Local institutions are important in shaping the outcome of adaptation to climate change. In the case of adaptation of local man-made systems, like a water drainage system, both the engineering system design and the institutional design need to be changed. What aspects of institutional design are relevant for the adaptive capacity of such systems? A well-documented case of adaptation in Dutch local water management was studied in order to reveal the manifestations of adaptation. A four-by-four matrix was used for institutional analysis to understand the interdependencies of institutions in the operation, design, financing, and building of water systems. In this case, four types of “institution” facilitated the adaptation of the water system: (1) new principles, norms, and values of local inhabitants with regard to water-system management, tax allocation, and land-use zoning; (2) the presence of stable, national laws that grant responsibility for adaptation of the physical system to local government; (3) adaptable, formal institutions that can be adjusted in response to local changes; and (4) a formalized master plan for implementation and a sufficient budget for steering the water board and stakeholders in their interactions. These lessons were drawn from a case of adaptation to changes in land use: the economy and demography of the area had changed the demand for stormwater drainage. Planned adaptation in response to other changes, like climate change, may benefit from a similar combination of institutions to integrate decisions on operation, design, financing, and building of public water works.