Our study focuses on the relationship between elected officials and managers in the context of local services management. We analyse the political–administrative interface using Weick’s theory of sensemaking. Our research, based on the case of water services management in Montreal, shows that the loss of expertise in the public sector, coupled with a lack of political vision, leads to a mismatch between the actions envisaged by the managers and the resources available. The organizational purpose needs to be politically defined in order to achieve a reciprocal influence in policy making. This collaboration, or complementarity of politics and administration, allows shared sensemaking that is essential both to a management diagnosis in line with the organizational mission and to strategic decision-making which takes into account the civil servants’ recommendations. Points for practitioners Some urban infrastructures, such as water infrastructure, are neither easily visible nor accessible. Thus, there is sometimes a wide gap between managers’ interpretation of the situation and that of the citizens and elected officials. This is a challenge for the development of common sensemaking. Elected officials must be able to count on a competent civil service that provides them with reliable information, enabling them to make trade-offs with all the relevant facts at hand. It is also in the public interest that elected officials maintain strategic control of the water activity in order for public action to efficiently contribute to the political vision.