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American Journal of   
Environment and Climate (AJEC)

Impact of  Climate Change on Water Security and Endorsing Importance of  Rainwater 
Harvesting Technology in Nepal

DipanTikhatri1*, Sabu Sharma Bhattarai2

Volume 2 Issue 3, Year 2023
ISSN: 2832-403X (Online) 

DOI: https://doi.org/10.54536/ajec.v2i3.1643
https://journals.e-palli.com/home/index.php/ajec

Article Information ABSTRACT

Received: May 07, 2023

Accepted: July 28, 2023

Published: September 06, 2023

The day-by-day increment in the concentration of  greenhouse gases (GHGs) in the 
atmosphere is widely believed to be a main contributing factor for climate change. It affects 
widely on diverse sectors such as water resources, agriculture, forestry, human health, 
biodiversity, and snow cover and aquatic life. Nepal is experiencing the adverse impact of  
climate change; this includes such as a variability in temperature and precipitation, overbank 
flooding from snow-fed rivers, and variability in available river and stream water quantity. 
Climate in the Nepal Himalayas is changing faster than the global average. Moreover, the 
changes in the high-altitudes have been found more pronounced than in the low-altitudes. 
Since, there is no definite trend that could be found in the annual precipitation records, 
clear decreasing trends could be seen in annual number of  rainy days during the study 
period of  1971-2000. The glaciers in the Nepal Himalayas are shrinking rapidly and there 
will be no glaciers left by 2180. An accelerated glacier melt will cause an increase in water 
availability at the beginning but ultimately a decrease in water availability after the glaciers 
disappear. This will widen the gap between water supply and demand. Changing climate may 
further exacerbate the water stress which already happening in Nepal due to the monsoon 
dominated climate. Climate change (CC) will also further increase the seasonal imbalance- 
too much of  water during rainy season and too less of  it during dry seasons. Rainwater 
harvesting technology has the potential to provide numerous benefits to communities and 
individuals, particularly in areas where water resources are scarce or unreliable. From the 
analysis and through our research work it is found that if  we can simply install and construct 
rainwater harvesting technology in our individual household only. It nearly fulfills about 
15-25% of  our domestic water demand. As in urban and rural area of  Nepal still nearly 
about 50% of  water demand is fulfilled by groundwater source which increase to 60-70% 
in dry season. The projected physical impacts of  climate change on water resources would 
have substantial socioeconomic impacts and consequences for Nepal. The hydropower 
potential and agricultural production would be seriously affected by global warming. A 
reduction in agricultural production would be experienced due to water security and have 
significant impact on the food security and livelihoods of  the subsistence farmers, who make 
the majority of  the Nepal’s population. As the urgent need for climate change mitigation 
remains crucial, putting all the necessary resources and institutions in place for future 
adaptation is indispensable. The Inter-governmental Panel on Climate Change (IPCC) has 
listed rainwater-harvesting as a key strategy for a planned adaptation in the water sector. The 
policy statements about rainwater harvesting-based climate change adaptation are currently 
not being effectively coordinated.

Keywords
Agriculture, Climate Change, 
Forestry, Glaciers, Runoff, 
Water Resources

1 Department of  Civil Engineering, Kathmandu University, Dhulikhel, Nepal
2 Faculty of  science, Health and Technology, Nepal Open University, Lalitpur, Nepal
* Corresponding author’s e-mail: deepankhatri74@gmail.com

INTRODUCTION
Water is an essential to life on Earth and is also vital for 
sustainable development. Without access to safe and clean 
water, humans and other life forms cannot survive. Access 
to water, safe and clean drinking water is recognized by 
the United Nations as a basic human right, essential for 
the realization of  all other human rights (UN Water, 2019). 
Water scarcity and security are becoming increasingly 
important issues as global demand for water continues 
to grow and climate change exacerbates existing water 
challenges. Climate change is leading to melting glaciers 
and changing river flows, which can affect the availability of  
water resources for human consumption, agriculture, and 
industry (UNEP, 2021). Change in precipitation patterns 
due to climate change can lead to increased competition 
for water resources, which can exacerbate tensions and 
conflicts between different users of  water.

