chapter - 4 flood situation and its …shodhganga.inflibnet.ac.in/bitstream/10603/45181/7/07...59...
Post on 04-May-2018
221 Views
Preview:
TRANSCRIPT
59
Chapter - 4
FLOOD SITUATION AND ITS MANAGEMENT
Many rain fed rivers which are originated from the Chhotanagpur Plateau and flow
down into West Bengal, are infamous for ages as wrought havoc with their seasonal floods.
This includes the Mayurakshi. Annual rainfall over the basin varies between 765 and 1607
mm with an average of 1200 mm of which 80% occurs during the monsoon season from
June to September. Some of the historically important floods in this river were recorded by
L.S.S. O'Malley in the Bengal District Gazetteers for the districts of Murshidabad and
Birbhum. For the district of Birbhum, O'Malley has noted “in 1787 there was a high flood
which it is said, in some places swept off villages, inhabitants and cattle, the crops on the
ground, with everything that was moveable.” O'Malley also recorded that “in 1806 the
Mayurakshi and Ajay had a sudden extraordinary rise and floods washed away whole
villages.” In September 1902, because of heavy rains the Brahmani and the Mayurakshi
overflowed their banks and inundated the surrounding country in some places to the depth of
12 to 20 ft.
4.1 Flood history of Mayurakhi Basin
The historical accounts as well as river related information shows us that in the
upstream part of Mayurakshi River we do not find any major flood event. From the
O’Malley’s accont of Bengal District Gazeteers of Santal Pargana, we came to know that
“Owing to completeness of the natural drainage of the district, floods are almost impossible
over a large area, but narrow streches of land in the valleys,and considerable portions of
the alluvial country lying between the Ganges and Rajmahal Hills,are liable to inundation
when the rivers are swollen by sudden rain.” Whereas in the downsteam part of the river in
the districts of Birbhum and Murshidabad floods are regular and recurrent events. Again
from the O’malley’s account of Bengal District Gazeteers of Birbhum we came to know
“excessive rain sometimes cause serious inundations from the river Ajoi,Hingla, Mor,
Bansloi and Brahmani .Formerly such inundations appear to have been both numerous and
disastrous.” O’malley’s account of Bengal District Gazeteers of Murshibad depicts “In the
western part of the district ,where the rivers partake more or less of the nature of hill
60
torrents, and are subject to sudden and dangerous freshets ,they often overtop their banks
,and flood the adjoining land in a single night, their fall being as rapid as their rise. During
the latter end of August 1884 the Mor burst one of its embankments, and flooded the town of
Kandi and the surrounding country, creating considerable alarm….” The districts in the
Southern parts of West Bengal and adjoining Chhotanagpur plateau experience heavy
precipitation particularly in the months of September and October consequent upon low
pressure developed in the Bay of Bengal, thus the rivers of these areas ,particularly in the
lower catchment areas of the Damodar, Ajoy and Mayurakshi experienced flood during this
time.
From Tarashankar Bandopadhyay’s account we find that “The Mayurakshi is famous
for its strong current. For seven or eight months in the year the river is a desert – sands
stretching from shore to shore for a mile and a half. But when the rains come, she is terrible,
demoniac. She races along, four to five miles wide, her deep grey water swamping
everything within reach. Then comes once in a while the Harpa flood, when the water, six to
seven cubits deep, rushes into villages nearby and washes away homes and granaries and
all else in its way. This does not happen very often though. The last time was about twenty
years ago.“
“From the historical records, it has been found that there are not so much major flood events
in the Mayurakshi basin before the inception of the Mayurakshi River Project. From
historical records, it has been found that two major floods occurred during the years 1787
and 1902. Kandi,Bharatpur and Burwan areas in Murshidabad district have however been
affected by flood a number of times. The areas are all well below Massanjore
dam”(DasGupta, 2001).
According to official standpoint, the contribution and role of Massanjore dam to the
flood scenario was described in the Birbhum District Gazeteer, 1975 as “RiveKopai, Dwarka
,Mayurakshi and Brahmani -----altogether with their numerous tributaries which drain into
Hijal Beel and other Beels of Kandi sub-division carry the run-off from 4500 sq miles
(11,655 sq km).Out of all these, the Massanjore dam controls only 718 sq miles (1860 sq
km). It is obvious that even if all the run-off from the catchment of Massanjore dam could
61
be held back at the reservoir, the effects would be negligible. Probably, this is the reason
why there is no provision of flood control in the Mayurakshi Project”
“Historic flood through Massanjore dam occurred during September 1999 and
2000.The catchment of Mayurakshi experienced very happy precipitation during 23.9.99 to
25.9.99.This rainfall pattern exceeds the 3-day storm recorded as the years of 1956,59,78
and1995 years ,which are considered to be major flood years in this part of country. This
catchment experienced rainfall of similar magnitude in 1898” (Dasgupta, A.2001). The
water levels in river Mayurakshi raised sharply .The gauge at Maharo recorded a jump of
10.13m between 24.9.99m to 25.9.99m. The conservation level of Massanjore Dam.
The sub-basin areas of the Bhagirathi-Hooghly are having certain distinctive features
of drainage condition which give rise to flood situation. Basin-wise there are quite a number
of rivers on the West bank of the Bhagirathi-Hooghly; these are Pagla-Bansloi, the
Dwarka-Bramhani, the Mayurakshi-Babla-Uttarasan, the Bakreswar-Kuye and also the
Ajoy. These rivers between them drain an area of 17,684 sq. km, spread over the state of
Jharkhand (the old Bihar Plateau), and districts of Birbhum, part of Murshidabad (west of
Bhagirathi) and Burdwan. They generate flood because of high rainfall in these basins and
limited carrying capacity of the river Bhagirathi between the towns of Jangipur to Kalna. In
this reach the Bhagirathi has discharge carrying capacity of maximum 1.1 lakh cusec. All
these rivers if receive rainfall simultaneously in their catchment areas can generate run-off
volume of any amount between 4 to 6 lakh cusecs at their outfall at the Bhagirathi, as it
occurred during the flood of September 2000. In this vast tract of land there is one structure
which interferes with the natural flow of flood water i.e. the Massanjore Dam. This dam,
constructed for irrigation, intercepts about 36.4% of the Sidheswari- NoonBeel- Mayurakshi
basin area of 5109 sq. km. It can discharge/generate only 16% of run-off that is likely to be
generated in case of simultaneous rainfall in these basins, west of the Bhagirathi, from the
Pagla-Bansloi to the Ajoy (including catchment of Ajoy). The flood in this zone becomes
voluminous because of the shape of the catchment area, its steep slope starting from a high
level plateau area and sloping sharply down to a flat terrain near the outfall of limited
capacity. This feature is again adversely affected by tidal condition as is generally noticed in
the month of September, the likely month of occurrence of flood. As it happens, the
62
contribution of dam discharge to the total flood volume is not much. The Massanjore Dam
cannot control any flood.
The years which faced such worst type of rainfall are1956, 1959, 1978, 1995, 1999
and 2000. The year 2000 may be designated as the year of the worst precipitation in terms of
quantum, intensity and duration. From the following paragraphs a brief description of flood
in these rivers which are all originated from the low hills of Chhotanagpur plateau and
Santal Parganas, belongs to torrential rivers (“their flow is torrential, when there is heavy
rain in one part, it usually rains heavily throughout the entire catchment causing high floods
in these rivers”---------‘Rivers of Bengal’,Vol-I,pg-41) namely Ajoy, Damodar and
Mayurakshi during these different years.
4.1.1 Year1956:
During the period of 20th to 27th of September,1956 prolonged rainfall over Gangetic
West Bengal and adjoining Bihar and Chhotanagpur due to a low pressure developed over
Bay of Bengal, a fairly widespread flood occurred in the lower catchment areas of the
Damodar, Ajoy and Mayurakshi. The low pressure developed at the head of Bay of Bengal
on the 20th September at afternoon. After crossing West Bengal coast near Sagar Islands by
the next afternoon it weakened into a diffused low pressure area and lay over Orissa and
adjoining areas till 26th of September. As a result widespread rainfall occurred over Gangetic
west Bengal and neighbourhood, and heavy to very heavy rainfall occurred on 26th, 27thand
28th September (Basu P. K, 2000). In the following the rainfall statements of Murshidabad
and Birbhum district where the lower catchment of Mayurakshi is located, are given---------
63
Table:4.1 Rainfall at some Districts/Stations during September 1956 Name of the districts
Gauge stations
Rainfall
Date of maximum Rainfall
Quantity (in mm) on day of Max.Rainfall
Period (September)
Quantity(mm)
Murshidabad
Berhampur Ajamgunj Patkabari
23-27 19-20 24-26 24-26
353 178 279 215
26th
20th 25th 25th
147 98 105 140
Birbhum Suri Bolpur Rampur Hat
26-27 25-27 25-57
365 233 366
26th 26th 26th
238 173 244
Source: Sechpatra, volume: 1, June,2001 4.1.2 Year 1959I
In 1959 two spells of heavy rainfall occurred in all the rivers of Central, Western and
Southern districts of West Bengal. The first spell occurred from 8th to12th September and
the second spell from 30th September to 3rd October. In the later spell, there was heavy rain
associated with a severe cyclonic storm formed in the East Central Bay of Bengal. It
remained stationary from the evening of 29th September till the morning of 30th and
intensified into a severe storm, and then it started to move north-westward and crossed the
West Bengal –North Orissa coast. By 3rd October it weakened into a low-pressure.
(BasuP.K,2000).As a result heavy rainfall occurred in the Gangetic West Bengal including
lower Damodar basin. The rainfall scenario during this time in the Gangetic districts of West
Bengal is presented in the following.
64
Table - 4.2 : Rainfall during September 1959 Sl.no Districts 1959 September 8th
to 12th (in mm) 1959 Sept/Oct.30th to 3rd(in mm)
1 Bankura 201 202 2 Birbhum 121 206 3 Burdwan 229 231
Source: Sechpatra, volume:1, June, 2001 4.1.3 Year1978
The year 1978 was an earmark of severe floods for the southern districts of West
Bengal when the Alipore observatory recorded a rainfall of 753 mm. during 26.09.78-
1.10.78. And the maximum rainfall in 24 hours was 369.60 mm. surpassing the 100 year
record. The storm rainfall that occurred in these spell during the period from 31st August to
3rd September was due to a depression overland that moved from east to west from
Midnapore to Daltonganj in Palamu district of Bihar through Bankura, Purulia etc. and
torrential rain resulted in four districts of the State.
The storm rainfall in the second spell was much more severe and affected the entire
Gangetic West Bengal. Heavy rainfall also occurred in the upper catchments of the
Mayurakshi, Ajoy and Damodar Basins. The deep depression lay centered below Daltonganj
and moved to Contai, Hazaribagh, Midnapore, Asansol and Baripada. The depression
persisted for a long spell resulting in continuous heavy precipitation in all the southern
districts.
65
Table-4.3 : Rainfall during September 1978
Station
District
1978 Total Rainfall (in mm) during the period
Maximum Rainfall in a day
31-08-78 to 3-9-78
27-9-78 to 1-10-78
Krishnanagar Nadia 87.50 348.70 (Rainfall data on 30-9-78 and 1-10-78 not available)
146.40 (29-9-78)
Bankura Bankura 281.60 417.20 175.40 (01-9-78)
Mukutmanipur Bankura 441.00 175.40 211.60 (01-9-78)
Midnapur Midnapur 350.60 284.30 251.80 (02-9-78)
Purulia Purulia 345.40 208.40 144.00 (02-9-78)
Alipore 24-Parganas 140.00 735.30 369.60 (28-9-78)
Dumdum 24-Parganas 168.30 556.10 326.90 (28-9-78)
Sriniketan Birbhum 102.40 636.10 341.80 (27-9-78)
Panagarh Burdwan 76.70 162.30 98.29
Sechpatra, volume: 1, June, 2001
4.2 Recent Floods
This catchments experienced heavy flood in 1956, 1959, 1978, 1995, 1999, 2000 and
2006. Amongst those, 2000 flood was the historic flood, next comes the 1978 flood.
(SechPatra, 2001). Besides, 2000 flood 1995 and 1999 floods have also resulted massive
devastation in the concerned basin. The area is perennially affected by flooding, the worse
of which happened in September 2000. Earlier floods of West Bengal did not normally
experience the extent and depth of flooding which occurred in 2000. This event is unique in
the scale of devastation that ensued. As the 2000 flood has surpassed the level of
devastation of magnitude of flooding in all the earlier floods of West Bengal in general and
this basin in particular, the author selects this year as a yardstick in this research.
66
4.2.1 Year 1995
In 1995 a heavy rainfall occurred which has resulted swelling of almost all the rivers
of the state. On 24th September, a depression was formed in North-West Bay of Bengal.
Under its influence, heavy rainfall resulted in almost all the catchment basins.
