At the heart of New Public Management (NPM) reforms lies a theory of accountability for results. In the past three decades, this normative idea transferred from the “Anglo-American heartlands” of such reforms to many other parts of the world. By means of an organizational ethnography of a Mexican water users’ association, the article shows that, in spite of reforms, such an organization can operate as a body that is largely unresponsive and non-transparent to its users and the regulatory authority. The management instead reverses accountability and shifts blame downwardly. Because culture shapes the reform from the inside, reform does not necessarily change and depoliticize managerial practice as intended but does have concrete implications for the practice and effects of accountability arrangements. The article argues that management performs accountability culturally, and this works to morally legitimate managerial conduct that is unaccountable for results and produces a sub-optimal financial and organizational performance. The case study contributes to an interpretive perspective that is applicable to a wide range of administrative reforms that promote accountability in different cultural and political settings. This study leads to specific recommendations to deal with the counterproductive results of NPM reforms in Mexican irrigation management.