Water and Urban Initiative
Working Paper Series
Number 03 — April 2015

Current Status of Water
Environment in Kathmandu
Valley, Nepal

Niranjan Shrestha Environmental Services Nepal Pvt. Ltd., Lalitpur, Nepal
Alaka Lamsal Environmental Services Nepal Pvt. Ltd., Lalitpur, Nepal

Ram Krishna Regmi United Nations University Institute for the Advanced Study of Sustainability,
Tokyo, Japan

Binaya Kumar Mishra United Nations University Institute for the Advanced Study of Sustainability,
Tokyo, Japan

Water and Urban Initiative
This working paper series shares findings produced as part of the research activities under the Water and Urban Initiative(WUI), a research project of the United Nations University Institute for the Advanced Study of Sustainability (UNU-IAS). TheWUI aims to contribute to sustainable development, focusing on developing countries in Asia, by providing policy tools and an
information platform to assist planning and implementing policies for sustainable urban and water environment.
To find out more, please visit unu.edu/research/water-and-urban-initiative.html© 2015 United Nations University. All Rights Reserved.
The views expressed in this publication are those of the author(s) and do not necessarily reflect the views of the United Nations University.Current Status of Water Environment in Kathmandu Valley, Nepal

ABSTRACTThis research has reviewed existing water quality management frameworks and spatial relationships between land
uses and urban water quality in Kathmandu Valley. Primarydata on water quality has been collected through samplingof river water from various locations within the valley. Similarly, review of secondary data and related literature fromvarious sources, field observation, interaction and discussion with concerned stakeholders of various governments
and non-governmental line agencies were carried out toperceive the existing water environment situation of thevalley. All these data and study indicates that urban water
quality in Kathmandu valley is not good enough to sustain
healthy water ecosystem. Deteriorating quality of river water has caused frequent cases of water borne diseases suchas diarrhea, dysentery, cholera, and skin diseases amongpeople living in riverside areas. It has also reduced thereligious, recreational and aesthetic value of rivers.
Keywords: urban water environment; urbanization;
wastewater; water ecosystem; sampling of river water;water quality modeling; river restoration activities; land use
planning

1. Introduction
Kathmandu, the Capital City of Nepal, is selected as oneof the study area for case study of low carbon urban water
environment project under research program titled ‘Waterand Urban Initiative (WUI)’ of UNU-IAS (United Nations
University - Institute for the Advanced Study of Sustainability), Japan. Increase in transient and migrant population inKathmandu leads to haphazard urbanization of Kathmandu
valley resulting in heavy pressure on existing natural resources. Water quality of rivers within Kathmandu, is deteriorating due to over population and its consequent stresson the environment. Water resources are being increasingly
polluted by domestic, agricultural and industrial wastes.
Kathmandu valley was at pristine condition before somedecades ago. People cultivated for their livelihoods. Mostof the valley floor was used for agriculture and farming.
After the onset of democracy in 2007, the valley witnessed
rapid immigration in past few decades. People who wereengaged in farming have shifted to urban life now. Largesewerage pipes were added to the rivers as river tributaries
to the river. The population of the 899-square kilometer valley has increased fivefold in the last 60 years, from 197,000
people in 1952 to 997,000 by the time of the 2001 census.
Meanwhile, the built-up area has increased by 134%, from24.54 square kilometers in 1989 to 57.32 square kilometersin 2006. Not only is the surface water the groundwater
depletion also very high.

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2. Method and Materials

This case study tries to assess the existing urban water
environment of the Kathmandu Valley through urban water
quality modeling for the sustainable urban water environment of the valley in future. This research has reviewed
existing water quality management frameworks and spatial
relationships between land uses and urban water quality
measured with biological, water chemistry and habitat indicators in some representative urban watersheds. Primarydata on water quality has been collected through samplingof river water from various locations to assess the urban
water quality within the valley. Similarly, review of secondary data and related literature from various sources, fieldobservation, interaction and discussion with concerned
stakeholders of various governments and non-governmental line agencies were carried out to perceive the existingwater environment situation of the valley.

3. Water Quality Management Frameworks
There are several legislative arrangements aimed at improving urban water quality in Katmandu Valley. The Water
Resources Act, 2049(B.S) focuses on the utilization of natural resources without causing any considerable damage tothe resource. The Aquatic Animal Protection Act, 2017(B.S.)
prohibits use of explosives and poisonous substances inany water bodies. Similarly, Environment Protection Act,
1996 (A.D.) focuses on environmental protection withproper use and management of natural resources. Likewise,
the Kathmandu Valley Development Authority Act, 2045
(B.S) empowers the authorities to regulate the environmental situation of the Valley in a more holistic manner.
The Industrial Enterprise Act, 2049(B.S) gives due consideration to environmental pollution problems and Waste
Water Management Policy (2006 A.D.) recognizes the needto improve compliance with standards and to improvecoordination among various stakeholder agencies to foster
public-private partnership and proposes separate sewerage for storm and sanitary sewage.

4. Wastewater Treatment Plants in Kathmandu
ValleyWastewater treatment plants have very important roles
in keeping city clean. Although government of Nepal has
recognized the problem and established various treatment
plants at well designed locations of the river reach, thetreatment are unable to function and the sewage mixes
directly into the rivers. The wastewater treatment plants
and their operational status are summarized in the Table 1
below:

Current Status of Water Environment in Kathmandu Valley, Nepal

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Table 1: Wastewater Treatment Plants, their capacity and operation status in KTM valley
Key: mld = million litres per day; Source: Timilsina 2004; Nippon Koie et al. 1999; Metcalf and Eddy 2000; ENPHO leaflet

Plant

Capacity (mld) and typeStatus

Dhobighat: receives wastewaterfrom the main urban area of KMC.
Constructed in 1978 with IDAfunding

15.4 mld. Oxidation Pond consisting of two primary anaerobic
ponds, one secondary facultative
pond, and a tertiary aerobic pond.
Wastewater requires pumping
from Sundarighat pump station.

