh rivers are very unpredictable and in some casesunstable This has placed them at constant risk from erosion but is most marked along themajor rivers and their estuaries The Jamuna is highly unstable and has occupied its presentcourse for approximately only the last 200 years Although over the last 25 years there is anegligible net Westward migration overall, both banks are eroding at a rate of about

70 m/year that shows no sign of abating (Nizamuddin, 2001) The Ganges and PadmaRivers erode their banks locally, while the lower Meghna is extremely active at Chandpur,

in the region of the Tetulia channels, and in the entire area of Bhola, Hattiya and SandwipIslands The impact of erosion can be sudden and dramatic, even when the riverbank isprotected Border river erosion is also an essential issue for Bangladesh

River training and erosion control can be very expensive in human terms because ofthe amount of land acquisition required The amount of land needed varies but often abroad strip of riverside land is required The Flood Action Plan (FAP) 21/22 investigations

of river training on the Jamuna required 42 hectares of riverbank land to be procured, sodislodging and disenfranchising many poor families from along the riverbank chars, oftenwith inadequate compensation for land and livelihood lost Future compensation for landacquired and livelihoods lost, on the basis of the Bhairab Bridge model would be expected

to be much more extensive and thus act as a disincentive to large-scale land acquisition

River training can also cause social conflict, especially if access to the river fornavigation and port facilities, fishing, irrigation, and livestock washing is disrupted.Facilities for mooring are still highly limited and are inadequate under some existing riverbankprotection schemes Many people have been displaced and outstanding cases and claimsarising from previous water sector projects have yet to be resolved Policy stresses theadoption of socially sensitive, multi-purpose schemes and adherence to participatoryplanning as ways of rectifying these fundamental points of conflict.

The popular structural options practicing in Bangladesh for erosion control are:

at midnight to track 5 km to a well to fetch a pitcher full of drinking water (NWMP, 2001) Inother areas the affected people relentlessly dug in dry riverbeds and ultimately ended upwith a pitcher full of foul smelling, muddy, brackish water unfit for human consumption.Water supplies, the environment, crops and navigation all fall under threat during droughts

In contrast to the high rainfall brought by the Southwest monsoon from May toOctober, there are months without rain in the dry season This can bring hardship to peopleliving in areas with poor access to surface water and ground water resources There weresevere droughts in Bangladesh in 1979, 1981, 1982 and 1989 and between November of

1998 and April of 1999; there was a period of 150 days with almost no rain in Bangladesh

A GoB report of the Task Force on Drought on what was seen as an impending

drought in 1995 noted that the rainfall in the monsoon had been below average in the NW,

SW, NE, SE and SC Regions (Fig 9.2) by 35%, 20%, 25%, 30% and 15% respectively.Corresponding reduction in surface water availability was expected to be 20%, 20%, 5%,10% and 5% Overall, it was expected that the areas under Low Lift Pump (LLP) irrigationwould reduce by 55,000 ha They also expected that GW level would fall by 0.5 m to 3 m,

and that 90,000 Shallow Tube Wells (STW) would be affected The report stated that aman

crop production in the 1994 season was reduced by 377,000 tons due to the effects of the

drought The effect of drought is more marked now that irrigated boro (dry season) rice

has become the major rice crop Streams and water bodies used for LLPs dry up, and STWsreach their suction limit of 7 m Farmers using LLP start abstracting water reserved forenvironmental needs STW can be lowered 2 m in pits to reach more water, but deepersetting is difficult When farmers draw the water down, there is a corresponding fall in thevillage hand pumps, which are also suction mode pumps, set generally on higher land andconsequently more vulnerable Women seek water from contaminated surface water sources

as a result, with corresponding risks to public health and welfare Thus water supplies, theenvironment, crops and navigation are all under threat during droughts

Drought monitoring and contingency plans will be prepared for regions thatexperience recurrent seasonal shortages of water These will include action to limit the use

of ground water to human needs if necessary Obviously, human needs must takeprecedence over non-consumptive needs The government can empower Local

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Government, or any local body it deems fit, to exercise its right to allocate water inscarcity zones during periods of severe drought This will clearly need to be plannedjudiciously to avoid bias in allocation to one sector at the expense of another.

Fig 9.2 Map of 8 hydrological regions as in NWMP, 2004.

