Rainwater in the news...

Waiting for the Rain in Kathmandu...

Posted by raindrop on August 6, 2013

Waiting for the rain

  • Rainwater harvesting can help preserve Kathmandu’s groundwater and combat the city’s increasing water crisis.



  • How many of you have installed a Rain Water Harvesting (RWH) system in your home? This question was asked by the facilitator in a programme I attended recently. An RWH system simply collects rainwater for household purposes, including drinking. So much water can be collected this way that most of it may not even be used. But since the monsoon season lasts for five months only, there is always a question of what can be done to fulfill water needs for the remaining months. This is why RWH has been linked to the term ‘recharging’, which essentially means letting the ground absorb water, which can then be extracted during the dry season.

    Everyone in Kathmandu is aware of the city’s water scarcity. Kathmandu Upatyeka Khanipani Limited is unable to fulfill the city’s total demand even in the wet season and groundwater is heavily extracted to compensate for this. While a study by the Japan International Cooperation Agency (JICA) in 1990 stated that the extraction rate of groundwater should not exceed 15 million litres per day (MLD) in Kathmandu, the current rate of extraction is much higher. As a result, Kathmandu’s groundwater level is decreasing by at least 2.5 metres per year. Monsoon rains are crucial to recharging groundwater but with buildings springing up like mushrooms on previously green fields and homeowners paving their compounds, we are preventing a huge amount of rain from entering the ground. This water often ends up on the streets and due to the poor drainage system, forms instant ‘swimming pools’. Water that could have been put to good use is left to stagnate, attracting insects and causing inconvenience to both pedestrians and motorists.

    However, there are measures in place that encourage the use of RWH. Those constructing new houses in Kathmandu can get a 10 percent tax rebate on their building permit fee if they include a RWH system in their design. The installation cost of RWH is certainly not cheap but in the long term, it can be quite beneficial for your finances. The payback period is usually ten to fifteen years and after that, you can enjoy free water supply. If you include a recharge pit, you will be doing a service to the entire community by replenishing groundwater and making sure you have enough water to pump out from the ground during the dry season. You don’t have to fear your well going dry or having to dig another deeper boring due to the diminished groundwater in the near future. Another good idea is to use permeable pavers for your compound and parking lots, which cost just as much as ordinary pavers but allow groundwater percolation and even plant growth while also minimising water logging. There are people who have installed RWH and recharging systems and are managing their water needs without the government water supply line. The harvested water can be used for everyday purposes and even for drinking after purification.

    The average annual rainfall in Kathmandu valley is as high as 1,600 mm. As per UN HABITAT, Kathmandu’s water need can be met by collecting water in just one fourth of the Valley area. However sad it might be, the truth is that Kathmandu today is characterised by dry stone spouts and empty places that were once ponds. RWH and recharging wells can be used to bring these parched structures back to life. Many still depend on these public taps and wells for water. A serpentine line in front of public water sources, especially during the dry season is a common sight. So RWH and recharging is bound to help the entire community. Fortunately, some communities, one in Bhuikhel pond near Swayamb-hunath for instance, have already taken up this practice. However, more communities need to embrace the system to bring perceptible change.

    Most of us are aware of the benefits of RWH and recharging, as well as the looming danger of water scarcity and land subsidence. So why is it that so few of us have RWH-recharging systems installed in our houses? It is time to ask ourselves if we are really putting our knowledge to use or are we just waiting for the government to introduce stricter laws? Should the government make RWH and recharging mandatory? Coming back to the programme that I attended, in case you are wondering how many hands were raised after that first question was asked, the answer is none.


    Pyakurel is a student of environmental science at Tribhuvan University

    Posted on: 2013-08-06 08:58