Rooftop rainwater harvesting in Nepal


Water in Nepal is not scarce in absolute terms, and most areas receive about 1500mm of precipitation each year, while certain areas may receive up to 5000 mm. However, many parts still experience water shortages, in particular during the pre-monsoon season (March-May). Sufficient and safe drinking water supply throughout the year is essential to Nepalese rural households. However, communities located higher in the mid hill region do not have access to water either because systems are too expensive or impracticable due to lack of electricity.
In this context, rooftop rainwater harvesting provides a local source of water for drinking or kitchen garden irrigation in many areas where conventional water supply systems cannot be provided, with significant impacts on health and livelihood improvement or rural households.


IntroductionRural communities are often unaware of the benefits of rooftop rainwater harvesting and are not likely to construct such systems on their own initiative. Locally available materials and labor can be used to construct the jars, but institutional support is necessary in order to provide technical inputs, raise awareness of the benefits, and provide support on construction and maintenance techniques. Rural communities play a central role during project implementation, but in contrast, their role during the pre-development phase is somewhat limited.

Operation and maintenance expenses are low, in fact, on average every household spends US$ 3,5 and 6 hours per year on maintenance tasks in the system. Although rainwater still requires boiling before drinking, it is healthier than other drinking water sources, especially during the monsoon.

In terms of benefits, every household saves on average 6.4 hours per day in water fetching, especially women and girls. Most women employ the time saved in reproductive activities, such as taking care of the children, cooking or cleaning, or on income-generating activities, such as selling of vegetables from the kitchen garden and livestock. Women have also more time available to participate in social and management activities such as studying, training or accounting. Major availability of water is also directly related to better hygiene practices and an improvement in health conditions in communities.

ObjectiveThe objective of this practice is to ensure water availability for drinking and irrigating kitchen gardens at a time when overall water availability is low.

Implementation of the TechnologyA rainwater harvesting system consists of three basic elements: a collection area, a conveyance system, and storage facilities (Figure 1). The collection area is the roof roof of the house, solid enough to shunt rainwater efficiently and to install a gutter system. The conveyance system usually consists of gutters or pipes that deliver rainwater falling on the rooftop to the storage facility. (Figure 2)

Implementation of rooftop rainwater harvesting system requires substantial initial investment of time and money from households for acquisition of materials, jar construction training and labour, transport of jars to homes, and home installation of jar and gutter system. 

The following questions need to be considered in areas where a rainwater harvesting system project is being considered:

  • Is there a real need for an improved water supply?
  • Are present water supplies either distant or contaminated, or both?
  • Do suitable roofs and/or other catchment surfaces exist in the community?
  • Does rainfall exceed 400 mm per year?
  • Does an improved water supply figure prominently in the community's list of development priorities?

If answer to these questions is yes, a rooftop rainwater system is a feasible water supply option. Further questions, however, also need to be considered:

  • What alternative water sources are available in the community and how do these compare with the rooftop catchment system?
  • What are the economic, social, and environmental implications of the various water supply alternatives (e.g., how able is the community to pay for water obtained from other sources; what is the potential within the community for income generating activities that can be used to develop alternative water sources; does the project threaten the livelihood of any community members, such as water vendors?)
  • What efforts have been made, by either the community or an outside agency, to implement an improved water supply system in the past? (Lessons may be learned from the experiences of the previous projects.)

All catchment surfaces must be made of nontoxic material. Painted surfaces should be avoided if possible, or, if the use of paint is unavoidable, only nontoxic paint should be used (e.g., no lead-, chromium-, or zinc-based paints). Overhanging vegetation should also be avoided.

Rainwater harvesting jars vary in size and costs. The financial cost of a 2,000 litre ferro-cement jar (Figure 3) and gutter system ranges between NRS. 6 000 and NRS. 8 500 (US$ 80 - 110). Costs depend upon delivery fees, which vary according to the number of jars delivered to one locality and the distance of the construction site to the road network, but could also vary according to construction materials.

 A rainwater harvesting jar of 1 000 litres is the minimum size recommended for a household of 2-4 individuals, since rainfall can be sporadic. Harvesting water from a roof area of 20 m2 could meet all drinking water needs of a family of 2-4 people from June to September (monsoon), and 30, 80, and 40% of the total water needs in April, May (pre-monsoon), and October (post-monsoon), respectively. 

 For a complete guide on how to build a rooftop rainwater harvest system, please visit:

For further information, you may contact:





Created date

Wed, 30/11/2011 - 13:57


FAO Strategic Objective 5 – Resilience, in FAO

Sustainable development cannot be achieved without resilient livelihoods. People around the world are increasingly exposed to natural hazards and crises – from drought, floods, earthquakes and disease epidemics to conflict, market shocks and complex, protracted crises. Worldwide, 75 percent of poor and food insecure people rely on agriculture and natural resources for their living. They are usually hardest hit by disasters.   

The recurrence of disasters and crises undermines countries’ efforts to eradicate hunger and malnutrition and to achieve sustainable development. People who rely on farming, livestock, forests or fishing for their food and income – around one-third of the world’s population – are often the most vulnerable and affected. Climate change, in particular extreme weather-related shocks, is exacerbating the situation. SP5 assists countries to increase the resilience of households, communities and institutions to more effectively prevent and cope with threats and disasters that impact agriculture, food security and nutrition. It focuses across all agricultural subsectors on . 

  • natural hazards and related disasters such as floods, droughts and earthquakes 
  • food chain threats caused by plant pests and diseases and animal diseases, as well as food safety threats such as radio nuclear contamination or avian flu
  • conflicts and protracted crises.

SP5 helps countries and communities to prevent and cope with these different areas of risks and shocks through normative guidance, technical standards and their implementation in the field. FAO resilience work feeds into global processes such as the Sendai Framework for Disaster Risk Reduction, the One Health approach for food chain crises and the Committee on World Food Security's Agenda for Action for addressing food insecurity in protracted crises. SP5 country support like the implementation of DRR good practices at country and local levels is delivered in close collaboration with and based on technical advice from FAO technical divisions, including AGA, AGP, CBC, FIA and FOA.


Previous, Climate, Energy and Tenure Division (NRC) in FAO

The Climate Impact, Adaptation and Environmental Sustainability team of the Climate, Energy and Tenure Division (NRC) develops the knowledge base on the impact of climate, climate change and climate variability on agriculture, and facilitates the use of this information and knowledge through field projects. The team also supports capacity development at national level by supporting governments to integrate disaster risk reduction in the agriculture sector as well as identifying, testing and validating in cooperation with various partners climate change adaptation and disaster risk reduction good practice options to build resilience of all actors in agriculture to the impact of climate change and extreme weather events.

Organic Agriculture work in FAO:

The coordination of FAO’s organic agriculture activities is housed in the Climate, Energy and Tenure Division. Since 1999, the Organic Agriculture programme works along three main areas:

  • Strengthening the ability to exchange information and to set-up organic agriculture networks, in order to ensure that producers, operators and governments have access to the reliable and quality information needed for informed decision-making, for directing research and extension, and for making investments;
  • Developing and disseminating knowledge and tools that support organic plant protection, soil and nutrient management, animal husbandry and post-harvest operations, especially in developing countries and market-marginalized areas;
  • Assisting governments in designing the types of legal and policy frameworks that provide support to farmers by facilitating the marketing and trade of certified organic products that meet international inspection and certification standards.

For queries related to climate change and disaster risk reductions, you can contact: or

For queries on organic agriculture, you can contact: Nadia Scialabba.