Table-4.4 : Rainfall (in mm) data for the period 21.9.95 to 30.9.95 along the
Mayurakshi Basin
Date Khusiary Maharo Tantloi Kuskarni 21.9.95 6.44 2.80 1.60 24.00
22.9.95 15.00 22.80 8.00 - 23.9.95 4.60 9.80 - - 24.9.95 - - - - 25.9.95 7.00 - - 11.20 26.9.95 9.00 25.20 11.80 17.40 27.9.95 203.20 181.00 122.60 84.00 28.9.95 44.80 19.00 1.40 2.20 29.9.95 1.20 - - 8.40 30.9.95 0.80 - - - Total 292.00 260.60 145.40 147.20
Sechpatra, January, 2008
Table-4.5 : Rainfall (in mm) data for the period 26.9.95 to 28.9.95 along the Mayurakshi Basin RainGaugeStation 26.9.95 27.9.95 28.9.95 Total (3 days) Rampurhat 44 148 156 348 Saithia 152 185 3 340 Berhampur 4 174 98 276 Nalhati 36 171 145 352
Sechpatra, volume: 1, June, 2001 4.2.2 Year 1999
In 1999,most of the rivers in the state were flooded, reservoirs were up to their
fullest capacity after heavy downpours followed by a depression formed over East Central
Bay of Bengal on 15th October 1999.The depression was intensified into severe cyclonic
storm moving south east ward on 16th ,then further intensified into very severe cyclonic
storm ,moving norh-north westerly direction on 18th.Then it laid centred on Keonjhar and
Puruliya on 18th evening and 19th morning respectively. From 20th it started to get weakened
67
over Gangetic West Bengal and adjoining Bihar, and Jharkhand and persisted as low
pressure trough over South-East Bay to West Bengal coast and Northern Bay from 20th to
23rd September. Under the influence of this system, heavy rainfall occurred at places
from15th to 24th October. The rainfall as recorded during this period at Mayurakshi basin is
shown below.
Table-4.6 : Rainfall (in mm) data for the period of 23.9.99 to 25.9.99 in Mayurakshi
basin STATION 23.9.99 24.9.99 25.9.99 TOTAL Mayurakshi basin Maharo 19.80 83.00 313.00 415.80 Massanjore 33.40 102.00 330.20 465.60 Tantloi 47.00 155.00 309.80 511.80 Tilpara 34.00 73.60 86.40 194.oo Khusiary 35.20 36.20 363.20 434.60
Source: Sechpatra, volume:1, June, 2001
The water levels in river Mayurakshi rose sharply .The gauge at Maharo recorded a
jump of 10.13 mt between 24.9.99 to 25.9.99 .The conservation level of Massanjore Dam.
4.2.3 Year 2000
The state of West Bengal experienced the most disastrous flood during September-
October 2000.A catastrophic flood ravaged nine districts, surpassed all previous records,
submerged 23756 sq km area and marooned 2.21 crores of population. The total loss due to
this flood is estimated to be Rs.5660.05 ( Irrigation and Waterways Department, Govt of
West Bengal,2000).The major part of south-western West Bengal and adjoinng plateau area
of Bihar –Jharkhand experienced excessive rainfall during the period of September 18th to
21st, 2000 due to the development of low pressure in Bihar plateau region. Thus West
Bengal faced a devastating flood in the basins of Bhagirathi-Hoogly namely Pagla, Bansloi,
Mayurakshi-Babla system, Ajoy, Damodar etc. Such type of rainfall was never experienced
in the recent history. Rainfall during the brief spell of three days even exceeded the total
annual rainfall and thus cast a wet blanket in the southern districts of West Bengal.
68
Table-4.7 : The scenario of damages in the affected districts Name of the District
Area Affected (ha.)
Crop Area Affected (ha.)
Population Affected (in lakh)
No. of Human lives lost
No. of Houses damaged
No. of Blocks (B) / Municipalities (M)
N-No. of flood shelter opened R-persons rescued
Bardhaman 359796 300400 33.25 70 2,15,695 B-25 M-9
N-4059 R-771224
Birbhum 282500 240300 33.0 228 Missing-10
4,57,947 B-19 M-5
N-422 R-192788
Murshi-dabad
524100 450600 44.0 663 Missing-97
4,90,313 B-26 M-7
N-6302 R-1257900
Nadia 390000 335000 39.57 312 Missing-34
556934 B-26 M-10
N-3454 R-730000
Hugli 290000 240100 34.70 29 215000 B-18 M-10
N-3350 R-610691
Medinipur 180600 99900 9.98 12 72,610 B-24 M-5
N-171 R-17341
North 24 Parganas
210400 155600 18.16 47 Missing-13
1,74,580 B-22 M-18
N-3521 R-429139
Haora 120000 77000 4.50 1 11923 B-11 M-3
N-205 R-27410
Malda 39740 22000 13.2 00 456 B-9 M-1
--
Total 2397136 19,20,900
218.18 1362 Missing-154
2194858 B-171 M-68
N-21484 R-4036493
Source : Government of West Bengal, 2000
69
Table – 4.8: Estimate of loss due to flood 2000 in West Bengal
In Rs. Crores Public health 99.36 Housing 350 Irrigation and Water ways 314.25 Drinking water 55.65 Municipality and Panchayet 150 Agriculture 3866 Animal Husbandry 186.70 PWD roads 329 Fishing 18.36 Small scale Industries 67.26 Food processing 10.00 Forest 0.68 Power/Electricity 50.18 Education 135.00 Transport 4.81 Small Irrigation 8.65 Others 14.17 Total 5660.05
Source: Ganashakti Patrika: (3/11/2000) Table – 4.9: Estimate of loss due to flood 2000 in animal resources and livestock District Live Stock affected Death and missing live stock Cattle and
buffalo Goat and sheep
Poultry Cattle and buffalo
Goat and Sheep
Poultry
Murshidabad 730,000 1,095,000 2,835,000 7,000 55,000 140,000 Bardhaman 194,689 102,127 206,008 14,341 9,949 62,351 Birbhum 975,000 495,000 1,202,000 7,341 3,138 4,579 Hugli 52,388 72,608 88,673 56 48 21 24 Pgs (N) 80,693 82,266 100,663 10 9 20 Nadia 151,377 146,530 172,867 38 49 640 Medinipur 77,110 47,420 0 43 30 25 Malda 0 0 0 0 0 0 Haora - - - - - - Total 2,262,257 2,040,951 4,605,211 28,829 68,223 207,636
Source : West Bengal Flood Emergency 2000, SITREP No. 9, UNICEF.
70
Table – 4.10: Damages to Eastern Railway No. of Sections affected 13 Total length of section 1366 Km Earthwork involved 8 105 man-days No. of breaches in the railway 236 Approx. cost of damage Rs. 41 Crores No. of bridges totally washed out 9
Source : Eastern Railway,2000.
In September 2000 flood the state of West Bengal suffered a sudden and catastrophic
flood, in terms of loss of lives and economic losses many of these people lost most of
their farming and domestic possessions and official figure recorded is 1320, though there is
evidence the figure may have been higher. In September 2000, Birbhum, Murshidabad and
Nadia Districts of West Bengal suffered a sudden and massive flood, together with other
districts of the state. A ‘lake’ 150 kms by 60 kms submerged the countryside, and then
moved south and slightly eastwards, doing further damage. The basic cause was a tropical
depression over Jharkhand, Bihar and Bengal for several days, at the end of the monsoon
season, when the ground had already reached field water holding capacity resulting
unprecendented rainfall in the catchment areas of tributaries of Bhagirathi namely Pagla,
Bansloi, Mayurakshi-Babla system, Ajoy, Damodar etc. This spell of rainfall exceeded the
total annual rainfall, resulting swelling of all rivers. The location might have been unusual,
but the timing of the event was ‘normal’. The monsoon brings heavy precipitation from June
to September, so that by the end of September tanks and reservoirs become usually full, the
ground sodden, rivers full, and bils inundated. The late and post-monsoon period of
September–November is also the season when it is most likely that a tropical depression will
move inland from the Bay of Bengal, releasing massive precipitation, and, with no
groundwater or surface water storage potential left, therefore causing major flooding. In late
September 2000 a slow moving tropical depression centred itself over the plateau areas of
Jharkhand, which constitute the upper catchments for the right-bank tributaries of the
Bhagirathi. Table 1 shows how much rain fell, and makes a comparison with other major
rainfall events in Bengal (Chapman,P and Rudra,K 2002).
71
Fig: 4.1 Satellite View of Bengal, Early September 2000 Source: Modis 8-day 500 m surface reflectance composite image from 5–13 September 2000, DFO 2000-61,
DartmouthFloodObservatory,Hanover,USA,digitalmedia,http://www.dartmouth.edu/~floods/2000images/20000913Mod9Bang.jpg,Accessed on 20 September 2005.
72
Fig: 4.2 Satellite View of Bengal, Late September 2000 Source: Modis 8-day 500 m surface reflectance composite image from 22–8 September 2000, mouth Flood Observatory, Hanover, USA, digital media, http://www. dartmouth.edu/~floods/2000images/20000928INd061.jpg. Accessed on 20 September 2005. Table- 4.11: Depressions which have given High Rainfall in West Bengal 1956 1959 1959 1978 1978 1995 2000 Annual
mm
Day
s in
S
epte
mb
er
23-2
7 S
ept
8-12
S
ept
30-0
3(S
ep-
Oct
)
31-0
3(A
ug-
Sep
27-0
1(S
ep-
Oct
)
26-2
8 S
ept
18-2
1 S
ept
“Mill
enn
iu
m
Flo
od”
An
nu
al
Murshidabad 256 141 370 276 470 1338 35.1 Birbhum 321 121 206 102 636 347 800 1234 64.8 Nadia 296 203 331 87 3 49 311 1401 22.2 Bardhaman 229 23 1 76 162 369 1271 29.0 Hugli 276 291 274 352 1516 23.2 Haora 331 254 122 1676 7.3 Purulia 142 168 345 208 169 1307 12.9 Bankura 201 202 281 417 50 1271 3.9
73
Medinipur 133 193 192 351 248 90 24 Parganas (Nand S)
284 276 298 154 646 151 160 1428 11.2
Source: Irrigation and Waterways Dept. of the Govt. of West Bengal, Indian Meteorological Department, Calcutta.
The above mentioned Table shows that rainfall in 2000 and its consequent
historical flood exceeded the records of earlier devastation of flood’ Table – 4.12: Damages caused by the flood at a glance Year : 2000 Year : 1978 Total Area affected 23756 Sq. Km. Area affected 30102 Sq. Km.
Crop Area affected 15110 Sq. Km. No. of districts
affected 9
Population affected 2.21 Crores Population affected 1.53 Crore
Loss of human lives 1320
Human lives lost 813 (765 missing, not accounted for)
Persons missing 159 Houses destroyed 11,07,029 House damaged 18.87 Lakhs Live stock lost 2,01,345
Blocks affected 171 Houses severely
damaged 5,92,169
Municipalities affected
68 Houses partly
Destroyed 2,05,213
Source: *Government of West Bengal.2000 **Indian Journal of Power and River Valley Development, February 1979
TABLE – 4.13: Affected areas in different districts in 2000 Flood
Sl. No.
Name of the District Total Area (hect.)
Affected Area (hect.) (I & WS)*
Affected Area (hect.) (IWMED)**
% difference of Affected Area
1 Bardhaman 702400 359796 102166 252.17 2 Birbhum 454500 282500 23263 1114.37 3 Murshidabad 532400 524100 213579 145.38 4 Nadia 392700 390000 177265 120.00 5 Hugli 314900 290000 62618 363.13 6 Medinipur 1408100 180600 41645 333.67 7 N. 24-Parganas 409400 210400 52611 299.92
74
8 Haora 146700 120000 16615 622.24 9 Malda 373300 39740 NA --
Source: * Irrigation and Waterways Department, Govt. of W. Bengal. ** Institute of Wetland Management and Ecological Design, Govt. of W. Bengal.
TABLE – 4.14 : Rainfall statements for the period of 18-09-2000 to 21-09-2000 in different rain gauge stations of Mayurakshi River basin Rainfall during preceding 24 hrs recorded at 8:30 a.m. on Station
18-09-2000
19-09-2000
20-09-2000
21-09-2000
Total Average Annual Rainfall (mm)
Rainfall Occurred during the 4 days in % of the Av.Annual Rainfall
Mayurakshi Basin System
Maharo 178.00 438.40 172.80 281.40 1071.60 1285.00 83.35% Kushiary 189.60 221.40 211.60 450.60 1073.20 1285.00 83.52% Massanjore 292.40 171.20 159.00 246.40 869.00 1285.00 67.62% Tantloi 411.20 398.80 175.60 495.30 1481.00 1285.00 115.25% Suri 217.00 618.00 96.80 135.40 1066.20 1285.00 82.97% Tilpara 163 553 94.2 100.4 910.6 1285 70.86% Rampurhat 247.00 488.60 403.70 237.80 1377.19 1285.00 107.17% Salar 57.00 393.00 330.00 58.00 838.00 1350.00 62.07% Narayanpur 49.00 327.00 208.80 162.20 747.00 1350.00 55.33% Kandi 30.00 332.80 250.00 65.00 677.00 1350.00 50.15% Kushkarni 221.40 256.00 117.20 357.40 952.00 1350.00 70.52% Average 1015.15
Source: Irrigation and Waterways Department, Govt. of W. Bengal.
