1.1. The Disaster Prone Ganges and Brahmaputra Delta
“He had heard it said, by one who knew them well, that the longer one studied the Bengal rivers the less one understood them; dread of their vagaries certainly increased with closer acquaintance.”Mr. J.N.D. La Touche in correspondence with Sir Robert Richard Gales on the Hardinge Bridge over the Lower Ganges at Sara, reported by Gales in 1917 .
1.2. Challenges of Training Rivers and Protecting Riverbanks in the Bangladesh Delta
- Bangladesh occupies the lower 8% of the Ganges Brahmaputra basin, which is dominantly shared by two powerful countries, India and China. The country has little influence on upstream basin and water resource developments and is strongly affected by sea level rise.
- The annual monsoon dominantly influences the water resources of Bangladesh. River discharges can change by 20-fold or more and water levels can rise by up to seven meters from dry season to monsoon season flows. Most of the flooding is caused by the monsoon rains from outside of Bangladesh, which are transported by the large rivers through the country into the Bay of Bengal.
- Bangladesh is affected by earthquakes. The eastern Himalayas have experienced some of the largest earthquakes in the world. While the alluvial soils dampen earthquake impacts to some extent, they are also prone to liquefaction. No major earthquake has hit Bangladesh in the last 70 years and all its major infrastructure, built over the last half century, has never experienced this unique loading case.
- Bangladesh is deprived of rock. It only operates one granite mine which extracts limited amounts of rock from several hundred meters below ground. The size of this rock is too small for riprap exposed to high flow velocities.
- The future channel pattern is of low predictability. There is a predictability of one to two years for the major rivers. Consequently, planning requires flexibility when determining the location of riverbank protection works, as erosion sites can suddenly shift.
- Long processing periods conflict with quick river changes. It typically takes several years between identifying an erosion prone location until the completion of the construction. During this time, the location of the works is fixed, while the river continuously changes.
- Budgetary provisions are focused on new construction and not on monitoring, evaluation, adaptation and maintenance. The Bangladesh Water Development Board (BWDB) allocates only approximately 10% of the funds required for identified operation and maintenance requirements. Its annual budget is only slightly larger than the total estimated annual requirement for operation and maintenance .
- The soils are mostly comprised of fine, easily erodible and variable alluvial deposits, consisting primarily of poorly graded sands and silts with locally varying percentages of mica. The topsoils are subject to liquefaction during earthquakes and slopes are subject to flow slides during fast scouring (or unloading at the toe). Subsoil investigations often do not provide a full picture of the variability of the soil due to a limited number of boreholes.
- Flowing water erodes the fine bed and bank material, even at low velocities. High velocities during floods create extremely deep scouring (up to 30 m vertical during one season). Waves are typically limited to approximately 1 m height.
- The structure, or riverbank protection works, is intended to separate the water from the soil and thereby preventing soil erosion. The challenge is to design cover layers that are flexible enough to adjust to changes of the underlying soil and at the same time being heavy enough to resist high flow or wave loading. This often requires careful balancing of opposing requirements, for example, heavy protective layers are favorable in withstanding high-flow forces but could destabilize slopes particularly on weaker soils.
- The performance of toe aprons determines the stability of riverbank protection and river training works. Aprons are necessary as dredgers cannot dredge to the deepest scour levels. Given the variable nature of flow and soil conditions, aprons add an element of uncertainty given that they are expected to provide self-launching protection over geotechnically stable slopes, separating the fast and highly turbulent flow from the easily erodible sands and silts of the riverbanks.
- The construction window is limited to times of low water levels and flow velocities (during the dry season from December to May). Even during this period, the rivers remain morphologically active, so construction must remain flexible.
