OBJECTIVE: This case study elaborates on the theme of crisis planning and addresses the question of the value of crisis plans and for whom. METHOD: This study is based on the data collected during a water pollution incident and consists of interviews, notes, and observations at a Municipal Council, County Administrative Board, and County Council in Sweden. RESULT: Merton's concept of manifest and latent function offers a new understanding in the discussion of crisis plans. The result is then related to how known the place, task, and situation are to them. The manifest function im-plies that preparing crisis plans are supposed to direct officials in how to act when a crisis occurs. However, the plan was not made by or intended for the operative personnel who handled the water pollution crisis. Rather, this study shows that the personnel acted on the basis of their professional knowledge and earlier experiences when handling the crisis, and their knowledge can be related to the context of the crisis, and how known the place, task, and situa-tion are to them. CONCLUSION: This research adds to the knowledge of the use of crisis plans. It shows that the importance of having a crisis plan is related to how known the situation and the place is to those handling the crisis, and if the task to be done is known to them. Knowing the place and task helps the personnel to improvise in an unknown situation, and the crisis plan is not used. The value of a crisis plan arises when the task is unknown.