Rainfall records till dates shows that this amount of rainfall of September 2000
never occurred before in Mayurakshi basin and it resulted “ in vast sheet of water flowing
down the whole of basin area breaking small boundaries to join the river Mayurakshi and
the Bhagirathi the main artery of the region. All river levels rose sharply breaching
different flood embankments as the flood discharge rose beyond the capacity of these rivers.
The rain was pouring in the Mayurakshi basin, after the Brahmani –Dwarka and the Pagla-
75
Bansloi (the two contiguous basins) received similar high rainfall. There was a time lag in
the run-off as the Pagla-Bansloi received rainfall rain sometimes earlier in relation to the
Dwarka-Brahmani, the Mayurakshi. The rainfall in the total area of 11,684 sq km of
Mayrakshi-Dwarka-Brahmani-Pagla-Bansloi river system came down to the river
Bhagirathi giving rise to devastating flood situation in the whole basin area” (Irrigation and
waterways Department,West Bengal,2000).
Figure 4.3. Flood Inundated Area of September 2000 Flood
76
Figure 4.4. Comparison of Total Annual rainfall of 2000 to Total Four Days rainfall of 2000
According to official statement ----
“One of the features of this flood which adversely affected the districts was ,very
high discharge in the rivers i.e. Pagla, Bansloi, Mayurakshi, Ajoy caused by unprecedented
rainfall in its catchment area.(The Massanjore Dam,the only control structure does not have
any flood cushion and can hardly help in a situation as it commands only 15.9% of the total
catchment of Mayurakshi basin and 10.2% of the combined catchment of Mayurakshi,
Bhagirathi and Ajoy at Katwa. There is no other control structure in the whole of the above
catchments. In fact the river gauge at Narayanpur in the district of Murshidabad rose by mor
than 4 M. even before the flood of Mayurakshi reached that point.The contributions from
very heavy rainfall in the catchment of these rivers viz. Pagla, Bansloi, Bramhmani are
almost equal to that of the Mayurakshi. It has been calculated that the Bhagirathi at the
outfall of Uttarasan River,passed a flood more than 6 lakh cusecs against its capacity of 1.3
lakh cusecs.” – After Basu. P. K (2001).
On the 18th of September, Tilpara barrage started to release water, highest discharge
released was reportedly 1076.38 cusec. The Deucha barrage on Dwaraka River and Baidara
77
on the Brahmani River, were outflanked simultaneously and consequently a huge sheet of
water rushed eastward and swept away many villages. On the 21st of September at 12 noon,
the Tilpara barrage released 256297 cusec of water . The combined peak contribution of
Ajoy and Mayurakshi systems into Bhagirathi at Katwa was measured to be 4.50 x 105
cusec. The hydraulic dam created thereon intercepted the southward flow of the Bhagirathi,
which received continuous upstream supply of water from Pagla and Bansloi River and the
Farakka feeder canal. At about 21.00 hrs on the 21st of September, the Bhagirathi breached
its left embankmen at Kalukhali (Murshidabad) and opened an alternate route through the
Gobra nala toward Jalangi River. The fast flowing water delinked the road and railway near
subarnamrigi Station and swept away three villages, namely Kalukhali, Baliramna and
Subarnamrigi, claiming 37 lives. The railway between Beldanga and Berhampur was
delinked at eleven points. All water rushed eastward and flooded extensive areas of
Murshidabad and Nadia. Some Engineers argue that the western reservoirs played vital
role in reducing the magnitude of flood by accommodating substantial amount of
water. The argument seems to be untenable. The flow of water in an uncontrolled river
system can never be abruptly high as happens in an controlled system when a reservoir
suddenly releases huge discharge. For example, the water level at Massanjore reservoir was
378 ft on the 17th September. This was raised to 40.260 ft on the 21st September when
200500 cusec of water was released.The water gained tremendous momentum and
destruction in the lower reach surpassed all previous records. Being located downstream,
pond level in Tilpara barrage was elevated from 202 ft to 211.40 ft and consequently 256297
cusec of water was released . The bankful capacity of the Mayurakshi River below Tilpara
barrage hardly exceeds 30,000 cusec. The excess water breached left bank embankment at
several places and rushed eastward toward the Bhagirathi. The flowing sheet of water
achieved a height of about eight feet and swept away many landmarks on its way. A striking
sequence of hydrological events was noticed. The flood in Birbhum district started on the
18th September when Baidara and Deucha barrages were outflanked. The situation became
worst on the 21st September when more than 2.50 x 105 cusec of water was released from
Tilpara. The water level in and around Katwa and Nabadwip towns abruptly went up from
knee-deep to more than three metres. The waters of Bhagirathi, which subsequently opened
a new outlet through Gobra nala, had already flooded and Berhampore, the district
78
headquarters of Murshidabad. Since the breach of the Bhagirathi embankment and Lalgola
bound Railway near Beldanga at about 9 pm on the 21st September, water logged Berhampur
got relieved, but situation in Nadia started to deteriorate. On the 24th of September, huge
sheet of water submerged 3900 sq.km. area and a population of about 3.80 million was
marooned.”- After Kalyan Rudra
According to the Irrigation and Waterways Department, West Bengal “ the
Department moderated peak flood between 18th and 21st September which rose to 2,86,115
cusecs could be moderated to 2,10,000 cusecs. This inflow was from a catchment area of
1860 sq km only. In the present case of Tilpara Barrage, the discharge as received from
Massanjore Dam was augmented by the inflow from uncontrolled catchment below the
Dam and the total flood discharge pass through the structure Any attempt to close any gate
when peak flow was passing could have resulted in collapse of the structure itself”. The
authority further explains that “if we had not operated the dam or if the dam would not have
been in its place the total flood peak at one point of time would have been 3,77,000 cusec
and the whole water would have passed down the Mayurakshi valley intensifying the
disaster that happened. With no significant flood storage space in the Massanjore about 30%
moderation of peak discharge could be done.”
4.3 Nature of Flood
Flooding take place since long before people established their first settlements. Flood
is defined as “a body of water rises to overflow land , not normally submerged” (Ward
,1978).We live in a land of million rivers. Sedimentation, changing course of the river, bank
erosion etc are the natural activities of rivers. Flood is also a natural event when the excess
water of river during the relative high flow overspills the bank and stretches either sides of
the flood plain. In fact the first civilisations started in flood plains as they provided fertile
flat grounds to be used for agriculture, which made it possible to leave the nomad style of
existence and remain at one location for a longer time. Living on a flood plain meant that
regular flooding had to be dealt with. Flooding was not managed in the beginning as no
technique was known and the occurrence of flooding was something you just had to live
with. Civilisations started along rivers like the Euphrates and Tigris (present day Iraq) and
the Nile (Egypt) as these offered fertile soils for agriculture. During floods people just had to
79
look for safe higher grounds, From living on mounts and running to higher grounds during
floods, the flood management strategies have developed in many ways over time. In fact,
people or rural Bengal welcome low-intensity flood as it deepens the rivers, improves
drainage condition and deposits fertilizing silt on the flood plain.
With the development of civilization, with ever expanding demand of human needs
from nature, human being has tried to intervene and control nature through their
technological progress. The expansion of magnitude and increasing rate of flooding reflects
how this natural propensity of flooding by the influence of anthropogenic influence has
changed their nature and character in terms of devastation. It is now admitted that the human
intervention into the fluvial regime in the guise of river management often impairs the
dynamic equilibrium of the rivers and thus aggravate the situation. This does not necessarily
mean that human intervention is the only major cause of flood. The intricate networks of
embankments, railways and highways criss-cross the land and impede the natural flow of
flood which remains stagnant for a longer period. Nowadays, high intensity flood maroons
larger are and often leaves behind thick layer of sand on the agricultural field and thus
makes the land non-productive.
For a long time the flood management strategies were based on measures several
structural measures. Structural schemes include the whole range of engineering adjustments
from localised river training works to the large-scale construction of embankments and
flood-control reservoirs. The most common solution to flood risk exposure was river
impediment through construction of levees, embankments, dredging, channelisation, canals,
and dams. The recent great floods all over the world, raises serious questions of the
efficiency of these measures and the significance of incomplete understanding of river
regime. For a long time, men with the pride of technological discoveries and progress have
treated nature as a means of their development or in other words their wish fulfillments. In
order to fetch their needs and demand they have ignored the ‘deep ecology’ of the nature.
Deep ecology is a contemporary ecological philosophy that preaches the interdependence of
organisms within ecosystems and of ecosystems within the biosphere. The planners and
scientists have underestimated the fact that all the elements in nature have been tied in one
string, if any element is damaged or if tried to control, the equilibrium in nature gets
disrupted. Arne Naess, a Norwegian philosopher, opined that in order to maintain the
80
equilibrium of nature every organism has their role to play, every landform has their effect.
But developmental planning measures of man have damaged this mechanism.
Now the time has come to think over the change of attitude to command and control
over river system and intervene the hydrological regime. West Bengal, being a riverine land
with 7104 km length of rivers, where the history of these many river courses have
experienced change of course in many times, is having 16,370 km long of flood control
embankment along the different rivers. In many places of West Bengal, earthen dam locally
known as ‘bodo’ bund have been built to intercept the channel in order to facilitate irrigation
during dry season. These embankments and bunds obstructed the sediments from
agricultural lands, thus accelerated sedimentation which have in many areas have raised the
river beds above surrounding levels. When these embankments is breached or overtopped by
flood water, the consequence is disastrous. Huge amount of water enter into the
surroundings and huge amounts of lands and homesteads gets sands covered. In 2000 flood,
the collapse of embankments and release of water from dam has resulted only in Birbhum,
5400 hectare agricultural field under sand heaps.
The dams were contemplated as a flood control structures during independence era.
After the independence, Prime Minister Nehru’s first commitments was to a combined
power, flood control and irrigation scheme on the construction of large dams. In the years
following independence of India from colonial rule, the large dam projects received a
political aura, when they were described as the 'temples of modern India'. The availability of
a large volume of monsoon run-off presented the main hopes in water management in the
country. Capturing this large volume of seasonal monsoon run-off in storage reservoirs and
making economic use of the same during the rest of the year was looked upon by visionary
planners and managers as the magic wand of prosperity and poverty alleviation. Thus came
the dream of a series of large dams on many Indian rivers. Today India ranks among the top
few 'big dam' countries with 4291 dams, next only to China and the U.S. There is no doubt
that the large dams and multipurpose river valley projects have provided food security to
India at a crucial period.(Bandopadhyay,J).However, with the passage of time, the
cumulative effects of serious negative impacts of these projects have become obvious,
raising serious questions on the desirability of dams. The span of opinions on dams range
from the Nehruvian faith in them as 'temples' to the well known critical stand of organised
81
movements against specific large dam projects. Several disastrous havoc floods occurred in
last decade in eastern India shows that release of excess water from reservoirs, lack of
preparedness and absence of holistic planning regarding flood management policies. The
lack of a scientific database, and automated measuring options of river discharges and
rainfall, especially in the upper catchments has further scaled down the scope of scientific
flood routing by dams (NCIWRDP 1999). In 2000 flood, excessive rainfall during the period
of September 18th to 21st September, when all the rivers, wetlands, ponds, bils are saturated,
Tilpara barrage started to release water. On the 21st of September at 12 noon, the Tilpara
barrage released 256297 cusec of water. Not only that, on 22nd September again huge water
more than lakh cusec was discharged. As a result the lower stretches of Pagla, Bansloi,
Mayurakshi-Babla system, Ajoy faced a devastating flood.
Table: 4. 15 Flood damages in India during plan periods Plan Period Financial Years Million Rs First Five years plans 1953-56 13,959 Second Five years plans 1956-61 15,259 Third Five years plans 1961-66 11,098 Annual plans(three years) 1966-69 14,387 Fourth Five years plans 1969-78 53,445 Fifth Five years plans 1974-78 49,748 Annual plans (two years) 1978-80 30,476 Sixth Five years plans 1980-85 76,603 Seventh Five years plans 1985-90 1,24,100 Annual plans (two years) 1990-92 16,788 Eight Five years plans 1992-97 26,236
Source: Disaster Report, 1999, New Delhi
From the above table it is clear that damages by flood have increased with passage of
time. This clearly reflects that how the nature, intensity and magnitude of flood have
deteriorated with time. Recent day floods become much disastrous than the previous day
floods. Thus we find that natural flood which is the nature’s natural bounty to human
civilization, the character and dimension has been modified by human interference to the
nature. The reservoir release is becoming a crucial cause of flood in recent days flood.
