DRAFT FOR DISCUSSION - March 2006
Background Paper No. 2
WATER RESOURCES OF THE
NORTHEAST:
STATE OF THE KNOWLEDGE BASE
Prepared by:
CHANDAN MAHANTA
INDIA INSTITUTE OF TECHNOLOGY
Guwahati, India
This paper was commissioned as an input to the Study on Natural Resources, Water and
the Environment Nexus for Development and Growth in Northeast India
1. Background
1. Due to availability of newer tools of rapid and advanced testing and monitoring, the
recent years have seen remarkable progress in generating vital data and development of
sound knowledge base in all fields of natural resources. This is supported by established
technologies such as Acoustic Doppler Current Profilers (ADCP), improved echo
sounding technology, real time kinetic global positioning systems, total stations, the
capability to integrate GPS outputs with total station and/or depth sounders, and
relatively newer technologies such as radar meteorology, soil vapour and extraction
technology, isotope studies for ground water monitoring and assessment, and continuous
real time monitoring with telemetric sensors to name a few. Yet, regions like the
Northeastern part of India continue to face the daunting task of creating a dependable
knowledge base for its chronically underdeveloped water sector. Even some of the
established data gathering technologies are yet to find applications in this part, often
leading to concern about the quality of data and subsequent information generated. On
the other hand, notwithstanding an extraordinary water resource potential, this region still
accounts for some acute water-starved pockets. Aggravating the situation is widespread
poverty, which increases the risk of early depletion of quality of resources with
accompanying environmental problems. The region also faces an increasing incidence of
unrest and insurgency. These are related to growing unemployment, poor economy with
lack of development, and a languid lifestyle often linked to shortage of means to utilize
available resources to support productive engagement.
2. A long-term water resource management programme designed to develop a critical
mass of indigenous productivity with the requisite technical, economic and social-cultural
means for sustainable development is an urgent need. Both capacity and demand for local
expertise to provide comprehensive evaluations of available water resources and ways of
utilizing them are needed. The future of the Northeast rests significantly on how
effectively concerted endeavors are made in the complex field of food security and water
productivity. With growing surface water pollution and geogenic contaminations like
Arsenic and Fluoride in groundwater posing serious health threats, the water quality issue
too is becoming increasingly critical.
2. The context
3. The value of the water resources of the Northeast is yet to be fully appreciated and the
intrinsic laws of the massive Brahmaputra-Barak system still to be understood. The first
step towards facing this task is to develop a sound knowledge base, a lack of which is
bound to affect the continuation of any development and management initiative at certain
point of time. Considering the dimension of the challenge itself, not to talk about the
complexity of issues, great effort would be required to achieve such a goal. Efforts, and
therefore achievements have been limited so far. Considering the urgent need of ensuring
safety of people’s lives and properties from recurrent water hazards, and that of
promoting social and economic development or improving ecological services and
impacts, it is important to take stock of the current status and put all out efforts to
strengthen the knowledge base.
1
4. Besides synthesizing available information, simultaneous research studies may need to
be integrated towards building a knowledge driven decision support system. Such
assessment and the synthesis, in the early stage, is bound to be affected by lack of
organised data, but once the gaps are filled, this can constitute the core of a strategic plan
of action for the promotion of a water resource development and management
programme for sustainable livelihood of people. A policy group can factor the knowledge
base into an overall strategy that can initiate practical measures and set definite goals
towards creating large numbers of water resource management endeavours and
enterprises.
3. Present status
5. While the need of addressing the social, economic and environmental dimensions of
the water issues or assessment of availability, along with its spatial and temporal
variations is being increasingly appreciated, whether it is quality or quantity assessment
of water demand by various user/sectors (agriculture, domestic, industrial,
environmental), a complete information infrastructure remains a far cry. Thus, one prime
objective of developing a systematic knowledge base should be to examine the current
understanding of integrated freshwater management quantitatively and qualitatively in
the region. Information potential includes the fundamental freshwater issues, state of
freshwater resources, existing policy packages, alternative policy packages, and gaps in
information and monitoring aspects to address the freshwater concerns. Data collection
process towards this effort encompasses the key domains of freshwater resources
availability (surface and ground water resources), water demand by various sectors and
assessment of future water availability.
6. A knowledge base should be adequate to enable best possible action. It generally
improves information flow from local management realities to decision-makers and back,
including improved engagement of stakeholders, integration of data, and raising funds to
build information systems. This is hardly the case with the Northeast. Thus, knowledge
management in the water resource sector in the NE is concerned with the development
and exploitation of water-centred knowledge focusing upon:
•
•
•
•
•
•
•
•
•
•
Identifying utilizable knowledge from previous studies and records
Getting hold of the knowledge , however limited, available with different
agencies and institutions
Transferring the knowledge in a form that facilitates use
Continuously working towards filling the gaps
Improving weak monitoring and quality control
Maintaining, sustaining, improving and updating the existing knowledge
as a tool for sustainable, reasonable, equitable water utilization
Appreciation of complexity of water issues and respecting traditions
Wise decisions based on quality knowledge
Holistic policy based on sound knowledge base
Knowledge driven solutions emanating from a knowledge management system
2
7. While the Northeast is considered, the inconsistency of available data in certain cases,
complete lack of data in other cases, and the weak existing hydrological network in the
region act as barriers to the development of a reliable knowledge base. Before initiating
any plan of action, it is necessary to gauge the hydrological networks and database in the
region. Besides natural data, a second category relates to economic and social aspects,
and another category to the aspect of regularities. Unless all these aspects are equally
emphasised, integrated water resources management would continue to remain a
theoretical exercise. In the NE, the knowledge to be managed is both explicit,
documented knowledge and tacit, subjective knowledge. Management of knowledge
therefore entails all the processes associated with the identification, sharing and creation
of knowledge. Systems for the creation and maintenance of knowledge repositories do
exist in some form or the other in the departments and agencies like the Brahmaputra
Board or the CWC, but a mechanism to cultivate and facilitate the sharing of knowledge
and organizational learning is missing.
