For this PhD thesis, the reports of human encounters with water were used to evaluate the allocation of duties and responsibilities within Holland’s urban communities between 1600 and 1660. This was done by systematically examining the reports of water-related issues in (a) notarial records and (b) petitions to the urban magistrates, originating from the cities of Alkmaar, Haarlem, The Hague and Rotterdam. Additional archival sources, such as patent applications, tendering documents, and legal records helped to put the findings from the notarial records and petitions into perspective. The overall conclusion of the thesis is that taking water as a viewpoint reveals that the urban communities of Holland were highly subsidiary in nature. Individual townspeople, men and women alike, knew how to fend for themselves, incidentally having recourse to other inhabitants, businessmen, corporations or magistrates. Together, they constituted a tiered society, wherein nearly each entity bore the responsibilities that fitted its capacities.