Nepal is considered one of  the top ten countries most 
vulnerable to climate change. The country is highly 
dependent on climate-sensitive sectors such as agriculture, 
forestry, and water resources, which are already being 
impacted by changing climate patterns (WFP, 2009). 
The increasing concentration of  greenhouse gases in 
the atmosphere, mainly carbon dioxide (CO2), methane 
(CH4), and nitrous oxide (N2O), is widely considered to 
be the primary cause of  climate change. These gases trap 
heat in the Earth’s atmosphere, causing a rise in global 
temperatures and disrupting the Earth’s climate system. 
The impacts of  climate change are widespread and affect 
various sectors such as water resources, agriculture, 
forestry, human health, biodiversity, and aquatic life. In 
Nepal, climate change has resulted in a rise in temperature 
and changes in precipitation patterns, leading to flooding 
and droughts in some regions. The country’s mountainous 



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terrain and dependence on snow-fed rivers also make it 
vulnerable to the effects of  melting glaciers and changing 
river flows.
Several studies have shown that the climate in the Nepal 
Himalayas is changing faster than the global average. The 
long-term hydrological, meteorological, and glaciological 
data from the region provide evidence of  these changes. 
The average temperature in the Nepal Himalayas has 
increased by 1.5°C since the 1970s, which is higher than 
the global average increase of  0.8°C, over the same 
period (Chaulagain, 2006). The changes in the high-
altitudes have been found more pronounced than in 
the low-altitudes. Although there was no clear trend in 
the annual rainfall records, there was a clear downward 
trend in the number of  rainy days per year during the 
study period from 1971 to 2000. The physical and socio-
economic impacts of  climate change with reference 
to water resources are also sensitive and critical in the 
context of  Nepal. River runoff, total water availability, 
Water quality, glacier extent, evapotranspiration and a 
temperature rise are main governing parameter of  water 
resources due to climate change. This warming trend has 
led to the melting of  glaciers and snow cover in the region, 
which has significant implications for water resources 
and hydropower generation in Nepal and downstream 
countries. The glaciers in the Nepal Himalayas are 
shrinking rapidly and there will be no glaciers left by 
2180. Climate change is likely to exacerbate water 
stress already occurring in Nepal due to its monsoon-
dominated climate. Climate change will exacerbate this 
seasonal imbalance. That is, there is too much water in the 
wet season and too little in the dry season. The projected 
physical impacts of  climate change on water resources 
will have significant socio-economic impacts on Nepal. 
Hydropower potential and agricultural production will be 
severely affected. A reduction in agricultural production 
would have significant impact on the food security and 
livelihoods of  the subsistence farmers, who make the 
majority of  the Nepal’s population.
The Intergovernmental Panel on Climate Change (IPCC) 
has identified rainwater harvesting as a key strategy 
for planned adaptation in the water sector. Rainwater 
harvesting helps reduce dependence on groundwater and 
surface water sources, which can be increasingly stressed by 
changing rainfall patterns and increased demand (Smit & 
Pilifosova, 2003). Most relevant policies, strategies, and laws 
are pre-climate change, do not offer significant value for 
developing specific climate change adaptation strategies, 
and are included in almost all policies for rainwater and 
there is no mechanism to coordinate the actions of  policy 
statements on storage and strategy documents.
Rainwater harvesting is the practice of  collecting and 
storing rainwater for later use, typically for household 
purposes such as drinking, cooking, and cleaning. The 
water is collected from rooftops and other hard surfaces 
such as pavements or driveways and stored in tanks or 
cisterns. This method of  water collection is often used 
in areas where access to clean and safe water is limited 

or expensive. Rainwater harvesting is a sustainable and 
cost-effective way to supplement water supply and reduce 
dependence on municipal water sources. It is widely 
practiced in many parts of  the world, including Nepal 
(ADPC, 2022). Nepal is a mountainous country, with 
the Himalayas covering much of  the northern part of  
the country. Approximately 86% of  the total land area 
is covered by hills and mountains. Forests covers about 
43.4% of  the country’s land area and agricultural land 
covers about 24.1%, almost half  of  the southern flatland 
of  Terai. The average annual precipitation in Nepal varies 
widely, ranging from less than 200 mm to more than 
5000 mm, with an estimated average value of  1830 mm 
(MoFE, 2019). This variability in rainfall patterns can 
have a significant impact on agriculture, water availability, 
and overall economic development in the country.