4. Surface water availability in the Brahmaputra and the Barak Basin
The Brahmaputra Basin
8. The Brahmaputra is a major international river covering a drainage area of 5,80,000 sq.
km., 50.5 percent of which lie in China, 33.6 percent in India, 8.1 percent in Bangladesh
and 7.8 percent in Bhutan. Its basin in India is shared by Arunachal Pradesh (41.88%),
Assam (36.33%), Nagaland (5.57%), Meghalaya (6.10%), Sikkim (3.75%) and West
Bengal (6.47%). The Brahmaputra traverses its first 1,625 km in Tibet, the next 918 km
in India and the remaining 337 km in Bangladesh. The average width of the valley is
about 86 km of which the river itself often occupies up to 20 km. The annual rainfall
varies from 100 cm to 400 cm, most of which occurs during the monsoon months of
May/June to September. Throughout its course in India the Brahmaputra is highly
braided with some well-defined stable banks, where the river width is narrow. All along
its course, abundant wetlands and back swamps are common in the floodplain.
9. The maximum peak of the Brahmaputra recorded at Pandu is 72,794 cumecs on 23rd
August 1962 and 78,449 cumecs at Jogighopa in 1972. The low water discharge at Pandu
is about 2,300 cumecs during the month of January/February. Observed maximum HFL
at Pandu is 49.66 M. The average annual run off (yield) of the Brahmaputra at Pandu is
49.43 m ha m (400 m ac. ft.) out of which about 80% of the flow occurs during the
monsoon. The maximum annual yield was 64.39 m ha m in the year 1977 (Vision 2020,
Water Resource Department, Government of Assam). The highest water level reached at
Bessamara was 88.01 m on September 16, 1987, while the lowest water level recorded
was 80.11 m on November 30, 1985 (Table.1). Most of its major Himalayan tributaries
experience flash floods during summer high flows (Sarma, 2005). NE is also
distinguished from the rest of the country by several water resource attributes (Table 2).
Table 1 Mean annual flow of the Brahmaputra River (WAPCOS, 1993)
Station
Period
Mean annual flow in million m3
3
Station
Period
Mean annual flow in million m3
Pasighat
1949–1962 and 1976–78
185,102.29 (5869.55 m3 s−1)
Bessamara
1977–1990
278,446.88 (8829.49 m3 s−1)
Bhurbandha
1977–1990
365,550.00 (11,591.51 m3 s−1)
Pandu
1955–1990
526,091.00 (16,682.24 m3 s−1)
Jogighopa
1955–1977
537,066.67 (17,030.27 m3 s−1)
(Source: Sarma, 2005)
Table 2: Water resources: availability and utilisation in the NE
Total water resources potential
537.2 km3 (30% of the country’s total)
Per capita water availability
18,400 cu m as against 2,208 cu m of the
country
Hydropower potential
44% of the country’s total (66,065 MW out of
country’s total of 1,48,701 MW) source:NHPC
Hydropower Potential developed so far
Only about 3% as against 16% of the country
Irrigation potential
4.26 million hectare (m.ha)
Present coverage of irrigation
0.85 m.ha (20% of the existing potential against
the national average of 56.4%)
Total replenishable Groundwater potential
26.55 km3/year against 431.42 km3/year of the
country (6 % of country’s total)
Groundwater Potential developed so far
4.3% (against the national average of 32%)
(Source: Goswami, 2001)
10. The basin is of irregular shape; the maximum east-west length is 1,540 km and the
maximum north-south width is 682 km (Dutta &Singh, 2004). The basin lies between
230N to 320N latitude and 820 E and 970 E longitudes. Land use pattern of the
Brahmaputra and Barak valley based on recent satellite data indicates predominantly
agricultural land and forest cover (Table 3).
Table 3: Land-use pattern of the Brahmaputa and Barak Valley
Type of cover
Area in hectares
4
Percentage of
total area
Forest
17,26,400
21.98%
Agricultural land
42,48,600
54.11%
Built-up area
21,100
0.27%
Water bodies
5,67,200
7.10%
Waste land
3,15,700
4.02%
Others
9,83,300
12.52%
78, 52, 300
100%
Total Area
Source: Basic Statistics of NER, NEC Publication (2002)
11. In Assam the basin receives 300 cm mean annual rainfall, 66–85% of which occurs in
the monsoon period from June through September. Mean annual discharge at Pandu for
1955–1990 is 16,682.24 m3 s-1. Average monthly discharge is highest in July (19%) and
lowest in February (2%). Most hydrographs exhibit multiple flood peaks occurring at
different times from June to September. The mean annual suspended sediment load is 402
million tons and average monthly sediment discharge is highest in June (19.05%) and
lowest in January (1.02%) (Sarma, 2005).
12. In the Brahmaputra valley, 66–85% of annual rainfall occurs during the monsoon and
20–30% occurs during the pre-monsoon season and in the winter season (less than 1% in
December, up to 2% in January, up to 4% in February and up to 6% in March). The first
spell of rain with high intensity occurs generally in the month of April. This is closely
related to the occurrence of the first flash flood in the otherwise smooth hydrographs of
the tributary rivers. The average daily discharge is highest in July and lowest in February.
On an average, July accounts for nearly 19% of the total annual discharge compared to
2% in February. Most of the hydrographs exhibit multiple flood peaks occurring at
different times from June to October (Sarma, 2005).
13. WAPCOS (1993) carried out a longitudinal profile of the Brahmaputra from
hydrological point of view (Fig.1).
5
Fig. 1 The longitudinal profile of the Brahmaputra River (modified after WAPCOS, 1993).
