Rainwater Harvesting - WWF, Nepal

Rainwater Harvesting at WWF Nepal Office, WWF's Green Office example

Background:
There is acute water shortage in Kathmandu Valley as is also the case in whole of Asia. Nepal's climate ranges from tropical in the lowlands to the arctic in the higher altitude. About 90% of the rain falls during the monsoon June to September. The temperature is varied place to place due to it's topography variation. Kathmandu Valley in September 2012 received 126 mm of rainfall, a record for
24-hour downpour since 1968, according to the Meteorological Forecasting Division (MFD)

Nepal is the second richest country in water resource in the world. However the capital city, Kathmandu faces acute drinking water scarcity. Most of people in the city cannot get clean and enough water for their daily usage. With the introduction of rain water harvesting in the WWF Nepal office in 2006, we moved a step
closer in practising what we preached on the grounds of conservation.

Definition:
Rainwater harvesting is the accumulation and deposition of rainwater for reuse. It is mostly used for water for garden, water for livestock, water for irrigation, etc. In many places the water collected is just redirected to a deep pit with percolation. The harvested water can be used as drinking water as well as for storage and other purpose like irrigation.

Method:
At WWF Nepal, all roof tops have been lined at the edges by a collecting canal that ultimately joins a tube that leads to tanks where water is stored. The system is very simple yet efficient to collect all the rain water from the roof tops.

Use:
The rain water collected thus has multiple use in the office, i.e. watering the garden, washing office vehicles and cleaning the office area. In addition to the above uses, the rain water harvested is also used to recharge the underground water. There is a lot of extraction of underground water in Kathmandu to meet the basic requirements for people. The water level is also slowly diminishing with over extraction in most places. At WWF Nepal, we also use the rain water to recharge the underground water by supplying the collected rain water into the well.

- Prajana Waiba Pradhan / Senior HR Officer, GO coordinator