Midwinter breakup and jamming on the upper Saint John River: a case study

Changing climates will likely result in more frequent midwinter ice jams along many Canadian rivers, thereby increasing the likelihood of flood damage and environmental changes. Therefore, the possibility of more frequent ice jams has to be considered during the planning of flood damage reduction measures, the design of waterway structures, and the enactment of measures to protect the environment. As a case study of midwinter jamming, four winter breakup and jamming events that occurred along an upper stretch of the Saint John River during the 1990s are described and the implications of similar midwinter jamming are discussed.