More we have tried to control the river and to obstruct their natural flow through several
82
structural measures we have deprived our future generation in order to get some short time
gain for present generation.
4.4 Flood Management Strategies: An Overview
Flood being a natural phenomenon, total elimination or control of floods is neither
practically possible nor economically viable. Hence, flood management aims at providing a
reasonable degree of protection against flood damage at economic costs. Floods are
recurrent phenomena in India from time immemorial. Every year some or the other parts of
the country are affected by floods of varying magnitude. Different regions of the country
have different climates and rainfall patterns and as such it is also experienced that when part
of the country is experiencing devastating floods, there is another part of the country at the
same time which is in grips of severe drought. Out of the total rainfall of India, about 75%
of it is received during the four months (June to September) due to the South-West monsoon
which is non-uniformly distributed in space as well. India is traversed by a large number of
river systems. The rivers of North and Central India are prone to frequent floods during the
South-West monsoon season, particularly in the month of July, August and September.
With the increase in population and developmental activity, there has been tendency
to occupy the flood plains which has resulted in more serious nature of damage over the
years. The National Flood commission (1980) has reported that out of 40 million ha flood
prone area, about 15.8 million ha area have been provided with reasonable degree of
protection so far. For minimizing the losses due to floods, various flood control measures
are adopted. The flood control measures can be planned either through structural
engineering measures or nonstructural measures. Structural measures comprise multipurpose
reservoirs and retarding structures which store flood waters, channel improvements which
increase floods carrying capacity of the river, embankments and levees which keep the water
away from floods prone areas, detention basins which retard and absorb some flood water,
flood-ways which divert flood flows from one channels to another and over all improvement
in the drainage system. However, it has been recognized that permanent protection of all
flood prone areas for all magnitude of floods by structural means is neither possible nor
feasible because of various factors such as financial constraints, cost-benefit criteria or
83
topographic limitations of the region. There should be emphasis on non-structural works
such as real time flood forecasting, flood plain zoning for management of the flood.
Recent work on floodplain management has suggested that the most noticeable
omission from previous decision-making policies was the social dimension of the proposed
projects. Although the physical properties of flooding and the economic aspects of
implementing flood alleviation schemes have invariably undergone quite rigorous analyses,
it has often been assumed that the social implications of any project would be insignificant
as far as the efficiency of the scheme was concerned. The basis of this assumption lay in the
belief that all floodplain inhabitants would respond rationally to minimise flood losses.
Unfortunately, this is not the case, since it can be shown that individuals perceive the flood
hazard differently and subsequently behave in different ways. Thus, floodplain behaviour
patterns which influence social efficiency are likely to be important.
In order to achieve his aim(s), the floodplain planner must select and implement a
flood alleviation policy, which will include one or more different schemes. The total range
of schemes available has not changed for many years, but the relative importance of each
scheme has altered so that the more limited selection policies of the past are gradually giving
way to wider considerations of overall flood plain management.
Several authors have classified the various flood alleviation schemes according to
different criteria, although all classifications retain the same broad items. For example,
compare the lists suggested by White (1964) and Sewell (1969).
White Sewell Land elevation Accept losses Flood abatement Public relief Flood control Flood proofing Emergency action Structural changes Structural changes to buildings Emergency action Land use changes Regulation of land use Public relief Insurance Insurance Control – land phase or channel phase
84
A more comprehensive classification was proposed by the Tennessee Valley
Authority, and later advocated by Relph (1968). This classification divides the schemes into
four categories based on the perceived action, or effect, of each. For instance:
1. Compensatory measures
a) Flood relief b) Flood insurance
2. Corrective measures (temporary) a) Flood forecasting b) Emergency action c) Structural alterations
3. Corrective measures (permanent)
a) Flood control b) Flood abatement
4. Preventive measures
a) Floodplain development and regulation
In this classification, compensatory measures include those schemes which rely on
the recoupment of losses after the flood event. Corrective actions aim to reduce the flooding
and are subdivided into temporary and permanent measures. Preventive measures involve
the reduction of flood losses by altering human activity rather than the physical forces of
flooding. Other classifications based on slightly different criteria have been put forward. For
example, Leopold and Maddock (1954) divided schemes into administrative, engineering
and land-control types, while other classifications have been based on the scale of the
adjustment.
For the purpose of this study, the adjustments have been classified into two broad
groups according to the degree of flood control which is exerted, mainly through
engineering works or other physical methods – namely A) Structural adjustment and B)
Non-Structural adjustment. Structural schemes include the whole range of engineering
adjustments from localised river training works to the large-scale construction of
embankments and flood-control reservoirs. Other structural measures include flood
85
abatement through land-use manipulation and some permanent flood-proofing techniques.
The non-structural or behavioural group of schemes generally requires a greater
involvement of the floodplain inhabitants and extends from the more passive use of loss-
bearing and public relief funds to the more active policies of flood insurance, flood warning
and floodplain zoning. As with most other classifications, certain problems arise. For
example, flood-proofing measures, which are conventionally taken together, have been split
between the two categories depending on whether they are permanent, and involve some
structural alterations, or whether they are temporary and occur in response to a flood
warning. However, this classification is considered useful because it reflects the trend in
recent years from isolated structural measures towards more varied methods. These later
strategies have frequently involved more than one flood alleviation scheme, and are
increasingly incorporating non-structural measures, such as flood-warning schemes and
insurance policies, in a more flexible approach to the problem.
There are three reasons for this change in emphasis towards non-structural measures.
Firstly, the failure of old structural adjustments effectively to reduce flood losses has
brought about a reappraisal of floodplain policies and a search for ‘new’ adjustments.
Secondly, the expenses of large scale-structural measures are relatively cheap to set up and
operate. Finally, the improved technology of recent years has greatly enhanced the
efficiency and reliability of certain non-structural measures are relatively cheap to set up and
operate. Finally, the improved technology of recent years has greatly enhanced the
efficiency and reliability of certain non-structural measures, such as flood forecasting and
warning schemes.
The social and behavioural aspects of flooding have probably always been an
underestimated element of efficient hazard response. However, the recent trend towards
non-structural adjustments, either alone or in combination with structural measures, has
placed a new importance on this dimension. The assumed behaviour of floodplain residents
is now an integral part of the operation many flood alleviation schemes and the actual
behavioural patterns require a more complete understanding than currently exists if flood
losses are to be successfully reduced in the future. It is an underlying premise of this book
that society’s present failure to contain floods is mainly attributable to the lack of
sufficiently broad ecological approach. In other words, the traditional dependence on purely
86
technical assessments and engineering control strategies has ignored the essentially human
dimensions of the problem, and it is argued that future progress will have to be based on
improved social feasibility as well as on technical capability and economic viability.
Different structural and Non-structural schemes are discussed in the following.
A) Structural adjustment
Traditionally, flood problems were approached through the implementation of large-
scale structural measures designed to control the physical characteristics of the hazard. The
policy was followed to such an extent, particularly in the USA during the 1930s, that
structural measures became a synonym for flood alleviation. In practice, therefore, the
range of adjustments open to the floodplain planner tended to become restricted to those
schemes, such as dams and levee systems, which confine flood waters to certain areas.
Complete control of a flood is impractical since, without tremendous over-investment,
it is virtually impossible to provide total protection from flooding. Instead, structural
measures simply alter the frequency and magnitude of flood events. The degree of
protection offered by a structure is normally incorporated into the design and planning
stages of the project.
Structural measures can be organised into three types of scheme ; (1) Engineering
schemes, which depend on specific control works constructed on a variety of scales ; (2)
Abatement policies, which attempt to control floods by land-use management during the
upland catchment phase of runoff ; (3) Flood proofing schemes, which offer protection to
individual buildings on the floodplain.
1. Engineering Schemes
a) Flood embankments and levee systems
Flood embankments and levee systems are designed to restrict water to well-defined
limits on the floodplain by the construction of artificial banks, as shown in Fig. This
adjustment allows controlled flooding of certain areas and provides relative safety for those
areas outside the flood-bank system. However, as with all structural measures, levees do not
completely eliminate flooding, since protection is limited to the design standards of the
87
project. Nevertheless, the relative cheapness of such schemes has made this measure very
popular, and genuine protection may usually be offered up to the design limits.
Despite the definite advantages of flood embankments, there are several limitations
to such measures. First, there may be ‘rights of way’ problems. For instance, a proposed
levee system in a city could conceivably run through many different properties, and it would
probably require considerable legal discussion with various owners before the scheme could
be approved. A second problem involves the technical aspects of project design and the
appropriate degree of protection to be offered. To a certain extent these issues will be
resolved by feasibility studies, but the general lack of hydrological data and knowledge of
previous flood limits may make calculation of the design standards somewhat arbitrary.
Following the construction of the embankment system, the problem emerges of finding a use
for the land still prone to flooding. Ideally, this land should be devoted to uses not seriously
affected by flooding. Ideally, this land should be devoted to uses not seriously affected by
flooding, such as car parking or recreational facilities, although in many urban centres this is
not always possible. Finally, flood banks must be regularly maintained to preserve design
standards of protection, particularly if they are made of a soft material such as earth.
b) Channel enlargement
The second structural adjustment, channel enlargement, is designed to control
flooding by confining the excess water to the channel system. The principle is to increase
the carrying capacity of the river by enlarging the channel cross-sectional area through the
zone to be protected, so that flood flows remain within the channel system. This adjustment,
like the flood embankments, is comparatively cheap and is particularly valuable in areas of
fairly intensive urban development where there may be a premium on land.
However, there are also some drawbacks to this measure. As with the levee system,
the channel enlargements may actively encourage development on the floodplain by crating
a false sense of security well above the design capabilities of the scheme. Again, this could
eventually lead to an increase in flood losses. A second problem concerns the maintenance
of the full effectiveness of the project, since such channels are frequently prone to silting.
When a channel is enlarged, the undersized stream will tend to deposit sediment on the
channel floor, and thereby progressively reduce the efficiency of the scheme below the
88
original design standards. Unless regular dredging takes place to counteract this process, the
scheme will eventually have little effect on high river floods.
One further disadvantage of channel enlargements is the effect on the timing of the
river, and the repercussion on communities downstream of the scheme. By increasing the
carrying capacity of the river, the roughness of the stream will also be reduced. As a result,
flood flows are transmitted more rapidly downstream where other communities may suffer
more frequent, or more devastating, flooding than before.
c) Flood relief channels
This scheme works on the principle of controlling flood flows by the use of a series
of channels, in addition to the natural channel, in order to store flood water and thereby
prevent the inundation of surrounding areas. The main advantage of this approach is that the
natural channel is not altered in any way that could be detrimental to the community, whilst
the construction of the relief channels is relatively cheap and easy, particularly if there are
no serious problems over land-ownership. The particular adjustment is most valuable in
rather flat lowland areas, where there would be wide-spread inundation and difficult
drainage problems without a channelised system of alleviation. It may not always be
possible to protect very large settlements in this way, but nevertheless, there are many
examples of settlements being protected by flood-relief channels.
The disadvantages of flood-relief channels are much the same as for levee systems
and channel enlargements, although in this case there is no problem of silting in the main
channel because normal flows are preserved. An additional problem encountered
specifically with relief channels is that of water management.
d) Intercepting or cut-off channels
Intercepting or cut-off channels are very similar in both construction and an
objective to flood-relief channels, except that most of the permanent river flow is diverted
into the artificial channels, while the natural channels are used only during more extreme
flood events (Fig.). The advantages and disadvantages of this approach are very similar to
those of relief channels, although a further criticism could concern the interference with the
natural channel.
89
e) Flood-storage reservoirs
The construction of dams and reservoirs as a means of managing water resources
has been employed for a very long time. For example, the ‘tank’ reservoirs of Sri Lanka date
from the third century BC, while larger structures have been found in North Africa and
follow the Roman occupation. Smith (1971) quoted examples in South America, including
those of the Aztecs constructed in the fifteenth century. In Europe, Leonardo da Vinci
suggested similar structures for the protection of Florence from flood control in Europe was
probably that at Pinay on the Loire in France, constructed during the early part of the
eighteenth century (Hoyt and Langbein, 1955). According to the same authors, the first
flood-storage reservoir in the USA was initiated by the Miami Conservancy District
following a disastrous flood in 1913.
Flood storage reservoirs work on the principle of partial flood control whereby
excess water is stored in the upper reaches of the catchment. Then, by careful regulation of
the hydrological system, the water is gradually released to protect the downstream
floodplain, as shown in Fig. The advantages of this adjustment are considerable. For
example, the floodplain inhabitant should have complete security from riverine floods up to
the design standards of the structure, while the downstream environment will remain
virtually unchanged. The structure will also have a relatively long life-span. However, there
are also several disadvantages associated with such a flood policy. To being with there is the
problem of finance, since the implementation of a dam is expensive, and the benefits to be
gained from flood protection may not warrant such a major undertaking. In addition,
reservoirs require large areas of land. Linsley and Franzini (1972) indicated that, for
effective flood alleviation, at least one-third of the total drainage basin should be under
reservoir control and it has been claimed by Hewlett and Nutter (1969) that, in the USA,
some 2 million hectares of land have been flooded in order to protect about 5.2 million
hectares downstream.
