Rain water harvesting is not the alternative but the necessity

Kathmandu, August 26

Nepal is the second richest country in water resources in the world and possesses 2.27% of world water resources. The multiple sources of water include glaciers, snowmelts from the Himalayas, rainfall and groundwater. There are more than 6,000 rivers including rivulets and tributaries in Nepal. And there is a sufficient amount of rainfall in monsoon season in Pokhara, Kathmandu and other different places of Nepal.

According to UN- Habitat, the average rainfall in Kathmandu valley is around 1,600mm, which is around twice the world average. But we don't really value it and see how unfortunate we are, not getting the sufficient amount of portable water due to overpopulation, unmanaged urbanization, lack of knowledge and advocacy. According to KUKL, the daily water demand at present is 32O million liters per day but the supply is only around 130 million liters per day. So we have to seek the better alternative to fulfill our water demand. Always depending upon the government and cursing it will be a stupid act. MY eyes were opened widely when I had a field visit on Dallu and observed how we can fulfill our water demand by rainwater harvesting system. So here is a little effort done by me to make all of you aware about it, which is totally based upon my observation.

MY fist spot was Bhuekhel Pokhari, where the ground water recharge was done by rain water harvesting so that the ground water table will replenish. Mr. Narendra Dongol, rainwater harvesting technical expert said, in collaboration with Centre for Integrated Urban Development (CIUD) funded by UNDP and Bhuekhel Community Development Committee, the ground water recharge of this pond was possible. This project was carried two years ago and completed with the cost of Rs 10 lakhs. This pond was mainly for storage, recharge and retaining of water. But due lack of technical knowledge, the use of black clay (Kalo Maato) as a bed layer on this pond, in summer the clay was crack so it could not retain the water and maintain its aesthetic beauty. But the ground water recharge is successful as the water is infiltrated from that pond and help in replenishing the ground water table.

MY second spot was Kathmandu Metropolitan City Office – Ward no 15, where the rain water harvesting itself was practiced in the office building. Mr. Dangol said, there is a storage tank of 12000 liters and recharge well. Previously, the water in recharge well was below 200 liters but now due to rain water harvesting it is more than 400 liters. Except in month of February and March they need to buy water and rest of the 10 months the rain water harvesting can fulfill the water demand of building. He further added that there are total 751 houses in this ward and 40-50 houses had accepted to install the rain water harvesting in their houses. 'The rain water harvesting is made mandatory to the newly constructed building in the Dallu and government also allows the 10% discount on the tax for those houses', said Mr. Dangol. He further added that in this ward there is the probability of construction of 1000 plus houses, in which also the rain water harvesting system will be mandatory, which would be the greater achievement for this ward.

Now, the third spot was 'the House of Mr.Dangol' himself where the rain water harvesting was practiced from last three years. The house had play group school in ground floor and his residence in upper floor. The catchment area of house is 110meter square. The total water demand of house is 1200liters/day. Among which 700liters of raw water is directly pumped from the recharge tube well and 500liters is from the treatment of grey water. The treated grey water is used for flushing in toilets, washing of cars and in gardening, whereas the raw water is used for cooking, drinking and bathing purposes. The treatment of grey water in his buildings was done by anaerobic raffle reaction and water is further sprayed through Narkat and Sarbadha. The offensive odor comes through it which is one drawbacks of treatment of water. He said that its cost two lakhs (Rs. 2,00,000) for him to install rain water harvesting system in his house. He has set the example of individual effort by installing the rain water harvesting system in his house and using the water free of cost after two years of his investment.

 The second last spot of my visit was on the laundry shop, where the shop owner, said that there is a reservoir of 15,000liters capacity, which can fulfill the water demand of six months for his laundry. He added us that he is in profit of Rs.36000 per year due to the rain water harvesting, which is the encouraging fact.

Finally, the last spot was the Community Hospital in Dallu, which had installed the rainwater harvesting system. It has the storage tank of 25-30 thousand liters of water. There is one settling tank, one recharge zone and one well to fulfill the water demand of hospital.

Hence, all above are the example set by individuals, community and helping hands like donor agency's effort to promote the rain water harvesting. If we didn't value the drinking water then it will be the most expensive thing to spend on to survive. So it is time to gear up our knowledge and use it practically to set the example of own self for survival. As KUKL also cannot fulfill our water demand so we shouldn't be on confusion that rain water harvesting system is alternative, in fact it is our necessity.

Nisha Aryal

Student of Bsc.Environmental Science and Management.