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[[category:Nepal]][[category:Water Management]]
''Arjun Paudel''

== ABSTRACT ==

The Bagmati River is the principal river of the Bagmati Basin (ca. 3640km2) in
central Nepal. The river, fed by springs and monsoon rainfall, originates in
the north of Kathmandu Valley (the capital of Nepal) and drains across the
Mahabharat Range to the Gangetic plain. The Basin transacts three distinct
latitudinal physiographic zones (Mountain, Siwalik and Terai) of the Nepal
Himalayas. Hard rock geological formations at the Basin headwaters stand
out as a resistant ridge complex compared to the weak and fragile rock
formations at the middle stretches of the Basin.

The Bagmati Basin currently faces a number of serious environmental and
ecological challenges. Urbanization and industrialization of the Basin
headwaters at Kathmandu contributed to water quality deterioration with
regional consequences on the aquatic ecosystem and on the health of the
downstream sub-basin’s user groups. Increasing population pressure on the
fragile mountain slopes has also resulted in the rapid degradation of the
natural resources. As a consequence, deforestation, soil erosion, landslides,
siltation etc. are occurring in the upper and middle sections whereas
sedimentation and flooding is frequent in the lower stretches of the
watershed. This synergetic effect is of concern for the sustainable use of the
resources and infrastructures.

The overall damage caused by the 1993 flood in the Basin has provided
impetus to Nepalese planners, engineers, environmentalists, policy makers
and stakeholders to think on the Basin-wide environmental perspectives for
the overall sustainability of the project. This paper deals with the various
facets of environmental management and monitoring of the watershed for
its sustainable development.

== INTRODUCTION ==

The Bagmati River originates just below the summit of Shivapuri Hill and is
fed by springs and monsoon rainfall and a number of tributaries as it flows
down from the Kathmandu valley floor and passes through the valley at
Chovar. The river is fed by a number of tributaries originating at
Mahabharat and in the Chure Range before it reaches the Terai at Karmaiya.
The Bagmati River Basin, based on morphology, land-use etc., can be divided into different sub-basins viz. Upper Bagmati, Upper Middle
Bagmati, Lower Middle (Terai) Bagmati and the Lower Bagmati (Terai) subbasin.
The total area of the Basin within Nepalese territory is about 3638km2.
In the 1991 census, the total Basin population was given as 1.6 million of
which 61.5 per cent inhabit the Upper Bagmati sub-basin, where the capital
city of the Kingdom of Nepal, along with other four municipalities including
a number of village development committees, are situated. It is also reported
that a total of 2174 out of 4271 water polluting industries operating in the
country are now in operation in the Upper Bagmati sub-basin.
Increasing degradation of the Bagmati Basin has been evident in recent years
due to rapid population growth and expansion of the urban areas within the
upper Bagmati sub-basin. Uncontrolled disposal of untreated wastewater
(domestic, industrial, solid waste leachate, agricultural runoff etc.) in the
rivers has far surpassed the assimilative capacity of the river. Likewise,
deforestation, soil erosion and landslides have been causal factors of Basin
degradation which is being increasingly threatened by damage to the
infrastructure of reservoir, barrage, canals, bridges and roads from debris,
tree and logs carried by the river during the monsoon season.

A comprehensive environmental study of the Bagmati River Basin was
carried out by the Water and Energy Commission Secretariat using a team of
experts to formulate concrete proposals for mitigation measures for:

• pollution abatement and improvement of the river water of the river
thereby enhancing its assimilative capacity;

• decreasing suspended solids and siltation in river beds, canals and
irrigated fields; and to

• minimizing threats to the stability of infrastructures.

The concept of Basin-wide planning for sustainable development is still new
to Nepal. A development programme based on, and implemented by,
administrative units could not handle and foresee the environmental
impacts in the surrounding vicinity. A basin is a land unit defined by the
natural barriers and the natural resources within such boundaries have
intricate relationships. Exploitation of one resource has a direct impact on
the other. The study was intended to evaluate the environmental conditions
of the existing Bagmati River Basin in order to help in the appropriate
selection of development projects for the Basin development in a sustainable
manner.