There are 57 international rivers flowing over Bangladesh with 54 of them entering fromIndia and 3 are from Myanmar There have been disputes over sharing the water of theinternational rivers There is only one Treaty signed in 1996 with India to share waters ofthe Ganges River in the dry season (January-May) Bangladesh needs these water sharingtreaties/agreements on all other international rivers to estimate the magnitude ofcross-border inflows in order to facilitate its water management plans Presently especially

in dry season due to upstream withdrawal/control most of the river flows fall dramatically

to a very low level on which Bangladesh has no control

9.2.5 WATER MANAGEMENT

During the past decades since 1960s huge investments (an average annual developmentallocation from the financial year 1990-1991 to 2000-2001 was 173 million dollars) havebeen made in flood management, drainage and irrigation schemes and to reclaim anddevelop many polder areas In these areas a careful water management is required to getoptimal results from the investments in the physical infrastructure and enable the farmers

to have a reasonable living However, although in the initial year after completion ofthe polder projects it gave remarkable results but now over the years the actual watermanagement in the Flood Control and Drainage (FCD/FCDI) schemes of coastal poldershas been below expectation, resulting in lower yields than were envisaged during thefeasibility, design and construction stages

Water management in FCD schemes is complex and fundamentally different fromtraditional water management in irrigation systems A distinct characteristic of watermanagement in FCD schemes is that there are many different stakeholders, each withdifferent, often-conflicting water management demands The stakeholder’s occupation

or the location of the land owns determine his level of interest in water control So,participation of stakeholders in the context of FCD schemes in Bangladesh is crucial forthe planning and design of sustainable water management schemes

The IPCC (2001) in its Third Assessment Report concluded that there was new andstronger evidence that most of the warming observed over the second half of the lastcentury was attributable to emissions resulting from human activities It further observed

observed sea level rise, through thermal expansion of seawater and widespread loss ofland ice Projected temperature, precipitation, extreme weather events and sea level risehave been summarized in Box 9.1 In Bangladesh and the adjacent region, mean observedtemperature change in the last century was 0.4°C, which is comparable to the observed

were observed in the same period The mean tidal level at Hiron Point (in the Sundarbans)

has shown an increasing trend about 4.00 mm/year Similarly near Meghna Estuary andnear Cox’s Bazaar it has registered a positive trend of 6.00 mm/year and 7.8 mm/yearrespectively The increment in SLR along the Bangladesh coast is much more pronounced

as compared to the global rate (SMRC, 2000)

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Bangladesh, one of the most densely populated countries in the world, is a victim offrequent natural calamities like tropical cyclones, storm-surges, tornadoes, floods anddroughts In the wake of global climate change, the SLR has emerged as a new threat TheSLR is likely to have greater impact on Bangladesh due to its low and flat topography and

a vast floodplain Since 21% of the population lives in the low coastal belt, any increase insea level will be a problem of ominous proportion for Bangladesh (SMRC, 2000) Sea leveland temperature rise, increased evaporation, changes in precipitation and resultant changes

in cross boundary river flows are identified as the agents of change, which cause the mostthreatening impacts in the natural, social and economic systems of the country

Climate change in the future may compound water resources management problems inBangladesh People in Bangladesh are generally adapted to natural climate variability.However, there is a necessity of a greater focus on adaptation in the context of climatechange when serious socio-economic damages are expected to occur In the waterresources sector, the following key areas have been identified for adaptation: drainagecongestion, reduced freshwater availability, disturbance of morphologic processes andincreased intensity and duration of flooding associated with river erosion and disasters.This chapter addresses possible impacts, key water management issues and adaptationmeasures for the water resources sector in the context of future climate change.Section 9.3 illustrates present water management practices Section 9.4 describes majorstudies carried out on the complex water systems in Bangladesh and states salient findings

An important characteristic for classifying Flood Control and Drainage (FCD) schemes isthe type of flooding they are subjected to This classification ties in with the four differenttypes of floods in Bangladesh, namely:

The tidal floods, is typical for the coastal zone Coastal areas consist of large estuarinechannels, extensive tidal flats, and low-lying islands High tides regularly inundate largetract of these areas During extreme monsoon storms freshwater runoff from the big rivers,combined with wind and wave set-up caused by strong Southern winds, inclines the seasurface on the Bay of Bengal Therefore the maximum water levels are higher than thepredicted tides Tide levels determine the inland tidal flooding with saline tidal waters,causes damage to standing crops

Wet season floods and water scarcity during the dry season are major challenges forwater resources development and water management in Bangladesh Cropping patterns

and crop yields in the floodplains are strongly affected by floods, as are fisheries andtransportation In coastal areas, salinity and cyclones are additional factors influencingfarming systems Over the years the primary objective of water management activitiesfocused heavily to increase agricultural production through the provision of one, or anycombination, of the following measures: flood control, drainage, reduction of saltintrusion, and irrigation.