Not operational, out of operation
almost since construction. Problem began with pumping wastewater and conveying throughunder-river sewer.

Kodku: receives wastewater bygravity from eastern core areas ofLalitpur. Constructed in 1978 with
IDA funding

1.1 mld. Oxidation Pond: consistsof two primary/anaerobic ponds,
one secondary facultative pond,
and one tertiary/maturation pond

Partially operational but inefficient
Poor O&M: Sludge accumulationand non-functioning flow-control
valve, resulting flow short-circuiting (less detention time).
Farmers tap raw sewage flowing
through sewers for irrigation

Sallaghari: receives wastewaterfrom some parts of Bhaktapur urban area. constructed in 1983 with
GTZ support

2.0 mld. Originally designed as
an aerated lagoon system using
diffused aeration equipment. The
plant is now converted to a nonaerated lagoon.

Partially operational
Difficulties related to pumping
and operation of mechanical aerators.
Farmers tap raw sewage flowing
through the sewers for irrigation.

Hanumanghat: serves only a small 0.5 mld. Originally developed aspart of the core area of Bhaktapur. an aerated lagoon
Constructed in 1977 with GTZ
supportPartially operating as an oxidation
pond/non aerated lagoon withlow efficiency

Guheshwori: constructed by High 17.3 mld. Activated sludge oxidaPowered Committee in 1999
tion ditch

In operation. High operating
costs: in 2005, it was over 10 million (about 65% of this was forelectricity). Foaming in aeration
tank is the major technical difficulty. There is also a sludge rise/floatation problem in the secondary clarifier (Sah 2006)

Teku: constructed by Kathmandu
Municipal Corporation

Constructed wetland – verticalflow bed

For treating septage (from septictanks). Not in operation

Madhyapur Thimi: constructedwith technical support fromENPHO as a pilot demonstration
activity of ADB, UN-Hbitat, andWater Aid Nepal

Reed Bed Treatment System –horizontal/vertical flow bed

In operation. Serves around 200
households, and receives about 30
m3/day of sewage. The municipality looks after the O&M.

Water quality sampling stations for water quality data
Whole drainage basin of Bagmati river territory was considered for the study. 21 sampling locations were fixed at Bagmati River and its tributaries. The stations were monitored
for two times for indicator parameters like Temperature,

Dissolved Oxygen, Biological Oxygen Demand, ChemicalOxygen Demand, Total Suspended Solids, Total Dissolved
Solids, Total Kjeldal Nitrogen, Total Phosphorous, Mercury,
Lead, Chromium, and Fecal Coliform.

Current Status of Water Environment in Kathmandu Valley, Nepal

4Figure 1: Water quality characteristics at various location Bagmati River

5. Results and Discussion
Bagmati River was found to be good at the source. As recommended by BBWMSIP (1994), the desirable BOD levelfor drinking and aquatic life is 4mg/l and bathing and agriculture is 10mg/l. At Sundarijal, the BOD and COD values
were found to be within the BBWMSIP guideline indicatinggood water quality. It can be observed from Figure 1 thatwith the increase in Organic load (BOD and COD) in riverwater, the dissolved oxygen decreases. BOD and COD arepollution indicator parameters mainly derived from Organic
wastes. The decrease in dissolved oxygen with the increasein BOD and COD can be credited to the use up of oxygenin the oxidation of the wastes.
At core city areas, the dissolved oxygen concentrations isbelow 1mg/l which shows that the water is anoxic and such
water is poisonous for aquatic lives (Chapman, 1992). As
the river flows downstream the river gets more polluted
and by the time the river reaches Chovar the river water
quality is analogous to grey water based on the greywater
characteristics as described by Metcalf & Eddy, (2003).
Similar observations were made by Lamsal, (2014),Tachmaho & Shah, (2013) in Bagmati river.

6. Nutrients
It is observed that Bagmati river water consists of excessive
nutrients. The concentration of Nitrates and Phosphates
is very high. The probable cause of this is the mixing ofhousehold greywater rich in nutrients.

Figure 2: Nitrate and phosphate value at two location of BagmatiRiver

7. Conclusion and Recommendation
All these data and study indicates that urban water quality
in Kathmandu valley is not good enough to sustain healthywater ecosystem. Instead of sustaining life, they havebecome the carrier of diseases and pollution. Deteriorating quality of river water has even caused frequent cases ofwater borne diseases such as diarrhea, dysentery, cholera,and skin diseases among people living in riverside areas. It
has also reduced the religious, recreational and aesthetic
value of rivers.

Current Status of Water Environment in Kathmandu Valley, Nepal

Although there are strict legislations regarding protectionof Bagmati river basin, the rapid deterioration of the basin
is due to problems in institutional arrangements, crosscutting issues in governmental agencies and lack of holistic
mechanism for the protection of the resource.
Besides various ongoing river restoration activities like construction of sewage diversion structures, concretizing riverbank for bank stabilization, altering river flow, flow modification, sewerage line construction work and river cleaning
campaigning, Effective management plan with appropriate
land use planning and various water quality improvement
measures is necessary for the sustainable urban water environment in Kathmandu Valley.

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