== NATURE AND SCOPE OF ISSUES ==

The Bagmati River Basin currently faces a number of serious environmental
and ecological challenges. Uncontrolled discharge of untreated wastewater
and solid waste into the Bagmati River in the upper sub-basin has degraded
the quality of surface water beyond acceptable limits. The impacts of water quality deterioration have regional consequences on the aquatic eco-system
and on the health and cultural, religious and aesthetic values of the
downstream sub-basin user groups. Similarly, the increased population
pressure on the fragile mountain slopes has resulted in the conversion of
marginal land into agricultural land, enhancing the rapid degradation in the
quality of the natural resources. Deforestation, soil erosion, landslides,
siltation etc., the results of excessive resource exploitation in the head
reaches of the Basin, have posed serious threats to the stability and
sustainable use of downstream infrastructures – the Bagmati barrage of the
Bagmati Irrigation Project and the Kulekhani reservoir of the Kulekhani
Hydroelectric Project.

Issues relating to the physical, biological, socio-economic and cultural
environment within the River Basin were reviewed and studied. The specific
issues considered during the study were to:

• assess environmental conditions of the Bagmati River Basin;

• conduct a comprehensive environmental analysis of the sub-Basin of
the Bagmati River Basin;

• make concrete recommendations for the mitigation of river pollution,
solid waste disposal and management, ill effects arising from the
extreme use of river water for drinking water and sewerage problems
in the Bagmati river Basin; and

• investigate the perceived threat to the Bagmati Barrage at Karmaiya
due to accumulation of debris and floating trees by landslides
upstream to the barrage and to propose concrete measures to avert
the threat.


== PROCESS AND PROCEDURAL CONTEXT ==

Environmental assessment study of development projects has been
introduced very recently in Nepal. After the preparation and approval of the
National Environmental Impact Assessment Guidelines, 1993, by His
Majesty’s Government, environmental impact assessment studies of the
larger projects have taken place. After the promulgation and enforcement of
the Environmental Protection Act, 2053, and Environmental Conservation
Regulations, 2054, in 1997 EIA has been mandatory. Since the scope of this
study differs from the project specific activities, the study processes did not exactly follow the provisions made in the Act, Regulations and the
Guideline. The following study processes were adopted to accomplish the
task by the team of experts:

=== Approval of scope of work ===

The proponent, using the available information and literature, finalised the
scope of the work and prepared draft Terms of Reference. Based on the draft Terms of Reference the consultants prepared and submitted the technical
and financial proposals to the proponent and the agreement was reached
between the parties.

=== Scoping finalisation ===

The consultants prepared an inception report identifying issues related to
the Basin and submitted it to the proponent for finalisation. A scoping
seminar was then arranged representing experts and stakeholders. The
environmental issues were presented, discussed and then finalised for the
study.

=== Field study ===

The field study was undertaken by the team of experts in order to collect
first hand the information on socioeconomic conditions, existing
environmental conditions, present activities in the Basin and collection and
analyses of river water samples at different stretches of the Bagmati River
and its tributaries. The information collected from secondary sources was
also verified during this period. Public hearings and discussions at different
locations within the sub-basin were conducted to get people’s perceptions
about the existing Basin environment and mitigation measures.

=== Report preparation and submission ===

Data concerning the sub-basin area was collected from different sources and
compiled, analyzed and interpreted. A report was prepared and submitted
to the client for review and comment. A seminar was conducted to present
the study findings at the central level. Detailed discussions were held on the
environmental issues and mitigation measures suggested for Basin-wide
planning. Based on the comments and suggestions made during the
presentation seminar, the consultants finalized the environmental study
report and submitted it to the client.