Objective
General Objectives
To present a water harvesting technology as one of  the 
appropriate solution to mitigate water scarcity due to 
climate change

Specific Objective
• To find Average Annually Rainfall intensity
• To find the average Quantity of  water that can be 

collected from Household
• To investigate relationship between climate change and 

annual precipitation pattern
• To analyze the benefits and significance of  Rain Water 

Harvesting Technology (R.W.T)
• To suggest appropriate design for conveyance and 

storage facility of  rainwater harvesting for individual 
household.

METHODOLOGY
Study Area
Nepal, country of  Asia lying along the southern slope 
of  the Himalayan and Mountain ranges. It is a land lock 
country located between India to the east, south and 
west and Tibet Autonomous Region of  China to the 
north. It is located in 28°23ˊ50ˊ N and 84°07ˊ32ˊ E with 
an area of  147,181 km2. According to the preliminary 
report of  National census 2078, the population of  Nepal 
has reached 2,91,92,480 and the annual precipitation is 
spatially variable with some central and northerly pockets 
of  the country receiving more than 3,000 millimeters 
(mm), the central and southern plains typically receiving 
1,500 – 2,000 mm, and some high-altitude areas in the 
north receiving less than 1,000 mm.

MATERIALS AND METHODS
Although the potential impacts of  climate change 
on water resources have long been recognized long 
time ago, relatively little research has been done on 
rainwater harvesting. The principle focus of  climate 
change research with regard to water security and rain 
water harvesting was to quantify the direct impacts of  



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changing precipitation patterns due to climate change and 
to identify the requirement of  rain water harvesting to 
reduce the impact of  water security.

For Quantification of  Storm water
Rational Method
In our research we have used rational method for the 
quantity estimation of  surface runoff  generated from 
individual household. The rational equation is the simplest 
method to determine peak discharge from drainage basin 
runoff. It is not as complex as other method, but is the 
most common method used for Quantifying storm 
discharge.
Rational Equation:
Q= CIA/360
Where:
Q= Peak discharge, Cubic meter per second C = Runoff  
coefficient
I= Rainfall intensity, mm/hour A = Drainage area, 
Hectare

Identifying Rainfall Intensity
The rainfall intensity is the depth of  water (in mm) 
received during a shower divided by the duration of  the 
shower (in hours). It is expressed in millimeters of  water 
depth per hour (mm/hour). For our research we take a 
data of  precipitation from 2015-2023 on yearly basis as in 
inch per year and converted them into mm/hr. We collect 
secondary data of  precipitation from weather spark then 
we analyze according to our requirement.

Finding the Value of  Coefficient of  Runoff
The runoff  coefficient (C) is a dimensionless coefficient 
relating the amount of  runoff  to the amount of  
precipitation received. It is a larger value for areas with low 
infiltration and high runoff  (pavement, steep gradient), 

Finding to Total Demand of  Water for Particular Area
As in the case of  Nepal there is a quite variation in water 
demand particularly from 45-135 liter per capital per day. 
Generally in rural area water demand is about 45-65 Lpcd 
and for urban area it varies from 100-135 lpcd. Here in 
our research paper we have taken its value as 110 liter per 
capita per day (lpcd).With the data from central bureau of  
statics (CBS) we have calculate the total domestic demand 
of  water for single day.