- Monitoring in the deep and fast-flowing rivers remains challenging. General surveys concentrate on water levels and bathymetries, while flow and sediment discharge data are not collected systematically. Some of the constructed works have been surveyed regularly (bathymetric surveys). The data on riverbank protection and river training works are sufficient to provide good indications on scour depth and underwater slopes, but insufficient for creating systematic risk-based designs. Systematic scuba-diving investigations have been conducted for some projects and contributed much to the understanding of the portion of the structures which are underwater (which is the majority of the structure).
1.3. This Article
2. Developments in River Training (Since the 1910s)
“The Bell bund method not only reduced the first cost of the bridge proper, but, what was of more importance, it reduced the cost of maintenance of the training works, which was such a formidable item with the spur system. In short, it made possible the construction of permanent and workmanlike bridges in situations where this had not previously been found possible. All honor to James Richard Bell!”Sir Robert Richard Gales in the Principles of River-Training for Railway Bridges, 1938 .
“The conclusion to which I have come is that the task of bridging the Lower Ganges is an exceptionally formidable one. Of this class of work nothing approaching it in difficulty has been attempted in India, or, indeed, so far as I know, anywhere else. The difficulty to which I refer is not in the building of the bridge, which is the usual straight-ahead bridge work, but in the training of the river so that it may not desert the bridge when built.”
“Bridging the Jamuna presented considerable economic and technical challenges to the consultants and contractors alike. Issues of particular complexity where the training of the braided river and the design and construction of the bridge foundations in an alluvial flood plain where the rock formation lies several km below the river bed. The scale of the undertaking, both with regard to river training and to foundations, is without precedent and makes the achievement of particular engineering interest.”
“The design of river training works for the Padma Bridge poses severe problems in river engineering, similar in nature but probably greater in severity than have been faced in other large bridge projects in Bangladesh. These problems include the very large scale and the periodic shifting of the river, the extremely fine non-cohesive boundary materials, the great potential depths of scour, potential geotechnical instability, and the high cost of traditional erosion protection materials such as rock riprap that have to be imported from abroad.”
- Purpose of river training: While the Ganges River training works focused on fixing a meandering river, the two other crossings narrow the multichanneled rivers from approximately 12 km upstream to 5 km under the bridge.The Jamuna crossing changed the braided river substantially downstream. After adjustment to the guide bunds, the Jamuna River flowed in a single 4 km wide straight channel downstream. This straight channel provided stability over a 15 km long reach; however, the subsequent downstream channel bifurcation increased the bank erosion in the Lower Jamuna . In 2012, the straight channel was destabilized through the capital pilot dredging project attempting to form a short cut of the outflanking channel between Sirajganj and the west guide bund . While this pilot project resulted in some 11 km2 of land reclamation between Sirajganj and the west guide bund, it led to erosion on the left bank downstream of the bridge.The river training works of the Padma crossing follows the outer enveloping curve of historic riverbanks and is therefore not expected to interfere with the natural channel development.
- Guide bunds with upstream protection versus continuous work: The Ganges crossing applied the guide bund principle to the largest river crossing built during British colonial times and has been successful for over a century. For the Ganges crossing, the importance of upstream work on both riverbanks to reduce the shifting of the meandering river was recognized. The same principle was applied for the Jamuna crossing and has been successful for one-quarter of a century. At the Jamuna crossing, both the shape and length of the guide bunds was changed from the British standards towards shorter, differently curved, and oriented works .For the Padma Bridge, the guide bund principle with upstream hard points was abandoned in lieu of continuous protection to avoid problems with outflanking flows . However, this was only necessary on one bank, as the other bank consisted of erosion-resistant material requiring little additional work in the area of the bridge. The major motivation for providing long, guiding revetments along the existing, more consolidated riverbanks instead of moving a shorter guide bund into the river as for the west guide bund of the Jamuna crossing, was to reduce the potential for geotechnical failures.