(Source: Sarma, 2005)
The Barak Basin
14. The Barak basin is spread over India, Myanmar and Bangladesh and drains an area of
41,723 sq. km in India. In India, the basin lies in the states of Meghalaya, Manipur,
Mizoram, Assam, Tripura and Nagaland with a total population of 6.2 million. Before
entering Bangladesh, the river bifurcates into two streams called Surma and Kushiara.
Further lower down, the river is called Meghna and joins the combined flow of the Ganga
and the Brahmaputra. The principal tributaries of the Barak in India are the Jiri, the
Dhaleshwari, the Singla, the Longai, the Sonai and the Katakhal. An average annual
surface water potential of 585.6 km3 has been assessed in this basin. Out of this, 24.0 km3
is utilisable water. The average annual yield of Barak at Lakhipur was observed to be
14,077 m cu m, while monsoon and non-monsoon averages are 12,073 and 2,004 m cu m
respectively (Barak Master Plan, 1988). Culturable area of the basin is about 13.04 m.
ha., which is 7.1% of the total culturable area of the country. Like Brahmaputra, floods
are an annual feature in the Barak basin, where the maximum flood prone area is of the
order of 4.33 million ha. The highest annual rainfall recorded was 4,194 mm in the year
1989 and the annual average is 3,400 mm.
15. As against the national per capita annual availability of water at 2,208 cu.m, the
average availability in the Brahmaputra and the Barak rivers is as high as 18,400 cu m.
Major contributions come from a few large tributaries (Fig.2).The catchment area of
Brahmaputra sub basin in India and Bhutan is around 2,40,000 Km2. At present there are
6
336 ordinary raingauges and 113 SR raingauges. Additional 68 SR raingauges and 636
ordinary raingauges in Brahmaputra catchment are needed to meet the WMO
requirement. Raingauge network in the Barak basin is too short of WMO standard.
Dehang (main stream)
Lohit (head stream)
Jia Bharali (Kameng)
Kopili Kalang
Other tributaries above Pandu
Subansiri
Debang (head stream)
Burhi Dihing
Dhansiri (S)
23%
37%
1%
2%
2%
6%
8%
11%
10%
Fig. 2: Percentage contribution of yield by the tributaries of the Brahmaputra
5. Water resource availability in the Major water bodies of the region
16. More than 3,500 wetlands, covering 1,01,232 ha. in the Brahmaputra valley which
have great significance as unique habitats for exquisite varieties of flora and fauna and
also as natural flood water retention basins (capacity not assessed yet) are getting
degraded owing to various factors, such as i) inorganic and organic deposits which
include sand, silt, clay, pebbles and other inorganic materials; this results in the reduced
depth of wetland; ii) the blockage of feeder channels and roads; iii) construction of
embankments, irrigation channels, roads; iv) reduced depth of many swampy area paving
the way for encroachment and cultivation.
17. In Manipur there are about 155 wetlands covering an area of 52,959 ha, of which
Loktak Lake (6,475ha) is one of the largest freshwater lakes in India. The Barak valley
has a good number of floodplain wetlands harbouring a great variety of aquatic
macrophytes. At present, there are nine important wetlands (haors) in the valley with a
total area of 134 sq. km. Despite rugged terrain, Sikkim does have several small lakes,
which are both spring-fed as well as river-fed. More than 10 natural lakes feature in
Sikkim Himalayas, which are the major storehouse of water and significantly contribute
to the stability of water ecology in the region.
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6. Groundwater Resources
18. Except for Tripura, in the other states of Northeast, the level of groundwater
development is low. The net ground water availability of the state worked out to be 2.30
BCM. Assam, has highest groundwater potential among the N.E. states, but presently a
mere 12.83% of groundwater is utilised. The over-all stage of ground water development
of the Northeast is shown in Table 4.
19. Manipur has groundwater potential of 3,153.67 MCM out of which utilisable
groundwater is 2680.61 MCM. The total annual ground water recharge is 0.38 BCM. The
net ground water availability of the state is 0.34 BCM after deducting the natural
discharge during non-monsoon. In Nagaland, because of varied topography, geological
settings, tectonic activity, infrastructural facility, ignorance of people, the over-all stage
of ground water development of the state is 2.86%.
Balance ground
water resource for
future use
BCM/yr
BCM/yr
BCM/yr
BCM/yr
BCM/yr
[%]
1.44
0.22
1.22
-
1.22
Neg.
3.71
0.47
0.08
21.01
2.68
0.46
1.84
Neg.
0.02
19.17
2.68
0.44
8.75
Neg.
3.97
-
-
-
-
-
0.11
0.10
0.62
0.56
Neg.
0.19
0.62
0.38
Neg.
33.43
-
-
-
-
-
24.89
3.15
0.54
under
5
Mizoram
estimation
6
Nagaland
0.72
7
Tripura
0.66
Under
8
Sikkim
estimation
Source: Central Ground Water Board, India
Level of ground
water development
Net draft
2
3
4
Arunachal
Pradesh
Assam
Manipur
Meghalaya
Available ground
water resources for
irrigation
1
States
Provision for
domestic,
industrial & other
uses
Sl.
N
o.
Total replenishable
groundwater
resource
Table 4: Ground water resource (dynamic) of North East India
Neg : Negligible
20. The groundwater has played and will continue to play a key role in meeting the water
needs even in the midst of abundance of rainfall and surface water due to
geomorphological and agro-climatic conditions generally prevailing in the North-Eastern
region. The catchment area is hilly with high slope with the result that major part of the
rainfall is lost in surface run off. Apart from this, numerous streams, small rivers, nullas
and springs also acts as carrier of ground water. For augmenting the sustainable ground
water resources of the region, the Central Ground Water Board has explored the
8
prospects of development of springs, roof top rainwater harvesting, and construction of
shallow tube wells across the region and worked out the estimated cost of such recharge
options.
21. The northern bank of the Brahmaputra river represents a mono-aquifer system and the
south bank reveals three to four prolific aquifer systems of Quaternary age. Due to poor
development of ground water, some of the areas are under water logged condition.