Finding Total Quantity of  Water That Would be 
Collected Through the RWH
We have used rational method for the quantification of  
water that can be collected from RWH technology for 
single day to month and annually for Bharatpur, Lalitpur, 
Pokhara and Kathmandu.
Finding percentage that RWH technology will cover to 
total domestic water throughout the year On the basis 
of  number of  household and area’s population we have 
determined and analyzed total amount of  water that can 
be collected or recharge through the rainwater harvesting 
and we find its contribution proportion to fulfill total 
annual domestic demand of  particular area.
The study was generally based on secondary data. More 
than 15 scientific journal articles published in international 
journals, several reports, few published books and some 
authorize websites were selected and critically reviewed. 
Here, syntheses have been drawn after reviewing those 
papers in order to calculate the rainwater harvesting 
technology design and water quantity and analysis the 
impact of  climate change in water security of  Nepal.

RESULT AND DISCUSSION
Climate change and water security
Climate change and water security are closely linked. 
As global temperatures rise, precipitation patterns are 
changing, causing more frequent and severe droughts, 
floods, and storms. These changes affect the availability, 
quality, and distribution of  freshwater resources, which 
are essential for human health, agriculture, and industry.
The per capita water consumption of  the Nepal, 35 to 
55 liters per capita per day (LPCD), which is significantly 
lower than the WHO standard, 112 to 150 LPCD. Climate 
change impact the resources of  water which will directly 
impact the per capita consumption of  water in Nepal. 
Agricultural sectors, crops, livestock and horticulture 
largely depend on the water sources mainly precipitation, 
rivers, ponds and groundwater. Variability in climate and 
precipitation patterns impact the soil moisture and rise 
in temperature rapidly increase the evaporation process, 
increasing the demand of  more water. The study of  
the selected area shows that if  rainwater harvesting 
technology is adapted, water demand can be fulfilled. As 
the depth of  groundwater table from surface is growing, 
area with high population like Kathmandu, Pokhara, 
Lalitpur, Bhakatapur, Chitwan, Dharan and Hetauda are 
not able to fulfill their water supply demand.

Table 1: Different Values of  C according to the surface 
material
Surface Runoff  Coefficient
Asphalt 0.70-0.95
Concrete 0.80-0.95
Brick 0.70-0.85
Roofs 0.75-0.95

and lower for permeable, well vegetated areas (forest, flat 
land).As in our research we have consider RCC frame 
structure and cement concrete roof  so we take a 0.8 or 
80% contribution of  precipitation to the surface runoff.

Finding Contributing Area or Catchment Area
Contribution area for the surface runoff  from the 
individual household is taken on the basis of  trend of  
land use and on the basis of  urban municipality’s average 
area of  1369 square feet (i.e. 4 Ana) and permissible 
ground coverage between 0.7-0.75.We have taken 70% 
coverage as a built-up area.



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Annual Precipitation Distribution
Nepal’s climate is highly diverse due to its topography, and 
it can be classified into five broad climatic zones based 
on altitude and precipitation patterns. The Terai region, 
which lies in the southern part of  Nepal at less than 
500m above sea level has subtropical monsoon climate 
characterized by high temperature and heavy precipitation 
during the summer to the high Himalayan region which 
lies in the northernmost part of  Nepal at over 5000m. 
Average temperatures decline from a peak of  over 24°C 
in the south down to sub- zero temperatures in Nepal’s 
highest mountains. Precipitation is spatially variable 
with some central and northerly pockets of  the country 
receiving more than 3,000 millimeters (mm), the central 
and southern plains typically receiving 1,500 – 2,000 mm, 
and some high-altitude areas in the north receiving less 
than 1,000 mm.
The northern regions of  Nepal receive rainfall from both 

the summer monsoon and winter precipitation, which 
is brought in by the westerly winds. Some areas in the 
central and northern parts of  the country, such as the 
Pokhara valley, the Kathmandu valley, and the eastern 
Himalayas, receive high amounts of  rainfall, while other 
areas in the northern highlands receive very little rainfall 
due to the rain shadow effect caused by the Himalayas.
Precipitation plays a critical role in supporting human 
well-being and ecosystems, and changes in precipitation 
patterns can have significant impacts on both. Rainfall 
and the timing of  snow melt and evaporation rate can 
all affect the amount of  surface water and groundwater 
available for drinking, irrigation, and industry. They also 
influence river flooding and can determine what types of  
animals and plants including agricultural crops. Changes 
in precipitation can disrupt a wide range of  natural 
processes, particularly if  these changes occur more 
quickly than plant and animal species can adapt.