The most commonly used structural options for flood control measures practiced inBangladesh are: a) river embankments, b) construction of dams, c) reforestation,d) network as drainage channels, and e) pump drainage

Flood Control and Drainage (FCD) schemes are located in the floodplains of the rivers

in Bangladesh and also in the coastal areas Embankments along the periphery provideprotection against river, or sea floods, or against salt intrusion Where necessary, sluicesare placed in the embankments to drain natural khals (natural channels which connect thelow-lying area and the rivers) Many inland FCD schemes have field depressions thatcontain water during most or all of the year, called beels, in their interior They are oftenconnected to rivers through a network of khals or man-made canals and can only bedrained when river levels permit

In most FCD schemes there are nowadays three distinct cropping seasons, namely:

Kharif-I (mid-April to mid-July), Kharif-II (mid-July to mid-November) and Rabi

(mid-November to April) From an agricultural perspective the FCD schemes are designedto:

• Protect standing aus against early river floods (Kharif-I);

• Expand the area under aman by excluding flood from the schemes (Kharif-II);

• Retain water in the system during the post-wet season (Rabi).

Water management is a dominant feature of life in rural Bangladesh It has many formsand is regulated by many institutions, including customary rights, traditions and socialnorms, as well as more formal types of organizations Every farmer, every fisherman andthe villagers who are not a farmer or a fisherman manage water, both individually andcollectively In addition, there are specialized groups whose whole livelihood depends ontheir ability to manage these resources: professional fishing communities, boatmen, netmakers, shrimp farmers, salt producers, irrigation pump owners and many others Watermanagement in FCD schemes is the control of water surpluses, shortages and quality

by adequate operation and maintenance of system elements as canals, sluices, andembankments to obtain optimal conditions for activities within the boundaries of the FCDscheme

All the stakeholders of a polder do not have the same interest So, conflicts are found inalmost all types of FCD schemes These conflicts prevail between:

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For various reasons operation and maintenance of the FCD schemes is not up to themark Lot of effort is still needed to improve this situation.

The rural economy of Bangladesh is changing under the influence of many other factorsthan water control interventions New crops and cropping techniques now emerged, newmarkets developed, transport patterns changed, population pressure increased, newinvestments are made, technologies for managing land and water improved and manyother developments imply that rural areas are experiencing dynamic transformations.FCD schemes created a physical environment for intensive cultivation with High YieldingVarieties (HYV) crops They helped in two ways first by saving crops for damages, secondcreated opportunity for irrigation practices

In most cases FCD schemes are justified on the grounds that they will improveconditions for agriculture More particularly, depending on the scheme, it is argued that(Flood Plan Coordination Organization, 1992):

level will encourage farmers to adopt more productive crops (rice varieties) whichcannot tolerate unmanaged wet season conditions;

for a given crop;

farmers, who are then encouraged to adopt HYV technology (which wouldotherwise entail high losses in flood years, while the costs of production are higher);

profitable and productive HYV boro in the dry season.

The primary objective of the FCD schemes of increasing food production has largely beenachieved The farmers are ready to invest in more input required by High Yielding Varieties(HYV), partly because there are fewer losses due to flooding (Flood Plan CoordinationOrganization, 1992) In some of the schemes, the targeted agricultural growth rates wereexceeded considerably In others, the targets seem to have been too high Most of the gain

in production has come from the shift to improved varieties of rice, which shows theconfidence of the farmers in the performance of the schemes Drainage congestion isthe major constraint to further growth in rice production Improvements in design andmaintenance would result in further increase, especially if the drainage problem can bedealt with adequately In a floodplain setting, some drainage congestion is probablyunavoidable and a costly solution may not be feasible The agricultural performances in the

In Bangladesh irrigation is categorized as either minor or major irrigation Minor irrigationcomprises mostly of farmer-operated and owned tube wells and low-lift pumps, and also asmall area irrigated by government owned DTWs and small Local GovernmentEngineering Department (LGED) projects (85%) Major irrigation comprises the Bangladesh

Water Development Board (BWDB) surface irrigation projects and accounts for 8% of thetotal Rest was covered by traditional irrigation practices Most of these BWDB projectshave flood control and drainage (FCD) component Irrigation in Bangladesh is thereforelargely in the hands of the private sector.

