Suman Shakya’s Home in Chakupat, Patan

The complete rainwater harvesting system for Suman Shakya's house in Chakupat.

Suman Shakya’s House in Chakupat

Municipality water supply is intermittent and doesn’t meet half the demand of the Kathmandu Valley population. Most of the well water in Kathmandu is yellow-tinted from the iron and has a smell caused by ammonia. People are forced to use this water for a lack of alternatives leaving their clothes stained and their taps and toilets stained and frequently broken. Mr. Shakya’s case was no different. His well water is rich in iron and he debated whether or not to even connect to the municipal line because of the difficulty and unreliability of the water. In this grim scenario, Mr. Shakya had no option other than buying tanker water for his family’s daily uses; both expensive (>3000 rupees per month) and increasingly unreliable because of frequent fuel shortages and high demand from other customers.

Luckily he met Tyler McMahon, a former Fulbright scholar who researched the economics of urban rainwater harvesting. Tyler, who is an environmental economics graduate from Colorado College, suggested both rainwater harvesting for direct use and groundwater recharge and bio-sand filtration for well water at Mr. Shakya’s house. With the help of senior technicians, Raju Dongol, Gokul Dangal, and Hem Narayan Shrestha, a complete rainwater harvesting system with bio-sand filtration was finally installed at Mr. Shakya’s house.

There was no problem installing the rainwater harvesting system at Mr. Shakya’s house, it was an economical choice saving him several purchases of tanker water trucks yearly. But since he was also willing to have bio-sand filtration system, his well water was sent for a lab test before installing the filter. Among the tested physio-chemical parameters Ammonia, Iron and Manganese content exceeded the National Drinking Water Quality Standard (NDWQS) value at the time of analysis. Also the bacteriological parameters were high, the water sample was contaminated with E-Coli bacteria and Coliform. However, this water after passing through two bio-sand filters, all of the water potability parameters were found to be within the NDWQS values.

Biosand Filtration before and after water comparison

Before and After Biosand Filtration

Mr. Shakya, who at first doubted the efficiency of the bio-sand filter, drinks the same well water. The complete rainwater harvesting system and bio-sand filter has made his family self-sustained in terms of water usage, no municipal connection is needed or tanker water trucks purchased. Additionally the system is environmentally sustainable. “While I have a system of extracting water from the well, I also recharge the excess water into well and contribute to nature’s cycle”-says Mr. Shakya with satisfaction.