Ice Jam Flood Risk Forecasting at the Kashechewan First Nations Community North Albany River
The Kashechewan First Nation (KFN) community is located on a floodplain of the north branch of the Albany River, on the west coast of James Bay. Each spring the town’s residents face the uncertain prospect of evacuation to limit damages caused by ice-jam flooding. The community has been evacuated on a precautionary basis on seven occasions of ice-jam related flooding since 1976, the most severe of which occurred in the spring of 2006. In 2007, Hatch was retained by KFN to assist with developing a remedial action plan for reducing the risk of flooding due ice-jamming at the community. The work was divided into two phases: 1. High Priority Emergency Measures; 2. Option Development for Permanent Remedial Works.
A component of Phase 1 was the development of an ice breakup flood forecast tool. The key criteria for tool development dictated that indication of a high risk of flooding must be provided at least 10 days in advance. A systematic approach to developing such a tool would typically include the installation of an extensive and costly hydro-meteorological station network within the river basin plus the collection and analysis of data from this network over at least a 25-year period to acquire enough information to produce flood forecasts. Unfortunately, this approach would not meet the community’s immediate need for assistance.
With only historical flow records having been collected 200 km upstream of the community, Hatch reviewed the available hydro-meteorologic data outside the river basin and identified correlative relationships based upon physical processes that provided a useful working algorithm for predicting snow melt and consequential ice jam flood risk using meteorological forecasts of temperature and rainfall. This work resulted in an innovatively simple relationship that provides a flood risk forecast with reasonable success. The tool complements and enhances the current flood monitoring program executed by the combined efforts of the Kashechewan community, the Mushkegowuk Council, Emergency Management Ontario, Ontario Ministry of Natural Resources, and Aboriginal Affairs and Northern Development Canada.