7. Potential of rainwater harvesting in the Northeast
22. Heavy monsoons notwithstanding, people in the hills suffer from acute water problem
every year in the dry season. The geological formations do not permit water retention,
runoff is quick, and springs and small streams dry off when there is no rain. There are
documented instances of indigenous rainwater harvesting systems used for cultivation, of
which some are ingenious. Settled agriculture is practised in the form of irrigated terrace
cultivation in parts of Nagaland and a few villages of Meghalaya. Channels are dug to
irrigate these fields. The other chief indigenous source of irrigation is the bamboo
irrigation system found in parts of Meghalaya, and in some villages in the Mokokchung
district of Nagaland.
23. Facing a water crisis every winter, the Mizoram government has taken up rainwater
harvesting on a serious note. The method envisages fitting semicircular rain gutters
fabricated with galvanised sheets to the eaves of roofs to collect rainwater, which are to
be stored in reservoirs for use during the dry season. Sikkim has, over the years, evolved
efficient water harvesting systems together with their traditional land management
systems. Though Mizoram is making good stride with respect to rooftop rainwater
harvesting, other states of the region are still on somewhat experimental stage.
24. The technologies of rainwater management are highly location-specific and are
determined by physiographic, environmental, technical and socio-economic reasons. The
main feature is to conserve rainwater where it falls, i.e. in the soil profile up to its
maximum capacity and in storage structures for crop irrigation at a later stage. Ultimately
the approaches have to be compatible with socio-economic adjustments of the target
population. Some of these requisites are in exploratory stage in the Northeast.
8. Current water demands in the Northeast
25. Various figures are reported as the irrigation potential developed and potential
utilized in official statistical documents published by the Government of India, the
Government of Assam, the North East Council, the Fertilizer, Association of India and
the Assam Agriculture University, Jorhat. In such a situation, the true picture with regard
to the status of irrigation cannot be properly gauged. Further, the status with regard to the
availability / use of irrigation for different crops is more or less unknown, as the cropwise irrigation data have not been updated since 1953-54 (Planning Commission, 2002).
9
26. Irrigation is the largest consumptive use of water in the Brahmaputra-Barak Basin,
which accounts for almost 91% of total water consumption. However, most of the waters
withdrawn for irrigation are lost as non beneficial depletion. The best possible way to
reduce non-beneficial evaporation is to use effective irrigation practices such as precision
irrigation techniques, adjustments of crop planting to match periods of less evaporative
demand etc, reducing water or polluted water flowing to sinks, increase water reuse etc.
Overall irrigation efficiency of the Brahmaputra basin is 32% and potential annual
evapotranspiration is worked out to be 1,144 mm, which is lowest among the basins
(Amarasinghe, 2005).
Environmental water requirements related to conservation of river courses
27. Most of the Indian rivers in general, and the Brahmaputra basin in particular, have
monsoon driven hydrological regimes, where 60 –80% of the total flow comes in 3-4 wet
months. Such rivers fall in highly variable flow regimes. The total EFR for such Indian
rivers, estimated on the basis of information calculated by Smakhtin et al., (2003), range
between 20% and 27% of the renewable water resources.
28. There has been little attempt has been made so far to establish environmental flows
and define its costs, benefits and incentives. Given that flow restoration is likely to
involve a re-allocation of water from current uses and users to in-stream uses, for
example for fish and wildlife, the social and economic impacts are likely to be
significant. However, the results of such regulation may vary substantially from one
situation to another. Outcomes will depend on whether, and to what extent, the net
economic returns generated by environmental flows exceed those of the original
development of the rivers water resources. In the NE region, rivers flowing by the tea
gardens, having intensive uses of fertilisers and pesticides, may require assessment of
environmental flow vs. carrying capacity, and much of the fund required for restoring
environmental flow may need to be borne through a “polluters pay” principle.
Current level irrigation and M&I supply
29. In the Brahmaputra basin, out of the total water withdrawals of 9.9 km3 (against 267
km3 for Ganges), irrigation accounts for 81%, domestic withdrawal 10% and industrial
withdrawal accounts for 9% (Table 4). Potentially utilisable water resources (PUWR) of
the basin are worked out to be 50 km3, out of which 90% is not developed at present. Part
of PUWR is withdrawn at present and depleted through various processes. The process
evaporation is the portion of PUWR, which is depleted through evaporation by the
process it was withdrawn for. This includes evapotranspiration from irrigation fields and
the consumptive use by the domestic and industrial sectors. This accounts for 3% of the
PUWR for the Brahmaputra basin at present (Table 5).
Environmental water requirement related to Ramsar and other conservation sites
10
30. A key step in any wetland conservation strategy is to define the desired ecological
character of the wetlands. In the NE, this critical aspect has not been accorded enough
importance. Many wetlands are already on the verge of losing their ecological character
mainly due to eutrophication. Incorporation of floodplain wetlands into an integrated
river basin management plan is of urgent necessity for overall management of water
resources. However, such integration is yet to take place in the region, including the
Ramsar sites.
9. Water demand scenario for the future
Water demands for the sub-basins of the Brahmaputra
31. In almost all sub-basins, maximum available irrigated area has been taken to be
constant up to 2050 and no significant fluctuation in future water requirements has been
projected. For computing water demand in different decades for irrigation, it has been
assumed that the minimum area required for meeting the food grain requirement for
population of the sub basins in that particular year will be brought under assured
irrigation. To work out the food grain requirement, the per capita consumption has been
assumed to be 590 gms and the average yield per hectare pre- kharif and kharif paddy
under irrigated condition is taken as 6 tonnes/ha/year (Mohile, 2001).
Total gross and net water demands
32. A gross demand of 62.4 bcm and a net demand of 27.6 bcm has been projected by
2050 for meeting domestic, industrial, livestock and agricultural requirements (Table 6).
