In the article I present the electronic version of the dictionary of hydronyms in Poland. It aims to collect a wide amount of water facilities (both flowing and standing) that have a name (or had it in the past). Each entry in the dictionary consists of the following information: the contemporary name of an object, the physical properties of an object (length, area), the geographic location, the chronological summary of historical records and the etymology of each name. Electronic version of the dictionary (with the assumption of availability online) allows editing the entries, as well as searching and sorting in the database according to multiple criteria and filters. In the article I describe the process of creation of the dictionary and its subsequent use. I also pay attention to the problems we face with data acquisition from different geographic information databases.