Kishnekale, agreed you know some technicalities, but I sensed you have not got enought opportunity to work on the field, particularly in the drinking water sector of KTM. Let me correct your few misconception. 1. valley does not get rainwater throughout the year. it has 9 dry months and 3 wet months. The rain cycle is not reliable except in june july throught the year. Interannual and decadal variabilities are high. Convective rains and sporadic cloud bursts are not easy to harvest. More than that the rainwater is not available during the driest period. So, rainwater harvesting as a supplement of drinking water supply has less chance of success despite some study projects and NGOs would show up their grand success in pilot studies. Notice that those projects are often funded to bring desired results rather than uncovering the truth. 2. High concentration of dust, aerosols and other air-pollutant coming from vehicular exhust is another problem which pollutes the harvested water as soon as it drops on a surface. Test-studies have indicated that at least 3 consecutive rain-days are required to clean up accumulated dust on a rain-harvesting surface despite proper maintenance during the dry-period. There are alternates but that need high alert level, proper awareness and more investment. 3. Permeability of soil of KTM valley is too low as it has 100 to 3000 m thick clay layer at its top. This has both pros and cons in many aspects but for drinking water, this clay deposit can't be seen as an advantage. Due to this high impermeable top layer, the rainewater does not infiltrate into subsurface deposit as people assume to happen so easily, but they get flown out from there because the landscape does not allow enough retention despite having comparatively flat land. On top of that massive concreting of the surface has reduced that possibility by almost 40%. Therefore the runoff coefficient of Kathmandu valley and bagmati catchment is very high compared to other river basins of similar hydrology. 4. Water yield of Dhungedhara and Wells are too low because they collect water seeped through clayee soil. Therefore they provide slow but consistent water supply. Also people often tend to forget that how our ancestors had prevented upstream infiltration catchment for those installation. For example, you might know the story behind how and why Sundhara stopped supplying its precious water after the construction of Karmachari Sanchay Kosh building. Adding a well or Dhungedhara is not that difficult but to assure this well or dhungedhara performing well requires a lot of knowhow, on which people tend to overlook. 5. Those traditional infrastructure was providing sufficient drinking water for conservative use of very small population in the past. Just see how the population sky-rocketed to 40 lakh from 5 lakh in last 30 years, and how their water consumption habit also increased too high. People these days want to have daily shower, flush toilets, hot-cold water running 24/7 in their tap (they are not getting, that is different but they want that to have in their home). Traditionally, Kathmanduits used minimal water for sanitation purpose and on top of that they had practiced traditional recycling techniques which made them self-sustained to meet their water demand. 6. Sundarijal reservoir, and upstream bagmati catchment could be effectively managed to reduce the level of scarcity, but not to eliminate. Also that needs high level of conservation programs and continued expensive effort in entire upstream bagmati watershed, which has been a huge project in Nepal for several years. It might not be good idea to blame them, but it is clear they are not yet successful to bring any significant outcome despite pouring so much money over the year. Let me assume, that program would be a 100% success and still that would not guarantee reliable water supply. 7. I agree with you, a 'safe' groundwater level is very very necessary, but it is degrading to a highly risky level due to haphazard domestic well construction, pumping here n there and failure to recharge the source. 8. I don't want to talk about Sthapit syndrome, we need such a person sometime, but we should be cautious enough to run behind blindly.