Once a reservoir has been constructed there may well be further problems. Like the
levee system, the reservoir is designed to control flooding only up to certain design limits,
and yet frequently the popular belief is in a complete elimination of the flood risk. If this
90
belief generates additional investment in the floodplain, then more property may be at risk
after the implementation of the scheme than before.
Another problem is that of silt accumulation. The very nature of reservoirs means
that they are particularly prone to silting, which can significantly reduce the effectiveness of
the dam in alleviating floods. Thus, Kazmann (1972) pointed out that up to one – eighth of
the storage assigned to flood control in some American reservoirs had been lost in the last
50 years. A specific example quoted was the Elephant-Butte Dam, which had lost 10 per
cent of its reservoir area and 16 per cent of its storage capacity in the 20 years up to 1957.
A further problem of flood-storage reservoirs concerns the operation of the scheme
in relation to water management. In order to operate the scheme successfully there must be
careful administration of the reservoir to ensure that water levels are drawn – down
sufficiently to cope with the next major storm. These operational problems are even greater
if the reservoir has been designed for more than one purpose. For instance, a flood-control
reservoir may incorporate some degree of water supply or power generation. These
multipurpose systems have developed primarily for economic reasons, because the benefits
accruing from the construction of a dam for one aspect alone were frequently insufficient to
warrant investment in the scheme. Unfortunately, multipurpose reservoirs tend to promote
conflicting priorities. For example, a major conflict arises between flood control operation
and water supply or power generation strategy when all are incorporated within the same
scheme. Flood control policies require the reservoir to be drawn-down to the lowest possible
level at all times, while water supply and power generation require the direct opposite.
Despite such conflicting interests, many multipurpose dams and reservoirs have been
constructed, incorporating such widely different uses as flood control, water supply, power
generation, irrigation facilities and recreational schemes.
91
f) Washland schemes
The washland method is essentially another form of water storage that reduces the
spatial extent of flooding by retaining peak flows in controlled areas. The scheme
incorporate a combination of the levee system and storage reservoir, since it works by
allowing the controlled flooding of certain areas, usually delimited by levee structures, and
holding water in 'washland’ zones until the flood peak subsides. This scheme is most
suitable for agricultural areas since, as shown in Fig., considerable redevelopment of the
urban fabric may be necessary in towns. However, the method can be useful for the smaller
floods.
There are some problems associated with the utilisation of washland areas. For
instance, the scheme requires large areas of flat land for storage, and although these may be
rented out to local farmers, there can be very little guaranteed economic return from them.
Also, washland schemes require careful river management if the maximum security is to be
obtained.
2) Flood Abatement Schemes
The second group of so-called structural adjustments to the flood hazard does not
depend on engineering technology. Instead, the basic aim of abatement policy is to reduce
flood peaks downstream, by a series of land-use changes upstream, so that the volume of
runoff and the timing of the flood hydrograph are altered. This is usually achieved by
retarding the flow of water during the land-to-channel runoff phase. Suggested changes
normally include forestation, which will not only delay water movement, but through
additional interception and evapo-transpiration will also ‘lose’ more water to the
atmosphere.
Not all workers agree about the effectiveness of flood abatement policies.
Crawford (1969), for example, claimed that any changes in land use would have to be very
extensive to have any significant effect on catchment hydrology, whereas Matson et. Al.
(1955) believed that forestry could effectively reduce runoff. Molchanov (1960) agreed that
forestry would alter stream hydrographs and reduce runoff, although he questioned the
effectiveness of such measures in particular geological and climatic conditions. Other
workers have made studies of the effects of forestry on runoff and, although most concluded
92
that forestry would change the flood hydrograph, they questioned the practicality of
abatement as a flood alleviation policy (Fleming, 1973 ; Law, 1956 ; Worly and Patric,
1971). On the other hand, Hoyt and Langbein (1955) described the case of White Hollow in
the Tennessee Valley Authority area where, during a twelve year period of active forestation
(1935-47), the flood hydrograph was altered so that flood peaks were reduced by 85 per cent
and lag time increased from 11/2 hours to 8 hours. No significant difference was found in the
volume of total runoff. In practice, there are very few examples of directly and deliberately
implemented flood abatement schemes and this may well examples of directly and
deliberately implemented flood abatement schemes and this may well explain why so much
controversy surrounds the policy. Overall, it would appear that flood abatement could be an
effective method of alleviating flood losses, but would require such large tract of land that it
is not a feasible proposition in all catchments. A useful review of flood abatement measures
in the USA and elsewhere has been presented by Ward (1978).
3. Flood Proofing Measures
Flood-proofing measures are neither entirely structural nor non-structural, and the
strategy has only recently been accepted as a viable alternative to the more conventional
alleviation schemes. In essence, flood proofing consists of adjustments to building
structures, and the contents of buildings, designed to reduce flood damage. These measures
can be either temporary or permanent.
Temporary measures include the blocking-up of seldom–used entrances to
buildings, the stocking of suitable shields to be placed in position of doors and windows
prior to a flood and the use of heavy sliding doors to product other entrances. Further
interior adjustments may include the greasing and covering of mechanical equipment prior
to a floor or the use of flood – prone areas of storing non-damageable goods. Although this
list is virtually endless, the effectiveness of all these measures relies entirely on the
individual house owner or factory manager being aware of the flood hazard and in his
receiving a flood warning so that such schemes can be implemented.
Permanent flood-proofing measures do not necessarily depend on the receipt of a
flood warning and include more structural alterations such as the raising of buildings above
the flood level, the permanent use of lower storage for car parks, or the inclusion of
93
pumping facilities in basements. Sheaffer (1967) even suggested in some circumstances the
intentional flooding of basements by clean water. In this way structural damage to the
building is prevented by the equalisation of pressure inside and out, and the basement does
not suffer from deposits of sediment, oil or sewage. Permanent flood-proofing measures can
be quite effective in reducing flood losses and are relatively cheap to install. They also
permit the building to continue functioning throughout the flood. Relph (1968) calculated to
potential efficiency of flood-proofing measures to be as high as 80 per cent in ideal
conditions and estimated that they could save up to 30 per cent of losses in less ideal
conditions. Jones (1971) also stressed the value of flood-proofing measures, even where the
probability of flooding was quite low.
However, there are several disadvantages with flood-proofing measures and local
conditions can significantly alter the effectiveness of certain measures. For example, flood
proofing tends to be less effective in high, fast-flowing floods of long duration than in small,
slower-moving floods of short duration (Sheaffer 1967). Consequently, Burton (1970) listed
six criteria for ideal flood-proofing conditions. These were where:
a) flood stage is fairly low and velocities not very high ; b) dams and dykes are not really feasible ; c) group action is not really possible and strong individual action can be encouraged ; d) groups shun government action and advice ; e) activities requiring sites need protection ; f) resource managers feel greater protection is required. B) Non-structural adjustment
The non-structural range of adjustments to the flood hazard is less well known than
the structural measures, although in recent years some of these measures have become much
more familiar. This situation has arisen for a variety of reasons. In some cases technological
improvements have made certain schemes more efficient, for example, flood-warning
systems. However, one of the prime reasons for this general trend is probably the inhibiting
cost of implementing large-scale structural alleviation schemes.
Non-structural measures are essentially behavioural adjustments, which rely on some
form of pre-planned action by floodplain residents prior to a flood. While some of these
94
measures amount to little more than a negative attitude to the flood hazard, others require
sophisticated responses in order.
1) Loss-bearing
Loss-bearing, or simply accepting the losses accruing from flooding, is probably the
most negative of all responses to flooding. No attempt is made by the people at risk to adjust
to the hazard, except to replace lost or damaged goods following a flood event. In theory,
this response could well be economically acceptable in rude benefit-cost terms, compared
with other measures of alleviating flood losses. However, this attitude is generally deemed
socially unacceptable, because the majority of people or commercial enterprises may have
little choice on site location and are exposed to psychological stress as a result of the hazard.
Equally, some members of the community may be unable to afford to replace their
possessions. This adjustment is found frequently in rural areas where other flood alleviation
schemes would be difficult to justify.
2) Public Relief Fund
Public relief, if relied on as a means of alleviating flood losses, is merely an
extension of the loss-bearing attitudes described above. In this case people in flood-prone
areas may come to expect, as a right, both financial aid and other types of support following
a flood. As a result, they may do very little to prevent future flood losses. Nevertheless,
following most floods, relief funds are set up by the local authorities in the affected area.
Relief funds are particularly beneficial to those individuals who could not themselves
afford to replace damaged property. Another advantage of this adjustment is that such
money collected is often roughly proportional to the scale of the disaster. For example, small
local flood events will attract aid from the immediate vicinity, whereas a major catastrophe
will generate financial support on a national, or even international, level.
3) Flood Insurance
This response to the flood hazard does not reduce flood losses, nor does it have any
effect on the flood characteristics. Instead, flood insurance allows the payment of the flood
losses to be made over period of years, rather than all at one time. Because of these apparent
95
limitations the Tennessee Valley Authority, in classifying alleviation schemes, placed flood
insurance in the compensatory division.
Traditionally, flooding was considered to be a high risk by insurance companies,
largely because of the apparently random nature of the event, and some companies have
been bankrupted by floods. Thus, Hoyt and Langbein (1955) cited the short-lived case of a
private company which was established after the Mississippi floods of 1895 and 1896, only
to collapse following the flood of 1899. More recently, improvements in flood prediction
techniques have made insurance a more efficient form of flood alleviation. Insurance
premiums can now more accurately reflect the potential damage, premium rates may have to
be a little higher to cover administrative costs, but even this difficulty could be overcome by
government support to the insurance companies.
4) Floodplain zoning
Floodplain zoning aims at reducing flood losses by controlling floodplain
development, rather than altering the hydrological characteristics in any way. The ideal form
of zoning would be evacuate the floodplain completely and return the land to its natural
state. For most areas this would be a highly impractical solution, involving high costs and
attendant social difficulties. Thus, the American Corps of Engineers have shown that the
costs of evacuation would generally outweigh benefits, with the most expensive item being
the provision of services at the new centre (Hertzler, 1961). Liebman (1973) also mentioned
the legal problems associated with such policies.
Alternatively, there have been numerous suggestions that floodplains should be
divided into distinct zones, each restricted to well-defined uses. For example, Murphy
former was defined as the river channel and such adjoining areas which were required to be
left clear for the safe passage of a flood of pre-determined magnitude, whilst the floodway
fringe was seen as the remainder of the floodplain and subject to land-use regulation. This
idea was refined by Kates and White (1961) who put forward a three-zone division, as
indicated in Fig. This plan include :
1. A prohibitive zone – where there should be no further development, except for essential
waterfront facilities.
96
2. A restrictive zone – where only certain essential development should be permitted.
3. A warning zone – where the inhabitants should receive warning of impending floods and
be regularly reminded of the flood hazard.
These zones were to be based on different degrees of flood risk assessed on the
return periods of particular flood levels.
5) Flood forecasting and warning schemes work
Flood forecasting and warning schemes work on the principle of reducing flood
losses through remedial action by floodplain residents and businessmen prior to a flood.
Mileti and Krane (1973), in a review of all hazard warning schemes, defined these
three sequential stages as (a) Evaluation, (b) Dissemination, and (c) Response.
(a) Evaluation
This is the first stage in any flood-warning system and involves the comprehension of
hydrological and meteorological process so that a suitable warning message may be
formulated. Naturally, this requires a full understanding of the hydrological response of a
catchment to a given input so that accurate forecasts can be made of the time of arrival of
the flood, the depth of the flood at its peak, as well as other characteristics such as duration
of flooding or velocity of flows. Flood forecasts are normally based on either the effect of a
given input of precipitation on the river flow, or on the relationship between river levels
throughout the hydrological system. The latter method, known as flood routing, generally
provides the more accurate warnings because relationships are more easily established
between upstream and downstream river flows than between precipitation and flows.
However, precipitation-based schemes can provide much earlier warnings which, in areas of
highly responsive rivers, may be the only way of giving several hours of flood warning.
b) Dissemination
The second stage in flood forecasting and warning systems has received less
attention in the past then evaluation stage and, as a result, many schemes have been less
effective than anticipated. Clearly, an efficient method of spreading a flood warning among
97
all flood plain residents and businessman is essential if time for effective remedial action is
to be allowed.
c) Response
The final sub-system, response to the warning message, has been almost totally
ignored by the authorities until recently, on the assumption that floodplain inhabitants would
always react in a rational manner to reduce flood losses. However, evidence from various
studies (Kates, 1962; White, 1964; James, 1974) now suggests that this assumption is
unjustified.
