Water distribution network sectorization projects currently underway in many Mexican cities consist of dividing the city distribution network into smaller sub-networks, or sectors, with one or at most two water inlets per sector. To design the sectors, water distribution network models are used, which review whether the proposed sectorization can adequately function hydraulically. For large network sectorization projects, however, additional algorithmic capabilities are needed, such as connectivity analisys, zone of influence and the contribution of each source on consumption. This paper discusses efficient algorithms of this type based on graph theory, implemented in a computer system.