The dependable flow of the Brahmaputra and Barak in the lean flow period is estimated
to be of the order of 3,000 m3/sec and 45 m3/sec respectively at their exit points. The total
groundwater potential of the two sub-basins, at about 31 bcm per year, can support for
240 days/annum, a draft of about 1,500 m3/sec. From a simple hydrologic point of view,
the groundwater draft may in the long run lead to more reduction in the surface flows.
But together from both sources, about 3,000 m3/sec of water is available (Mohile, 2001).
The net withdrawal from the system, including groundwater, would be of the order 239
m3/sec in February, which is lower than the lean flow of 304 m3/sec. It is suggested that
the low lean flow may be sufficient, subject to satisfying any environmental flow
requirement.
Future water demand and food requirement in Northeast India
33. Using the medium projection of India’s 2050 population at 1.64 billion, the
population of Northeast India by 2050 is estimated at about 80 million from its present 38
million. Based upon present consumption of around 500 gm per capita per day, the
projected 2050 population of 80 million would, require 16 million tonnes of food grain
annually. However, development of irrigation in this part of India is not encouraging and
the region is food deficient. Production of food grain in 2002 is only 5.9 million tonnes.
Unless adequate attention is paid to increasing food production, the region would have to
11
depend largely on imports. However, considering the large water potential and available
land, self-sufficiency is a desirable and achievable goal (Mohile, 2001).
International Dimensions
34. Brahmaputra-Ganga-Meghna constitutes perhaps the most complex of all
international water negotiations. The combined scale of the environmental, social and
technical issues has no equivalent anywhere else in the world. Given the scale of these
problems and the paucity of regional resources that can be garnered to address them, it is
not surprising that the negotiation of international cooperation should be protracted and
uncertain.
35. A memorandum of Understanding (MoU) has been signed between India and China
in January 2002 for provision of hydrological information by China to India namely
rainfall, water level, discharge and other relevant information on Yarlung, Zangbo, and
Brahmaputra River in respect of three stations namely Nugesha, Yangcun and Nuxia in
the flood season. The information is being furnished from 1st June to 15th October every
year and is used for flood forecasting in the Northeast.
10. Current and future utilisation of water resources
36. The Brahmaputra Board was established as a statutory body under the ministry of
water resources to plan for and to implement projects to harness the Brahmaputra-Barak
system for hydropower, flood control and economic development. The Board has so far
identified a series of “Drainage Development Schemes” that include hydropower dams,
embankment reinforcement and other multipurpose projects. These projects are included
in the respective Master Plans approved by the Government of India. Several studies
suggest that it is likely to be economically unfeasible to transport water from the
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Table 5: Water withdrawals and water accounting in River Basins of India
Industrial
Total renewable water
resources
Potentially
utilisable water
resources
Km3
645
4.4
6.4
5.3
2.4
8.8
14.0
7.8
17.9
12.4
19.9
9.9
41.0
41.1
81.6
266.8
%
91
78
88
89
79
91
94
87
89
92
91
81
90
91
97
91
%
5
15
8
5
13
6
4
7
6
5
5
10
6
6
2
5
%
4
7
4
6
8
3
2
6
5
4
4
9
4
4
2
4
Km3
1887
3.8
12.4
11.0
48.4
28.5
6.3
14.9
21.4
45.6
66.9
585.6
78.1
110.5
73.3
525.0
Km3
1034
4.8
8.5
6.6
10.2
21.7
10.3
21.2
27.8
43.9
63.6
50.0
77.9
109.8
60.3
386.5
(Amarasinghe, 2004)
13
PUWR not
developed at
present
%
11.0
12
13
19
5
10
18
10
13
6
7
4
13
7
25
11
Unutilisable
outflow of
return flow
%
24.4
46
21
39
5
12
60
17
24
12
10
3
24
16
48
26
Non-process
evaporation
Process
evaporation
% of PUWR
Unutilisable
outflow of
PUWR
All basins
Sabarmati
Subarnarekha
Mahi
Meghna
Brahmani &Baitarani
Pennar
Tapi
Cauvery
Narmada
Mahanadi
Brahmaputra
Krishna
Godavari
Indus
Ganges
Total
Domestic
River basins
Water accounting
Irrigation
Water withdrawals
Sector Withdrawal- % of total
%
2.9
5.9
4.4
3.7
1.9
2.1
5.2
1.9
3.3
1.3
1.6
1.5
2.4
1.7
5.2
3.2
%
3.1
3.2
3.8
2.9
2.7
2.0
7.9
1.4
2.8
1.2
2.2
2.4
2.0
2.3
6.1
3.0
%
59
33
58
35
85
74
9
69
57
80
79
90
59
73
16
56
Table 6: Total gross and net water demands
Gross demand
(bcm)
Consumption
(%)
Net demand
(bcm)
Domestic water supply
Rural
Domestic
Livestock
Total (rural)
2.920
0.694
3.614
----50
----1.807
Urban
1.533
30
0.459
Sub-total (1)
5.147
Industrial (2)
5.147
20
1.060
Agricultural
Surface water
Irrigation
--35.200
---
--44
---
--15.500
---
Groundwater
16.900
50
8.500
Sub-total (3)
(agriculture)
52.100
---
24.300
Total (1+2+3)
62.39
Sector
2.266
27.630
(Mohile, 2001)
Brahmaputra to other states and one way that river can be beneficial is by harnessing the huge
hydropower potential and diverting power to the other states (Biswas & Uitto, 2001). The
hydropower potential developed in the N.E. region so far including those under construction is
about 6 % of the total assessed potential.
Region-wise hydro power potential of the NE states
37. More than 80% of the hydro-power potential of the region is located in Arunachal Pradesh
(32 % of the national potential. Dehang, Dibang, Kameng, Subansiri, Teesta, Kolong-Kopili and
Lohit, along with upper Brahmaputra predominate the number of projects identified in the
Brahmaputra Basin. Comparatively, number of projects identified in Barak and lower
Brahmaputra is smaller. Four hydro-electric projects have been already executed without any
flood storage provision on rivers flowing through Assam.
