There are several off-grid sources of water, including rainwater catchment, wells, rivers and humidity in the air itself. The first goal of any homestead is to identify a water source and begin to protect and manage it. Even when there is no water source apparent, there will be when it rains.
Catching rain water from your roof is the most accessible source of water off-grid. Everyone gets at least a little rain, and if you size your roof and storage to match your annual rainfall, you need never go without water.