The frequentness of serious natural disasters will rise against the background of climate change in the next decades. One of the most severe impacts of natural disasters is the interruption of drinking water supply. Contaminated water causes the death of thousands of people worldwide every year. Mobile waterworks used by aid organizations are sophisticated systems with high demand of energy, skilled personnel and chemicals. They are designed to supply larger communities in the range of (several) thousand people but small and secluded areas can not be reached. The Department of Sanitary and Environmental Engineering (DESEE) at University of Kassel developed a small, transportable and easy to use dead-end membrane filtration unit for basic water supply in cases of natural disasters for small groups in the range of 200 up to 500 people in remote areas, the “WaterBackpack”. Experimental long-term series show that the unit is able to provide water in sufficient quantity and quality for the defined use case. Tests with contaminated surface water revealed, that a minimum flux of around 5 L m−2 h−1 can be kept up over a period of more than two month without any cleaning or maintenance.