- Underwater works: Similar to the developments of the layout of guide bunds and upstream supporting works are the developments of the underwater protection. While the Ganges crossing depends on aprons placed in the dry above low water level and continuously maintained through additional dumping, the other two bridges depend on deep computer-aided dredging with cutter suction dredgers to approximately 25 m below low water level (for example ). Dredging provides the advantage of allowing a deep placement of the apron closer to the design scour depth. This reduces the uncertainties, as much of the underwater slope can be fully protected on a geotechnically stable slope. This deep apron has proven successful as scouring only surpassed the apron level at each guide bund of the Jamuna crossing once in 20 years . However, at the northern bank at the Padma Bridge, the bed levels were below the dredged apron level immediately prior to construction (2011–2014), showing how the ability to launch is still a critical feature of the aprons.
- Crossing location: Dredging and placing the underwater protection under still-water conditions dictated the location of the Jamuna crossing . The area for the right guide bund in the river perpetually shifted with the location of a suitable char (river island). The right guide bund as well as the bridge location could only be fixed one year after the construction contract had been signed during the dry season (1995/1996).In case of the Padma Bridge, the location of the crossing was fixed as the land acquisition for the road alignment was already underway. The closeness of the southern approach road as well as of several resettlement villages to the river was a secondary reason for abandoning the guide bund and hard point concept, as erosion in between them would have threatened both the road and the settlements.
- Protective elements: Apart from setting the apron at deeper levels, the protective elements were also changed. While the Ganges crossing depended solely on “one man armor stones” (30 to 75 kg), which were carried individually by workers, the Jamuna Bridge used 10–100 kg riprap for the slope protection while a widely graded riprap was placed as falling apron (1–115 kg). The underwater slope was first covered with “fascines”, a two layer geotextile filter cloth attached to bamboo frames of up to 30 × 155 m (4650 m2) in size and sunken through boulder ballast, before the riprap was placed.At Padma Bridge, given the risk of working in flowing water, fascines were replaced by three layers of 125 kg geobags, which can be placed quickly and are stable to flow velocities of up to 3 m/s . This bag-filter layer is covered with graded riprap weighing between 40 and 1000 kg in the more exposed curvature on the right bank and both bridge area. The upstream areas are protected with multiple layers of geobags alone. The toe protection included additional risk mitigation measures: the apron is up to 65 m wide to reduce the risk of failure from flow slides during rapid scouring and follows an adaptive approach with upgrading of the apron immediately after launching. All aprons consist of geobags because of their wide, flat dimensions and flexibility which reduces the void ratio and prevents winnowing. When dumped close to the surface by using dumping guides, high precision in layer thickness and coverage can be achieved.
- Learning by doing: Much was learned from failures, particularly at the Ganges crossing. After some smaller failures during previous years, the upstream part of the right guide bund failed on 26th September 1933, followed by a second major slip on 25 October 1934 . At this time, the flow was approaching the guide bund under a strong angle and it is highly likely that the apron failed through winnowing. The failure of the guide bund resulted in major physical hydraulic model investigations to assist repair works. As part of these investigations Inglis studied the performance of aprons consisting of angular and rounded rock and indicated the launching on 1V:2H slopes in single layer, first discussed in the paper of Gales, 1938  and finally published in 1949 .At the Jamuna crossing, a number of flow slides developed during construction along the dredged slope of the western guide bund . As a result of these slides the underwater slope was changed from 1V:3.5H to 1V:5H or 1V:6H. In 2006 the Jamuna crossing western guide bund developed a deep (more than 45 m below average flood level and some 18 m below apron setting level) but only 200 m long scour hole along the falling apron at the upper curve . The scour hole was associated with outflanking flows from upstream and was deeper than the design scour. In 2007, the lower slope protection in this area failed. One explanation is that rapid repeated scouring at the toe triggered slides of loose deposits down the protected slope and flow slides under the fascine mattress due to sudden unloading.
- Adaptation and maintenance: The guide bunds at the Ganges crossing appeared to be supplied regularly with rock directly from the railway tracks that run parallel to the guide bunds (see ). The deeper apron setting level at the Jamuna crossing has reduced the required maintenance works and only one failure has been reported.