Originally, flood forecasting was very primitive and warnings were dependent either
on local knowledge of the hydrological conditions or on the personal decisions of a man
leaving near the upper reaches of the river riding down the valley to warn others of the
impending disaster. With the advent of the telegraph, flood forecasting was transformed into
a more efficient response, since warning message could then be transmitted further in
advance of the approaching flood, thus lengthening warning times. As a result, several
official warning schemes were developed in the second half of the nineteenth century. In
1854, for example, such a scheme provided three days’ warning of flooding on the Seine in
France. By 1866 similar projects were operating in Italy and Bohemia and, by 1871, had
reached the USA (Hyot and Langbein, 1955).
Flood forecasting and warning systems continued to develop from that time, helped
by other improvements in communications such as the telephone and radio, and by advances
in data-collection equipment. Rain and river-level gauges gradually became more
sophisticated instruments, which could record data over longer periods and also provide
information from relatively inaccessible places, thereby improving the understanding of the
hydrological system. The innovation of telemetry gauges for rainfall and river levels in the
1960s finally made flood forecasting an important alleviation measure.
A more recent advance in flood forecasting occurred with the provision of self-
operating flood-warning gauges. These are an extension of telemetry gauges and such
devices can activate a flood warning if any of the pre-set conditions are reached. This type
of warning scheme has tremendous advantages over other systems, since it can maintain
continuous surveillance and will automatically issue a flood alert immediately there is any
98
danger. Computers have now been adapted for this scheme, so that large volumes of data
can be analysed quickly and efficiently, thus adding to the effectiveness of the scheme. The
use of satellites is also a valuable asset to flood forecasting.
6) Weather modification
Weather modification has yet to be tried on an operational basis as a means of
alleviating flooding, although such measures have been employed to aid water supply and
to suppress hail damage in many countries. The most widespread form of weather
modification at present relies on the seeding of clouds to encourage precipitation to fall in
certain areas rather than others. As a result, this technique represents a new alleviation
scheme with possible potential for floodplain planer. However, Haas (1970) stressed the
dangers of weather modification without a full consideration of all the complex
consequences, although Farhar (1974) carried out a study into the social implications of
weather modification and found opinions generally favourable. This was after a major flood
in Rapid City, South Dakota, had been proceeding by cloud-seeding to prevent hail damage
to crops. On the other hand, the whole methodology is highly controversial, as indicated by
Sewell et al (1973).
4.5 Global strategies: Flood Management Policies in Different Countries
In the early 20th century, floods were studied in the context of the physical sciences.
Now they have become an important sub-field of natural disaster studies. One early attempt
to study flood damage dates back to the Ohio River flood in 1913. However, the first
theoretical study on human reaction to flood disaster was the seminal work of Gilbert White,
“Human Adjustment to Flood”, published in 1945, Which was the first to study flood
perception in the light of mitigation needs (Marincioni, 2001).
In the following paragraphs flood management strategies from few developed and
developing countries are discussed- ( Bruen,M , Gebre,A.F. ,2001 )
99
4.5.1 Flood management strategies from few Developed Countries
In the developed countries structural measures have been used widely to alleviate
floods, which include dams, dykes, diversions such as waterways and bypasses, and channel
improvements etc. If we observe the flood management strategies of these advanced
countries we will find that several non-structural or behavioural group of schemes which
include flood monitoring and forecasting using modern telecommunication technologies and
internet ,flood relief and assistance, flood insurance, flood warning, public awareness
programme etc.In these countries various institution, agencies are working on the flood
mitigation assistance program which include pre-disaster mitigation, emergency program
and post disaster programme, nation-wide training program on emergency management
practices such as mitigation, preparedness, response and recovery. The basic feature of
flood management practices of these countries were for a long time was much dependence
on implementation of large-scale structural measures designed to control the physical
characteristics of the hazard. The policy was followed to such an extent that structural
measures became a synonym for flood alleviation. However, in recent years trend towards
non-structural adjustments which are essentially behavioural adjustments, either alone or in
combination with structural measures, has placed a new importance. In this regards, it
should be remembered that these countries are characterized by low population density,
high GDP in Tertiary and Quaternary sectors, high literacy rate and having good ranks in
Human Development Index.
4.5.1.1 : CANADA
Flooding is the number one natural disaster in terms of property damage in Canada.
Like every other country, Canada has been using structural and non-structural measures to
alleviate floods, which include dams, dykes, diversions such as waterways and bypasses,
and channel improvements. Responsibility in Canada for mitigating the physical effects of
flood hazards is spread among seven groups – the federal government (research), joint
federal-provincial arrangements (on reducing flood damage), the provinces (flood mitigation
and setting construction standards), municipal authorities (flood mitigation and enforcing
building standards), public institutions (research), the insurance industry (promoting
100
mitigation), and individual homeowners (private mitigation efforts) (ESA). Environment
Canada is the large governmental department responsible for monitoring and protecting the
environment including natural hazards. Environment Canada (EC) advises provides
forecasts and warnings to the general public on weather, flood and ice. EC has a flood
Damage Reduction Programme (FDRP), which its goal is to discourage development in
high-risk floodplains through flood mapping agreement and public education or non-
structural means of flood control. In each designated area Provincial and Federal
government agreed not to build, approve or finance inappropriate development, not to
provide flood disaster assistance for development after the designation as flood-prone. And
it is also agreed that the provincial authorities to encourage local authorities to zone on the
basis of flood risk (EC 2000, ESA 2001). Emergency Preparedness Canada (EPC), in co-
operation with the provinces, has responsibilities of advancing the state of civil emergency
planning in Canada; providing financial programs for the attainment of a uniform standard
of national preparedness; alleviating the costs of post-disaster recovery; and administering.
There is neither private nor government flood insurance available (CPCU), though it is
beginning to strengthen its role (EC). However, government programs such as the EPC and
Disaster Financial Assistance Arrangements (DFAA) provide relatively generous disaster
relief due to flooding (CPCU 2001).
4.5.1.2 :USA
The Federal Emergency Management Agency (FEMA), an independent agency
reporting to the President, is the government body responsible for emergency including
flood risk management, programme of mitigation, preparedness, response and recovery in
the US. There is National Flood Insurance Program (NFIP) which is managed by the
FEMA’s Federal Insurance Administration and Mitigation Directorate. FEMA has also
National Mitigation Strategy that sets forth-major initiatives in areas of hazard identification
and risk assessment; applied research and technology transfer; public awareness, training
and education; incentives and resources; and leadership and co-ordination.
NFIP offers federally backed flood insurance available to communities that agree to
adopt and enforce floodplain management ordinances. Therefore, its operating expenses and
101
flood insurance claims are not paid for by the taxpayer but through premiums collected for
flood insurance policies. NFIP also delivers building standards, credits and grants to
community flood mitigation planning projects. The Flood Mitigation Assistance Program is
a pre-disaster mitigation program created by the National Flood Insurance Reform Act on
1994. This program provides both project and planning grants annually for flood hazard
mitigation planning and projects with direct demonstrable benefits to the NFIP insurance
fund.
4.5.1.3 : IRELAND
Ireland’s risk in the area of natural disasters is those caused by "extreme weather",
such as flooding. Flooding is caused by excessive rainfall combined with insufficient
capacity to convey the water without overflowing the watercourses. The government has set
up a flood relief programme and arterial drainage maintenance, operated through the
Engineering Services of the Office of Public Works (part of the Department of the
Environment and Local Government), which designs, constructs and maintains flood relief
and drainage works and river engineering generally. It has a nation-wide infrastructure of
staff and facilities and is well placed to respond to national and local demands. The services
department also provides advice on flood related matters to local authorities throughout the
country and to private sector engineering consultants.
In relation to flood monitoring and forecasting, the Environmental Protection
Agency (EPA) is responsible for the implementation and co-ordination of the national
hydrometric programme. The purpose of the programme is to collect information on the
levels, volumes and flows of water in the rivers, lakes and groundwater of the State. This
assists in providing comprehensive and integrated water resources data system for
management, development and environmental protection purposes. The network of some
1200 gauging stations on rivers and lakes are operated mainly by the Office of Public Works
and the Local Authorities. In addition to the coordinating activity, the EPA also processes
the collected data and undertakes calibration checks and spot checks to verify the reliability
of the data.
102
4.5.1.4 : UNITED KINGDOM
The Department for Environment, Food & Rural Affairs (DEFRA), (formerly
Ministry of Agriculture, Fisheries and Food), with the Welsh Office, has overall policy
responsibility for flood defense and coastal protection in England and Wales. In Scotland,
the Scottish Office shares some of these responsibilities and acts through the Scottish
Environmental Protection Agency. DEFRA gives financial support to flood and coastal
defense operating authorities; publishes advice and guidance for the operating authorities to
encourage proper consideration of technical, economic and environmental issues when flood
and coastal defense schemes are being planned, designed and implemented. DEFRA also
funds research programmes aimed at improving understanding of the natural processes
involved in flooding and coastal erosion, examining techniques for the design and
management of defenses, and furthering environmental interests.
Operational responsibility for flood defense falls to three types of operating
authority: the Environment Agency (EA), Internal Drainage Boards (IDBs) and Local
Authorities. EA supervises all matters relating to flood defense. EA also has a Flood
Warning Service and has a duty to survey matters relating to flooding, including
identification of areas where flood defence problems are likely. Local authorities are the
operating authorities for ordinary watercourses, except in internal drainage districts, where
the powers rest with IDBs. Local planning authorities are responsible for preparing
development plans and controlling development, principally in relation to location and
amenity, both in the flood plain and in river catchments.
In terms of planning flood control schemes, the design of related structures and the
impact of other developments, the standard reference has been the Flood Studies Report
produced in 1975 by the NERC (Natural Environment Research Council). This provides
forecast flood characteristic information for all catchments in the UK. Physically based and
dynamic methods for flood estimation, many of which are mentioned in the new UK Flood
Estimation Handbook, released by NERC in 1999, are used in conjunction with a new set of
flood hazard maps for operational purposes produced by the Environment Agency which
incorporate aerial imagery in some cases. Flood defenses remain the responsibility of the
103
relevant landowner unless they are adopted by the operating authorities. A large number of
flood defenses are therefore privately owned and maintained. Recently, EA has launched
public awareness campaign, mailed plastic flood kits containing practical information and
advice, and made available new national telephone information line, which provide 24 hours
flood warning information. During flood disaster emergency cases, the Environment Agency
has recently taken the lead role from the police for disseminating flood warnings. Despite
high premiums, in the UK the majority of homeowners purchase private flood insurance
packaged with storm coverage as part of the standard homeowner’s policy. No government
insurance is available, but the government, paired with various not-for-profit organisations,
can easily care for the small minority without flood insurance.
4.5.1.5 : GERMANY
The responsibility for flood prevention measures and retention areas rests at state
level with the Ministry of Transport and Environment. However, each State (Bundesland)
has its own emergency legislation, which defines the responsibilities between regional and
local level. The levels of authority involved in emergency planning and the extent to which
different authorities are involved differs from state to state. Floods of the river Rhine have
occurred almost annually since the beginning of the 1990s. The majority of the regions have
installed extensive equipment for river monitoring using modern telecommunication
technologies. Information is gathered at a central level and river level information is also
available via internet. There is information exchange between states. All State Services are
connected to the DWD, German Met Office
During crisis phase flood retention zones are managed at two levels:
1. Local rain water retention: local level (administrative counties/ county boroughs);
2. Regional retention: State level (Ministry of Transport and Environment).
In the event of flooding, a level 1 rain water retention zone can be opened with the
Mayor’s authority. For level 2 regional retention zones, special directives describe the
procedure in the event that a retention zone is flooded. For example, the directive for the
104
Rhine is based on an international co-operation agreement between Baden-Würthemberg
and the Alsace (France). The State Ministry of Transport and Environment makes the final
decision. Apart from flood forecasting, warning and information dissemination, structural
measures such as dikes, river training, diversion canals and flood retention reservoirs are
common flood protection measures in Germany.
4.5.1.6 : FRANCE
Unlike many other European countries, responsibilities are divided between two
main ministries: the Ministry of Interior for aspects related to civil protection (crisis
management) and the Ministry of Environment (and at a lesser extent the Ministry of Public
Works and Agriculture) for prevention activities.
The prevention policy defined by the French State is put into action by decentralised
services at regional or departmental levels. At national levels, the Ministry of Environment
and two of its directorates (Directorate of Water, and Directorate of Pollution and Risk
Prevention) are in charge of all the activities related to prevention, especially the setting up
of the national programme for identification and mapping of risks, and definition of
protection and prevention measures. The hydrological service is generally in charge of the
producing flood risk maps.
For flood forecasting, the operational maintenance of the data collection network and
the forecasting tasks themselves can be done either by a specific service of DIREN or,
depending on historical context, by another public service from the Ministry of Public
Works or from the Ministry of Agriculture. In crisis phase, the Directorate of Public Defense
and Safety, DDSC, (under the Ministry of Interior) ensures protection of persons, assets and
environment; manages national emergency services and co-ordinates the action of local
rescue services responsible for aid operations. Communication between various rescue units
is assured by means of radio and phone via a central unit localised at CODIS.