Figure 1: Average Annual Precipitation of  Nepal (1985-2021) Source: The soil of  Nepal, 2021

Figure 2: Average Annual Mean Precipitation (mm) of  Nepal over the period 1901-2020



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Rainwater Harvesting Technology
Water harvesting is the process of  collecting and storing 
rainwater or other sources of  water, such as groundwater 
or surface water, for later use. The two common rainwater 
harvesting technologies are surface runoff  harvesting and 
ground recharge.

Surface Runoff  Harvesting
This type of  rainwater harvesting involves collecting 
and storing rainwater that runs off  from the surface of  
roofs, roads, and other impermeable surfaces. The water 
is collected in storage tanks or reservoirs, and can be 
used for various purposes such as irrigation, livestock, 
and household use. This technique is relatively simple 
and cost-effective, but it requires regular maintenance to 
ensure that the storage tanks are clean and free of  debris.

Groundwater Recharge
This type of  rainwater harvesting involves storing 
rainwater underground in order to recharge groundwater 
reserves. The technique involves capturing rainwater in 
storage tanks or ponds, and then slowly releasing the water 
into the ground through recharge wells or infiltration 
basins. This helps to replenish the groundwater supply 
and reduce the risk of  groundwater depletion. This 
technique is more complex than surface runoff  harvesting 
and requires careful planning and management to ensure 

that the groundwater is being recharged effectively.
Both of  these rainwater harvesting technologies have 
their own advantages and disadvantages, and the choice 
of  which one to use depends on various factors such as 
the availability of  space, local rainfall patterns, and water 
demand. The characteristics of  water harvesting can 
vary depending on the specific method or system used, 
some of  the general characteristics are collection surface, 
collection efficiency, storage capacity, water quality, 
maintenances, sustainability and cost.

Purpose of  Rainwater Harvesting Technology
The rainwater harvesting depended upon the technique 
of  water harvesting adapted in the area. The main purpose 
of  rainwater harvesting achieves the water demand of  the 
household, community and society. This can also relief  
the burden of  the government to supply water and to 
meet the increasing demands. As population is growing, 
demand of  water is increasing, government of  Nepal is 
struggling to provide adequate and reliable water supplies. 
By introducing rainwater harvesting to the communities, 
the stress on centralized water system and infrastructure 
can be reduced.

Design of  Rainwater Harvesting
The below drawing is the suggested design after the study 
and analysis of  data.

Figure 3: Average monthly precipitation (mm) in Kathmandu, Bharatpur, Pokhara and Lalitpur over the period of  
2015-2022



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Figure 4: Option 1: Using rainwater harvesting technology directly to fullfill domestic water demand (As a storage)

Table 2: Designing Storage Tank for Individual Household
Area Average No person 

in household
Water requirement 
per day

Water accumulated 
per month

Tank capacity Required per 
House

Kathmandu 7 770 3450 liter Min.8000 liter
Pokhara 5 550 3845 liter Min.10,000liter
Lalitpur 5 550 3757 liter Min 10,000 liter
Bharatpur 5 550 4053 liter Min10,000 liter

Figure 5: Option 2: Using rainwater harvesting technology as a ground water recharge method to increase ground 
water table

Benefits of  Rainwater Harvesting Technology
Rainwater harvesting technology has several benefits 
for communities and individuals, particularly in areas 
where water resources are scarce or unreliable. Rainwater 

harvesting technology has the potential to provide 
numerous benefits to communities and individuals, 
particularly in areas where water resources are scarce or 
unreliable.