3. Developments in Riverbank Protection (Since the mid-1700s)
“A spur may be defined as any solid projection from the river bank into running water, which is the cause of stationary, eddies. The spur form, intentional or unintentional, is the cause of most of the difficulties which afflict river-training.”Sir Robert Richard Gales in the Principles of River-Training for Railway Bridges, 1938 .
- The early period is characterized by sporadic works for protecting towns or ferry terminuses, dating back to the 18th and 19th centuries and dominated by the large river crossings of prominent British railway engineers in parts reported in the previous section.
- After independence from India in 1947, town protection appears to have become more frequent. However, documentation is scarce and difficult to trace. In the mid-1960s, the construction of flood embankments started (for example, [33,34]), which, in more recent times, are the driving factor for riverbank protection.
- Long guiding revetments began to be constructed to protect two irrigation schemes in the early 2000s . This led to the development of cost-effective geobag revetments . While widely applied today, specific aspects are still under a continuous development process, with technical refinements being piloted and applied . New technologies are currently being tested including grout-filled jute mattresses .
3.1. The Early British Period (1750s until 1947)
“The difficulty of stopping this cutting action [related to river bends] was very great; groynes intended to turn the current were generally soon washed out, and even revetting along the bank line could not be altogether depended on, as the silt might run out through it, so that cutting might take place actually under the pitching.”(Mr. LaTouche in correspondence with Mr. Gales reported in 1917 ).
“At the spur which was erected at Goalanda there was a bend scour of 180 feet on the up-stream side, but that did not affect the stability of the spur, the ultimate failure of the spur was due to the boring action of the whirlpool on the unprotected downstream side of the spur.”(Sir Bandford Leslie in discussions with Mr. Gales, reported in 1917 ).
“When the river had (so to speak) made up its mind to move its bed it was not easily stopped. A spur costing nearly £120,000 had failed to keep the Ganges from washing away the station of Goalundo, at one time the river terminus of the Eastern Bengal State Railway; the whole of the buildings constituting the railway station and staff-quarters were swept into the river in a few days.”(Mr. LaTouche in correspondence with Mr. Gales, reported in 1917 ).
3.2. Town Protection and Embankments (Since 1947)
“Sirajganj town protection work started in the British period. The work was strengthened in 1964 with brick mattressing, which was washed away in 1969. During the seventies more than 2 km revetment made of sand-cement blocks was built but was again destroyed during 1985 flood. At that time the protection was enhanced with the construction of the Ranigram Groyne at slightly upstream of the town on the right bank of the Jamuna river. The groyne was 854 m long (305 m in water) and involved 62,300 m3 of cc blocks. Army engineers were involved with BWDB personnel during the construction period. The construction was delayed due to fund problem and shortage of cc blocks. To cope with the situation, abandoned railway wagons had to be dumped at some places. This attempt was not, however, successful. In May 1986, a larger damage of the structure occurred whose value was estimated at about BDT 1 crore. Both the groyne and the revetment, which were provided with concrete block armour but no filter layer, were subjected to regular damages during monsoon. To increase safety factor against anticipated severe erosion hazard, the Sirajganj Hard Point was reconstructed integrating the groyne and the revetment during the period 1996–1998 under River Bank Protection Project (RBPP).” The Hard Point failed repeatedly with major investments for reconstruction and adaptation in 1999, 2002, 2005–2012, and finally 2013–2014.
- Lack of timely allocation of funds;
- Use of unsuitable materials and construction methods, and
- Inadequate designs due to lack of research work (morphological understanding, hydrodynamic forces, soil properties etc.)” .