Irrigation
38. According to the Central Water Commission, the total irrigation potential of the NE states is
estimated at 36.65 lakh hectares (NEDFI, 2002). Assam has the highest irrigation potential of
2,670 cu. km. However, both in Assam and Arunachal Pradesh, the ratio of gross irrigated area
to gross cropped area has declined over the years which indicates that many secondary crops are
no longer irrigated due to absence of adequate facilities.
14
39. There is need of irrigation during the Kharif season. During the spell of moisture stress in
non-monsoon, the crop yield is only one tonne per hectare as against 3-4 tonnes per hectare in
other parts of the country with established irrigation. Irrigation statistics of CWC for each state
shows that except for Assam, the other states do not have comprehensive statistics on the
irrigation front.
40. A perusal of the projected values indicates that irrigation potential likely to be created at the
present rate will fall considerably short of the total net area sown of 27 lakh hectares, even at the
end of 2020 A.D. At the end of the projected period it will be only 16.12 lakh hectares. The
aggregated irrigation requirements for the Brahmaputra basin is estimated to be 1.95 million ham for kharif and 3.25 million ha-m for Rabi, while the total figure for the basin as a whole stands
at 5.2 million ha-m (Goswami et al., 2004).
Navigation
41. The Brahmaputra and Barak including their tributaries are used extensively by local
communities for local transport, irrigation and agriculture, yet their potential as major inland
waterways remains untapped. Successive governments have given funds and priority to roads
and railways, setting these as more effective tools of infrastructure support and overall
development (Planning Commission, 2002).
42. Inland water transit and trade in the Indo-Bangladesh route need to be revamped and lacunae
such as different procedures of evaluation of goods by customs staff from either country, delay in
freight remittances, lack of availability of night navigation and limited number of ports of
calls/customs stations has to be addressed (Planning Commission, 2002).
43. Brahmaputra being a highly braided and meandering river, there is need of developing
several navigable channels, especially in the dry months. Development of short distance travel
and freight, in addition to long term and long distance transport would be cost effective and
benefits would accrue to local communities. Revamping and renovation measures of the IWT
include improvement and modernisation of vessels with installation of basic equipment required
for safe travel. The integration of the rail, road and inland waterway movement, setting up of
inland container depots at the dispersal points served by rail, road and water is essential.
Dredgers may be purchased instead of leased and used in the low draft season (November –
April) continuously to maintain, deepen and widen existing channels.
Fishery
44. There is no reliable data on the fish production. The State Fisheries Departments do not have
any machinery to collect fish catch statistics from rivers, beels and ponds. Often there seems to
be bias in estimates. 11 Kg per capita is considered as annual requirement of fish. Assam's fish
production can meet only about fifty five per cent of the estimated requirement of 280 thousand
tonnes, since internal production stands at around 160 thousand tonnes (Department of Fisheries,
1997-98). The deficiency is met by importing fish by private traders from other states. According
to the Department of Fisheries, the state imports around 20,000 tonnes of fish annually (Planning
Commission, 2002).
15
45. Assam has not been able to utilize its full potential of fish production, despite the initiation in
1995-96 of an eight year programme for improvement of pisciculture in the state under the
World Bank aided Assam Rural Infrastructure and Agriculture Services Programme (ARIASP).
The gross value of fish production in the state in 2000-01 is estimated to be around Rs 640.00
crores (Planning Commission, 2002). Technology, development of water resources, local
entrepreneurial efforts and adequate provision of fund are required for the development of
aquaculture in the state. According to the Department of Fisheries, the state has the potential to
reach its production level up to 400 thousand tonnes annually (Planning Commission, 2002).
Water Tourism and Recreation
46. The water-tourism opportunities and adventure sports potential of the Brahmaputra-Barak
system has hardly been harnessed so far. Except for small scale localised initiatives and
occasional one-time events, there are very limited water tourism sites developed. Recently, some
of the adventure sports activities like para-sailing, water sports, river rafting and angling are
being promoted by the Department of Tourism. There is an annual angling competition held at
Bhalukpung-Potasali every year in November in which Indian and foreign tourists participate. In
Sikkim, rivers Teesta and Rangit offer long stretches which are ideal for safe rafting. The icy
cold waters of the rugged Teesta have a series of rapids with varying intensity which offers one
of the finest rafting stretches in the world. Overall, water tourism potential in the NE is very high
but no organised assessment is available.
11. Water resources projects
47. Government of India’s grand plan to double electricity generation in the country, termed as
50,000 MW hydroelectric initiatives, proposed 162 new hydroelectric projects in 16 states of
India, of which 62 are in the Northeast, with proposed installed capacity of 30,416 MW. Most of
the projects are proposed on inter-state rivers. Flood control programme in most of the basins
and tributary sub-basins are dependent on inter-state cooperation and a spirit of accommodation
of interest of the concerned states for larger benefit of the people.
48. Anti-erosion projects include continuous bank revetment with launching apron, closing of
breach, raising and strengthening of existing embankments, construction of check bunds, channel
cutting, providing boulder and other protection works, bank pitching and other temporary river
training works. Detailed proposal for augmenting and improvement of the existing flood
management infrastructure (short-term) required for the next 10 years (1997-2007) was prepared
after a detailed scrutiny. An ambitious plan for flood control has been submitted by the
government of Assam to Asian Development Bank for funding in 2006.
Concordance of the visions of “water resources development” implicit in the planning
approaches of the various stakeholders agencies.