== APPROACH TAKEN ==

The study approach was initiated through the collection of secondary
information. The collected information was reviewed, analyzed, interpreted
and evaluated in a meaningful way to meet the study objectives. Most of the
secondary information available in the limits of political boundaries was
transformed into the Basin context. As the study emphasizes river pollution
and the effects of erosion and sedimentation at the Karmaiya barrage site,
the field study was mainly focused on these issues. However, other
environmental issues were also dealt with, to some extent, with the objective
of assessing their effects in terms of the sub-basins. In order to collect
baseline data and information about the state of the existing environment in
the Basin, separate matrices on baseline conditions and problems concerning
natural resources and environment were developed and used for this purpose. 
The matrix on baseline conditions and problems definition
regarding natural resources was designed to incorporate information about
the importance, extent of current use, availability of resources for future
economic development, likely future demand, conflicts and availability of
alternative resources. Likewise, the matrix to collect data on baseline
conditions regarding the environment included the significance, extent and
trends of environment degradation, effectiveness of current control
measures, extent of environmental degradation with new protection
measures and the need for new environmental protection measures. A
checklist on the status of data availability on the Basin was also developed
and used to facilitate the study objectives.

Study approaches taken in order to accomplish the task were the following:

Physical Resources 


=== Maps collection, analysis and interpretation ===

Land use, land system, land capability and geological maps of the Basin
were collected and analyzed. Based on these maps, different thematic maps
on land stability, hazards and soil erosion potentials were prepared and
used to qualify the existing environmental conditions of the Basin. Similarly,
topographic maps and meteorological maps were collected to prepare
drainage and elevation and physiographic maps.

=== Water quality ===

Water quality data available were transformed into the Basin river stretches
to qualify the river water quality status in the Basin. For this purpose, river
water pollution from both point and non-point sources based on population,
livestock, agricultural inputs etc., was evaluated in the Basin in order to
assess the river water quality of the Bagmati River system. In addition river
water samples at different locations were collected and analyzed to monitor
the present status of source pollution indicative parameters.

=== Hydrology and meteorology ===

Hydrological assessment of runoff from the Bagmati River Basin was carried
out on the basis of the available hydrological data. Frequency analysis was
carried out on the annual extreme series on annual extreme flows of streams.
Computation of average rainfall over the Basin and rainfall characteristics
such as monthly mean and the maximum daily rainfall were also computed.
Frequency analysis was carried out on the annual extreme series of daily
rainfall. Based on the rainfall data a relationship between monthly
precipitation and monthly runoff was established and was used for the
purpose.


=== Sediment transport ===

Suspended sediment data collected from secondary sources was analyzed
and a relationship between sediment load and river discharge was
determined using suspended sediment data with river flows and Basin
rainfall.

===Soil erosion===

The Basin conditions with respect to soil erosion were evaluated using
available secondary information. Information on soil types, vegetation
cover, landslide inventory maps, land utilization maps, settlement patterns,
human & livestock activities and soil erosion potential and hazard maps was
collected and verified with limited field observations in the Bagmati Basin.

=== Biological resources ===

Available information on vegetation, flora and fauna, land-use pattern,
maps, and other publications were reviewed to analyze the status of biodiversity.
A limited field survey was conducted to fill the data gaps on
aspects of the terrestrial biological. Similarly, a limited field survey using
structured and unstructured questionnaire formats for the local fishermen
was conducted to analyze the status of aquatic bio-diversity, listing of rare
and endangered species, identification of critical river stretches and
relationship between water quality and aquatic life.

=== Socioeconomic resources ===

Information on population, health and education, water supply, sanitation
and solid waste management, economic activities, professional status,
agriculture and industries was collected and analyzed. Different techniques
and tools were used to verify the information during the field survey period.

=== Cultural resources ===

Secondary information on the ethnic composition of the people residing in
the Basin was utilized to broadly categories the cultural traditions and their
interrelationship with the environment. Places of archeological significance
and their state of conservation were discussed, based on secondary
information with verification during the field survey.
Major environmental issues were first identified and analyzed for their
environmental implications in terms of extent and magnitude in the Basin
area.

== RESULTS AND IMPLICATIONS ==

The extent and magnitude of the impacts of the issues concerning the Basin
environment and their implications vary greatly in different parts of the
Bagmati River Basin. The environmental impacts of the following issues
were considered to be the major ones in the Basin.