3.3. The Flood Action Plan (1990s)
- Permeable spurs to reduce the flow velocities: The FAP 21 bank protection pilot project developed this concept between 1991 and 1992 and implemented a series of seven permeable groynes just upstream of the Garghot River at Gaibandha from 1994 until 1996 . The initial works consisted of six permeable spurs, typically spaced at 200 to 300 m, protecting some 2 km of riverbank. The pile rows were connected to the floodplain through cofferdams.During the first flood in 1995, the cofferdams eroded in places due to deep downstream scouring (refer to Sir Bradford Leslie’s quote on the Gaolando spur in Section 3.1) and were replaced by additionally permeable piles (Figure 5). There is some controversy about whether or not the spurs work because of the lack of deep channels in the vicinity of the structure. On the one hand, this may imply that the structures are inducing sedimentation; however, this could be a result of the natural river morphology as this reach is extremely morphologically active with a high braiding index. Nevertheless, these structures are not advantageous for navigation purposes.
- “Hard points” spaced along the existing riverbank: Hard points were developed as an attempt for an economic solution to the increasing erosion of the Brahmaputra Right Embankment during the 1980s (Section 3.2). The planners of the Master Plan Report for protecting the Brahmaputra Right Embankment arrived at far-spaced, short (600 m), revetments to protect sections of the riverbank, termed “hard points”  (Figure 6 and Figure 7). The revetments are connected to the flood embankment over the floodplain with a cross bar. The land in between adjacent hard points was allowed to be eroded, requiring the retirement of the flood embankments. As important construction element, hard points introduced dredging and systematic underwater scuba-diving investigations to riverbank protection.The case of riverbank protection alongside 14 km of riverbanks with the approximately 2 km long hard point of Sirajgnaj Town Protection in the center demonstrates the limitations of this concept and the difficulties with widely spaced disaggregate protection. As mentioned in Section 3.2, the modern work at Sirajganj started with the construction of Ranigram Groyne in the mid-1980s (Figure 6). However, the groynes could not protect the downstream town effectively. Therefore, Ranigram Groyne was incorporated into the 2 km long hard point built during the second half of the 1990s.This hard point served the dual function as the starting point for funneling the Jamuna River towards the 5 km wide Jamuna bridge crossing and to protect the growing town. The upstream area was believed to be protected against outflanking flow through Sailabari Groyne built in 1978. Downstream, the west guide bund of the Jamuna bridge crossing shifted the riverbank 4 km into the river corridor towards the east.During the bridge studies, a second groyne was initially considered necessary between Sirajganj town protection and the west guide bund but dropped after additional confirmation about worst-case outflanking scenarios. The Sirajganj town protection was completed in 1998 and experienced its first flood with outflanking flows.The 1998 record flood destroyed the upstream termination, around the head of the old Ranigram Groyne. After reconstruction in 1999, the next major change occurred when Sailabari Groyne failed in 2005. Consequently, the upstream protective flood embankment eroded, and the town was devastated during the high 2007 flood. To secure the reconstructed embankment, the BWDB built an 8 km concrete block revetment along the outflanked bank line upstream of the town. However, the embayment filled in quickly over the coming years. Erosion occurred downstream between the town and the west guide bund around 2006 and 2012. While the erosion was less than the design case , the BWDB intervened through the capital pilot dredging project in 2012. The secondary purpose of this intervention was the reclamation of land for industrial development. In addition, the capital pilot dredging project changed the channel pattern from upstream of the town to downstream of the bridge crossing by dredging a new channel. As part of the dredging, two cross bars each were built over the approximately 6 km long outflanked areas upstream and downstream to reclaim the eroded land. The BWDB adapted the town protection around 2014, as the apron systematically failed when reaching just beyond design level. To this end, approximately 110,000 m3 of rock was placed systematically over the launched apron and building an additional apron in front (more than 55 m3/m) at an equivalent cost of approximately USD 9.5 million. The last work on the cross bars was completed in 2019.
