Back to my earlier proposal, I have seen from experience that the introduction of certain "advanced" technologies creates a dynamic of its own. Take the mobile phone for instance. My grandmother was at an advanced age when I left her in my car to go and buy something. While there my brother called and she read the name and took the phone, managed to answer and by the time I came back they were in the midst of a conversation. Both my brother and I were "shocked"! I bought a new phone for myself and let her keep mine. It became an experiment for me. I kept buying her newer more advanced phones and she would fumble a bit like the rest of the people but then learn to use most of the ordinary regular functions with as much ease as anybody.
The first man to describe how to end a slum carried out the project with the least amount of drama or large amounts. In short he spoke to the people in the slum as widely as he could. You would call that Focus Group discussions or PRA etc. My experience is that there is no need for surveys. Just talk to people. He identified their main problem to be sewage. If they could just get a sewage system their lives would change. He asked if they want it to each house. They said it did not matter. They could connect to it themselves. He asked if they want toilets (WCs supplied) they answered they would be grateful but could do it on their own. Thus he got funding and installed a sewage system. The few objections by some people who had encroached on public land were settled by resident committees. He would often find the houses located in the path of the sewage system had already constructed their part and would be connected as soon as the section was complete. Locals learned plumbing and taught others. Masons were trained by other masons, people manufactured their own WCs from clay and many learned how to do it and started new careers as toilet makers.
You would find from this description that the problem with "development" in Kenya is the tendency to impose it on people.
Now look at what Waiguru is doing in Kibera. Good work but she has added politics to it. Those trenches are Uhuru's trenches. If you can't hit Uhuru because of his security, you can do some damage to him by destroying his trenches. It would be different if the locals were involved in the planning of the project. The youth from the slums would then do the job and even be allowed to write their names on the sections they have covered. They would be rewarded with being taken in to NYS to further their training as masons, carpenters, electricians, clay toilet makers etc.