WaterAid is a good one. In ...
Published by Mark Kessel, Senior Laboratory Technician
WaterAid is a good one. In the Thar Desert region of India, there is Jal Bhagirathi Foundation (JBF) who works to build capacity in villages in terms of recharging aquifers and growing leadership and have a pro-poor policy stance. They tend to revitalize traditional water collection systems such as stepwells, tablas, tankas, etc...
Another organization who is UK based, is Wells For India . They may go beyond the border and do great work. Also, Excellent Development is UK based and do a lot of work in Africa with Sand Dams, but they have started work in India alongside JBF, also working on Sand Dam technology.
As far as technologies and restorations in your region, it would all depend on the history and contemporary conditions of your water systems, the terrain, culture, etc... and what NGO or leadership would be able and willing to help.