=== Water quality of the Bagmati River ===

Several studies have been carried out over the last decade to assess the
Bagmati River water quality. However, these studies are considered within
the Upper Bagmati sub-basin (Kathmandu valley river stretch) only. Apart
from the study conducted by the Department of Hydrology and
Meteorology for a period of four years (1992 -1995), other studies do not
provide time series data on the river quality for all seasons of the year. All
the studies have reported that the water quality of the Bagmati River in the
Kathmandu valley is of very poor quality, chemically and bacteriologically,
and unsuitable for any freshwater fauna and flora for most of the dry
season. However, in the rainy season (June - September), water quality
improves considerably due to the increase in the assimilative capacity of the river. River water quality in the upper Bagmati River stretch is rapidly
declining so much that the river is merely a sewer in the dry season. Stanley et al., 1994 have mentioned that the Bagmati River water within the
Kathmandu valley is not fit for drinking water, recreation and irrigation
purposes.
 
Paudel et al., 1995 have estimated that the daily BOD5 generation in the
Kathmandu valley from industries and people is about 42 tons. In the dry
season the Bagmati drains only 40 per cent of the daily BOD5 generation and
the remaining is retained in the valley itself which is becoming a major
source of land and ground water pollution.

[[Image:Pagmati-river.gif]]

''Table 1: Water quality along the Bagmati River''

From water quality analyses results, it is found that the water quality of
tributaries of the Bagmati River outside the valley is found to be good and
can be used for a variety of purposes. River water quality at different
sections of the Bagmati River is presented in Table 1 above and Figures 2-4.

River water quality analysis data shows that the river water within the
valley is bad but as the River passes through the valley the quality of water
improves slowly. After mixing with Kulekhani River water, Bagmati River
water quality improves considerably. This situation continues after mixing
with other tributaries originating in the hills and Chure as well. Water
quality along the Bagmati River outside the valley seems to be improved till
it passes through Karmaiya. However, the river water quality seems to
deteriorate at Bramhapuri due to the disposal of partially treated industrial
effluent from a Sugar Mill. WECS/NESS 1997 has mentioned that the sugar
mill has already started the construction of an effluent treatment plant and
by the time this is completed the main pollution source will be controlled in
the region.

The deterioration of water quality in the upper Bagmati sub-basin has far
reaching implications for the entire Bagmati river stretches because of the
location of the sub-basin at the Bagmati headwaters.

It is reported that the decline in the river water quality has a direct
detrimental impact on the health of the water user groups downstream of
the Bagmati Basin. Incidents of diarrhoea, typhoid, jaundice, cholera and
skin diseases are of common occurrence among the user groups. However,
there are no specific surveys with regard to this. The riverside inhabitants
complain of the occurrence of such diseases in the dry season when they
have no option other than using the river water to meet daily demand.

Livestock toll is even higher in the dry months due to water related diseases.
The polluted river water has seriously impaired the aquatic ecology and biodiversity
along the Bagmati River. Fresh water fish have been completely
wiped out from their habitats in the upper sub-basin and are declining in the
river stretches of the upper middle and lower middle sub-basins.
The river is losing its religious and spiritual significance. The sacred river
water for Hindu devotees has now become filthy and unsuitable for use on
religious and cultural grounds.

=== Sedimentation and flooding ===

Sedimentation and flooding in the Bagmati Barrage and Kulekhani
Reservoir have been identified as one of the major environmental issues in
the Basin posing serious threats to the sustainability and the effective use of
the infrastructures. Excessive erosion in the upland mountains and flooding
and sedimentation in the plains and valleys are envisaged to be the common
features in years to come. In other words the Bagmati Barrage & Kulekhani
Reservoir will be under a constant threat of floods with a high concentration of sediment load. The environmental implications for such structures, in the
event of floods, are well exemplified by the flood of July 1993. Sediment
deposits in front of the barrage at Karmaiya caused wide-spread floods in
the Sarlahi and Rautahat districts. The damage to human lives and property
was immense. Similarly, it has been estimated that over 7.71 million m3 of
sediments were deposited in the Kulekhani reservoir in three days of rainfall
in July 1993, which is very high compared to 1.18 million m3 of sediment
deposited per year during the last 15 years.