49. Little organised information is available on implicit water resource development initiatives of
allied agencies, e.g., rural development, forestry. Concordance or otherwise of visions of water
16
resource development plans of such stakeholder agencies is thus difficult to ascertain. Water
resource development plans in the North East have not taken off apparently due to such problem
1) lack of coordination among different departments 2) institutional instability and rampant
corruption, 3) weak coordination amongst the N.E. states, 4) lack of priority to water
conservation issues and 5) absence of demonstrated successful endeavours.
50. There is no regional consensus about how to confront various water sector issues in a
systematic and balanced manner. The stakeholders have diverse proposals and views, some of
them conflicting in nature. Convergence of views can entail transparent and mutual dialogue
amongst the stakeholders that provides for collective construction of a future scenario for the
development of water sector in the region and the guidelines to achieve it. Thus, there is a scope
to organize within the framework of water resource development of the N.E. region, an extensive
regional dialogue and participatory strategic planning process to produce a common agenda for
water resource development in the region and a strategy for sustainable development. An agenda
for sustainable and harmonious water resource development recognized by the stakeholders and
adopted by the NEC or MoDONER can be a starting point. There is a need for a platform of
relationships and coordination mechanisms among governmental and non-governmental
stakeholders, which will help prevent duplication of actions and improve nature and output of
financial investments. Establishing relationships and dialogue to analyse discrepancies and
conflicts and to explore negotiated points of agreements are expected to pave the way for
consensus.
Issues of trade-off and conflict, requirements for cooperation, and opportunities for synergistic
development between multiple projects/plans.
51. Trade off is yet to be a familiar terminology in the water resource sector of the region, but the
need is already obvious in the current water related activities. For instance, trade off is necessary
between flood and erosion control measures and roadways, railway and navigation sectors.
Often, embankments constructed to prevent spilling of flood water result in increased flood
peaks and water levels along the rivers. Waterways under the bridges and drainage structures
underneath the railways and road embankments, designed not considering peak flows, turn out to
be inadequate in due course. Anti erosion measures in the form of spurs, dikes taken up by the
state governments to protect specific areas often cause adverse effect to road and railway
structures located upstream or downstream. On the other hand, constricted railway or road
culverts have become an issue of conflict in recent years, due to their apparent role in water
logging and drainage congestion. Recent civil society resistance to large water infrastructures is
another case in point where trade off will be essential.
12. Bibliography of technical and engineering knowledge
52. Organised documentation of technical and engineering knowledge on the water resources of
Northeast is limited. The Brahmaputra Board has prepared Master Plans in three parts, namely,
17
Master Plan Part-I for mainstream of Brahmaputra, Master Plan Part-II for the Barak River and
its tributaries and Master Plan Part -III for thirty nine tributaries of Brahmaputra and eight rivers
of Tripura for flood management in both the Valleys. The Master Plans envisage storage dams,
embankments, anti erosion measures, town protection works and schemes to prevent drainage
congestion covering the flood- prone areas in the Northeast. They are the few comprehensive
documents with synthesis of available relevant information. Each of the master plan is
accompanied by atlas volumes containing maps and drawings of the basin.
Technical challenges of development of water infrastructure in the region
53. The excessive flow in the rivers and recurrence of flood and erosion continue to be an
insurmountable problem. The Brahmaputra and Barak and their tributaries and sub-tributaries
cause major hazards during the monsoon season each year in the form of flood, bank erosion and
drainage congestion. Besides, the fragile physiography of the region, heavy rainfall induced
excessive sedimentation, frequent earthquakes, hill/land sliding, deforestation/watershed
degradation, inadequate drainage and encroachment of riverine area- all these pose unusual
challenge for developing water infrastructure in the region. The problem of the Barak valley too
are complex and stem mainly from the river flowing along higher elevation with large areas
subjected to inundation and drainage congestion with prolonged high stages of the river.
Impact of climate change on water resources availability and utilization potential
54. Climate change impact on the colossal water and sediment load, (one of the highest in the
world) injected from the Brahmaputra-Barak system during the southwest monsoon is
phenomenon of critical consequence to the watershed. Strategic watersheds like the Brahmaputra
are such that early signs of global climate change would appear earlier in such places of most
sensitive nature. The thermal and dynamic influence of the Tibetan Plateau affects the climatic
modulation of dissolved and particulate material fluxes through the Brahmaputra and also
impacts upon the relationship between spatial distribution of water and ecosystem diversity.
However, documented study is hard to find on these aspects.
55. An assessment of the implications of climate change for hydrological regimes and water
resources using scenarios developed from Hadley Centre Model Simulations indicates that by the
year 2050, the average annual runoff in the river Brahmaputra will decline by 14 %. Studies have
indicated that the impact of snow melting in the high Himalayas will lead to enhanced flood
disasters in the Himalayan catchments including the Brahmaputra. Singh (1998) suggests that an
increase in surface temperatures will lead to a rise in the snowline, increasing the risk of floods
in the basin during the wet season, as well as early onset of snowmelt flows.
13. Quality of knowledge and identification of gaps
56. If the current volume of data generally scattered over different organisation is considered,
one may have the impression that a reasonable database does exist. Indeed the concerned
departments have been carrying out the data collection task quite regularly, though quality
control and quality assessment remained a critical issue. There has been a general academic
18
concern about the quality of the data. To convincingly refute such concerns, and to establish the
scientific validity of the data, it may be a good idea to put the existing database through a
mechanism of verification before use. Notwithstanding the quality issue, the fact remains that
considering the size and the complexity of the Brahmaputra-Barak system, when compared to
similar large river systems of the world, data availability is still grossly inadequate. This is not to
say that assessment may not be drawn based upon existing database, but one must exercise
adequate caution on using these data sets for applications such as developing numerical models,
that may lead to unreliable inferences.
57. Simultaneously there is need for continuing support to strengthen water flow monitoring and
assessment and thus to build credible future data sources for the knowledge base. A thorough
assessment of water quantity and quality and mid term and long term threats to water
availability, utilization, quality, as well as analysis of alternatives that can address any threat, and
the development of suitable basin model components to facilitate integrated water quantity and
quality analysis will ensure that the knowledge base and the basin modelling package can
adequately deal with important management issues.