- Reinforced cement concrete (RCC) spurs pushing the river away from the bank: Due to the high cost of the “hard points”, the BWDB started developing and building a more cost-effective solution, termed RCC spurs, in parallel to the development of the hard point concept, from approximately 1996. The RCC spurs (Figure 8) were designed to close developing bank line channels through an earthen dam or shank protruding up to a kilometer into the river. The fortified head of the spurs was built on an adjacent char and consist of a 150 m long concrete wall carried by two rows of 25 m long bored piles and protected against scouring by an approximately 20 m wide radial apron made of concrete blocks. The spur heads were expected to deflect the river and allow siltation of the bankline channel in between the shanks. Typically, two spurs were built several kilometers apart.The concept of RCC spurs is superior to the “hard point” concept as it turns riverbank erosion into floodplain reclamation. The performance, however, was dismal, as the spurs failed rapidly when under attack. The combination of unconsolidated soils, lack of a filter layer and rapid scouring events triggered flow slides and lead to widescale failure of the structures. In total, 18 spurs were built in the Jamuna, 9 in the Ganges and 9 in smaller rivers such as the Teesta. The total investment amounted to some USD 125 million (in 2019 prices), with an average cost of approximately USD 5 million per spur in the Jamuna, nearly 3 million for the Ganges and 1.2 million for the smaller rivers. In total, 12 spurs in the Jamuna and 4 in the Ganges were destroyed or partly destroyed not even two decades after initial construction and the concept has substantially failed.
3.4. Long Reach Protection (Since Early 2000s)
- There is no stable riverbank protection in Bangladesh without adaptation and maintenance works.
- Toe protection aprons work only under limited conditions. Aprons (a) must sit on consolidated soils (stable at angles of 1V:2H), (b) launch only in a single layer (the launched apron is prone to winnowing failure and consequently requires upgrading to multiple layer thickness), (c) are susceptible to flow slides during rapid scouring and therefore should be made as wide as possible.
4. Experience and Lessons Learned
“What has already been done at Dibrugarh deserves to be made known throughout India, and indeed the whole world. It is a story of challenge taken and met with firm determination, hard work, and all round cooperation leading to success.”Jawaharlal Nehru, Prime Minister of India on 29 August 1955 after completion of the Dibrugarh Town Protection works in upper Assam within one dry season . (Dibrugarhis located on the Brahmaputra River some 600 km upstream from the Bangladesh border. Parts of the town eroded as a consequence of the widening of the Brahmaputra after the Great Assam Earthquake in 1950. During the second dry season a 6 mile long flood embankment and drain were added. The work still protects the town today.)
4.1. Knowledge-Based Development Drives Change
4.2. Revetments Are Superior to Spurs
4.3. Learning by Doing—A Flexible Design Approach for Dynamic Rivers
4.4. The World of Aprons—A Fine Line between Success and Failure
- Aprons do not work on unconsolidated, recently deposited soils, which form natural slopes of less than 1V:2H.
- Aprons do not work along narrow convex curvatures, such as at the end of a spur, because of the limited material available to cover the ‘cone-shaped’ underwater slope.
- Uniform, hard elements do not work as aprons in sand-bed rivers. The large voids or gaps between individual elements result in substantial winnowing leading to the steepening of the slopes and eventually geotechnical failure. Observations show that geobags do not steepen the underwater slope significantly after repeated flow attacks (Figure 14).
4.5. Geotechnical Design Is Fundamental for Stable Riverbank Protection
4.6. The Adaptive Approach for Sustainable Riverbank Protection
- Predicting the river behavior in order to facilitate the planning process.
- Multi-year allocation of funds to river reaches. As the erosional attack can suddenly shift, especially after high floods, the riverbank protection activities need to follow the river behavior. This is best performed when working over longer river reaches (some 60 to 90 km in length) as there the annual requirements average out.
- Design driven by geotechnical considerations. The construction methodology must be chosen in line with, and the selection of the apron width depend on the subsoil conditions (Figure 15). It is essential to reassess the location prior to construction as the bank lines can erode after planning and design.