105
Some of the services involved, such as forecasting services, use meteorological radar
data acquired from a specific terminal (Meteotel, developed by Meteo France) via ground
phone transmissions, seldom aerial photographs.
4.5.1.7 : SOUTHAFRICA
Responsibility for disaster management including flood defense lies with provincial
and local governments. There is National disaster management centre with objectives such
as: to promote an integrated and coordinated system of disaster management, with a special
emphasis on prevention and mitigation, by national, provincial and municipal organs of
state, statutory functionaries, other role players involved in disaster management and
communities. They also have national flood policy. Recently the South African government
has established National Flood Relief Fund, to assist flood affected communities.
The University of Cape Town (1998) runs a new disaster mitigation for sustainable
livelihoods project (DiMP). DiMP works in the emerging field of disaster mitigation or risk
reduction. The work aims to minimise the impact of natural and other threats through
focused development action. DiMP's involvement in risk reduction education has included a
collaborative research and development project with the University of Natal's Department of
Adult and Community Education, as well as with partners in Lesotho, Namibia, Zambia,
Zimbabwe and the Northern Province.
4.5.2 :Flood management strategies from few Developing Countries
4.5.2.1 : CHINA
China has a long history of flood control, and an equally long history of political
intervention. Some of the earliest Chinese efforts to tame rivers date as far back as 2200 BC,
when the Great Emperor Yu was credited with saying, "Whoever controls the Yellow River
controls China." Floods occur regularly in southern China, especially during the monsoon
season from June through September. In 1998, the government formulated a National
Disaster Reduction Plan with the objectives of developing structural measures, popularising
the application of scientific and technical methods, raising public awareness and establishing
106
a comprehensive operating mechanism for disaster reduction work. There is some legal
background in the “Flood Prevention Law of the Peoples Republic of China”. The
government has recently approved the formation of China National Centre for National
Disaster Reduction. The Chinese also uses structural measures to prevent and control floods,
such as the recent Three-Gorge Project on the Yangtze River and the Xiaolongdi Project on
the Yellow River. They have also built at least 319 large dams and 2252 medium sized dams
in the last century. Departments within the Ministry of water resources are directly or
indirectly responsible for such schemes.
4.5.2.2: BANGLADESH
Flooding is a fact of life to the people of Bangladesh and they demonstrate great
resilience and skill in coping with it. Very little part of the country is more than 20m above
sea level, and apart from a few small hills in the North and Southeast, the country is totally
flat.
In Bangladesh, a country hugely vulnerable to floods, attitudes to floods and flood-
prone areas are not as lucid as some experts often believe (Fordham M., 1998). In a study
conducted to see how the views on flooding differ within communities, the result showed
that the farmers were least concerned of all. For them, floods were part of life, which they
learned to adjust to, and they knew the easy accessibility of floodplain sites, and the benefits
that floods bring in terms of fertility, and moisture content to the soil (Thomas, 1997,
Marincioni, 2001).
During the major floods to hit the country, in the summer of 1998, the benefits from
flood risk and environment were seen to be in some kind of balance (Fordham, M., 1998).
Training and public awareness buildings are the major components of its non-structural
disaster prevention and mitigation programme. The National Disaster Management Council
is responsible for formulating and reviewing disaster management policies and for issuing
relevant directives.
Under the Ministry of Disaster Management and Relief, the Disaster Management
Bureau is engaged in developing national disaster plans and guidelines and ensures early
107
warnings, information dissemination among the public. Early warnings and flood forecasts
are issued from the Storm Warning Centre and Flood Forecasting and Warning Centre.
Development planners do have also to produce appropriate physical plans for flood-prone
areas. New highways in flood-prone areas are designed to remain open during floods.
4.6 INDIA :Flood Management Programmes
In India, systematic planning for flood management commenced with the Five Year
Plans, particularly with the launching of National Programme of Flood Management in
1954. During the last 45 years, different methods of flood protection structural as well as
non-structural have been adopted in different states depending upon the nature of the
problem and local conditions. Structural measures include storage reservoirs, flood
embankments, drainage channels, anti-erosion works, channel improvement works,
detention basins etc. and non-structural measures include flood forecasting, flood plain
zoning, flood proofing, disaster preparedness etc.
The various flood management measures undertaken through the successive five
year plans are summarized below.
Table-4.16: Flood management measures undertaken through the successive five year plans
1. Flood embankments 34397.6 1 km 2. Drainage channels 51317.50 km 3. Towns protection works 2400 Nos. 4. Villages raised 4721Nos.
Source: Ministry of Water Resources (http://mowr.gov.in)
In West Bengal, reservoirs constructed with exclusive flood control storage include
Maithon, Panchet, Tilaiya and Konar in Damodar Valley; Chandil dam on Subarnarekha
River and Rengali dam on Brahmani River. In addition, a live storage of 177 billion cubic
metres created so far in the various reservoirs for irrigation, hydropower generation,
drinking water etc. also help in reducing flood intensity by storing part of the flood waters in
them.
108
The flood management measures undertaken so far have provided reasonable degree
of protection to an area of 15.81 million hectares through out the country. State-wise break-
up of the achievement in flood management is as below: -
Table-4.17: State-wise Physical Achievement of Works under Flood
Management(2000)
Sl. No.
State/ UT's Length of Embank- ment (km)
Length of drainage channels (km)
Towns/ Village Protection Works (Nos.)
Village raised/ Protected (Nos.)
Area benefitted In million (M.ha.)
1. Andhra Pradesh 2100 13569 68 21 0.54 2. Arunachal Pradesh 2 - - - - 3. Assam 4454 851 660 - 1.6357 4. Bihar 3454 365 47 - 2.949 5. Goa 10 12 4 6 0.0001 6. Gujarat 104.12 271 805 30 0.4827 7. Haryana 1144 4385 448 98 2.0 8. Himachal Pradesh 58 11 - - 0.0097 9. Jammu & Kashmir 230 14 12 5 0.2173 10. Karnataka - - - - 0.0008 11. Kerala 116.7 29 4 6 0.0555 12. Madhya Pradesh 26 - 37 - 0.0040 13. Maharashtra 26 - 26 - 0.0010 14. Manipur 360 126 1 1 0.130 15. Meghalaya 112 - 8 2 0.0011 16. Mizoram 1 1 - - - 17. Nagaland - - - - - 18. Orissa 6515 131 14 29 0.4800 19. Punjab 1370 6622 3 - 3.19 20. Rajasthan 145 197 25 - 0.0816 21. Sikkim 7 12 6 - 0.002 22. Tamil Nadu 87 19 46 4 0.1220 23. Tripura 133.30 94 11 - 0.0251 24. Uttar Pradesh 2681 3593 64 4511 1.599 25. West Bengal 10350 7129 48 - 2.2005 26. A&N Island - - - - -
109
27. Chandigarh - - - - - 28. Dadra & Nagar
Haveli - - - - -
29. Daman & Diu - - - - - 30. Delhi 83 453 - - 0.0780 31. Lakshadweep - - - - - 32. Pondicherry 61 20 - - 0.004
Source: Ministry of Water Resources (http://mowr.gov.in)
4.6.1 Important Flood Management Policies of India After the unexpected heavy floods in 1954, the Government of India took several
steps to constitute a number of committees to study flood problems in India. Some important ones are: Policy statement (1954). High level committee on flood (1957). Policy statement (1958). Ministerial committee on flood control (1964). Ministers committee on floods and flood relief (1972). Working groups on flood control for five year plans. Rashtriya Barh Ayog (1980). National water policy (1987). National commission for integrated water resource development plan (1996) Regional task forces (1996). National Water Policy (2002)
The above mentioned commissions on flood have given valuable recommendations
on different aspects of flood management. Many of the recommendations are applied in the
field in India. However, some of these are not accepted by various agencies. In addition, it is
also observed that some of the recommendations are not effective in Indian context
The Damodar Valley Corporation Act No. XIV Of 1948,was an important attempt in
flood management policies of India after Independence which provide the establishment
and regulation of a Corporation for the development of the Damodar Valley in the provinces
of Bihar and West Bengal. The Damodar Valley has been ravaged frequently by floods of
varying intensities. As a result, the Governor of Bengal appointed a Board of Inquiry headed
by the Maharaja of Burdwan and the noted physicist Dr. Meghnad Saha as member. In their
report, the Board suggested creation of an authority similar to the Tennessee Valley
110
Authority (TVA) of United States of America. The Government of India then appointed Mr.
W.L. Voorduin, a senior engineer of the TVA to make recommendations for comprehensive
development of the valley. Accordingly, in August, 1944, Mr. Voorduin submitted his
"Preliminary Memorandum” where he suggested a multipurpose development plan
designed for achieving flood control, irrigation, power generation and navigation in the
Damodar Valley .By April 1947, full agreement was practically reached between the three
Governments of Central, Bengal and Bihar on the implementation of the scheme and in
March 1948, the Damodar Valley Corporation Act (Act No. XIV of 1948) was passed by the
Central Legislature, requiring the three governments – the Central Government and the State
Governments of West Bengal and Bihar (now Jharkhand) to participate jointly for the
purpose of building the Damodar Valley Corporation.
Four main strategies have been adopted over the years. These are 1) modification of
floods, 2) modification of susceptibility to floods, 3) modification of the loss burden, and 4)
bearing the loss.
The first policy statement on floods in India was made in 1954 following severe
floods. After independence The High Level Committee on Floods in July 1957 made a firm
declaration in the Parliament that country will do all that is possible to curb and confine
floods more and more. The committee pointed out that absolute immunity from flood
damage is not physically attainable by known methods of flood control. It was
recommended that flood plain zoning, flood forecasting and warning be given priority.
Massive programme of structural measures with the construction of dams and reservoirs
were taken up with flood control as one of the major objectives. With the adoption of this
latest technology the superiority of science over nature was supposed to have been
established. But because of predictable pattern of rainfall, the flood moderation through
reservoir detention and its releases failed to achieve the desired level of objective. The
limitation of structural intervention was compounded by another important social factor. The
dichotomy of interest between people affected by submergence of lands due to reservoirs
and that of people of the benefited area came to surface. This conflict has come up sharply
into focus in recent times. With these factors new tension was added in the parlance of flood
-'the reservoir release, a cause of flood'. The different reservoir releases during
111
monsoon months suddenly came to the forefront as a dominant issue of flood and at
times even replacing the extreme adverse natural causes. All these relevant factors and
recent experiences of other countries induced changes at policy decision level. Thereafter, a
number of committees, task forces and commissions have dealt with policy matters. The
work of the National Floods Commission (1980) is the most comprehensive. The National
Water Policy documents of 1987, 1999 and 2002 laid down many policies on flood
management. In 1999 policy of National Commission for Integrated Water Resources
Development, stress was given to control flood just after independence gradually took a turn
towards an achievable pragmatic approach of flood management.
National Water Policy (2002) emphasizes on a master plan for flood control and
management for each flood prone basin. The policy envisaged that adequate flood-cushion
should be provided in water storage projects, wherever feasible, to facilitate better flood
management. In highly flood prone areas, flood control should be given overriding
consideration in reservoir regulation policy even at the cost of sacrificing some irrigation or
power benefits. It was declared that along with physical flood protection works like
embankments and dykes will continue to be necessary, increased emphasis should be laid on
non-structural measures such as flood forecasting and warning, flood plain zoning and flood
proofing for the minimisation of losses and to reduce the recurring expenditure on flood
relief. Strict regulation of settlements and economic activity in the flood plain zones along
with flood proofing should be adhered to minimize the loss of life and property on account
of floods. The flood forecasting activities should be modernised, value added and extended
to other uncovered areas. Inflow forecasting to reservoirs should be instituted for their
effective regulation.
The country has to shift its strategy towards efficient management of flood plains,
flood proofing, flood forecasting, disaster preparedness and response planning. Flood
fighting and flood insurance, as-there are no solutions for complete protection against flood.
If we analyze this recently declared policy decision of National Commission for
Integrated Water Resources Development, 1999, for the first time it was officially admitted
that flood has to be tackled in a participatory mode. All the items of flood management
112
as identified the Commission in the aforesaid paragraph will have to be implemented in
people's mode otherwise will also be an exercise in futility in the long run.
4.6.2 Flood Management Programmes In India
The flood management and control are necessary not only because the floods impose curse
on the society, but the optimal exploitation of the land and proper management and control
of water resources is of vital importance for bringing prosperity in the predominantly
agricultural based economy of this diversely populated country; and this can not become
technically feasible without effective solution of flood problems. These measures are
grouped as structural and non structural flood management measures.
a) Structural measures
Over the centuries a variety of structures have been evolved to mitigate the flood
hazard. Their aim is to reduce flooded area, or depth of flood water, or flood discharge. The
main thrust of the flood protection programme in India so far has been in the nature of
structural measures like:
• The construction of dams and reservoirs for the temporary storage of flood waters.