58. Several issues are rather obvious. There is a strong case for bringing together all the existing
database and information source to one place (NEC, Brahmaputra Board, WRD). It is clear that
the knowledge base is weak in almost all disciplines, technical and non-technical both in its
quality and dimension. A regional but non-uniform database exists; but data characterization
remains a problem, rendering comparison of different sources hazardous. Existing mechanism
within umbrella organizations needs to be strengthened to address this issue.
59. Field-based work force is a vital source of practical knowledge but they are often
inadequately trained and underutilized. Building a knowledge base into an effective tool requires
consistent work over large areas and long years. It also requires working relations and data
exchange between sector institutions. None are in place at the moment. Data collection staffs are
required to work in a coordinated fashion with others working on water resource assessment so
that data continues to be relevant to current problems, adequate for the assessments and so that
data users can rely on quality of
data. Data need to be converted into information and
knowledge, which in turn feeds into decision support systems, assisting in addressing priority
issues.
60. Some anticipated changes (e.g. climate impact) are not clearly understood. Existing climatesurface-groundwater observation network needs improvement. Divergent procedures hamper
accuracy and ability to use available data. Coverage of groundwater quality data needs to be
spread out, particularly in the hill states. Environmental issues though are of major concern, is
seldom given priority. Water related studies undertaken by research institutions are limited.
There is likelihood of inaccuracy in estimation of flood damage and related statistics.
61. Attempt should be made to fill the knowledge gaps through systematic, proactive and
participatory process. More integrated science & technology with better forecasting tools are
needed to enhance the hydro-meteorological monitoring system integrated with online
measurement instrumentation.
19
62. Enhancing the knowledge base also calls for integration of traditional knowledge wherever
found appropriate, as there is a general belief that several indigenous societies of NE are known
for sustainable water management practices. Apart from stakeholders participation in water
management issues, sound information systems, better access and exchange, open information
policy can help to improve the knowledge gaps. Similarly, enhancing education, communication
and participation to facilitate community involvement may contribute to improved planning and
management. Hydrological and meteorological information for general water resource
management need to be strengthened, besides flood forecasting.
63. Availability of data for evaluation of completed water management projects by experts need
to be ensured. Cross sectoral collaboration is a sine qua non for broadening the knowledge base.
There is also need for specific studies targeting supply and demand. Model studies for analysis,
planning and management of wide range of water resources and environmental problems and
wider application of remote sensing and GIS technology for water resource development action
plan would augment the scientific data base. Other areas where knowledge base needs to be
strengthened are water hazard mapping and groundwater mapping, water harvesting potential
assessment, trade-off analysis and potential conflict resolution assessment, and climate change
impact study. Any future water resource assessment in the region, apart from taking into account
fund requirements for the sector, should also consider the aspects of environmental water
requirements, water quality control, and impact of virtual water trade in future as also integrated
land and water management for food and environmental security. Last but not the least, long
term human resource development and training plan is an important factor in ensuring a quality
knowledge base.
14. Conclusion
64. Addressing the vast needs immediately is difficult. However, there are several priority
aspects that are essential to bring the current knowledge base to a level of acceptability to start
with any meaningful water resource management initiative. Strengthening the water quantity/
quality monitoring and assessment mechanism to consolidate the knowledge base is such an
urgent need. Radar alternatives for real time measurement of velocity and depth profiles across
streams/ channels along with improved rainfall data set combining rain gauge data with weather
radar data is one example. With such real time data, model studies for analysis, planning and
management of wide range of water resources and environmental challenges will be possible. As
in the case of the Yellow River, once a fully dependable decision support system befitting the
complex water resource scenario of the Brahmaputra-Barak system is in place, the creation of a
‘Prototype Brahmaputra’, a ‘Digital Brahmaputra’ followed by a ‘Model Brahmaputra’ can
become a reality, paving the way for its optimized management.
65. The extent of people’s dependence on a large river system like the Brahmaputra-Barak has
rarely been fully realized to offer appropriate water management efforts. Knowledge of the
Brahmaputra-Barak system, considering its strategic location and critical implications, must be
improved. How such a large water system will respond to future geo-biophysical changes must
be investigated. Gaining scientific knowledge to build sustainable technological responses falling
under the consideration of integrated, interdisciplinary efforts that will convincingly link
development with societal benefits such as flood hazard mitigation and hydropower development
20
is thus overdue. More integrated science & technology and better forecasting tools will enable
exploration of potential "win-win" opportunities for sounder water resource management, for
example, managing the river to minimize water hazards, and maximize natural resource
conservation, watershed protection along with less obvious benefits such as carbon sequestration,
simultaneously.
66. Finally, it may not be necessary to manage all the knowledge that one can lay hands on, but
to focus only on relevant and critical knowledge that will also help to clearly map the knowledge
needs, besides developing clear parameters for assessing the effectiveness of the knowledge
base. To conceive and realize a water resource knowledge management system, the concerned
agencies will require articulating a knowledge management strategy in clear terms that is in
alignment with the broad water resource management strategy. In case of the Brahmaputra-Barak
system, this may evolve by weaving together several random repositories to establish a pattern in
the form of critical issues involved in implementing a overall water resource management
programme, the constituents of required knowledge management architecture, and the
interrelationship among different components.
67. Due to the information revolution, what is significantly different today is the ability to
manage “knowledge” within one single organization. Knowledge is defined as the “capacity to
act”. What is needed at this stage is i) what the water resource organizations of the Northeast
know, how they use what they know, and how fast they can know something new, ii) an explicit,
disembodied, consistent representation of available knowledge and information; and iii) a
systematic and organized attempt to generate new knowledge within an umbrella organization
that has the ability to store and use knowledge for improved performance.
21
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