- Construction as per actual river requirement. The work is implemented based on surveys few days before dumping the protective materials. This ensures that the underwater slope and apron are reliably covered to meet the design intent.
- Preparation of as-built drawing to document the initial construction of the works.
- Monitoring and evaluation. Regular monitoring starts immediately after construction and continues during the first two years when significant morphological changes are expected around the structure (for example Figure 12). This provides information on the status of the works and also signals when adaptation works are necessary.
- Adaptation works are constructed (Figure 10). When an apron launches more than 5 to 8 m vertically (slope length 11 to 17 m), adaptation works, or the upgrading of the single layer launched slope protection to multiple layers, are required. Further, an additional apron is constructed at the bottom of the launched slope in order to move the scour further away from the bank line. Adaptation works are ideally packaged for river reaches with five-year on-call contracts providing annually flexible allocations wherever required.
- Maintenance for the long-term sustainability of the works. This includes the repair of local failures, such as slides due to undetected zones of weaker subsoil.
Conflicts of Interest
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|Bridge name||Lower Ganges or Hardinge Bridge and Pakshey or Lalon Shah Bridge||Jamuna Multipurpose/Bangabandhu Bridge||Padma Multipurpose Bridge|
|Bridge length||Hardinge: 1578 m||4800 m||6150 m|
|Bridge type||Hardinge: Rail|
Lalon Shah: Road
|Road and rail||Road and rail|
|Start of planning||1887||1972||1987|
|Construction period||Hardinge: 1910–1915|
Lalon Shah: 2000–2005
(Railway bridge construction has started in 2020)
|RTW: Guide bunds||1000 m (left bank)|
1000 m (right bank)
|3070 m (left bank)|
3260 m (right bank)
|1400 m (left bank)|
10,800 m (right bank)
|RTW: Upstream||Sara and Raita works (left bank)|
~2400 m (right bank)
|1550 m at Bhuapur (left bank)|
2500 m at Sirajganj (right bank)
|RTW length/Bridge length||302%||216%||197%|
|Original cost of Bridge/RTW/Total in original currency||1.2/0.6/2.3|
1917 GBP (million)
2000 USD (million)
2019 BDT (billion)
|Equivalent 2019 cost of Bridge/RTW/Total|
(in USD million)
|RTW to bridge cost ratio (%)||51%||150%||77%|
|2019 km cost of Bridge/RTW|
(in USD million)
|Location||Type of Works||Implementation Period||River||Material Used|
|Sirajganj||Spur/revetment||1940s until 2014||Jamuna||Mixed materials|
|Chandpur||Spur/revetment||1960s until 2019||Padma/Lower Meghna||Mixed materials|
|Rajshahi||Spur/revetment||1960s until 2010s||Ganges||Mixed materials|
|Kamarjani||Permeable spurs (PW)||1994 until 1997||Jamuna||Steel piles|
|Kalitola Groyne||Spur||1980s until 1998||Jamuna||Mixed materials|
|Bahadurabad||Revetment (PW)||1995 until 1998||Jamuna||Mixed materials|
|Betil and Enayetpur||RCC spurs||2001/02||Jamuna||Concrete blocks|
|Sirajganj||Betil and Enayetpur||PIRDP, Kaitola|
|Type of works||Hard point||RCC spurs||Geobag revetment|
|Design and construction phase||1990s||1990s/2000s||2000s|
|Construction completed||1998||2002||2004 under water|
2008 above water
|Adaptation and reconstruction during first 10 years||6 times||7 times||0 times|
|Kilometer cost (in BDT million), initial investment (and bracketed values in 2019 prices)||2218 (6780)||1109 (2785)||119 (276)|
|Adaptation and repair:In percent of construction cost||30%||120%||0%|
|Date (Oct–Oct)||2015 to 2016||2016 to 2017||2017 to 2018||2018 to 2019|
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