[[Image:Bagmati-river2.gif]]

''Figure 2: pH variation along the Bagmati River''

''Figure 3: DO variation along the Bagmati River''

''Figure 4: COD and TES variation along the Bagmati River''

=== Mitigation measures ===

Mitigation measures were formulated with the objective of minimizing the
negative impacts on river water and erosion and sedimentation in the Basin.

The mitigation measures for river pollution include:

• setting of effluent standards;

• setting of ambient river quality standard;

• construction of wastewater treatment plants in the Kathmand Valley;

• on-site sanitation;

• effective solid waste management;

• ban on river bed sand mining in the upper Bagmati sub-basin; and

• increase assimilative capacity of the river in the upper Bagmati subbasin.

The mitigation measures for erosion control and sediment transport at the
Bagmati Barrage and Kulekhani Hydroelectric Power Reservoir include:

Short term measure

• physical intervention

Long term measures

• land stabilization and erosion control;

• conservation of forest resources;

• reforestation of degraded forest;

• discouraging conversion of forest into agricultural land; and

• discouraging traditional agriculture practice on sloping or unleveled surfaces.

In view of the present institutional arrangements, availability of information
and management, establishment of a National Water Resources Research
and Information Centre has been suggested.

== LESSONS LEARNED ==

The concept of Basin-wide planning for sustainable development is still new
to Nepal. The present practice of planning and implementation
programmes, based on administration boundaries i.e. districts and village
development committees irrespective of the Basin, has serious
environmental implications in the balanced natural environment in Nepal.
The environmental constraints posed by the natural boundaries of the
ecosystems are very important in sharing the fruits of development on an
equitable and sustainable basis. Exploitation of one resource has a direct
impact on the other. But this factor was never considered in most of the
earlier development initiatives in Nepal vis-à-vis the development effort
which could not achieve the goal of poverty alleviation of the Nepalese
people. Development activities thus implemented have resulted in serious negative impacts on adjacent areas due to the creation of imbalances in the
existing environment.

Uncontrolled disposal of raw sewage and industrial effluents in the Bagmati
River system has created serious health concerns for the downstream water
user groups. Likewise deforestation, agricultural malpractice in the uplands
and excessive exploitation of natural resources has increased the rate of
erosion, and mass wasting and sedimentation in downstream areas has
posed serious and constant threats to the overall stability of infrastructures.

In view of the experiences and the lessons learnt from the past, the concept
of Basin-wide planning has been felt necessary for sustainable development
in Nepal. Mitigation measures have been formulated, based on the present
environmental conditions and study recommendations, with regard to river
water pollution and short term and long term measures to curb the present
rate of erosion and sedimentation are envisaged to be effective for the Basin
environmental management.


== LIST OF RELEVANT PUBLISHED PAPERS OR OTHER SOURCE MATERIAL ==

Nepal Environmental and Scientific Services (P) Ltd. (1997): Environmental Study of
Bagmati Watershed and Mitigation of River Pollution, Final Report, Water and Energy
Commission Secretariat, Ministry of Water Resources, Kathmandu, Nepal.

Paudel A. (1998): Bagmati River Water Quality Management: problems and
constraints, paper presented in a seminar organized by the Department of Water
Supply and Sewerage, Society of Public Health Engineers Nepal, UNICEF-Nepal and
World Health Organization held on 22 - 23 March, 1998 in Kathmandu, Nepal.

Stanley International Ltd., Mott MacDonald Ltd. and East Consult (P) Ltd., (1994):
Bagmati Basin Water Management Strategy and Investment Program, Final Report, His
Majesty’s Government, Ministry of Housing and Physical Planning/JICA/The World Bank.

''The author:''

Arjun Paudel
Senior Divisional Engineer
Department of Water Supply and Sewerage
HMG, Nepal
GPO Box 7301
Kathmandu
NEPAL