Ground water is the most important source for domestic, industrial and irrigationsupplies at present Present trends in ground water development for irrigation have shownthe alluvial aquifers of Bangladesh to be amongst the most productive in the world Theaquifer is recharged through rainfall and flooding, and replenishes every year, exceptbeneath Dhaka City where ground water abstraction now exceeds recharge The estimate

of potential recharge is particularly sensitive to the deep percolation characteristics of thesub-soil, monsoon rainfall depth and the extent of flooding during the monsoon

Expansion of ground water irrigation nevertheless causes seasonal water levels todecline further, although in those areas where irrigation is already highly developed, thisresults in a small change from the current levels Increased seasonal draw down is ofsignificance both to rural water supply planning, as well as to the types of technologiesrequired for irrigation abstraction Fully understanding the sustainable limits of GW useand the impacts that quality has on its utility, and the long-term strategic implications

Fishing is the main source of income for the professional fishing communities foundthroughout Bangladesh These communities are increasingly facing problems, withdeclining fish stocks and reduced access to open water bodies These processes areaggravated further by hydraulic structures, through interrupting fish migration andexcluding floodwaters The farmers on the other hand require more secure watermanagement conditions by expanding both irrigation and farming areas The presentavailability and future sustainability of both subsistence and professional fishing is a keyaspect of water management in the polder areas

Fisheries and FCD development are in principle in conflict with each other The sweetwater capture fisheries resources are dependent on inland water bodies The annualflooding and post-flood standing water in the floodplains has a significant role in fishproduction In the wet season, floodplains play the primary role of re-population andincrease of biomass in open water fishery production systems However within the floodcontrolled areas the culture fisheries have expanded dramatically in the recent years(BWDB, 2000)

Flood protection schemes bring about overall improvements, through the reduction offlood depth to ensure more secure environments for living as well as for agriculture.However, they can also bring about drastic changes in the natural water regime, which mayresult in an imbalance in aquatic environments and ecosystems For example, structuralinterventions disrupt the free flowing environment of the floodplains Moreover,continued congestion, or stagnation can prevent natural flushing and lead to the spread ofwater-borne diseases that may threaten public health Total elimination of floodwater canalso severely impact ground water recharge Cultivation, land settlement, vegetationclearance, hunting and fishing, all have increased in the scheme areas as population densityhas increased at an alarming rate over the last few decades The FCD schemesundoubtedly contribute to the loss of bio-diversity particularly of aquatic, birds andvegetation species

Analyzing the description presented above it is clear that the water development inFCD schemes have a wide diversity in demands and interests of the stakeholders It shows

a wide scope for integration among the various aspects of water development, especiallyenvironmental, agricultural and institutional aspects In the past no legal framework and

no water rights for stakeholders participation in the development and management of FCDschemes were defined Recently this has been outlined for new reclamations, as well as forimprovements in the existing schemes Conceptual understanding and recognition of theimportance of operation and maintenance in FCD schemes need to be improved Now ithas been mandatory to conduct Environmental Impact Assessment (EIA) for all types ofFCD/I projects

FCD schemes need to develop sustainable means for the operation and maintenance ofhydraulic structures and watercourses This requires a sound and sustainable financial base.This has never been the case within any responsible agency, specially the BangladeshWater Development Board, which continually suffers from inadequate Governmentbudget Which demands for the need for alternative financing This need resulted in theproposal that the stakeholders should pay for, or contribute to the services they receive.Measures would have to be taken to transfer at least a part of the responsibilitiesand financial contribution to operation and maintenance of irrigation and drainageinfrastructure from the public sector to the stakeholders Legal provisions for collection ofwater fees have been brought in place for some years Application of these rules has beeninadequate and the collection of fees is minimal

Bangladesh has suffered from the twin problems of ‘floods and droughts’ for centuries.After the country had suffered from unprecedented floods in two consecutive years 1954and 1955, a flood commission was constituted in December of 1955 by the government tolook into the problems and to advise on remedial measures (East Pakistan Water andPower Development Authority, 1964) Subsequently, a UN Technical Assistance Missionpopularly known as the Krug Mission reviewed the gigantic problems associated with thefloodings and submitted a report in 1957 Based on the recommendations of the KrugMission, the East Pakistan Water and Power Development Authority (EPWAPDA) wascreated in 1959 for the unified and coordinated development of the water and powerresources in the present Bangladesh

In the context of the increased need for agricultural development, in 1961, the EastPakistan Agricultural Development Corporation (EPADC), presently the BangladeshAgricultural Development Corporation (BADC) was created to supply seed, fertilizers,pumps and other production inputs to farmers

The EPWAPDA, with the help of the International Engineering Company Inc (IECO),prepared a Master Plan for water resources development in 1964 (EPWAPDA, 1964) Thisplan marked the beginning of the formulation of an integrated plan for flood control anddevelopment of water resources of the country The Master Plan organized the limitedavailable hydrological data and recommended emphasis on systematic and scientific

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