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Table 3: Showing the Potential Demand of  Kathmandu, Pokhara, Lalitpur and Bharatpur can be Fulfilled by 
Rainwater Harvesting Technology
Area:-Kathmandu
Average Rainfall (mm/hrs.) 0.078
Quantity of  water collected from single household (MLY) 0.042
Population (Numbers) 2933523
Average no of  household (H.H) 437,354
Domestic water demand (DWD-LPD) 100
Total domesttic water Demand (TDWD) (MLY) 117780.94
Quantity of  water collected from total household (MLY) 18090.79
Potential Demand Full filled by the (RWH/DWD) 0.155

If  Every House of  Kathmandu will be equipped with the rainwater harvesting Technology, simply it can fulfill nearly about 15.5% of  
total domestic demand of  water annually.

Area:-Pokhara
Average Rainfall (mm/hrs.) 0.087
Quantity of  water collected from single household (MLY) 0.0461
Population (Numbers) 5,18,452
Average no of  household (H.H) 101,699
Domestic water demand (DWD-LPD) 110
Total domesttic water Demand (TDWD) (MLY) 20815.8478
Quantity of  water collected from total household (MLY) 4692.0844
Potential Demand Full filled by the (RWH/DWD) 0.2254

If  Every House of  Pokhara will be equipped with the rainwater harvesting Technology, simply it can fulfill nearly about 22.54% of  
total domestic demand of  water.

Area:-Lalitpur
Average Rainfall (mm/hrs.) 0.085
Quantity of  water collected from single household (MLY) 0.045
Population (Numbers) 468132
Average no of  household (H.H) 97,394
Domestic water demand (DWD-LPD) 110
Total domesttic water Demand (TDWD) (MLY) 18795.4998
Quantity of  water collected from total household (MLY) 4390.17
Potential Demand Full filled by the (RWH/DWD) 0.233

If  Every House of  Lalitpur will be equipped with the rainwater harvesting technology, simply it can fulfill nearly about 23.35% of  
total domestic demand of  water.

Area:-Bharatpur
Average Rainfall (mm/hrs.) 0.093
Quantity of  water collected from single household (MLY) 0.0486
Population (Numbers) 369377
Average no of  household (H.H) 77,838
Domestic water demand (DWD-LPD) 110
Total domesttic water Demand (TDWD) (MLY) 14830.49
Quantity of  water collected from total household (MLY) 3786.2
Potential Demand Full filled by the (RWH/DWD) 0.255

If  Every House of  Bharatpur will be equipped with the rainwater harvesting Technology, simply it can fulfill nearly about 25.5% of  
domestic demand of  water.



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Overall, rainwater harvesting technology can help to fulfill 
water demands by providing a reliable and sustainable 
source of  water for households and communities. By 
reducing reliance on municipal water supplies, conserving 
water resources, and promoting sustainable water 
management practices, rainwater harvesting can help to 
ensure that water needs are met now and in the future.

Problems of  Rainwater Harvesting Technology
Rainwater harvesting technology can provide a sustainable 
source of  water for households and communities, there 
are potential challenges and limitations that need to be 
considered when implementing these systems. Limitation 
of  water availability due to variation in precipitation 
patterns, water quality issues, maintenance requirement 
to ensure the collection, storage and distribution system, 
installation cost and legal issue are some of  the problems 
regarding the rainwater harvesting technology.

