LTReikšminiai žodžiai: Lietuvos Didžioji Kunigaikštystė (LDK; Grand Duchy of Lithuania; GDL); Valdymas; Struktūra; Eksploatacija; Lietuvos Metrika; Grand-Ducal Estates; Management; Structure; Exploitation; Lithuanian Metric.
ENThe article presents the characteristics of the source base and proposes methodology of research on an important economically and communicatively element of the geographical environment, which were the water resources o f the Grand Duchy of Lithuania (until the end of the sixteenth century). [From the publication]