Rain water harvesting in Kathmandu

The capital city Kathmandu, always facing problem of availability of water to its minimum level of consumption can be partially reduced by the process of rainwater harvesting. And, if proper methods and long term plan is executed then even it can bring a drastic change. In recent years, many residential houses in the valley are well engaged in rainwater harvesting. They are using simple method like just hanging plastics and collecting water as well as planned ways like collecting water from the roof, filtering and storing in underground water storage tank.

Now days, even many commercial buildings are using the mechanism of rainwater harvesting and they are capable of storing thousands of gallens of rain water. If we go out of valley, in Palpa, there is Mission Hospital. This hospital has used rainwater harvesting mechanism and stores enough water during rainy season that fulfills the need of water for one year serving 500 bed patients and all hospital works. Even I used this mechanism in this rainy season and collected enough water. Here I will provide some mechanism for rainwater harvesting.

How to harvest rainwater:

1. Rooftops: If buildings with impervious roofs are already in place, the catchment area is effectively available free of charge and they provide a supply at the point of consumption.
2. Paved and unpaved areas i.e., landscapes, open fields, parks, stormwater drains, roads and pavements and other open areas can be effectively used to harvest the runoff. The main advantage in using ground as collecting surface is that water can be collected from a larger area. This is particularly advantageous in areas of low rainfall.
3. Waterbodies: The potential of lakes, tanks and ponds to store rainwater is immense. The harvested rainwater can not only be used to meet water requirements of the city, it also recharges groundwater aquifers.
4. Stormwater drains: Most of the residential colonies have proper network of stormwater drains. If maintained neatly, these offer a simple and cost effective means for harvesting rainwater.

These are some mechanism which are being used for rain water harvesing. This methods of collecting water in Kathmandu valley is increasing day by day. As the problems of water deficiet is rising in capital, people are more conscious on alternating water sources. In my views, government should motivate local people at its each level to use this technology.