• The construction of embankments (dikes or levees) and flood walls
• The improvement of river channels to enlarge their discharge carrying capacity.
• The construction of bypass and diversion channels to carry some of the excess flood
water.
In India, between the period of 1954 to 2000, 33,630 km of new embankments and
37,904 km of drainage channels have been constructed. In addition, 2337 town protection
works have been completed and 4705 villages have been raised above flood levels. Barring
occasional breaches in embankments, these works have given reasonable protection to an
area of about 15.8 million ha.
b) Non-structural measures
Non-structural measures strive to keep the people away from flood waters, bearing in
mind the stark reality that the flood plains in fact, belong to the river and that the flood
113
perceived only as curse, could be turned into a blessing in disguise in some ways. It
contemplates use of floodplains judiciously, simultaneously permitting vacating of the same
for use of the river whenever the situation calls for. This technique allows the use of flood
plains reducing the disaster dimension, while retaining its beneficial effects. Some of the
popular non structural measures are discussed in brief here under:
i) Flood forecasting: Flood forecasting enables forewarning as to when the river is going to
use its floodplain, to what extent and for how long. With reliable advance
information/warning about impending floods, loss of human lives and moveable properties
and human miseries can be reduced to a considerable extent. Flood forecasting and flood
warning in India was commenced in a small way in the year 1958 with the establishment of
a unit in the Central Water Commission (CWC), New Delhi, which is now responsible for
issuing forecasts at 157 stations, of which 132 are for water level forecasting and 25 for
inflow forecasting, used for optimum operation of certain major reservoirs. These 150
stations are located in 11 flood prone states and two union-territories. The total number of
forecasts issued by CWC increased from 6964 in 1978
to 8566 in 1990. The percentage of accurate forecasts also increased from 82 in 1978 to 95
in 1989 (CWC, 1996). To improve the quality of forecasts further, the modernization of
existing networks has been undertaken with international agencies and nations such as
UNDP, USAID, World Bank and Denmark.
ii)Dam break flood wave simulation: Worldwide many types of dam break models exist
ranging from simple computations based on historical dam failure data that can be
performed manually to complex models that require computer analysis. These models
simulate the breach on the dam, and route the flood through the reservoir considering the
breach, and subsequently route the flood hydrograph from the failed dam through the
downstream valley. Such information is very useful for planning purposes.
iii) Flood inundation mapping: For flood mitigation measures and land use planning, flood
inundation mapping is an important activity. The Satellite remote sensing technology is
extremely useful in monitoring the dynamics of water spreads during the floods. Analysis of
remotely sensed data gives a reasonable accurate assessment of water spread directly from
the satellite images.
114
iv)Flood plain zoning:
A flood plain zoning means categorizing various zones based on administrative
legislations for planning and development of the flood plains for various purposes such as
agricultural activities, play fields, industrial areas and residential areas etc. Preparation of
flood plain zoning maps takes into consideration the inputs from flood inundation, flood
hazard and flood risk zone maps (NIH, 1988-89). The important aspect of zoning is that it
can be used to regulate what uses may be conducted and how uses are to be constructed or
carried out. Zoning is also used to restrict reverie or coastal areas to particular uses, specify
where the uses may be located and establish minimum elevation or flood proofing
requirements for the uses. However, many flood prone states in India have not adopted the
recommendations regarding flood plain zoning and a task committee for this purpose is
essential.
iv) Flood Insurance
In developed countries flood insurance scheme is found to be most effective method
to regulate the land uses in the flood plain. Basically under this scheme, depending upon the
nature and location of establishment in the flood plain, insurance premiums are charged. The
insurance plan is in such a way that very high premium are charged from the persons going
for the costly establishments in the flood plain very close to the river banks. In India, at
present, this scheme is not yet implemented.
Vi)Decision support system for real time flood warning and management:
Decision support system for issuing the flood warning and managing the flood in real
time is an advance software which is capable of providing the information to the decision
makers for taking the necessary measures for managing the flood in real time. Such system
requires the spatial and temporal data bases which include the basin characteristics,
hydrometreological variables, social and economical data etc. The data bases are linked to
the mathematical models developed for each component of DSS. The temporal information
about the hydrometreological variables are made available in the real time and the system
provides the hydrographs of the river stages and corresponding discharges at required lead
times. Such information are very much useful for the decision makers to take necessary
115
actions for preparing the evacuation plan in real time during the flood. For the development
of such DSS in India, efforts are being made by some academic and research institutions on
pilot scales. However, under the World Bank funded Hydrology Project II, which is likely to
start in the month of October 2005, the development of DSS for real time flood forecasting
is one of the important proposed activities. The hydrology project II is being implemented
by Ministry of water resources. In this project 13 states and 8 Central agencies are
participating.
vii) International cooperation:
India is drained by a number of international rivers that originate beyond its borders
and flow into India. India shares river systems with six neighboring countries: Viz. Nepal,
Bhutan, China, Myanmar, Bangladesh and Pakistan. Bilateral cooperation for various flood
management measures is essential for India and the concerned country. Government of India
has already taken some initiatives in this regard. However, more active participation in the
subject is required.
4.7 Flood management Programmes in West Bengal
In view of its geographical location at the tail end of the Ganga Basin and several
other Himalayan rivers, the problem of flood management and drainage in the State is quite
acute. Several committees have examined the problem and suggested the remedial measures
at different times. These are being implemented in stages since the year 1954. The measures
generally implemented are the embankments and river training works, improvement of
drainage systems, providing flood storage in reservoirs, construction of multi-purpose
reservoirs etc.
The State had taken measures mentioned above which resulted in providing a
reasonable degree of protection to an area of 2.077 mha. out of a total flood prone area of
3.816 mha. the important storage projects which are giving benefits by virtue of flood
storage specifically provided in the dams, are the D.V.C. system of reservoirs and in a
limited way the Kangshabati reservoir. The flood storage is not fully available for
moderation as the acquisition of land between the FRL & MWL in the Panchet and Maithon
116
Reservoirs of the DVC system has not been made due to various factors. A committee was
set up to examine this aspect and it submitted its report. Inspite of this lacuna, the flood
cushion available in the two reservoirs has helped in reducing the effect of flood intensity in
the lower reaches in most of the years in the past.
4.7.1 Dams as the flood Control Measure
The dams were contemplated as a flood control structures during independence era.
The British Engineers built some low structure called rivers like Damodar, Bakreswar and
Kangshabati exclusively for the purpose irrigation. The Damodar Valley Corporation was
first and only project of Bengal that was launched with the objective of flood control along
with irrigation and power generation. The project was initially drawn with eight reservoirs to
water during the monsoon but only four of them were built up. The reason partial
completion of the project was non-acquisition of land and also inadequate fund. However,
the four reservoirs have moderated the peak discharge but failed ensure the total protection
from flood. There are many reasons for such part failure. Three major causes are : a) No
structural measure can be totally fail b) The dams were contemplated on incomplete
understanding of geomorphology of the basin c) the dams had no scope to regulate the
generated n the uncontrolled catchment area d) the capacity of the reservoir were not
enough to accommodate the upstream flow totally.
There is hardly any scope of building any more dam within the territory of West
Bengal because terrain here is mostly flat. It is now admitted that total freedom from flood is
neither possible nor desirable as flood also plays many ecological role. The National Flood
Management Policy (2008) realized that structural measures are not enough to combat flood
and desired to make a paradigm shift to a pro-active prevention, mitigation and
preparedness-driven approach.
4.7.2 Flood prone areas of West Bengal pro-active preparedness
The first condition for sustainable flood management programme is holistic understanding
of the geo-hydrology of the basin. In case of the transboundary rivers, it is necessary to
develop international and inter-state collaboration for exchange of hydro-meteorological
117
data. No flood management plan can be successful without flood vulnerability map and the
National Remote Sensing Agency is entrusted to prepare such map by January, 2010. The
areas of drainage congestion are to be identified and necessary steps should be taken for
quick discharge of flood water. The culverts below railways and highways are to be widened
based on experience of preceding floods. The palaeo are moribund channels may act as best
outlets of water. Any interception across these channels should be removed and selective
dredging may be done to resuscitate them. The wetlands are natural reservoirs of water and
all precautionary measures are to be adopted for conservation of wetland.
4.7.3 Early warning
So far, there is a clear limitation in instrumentation-based technology to predict with any
accuracy, the occurrence of landslide, earthquake and river erosion. But there are indigenous
ways available by which the local community could and in fact does come to know early of
the impending disaster. Floods, drought and cyclone could however, be predicted with some
degree of accuracy. While the Central Water Commission in association with Irrigation and
water Resources Department, Government of West Bengal, are authorized to anticipate
floods. Indian Meteorological Department is authorized to do likewise for meteorological
drought and cyclone.
The technology, infrastructure of early warning on floods, drought and cyclone do
exist. Rainfall gauges, river gauge, wireless sets, dam discharge data, cyclone tracking
satellite are all in place and do their job. Models exist to interpret the data and predict the
next course of action. Emergency control rooms are opened at the Relief Department,
District Magistrate’s office. Irrigation & Waterways Department etc. River gauge stations
are supposedly manned for 24 hours during June to October. Further, two emergency
telephone nos. 1077 and 1070 have been assigned to the Relief Department which are
supposedly ON for 24 hours from June to October. Interestingly, this period covers disasters
like flood, landslides drought and erosion, but not cyclone. Cyclone season is normally April
May and November in this part of the country.
118
A gap lies in linking the information and data with the vulnerable community so that
it is of use of them. This requires a rethink on information dissemination and use
mechanism. The present framework considers that information is to be used only by
administration whereas experience all over the world have shown that information
dissemination and use to and by the local community actually reduces vulnerability and
greatly improves preparedness. Recent action research on early warning has come out with
detailed recommendations that may be referred in this context. One such example is linking
the community near Kandi (Murshidabad), a place at the tail end of Mayurakshi system with
Tilpara Barrage authority near Suri (Birbhum) almost 150 kilometre upstream that helps
them to receive dam discharge information 48 hours early so that the community remains
prepared. Another good example is to dedicated website to inform river gauge position, dam
discharge, rainfall and flood prediction on a daily basis, which unfortunately remained in
operation only for two years form 2001.
4.7.4 Strengthening disaster preparedness and response Planning
Strengtheing preparedness of family, community, Panchayates and administration is
perhaps the most significant approach in recent times. Born of international experiences,
refers to measures to improve understanding and collective confidence and readiness of the
family, community and that of administration to face disaster. Preparedness has three main
aspects.
Family level preparedness means the measures by which, the family stocks food, fuel
and fodder, prepares shelter etc. Community’s preparedness refers to creation of community
volunteer task forces (on warning, search and rescue, water-sanitation, shelter management,
carcass disposal etc.) training them on their job .Institutional preparedness refers to special
rescue forces (Professional team for rescue, resue boats, expert drivers, rescue equipment
etc.). Pre-positioning of large stocks of food, medicine, anti-venom, emergency medical
team, emergency transport vehicle, diarrhoea control measures, emergency engineering team
for road and bridge repair, amblances, boats, emergency communication equipment, route
maps, etc. preparedness of staff, of course West Bengal needs collaborative partnership
between Government and civil society to minimize the risks of disaster. The focus has to be
119
on the community who face the real brunt of nature’s revenge against us for all the sins that
we have committed in the past and continue to commit in the present and future. However, it
is indeed possible to minimise the risks and impact of disaster if we act together in all
earnestness. The way forward is to build a disaster management policy at the state level,
where the government and civil society commit themselves to supplement and cheer each
other.
4.7.5 Flood plain zoning
In West Bengal scenario the task of flood plain zoning is all the more difficult
because of high density of population and existence of large flood prone areas. But in spite
of the possibility of being resisted by a section of people it has now become, imperative to
stop encroachment of river beds/ drainage channels there by obstructing the natural path of
the river/ drainage artery. West Bengal flood 2000 has very emphatically underlined this
point. A larger section of people through their sufferings found out how a handful of greedy
persons for their personal gain almost completely choked the only drainage artery, for e.g
the Ichamati river. With co-operation of all it was possible for the administration to remove
all encroachments length of about 45km. Here all relevant departmental officials acted under
the umbrella of Panchayat Raj Institutions (PRIs). Just a month back (Sept.01) it was
possible to remove encroachers from one of the old and important drainage arteries of the
City (Tolly's Nala). These facts only strengthens the argument that if for a right cause we put
forward our solutions before public and convince them then with their co-operation many
difficult decisions can be Implemented. In West Bengal the PRIs render great help in such
occasions.
In the perspective that the State has about 42% of its geographical area marked as
flood prone it is not humanely possible to relocate structures and developmental activities
and any Legislation will remain unimplemented. So the idea of preparing the flood zoning
maps are to be accepted and all future developmental activities are to be guided by this map.
Relocation of already completed activities can be attempted in some specific cases if that is
absolutely necessary in greater interest. In such cases the role of pros are vital. Very recently
in West Bengal, District Planning Committees have been formed. These Committees can
top related