Law, Policy and Strategy
The Inter-governmental Panel on Climate Change 
(IPCC) has listed rainwater-harvesting as a key strategy 
for a planned adaptation in the water sector. Most related 
policies, strategies and legislations are pre- climate change 
providing no significant value for the formulation of  
specific climate change adaptation strategies and that 
there is no mechanism to coordinate actions for the 
policy statements about rainwater- harvesting that are 
found strewn in almost all policy and strategy documents. 
There is no mechanism to coordinate actions for the 
policy statements about rainwater-harvesting that are 
found strewn in almost all policy and strategy documents. 
There is no mechanism to coordinate actions for the 
policy statements about rainwater-harvesting that are 
found strewn in almost all policy and strategy documents. 
For a more effective adaptation to climate change, 
based on rainwater harvesting, actions are suggested to 
mainstream rainwater harvesting-based adaptation into 
development; to design adaptation as a phased process; 
integrate mitigation and adaptation; put in place effective 
systems for assessment and mapping of  vulnerability; 
avoid maladaptation; establish the centrality of  disaster 
risk management in the institutional setup for rainwater 
harvesting-based climate change adaptation.
In Nepal, the law, policy, and strategy related to rainwater 
harvesting are mainly aimed at promoting sustainable 
use of  water resources, increasing access to safe drinking 
water, and reducing water scarcity. National Water 
Supply and Sanitation Policy 2006, recognizes rainwater 
harvesting as sustainable and cost- effective means of  
providing safe drinking water and also National Drinking 
Water Quality Standards 2007, provide guidelines for the 
design and construction of  rainwater harvesting system. 
Local Level Drinking Water and Sanitation Master Plan 
2016, outlined strategies and action plan promotion of  
rainwater harvesting systems and provides guidelines for 
their design and construction. There are also several I/
NGOs and government agencies promoting rainwater 

harvesting. Although, important of  rainwater harvesting 
was highlighted for a long time, appropriate strategy and 
action planning has not been seen on action at often. 
Therefore, promotion of  rainwater harvesting in Nepal 
is an important strategy for ensuring sustainable water 
management and improving access to safe drinking water.

CONCLUSION
Rainwater harvesting technology has the potential 
to provide numerous benefits to communities and 
individuals, particularly in areas where water resources are 
scarce or unreliable. Climate change impact on the water 
security and impact the temperature and precipitation 
patterns, rainwater harvesting technology has the potential 
to provide numerous benefits to communities and 
individuals, particularly in areas where water resources are 
scarce or unreliable. Promotion of  rainwater harvesting 
in Nepal is an important strategy for ensuring sustainable 
water management and improving access to safe drinking 
water, especially in rural areas. The laws, policies, and 
strategies outlined above provide a framework for the 
implementation of  rainwater harvesting initiatives at the 
national and local levels in Nepal.
From the analysis and through our research work it is 
found that if  we can simply install and construct rainwater 
harvesting technology in our individual household only. 
It nearly fulfills about 15-25% of  our domestic water 
demand. As in urban and rural area of  Nepal still nearly 
about 50% of  water demand is fulfilled by groundwater 
source which increase to 60-70% in dry season. If  we 
can implement the rainwater harvesting technology it will 
also help to excessive extraction of  ground water. In near 
future due to rapid population growth, urbanization and 
climate change, demand of  water is going to be excessively 
increased which ultimately create the water scarcity. So 
our concern authority and local government should 
identify rain water harvesting technology as essential part 
for the ground water recharge and for water resources 
conservation. Every metropolitan city, municipality and 
rural municipality should make guidelines and standards 
for rainwater harvesting technology. They have to make 
a mandatory bye law for the compulsory construction 
and installation of  RWH technology to get a building 
completion certificate for newly constructed buildings 
as well existing building also. Local government should 
start to increase ground water infiltration rather than 
the surface runoff  by reducing the ground coverage 
percentage and promoting rain water harvesting concept.

LIMITATIONS
• As the design study analyze only single household 
domestic demand of  rainwater harvesting, entire rainfall 
harvest is not covered.
• The study area is vast and more research time is required.
• Lack of  availability of  data and document related to 

the study.
• Financial Aspect is also one of  the limitation of  the 

study.



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Acknowledgement
We would like to thanks our professors and friends who 
provided insight and expertise that greatly assisted the 
research. Also like to thank them for the comments that 
greatly improved the manuscript.

REFERENCE
Ayele, Y. A. (May 2014). Rainwater Harvesting for Climate 

Change Adaptation in Ethiopia.
Chaulagain, N. P. (2006). Impacts of  climate change 

on water resources of  Nepal: The physical and 
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