Dear Badri, I understand ...
Published by Arend van Riessen, Freelance Consultant at Various organisations and programs
Dear Badri,
I understand the existing situation is a mix of different more or less independent water supply schemes serving all those (up to) 25,000 people living scattered and in bazaars on a hill hundreds of meters above rivers and other potential sources. The report looks as if you like to replace everything by one pumping scheme or to merge all schemes and add water from a pumping scheme. Your request suggests that cost and reliability of electricity might be a obstacle for operating the system. The only alternatives seem to be solar power and rams.
The suggested Water Rams have been tried on small scale in Nepal since long ago, but did not catch on. There must be reasons for that. There are issues with theft and hooliganism for such technologies, but the main issue is probably that water has first to come from high up and where in Nepal you will find large quantities of water (25000 people) high on the hill at the other side of the river?
Solar powered pumps seem more feasible, but have in Nepal not been proven yet for longer periods and larger schemes. In a country where only 60-70% of water supply schemes is reasonably functional and large schemes have more problems than medium/small schemes, you need more guarantees that the owners can maintain and operate the schemes without too much problems and for a long time. I think you can only go for solar if you dont merge all the small schemes and keep them separate and "small". The most relevant source of info for your Gorkha might be DOLIDAR's RWSSP-WN project (Pokhara office), which has built solar powered water supply schemes and should by now have enough experience to share best practices, dos and donts.
Best wishes, Arend