Simply put, we don't choose the communities.
We leave site selection up to our partners who often get connected to communities directly.
When people in the community know what they need and ask for help, we call that 'community demand.' It is essential to have the communities already read to contribute their time and energy to the project.
Each of our partners has specific criteria that they look for when engaging a community, but the biggest qualification is simply a willingness of the community to take an active role in the project.
(You might also be wondering if you can request us to do a water project in a particular community that you know of. Because of our model of working with partners in the field, we do not take direct requests for projects.)