Ice accumulation at a water intake: a case study on the Mille-Iles River, Québec

Abstract

The blockage of water intakes by ice is recurrent in northern rivers during winter. Previous field studies have monitored field conditions leading to ice blockage and provided a review of mitigations methods. However, to improve the efficacy of these measures, the mechanisms that create the blockage need to be locally measured. For this purpose, a field campaign was implemented to monitor a water intake on the Mille-Iles River at Terrebonne, Quebec, during the winter of 2020-2021. Results from this study showed that ice accumulation on the trash rack had an average growth rate of 1.35 cm/hr and reached a maximum thickness of 24 cm. The release rate of these trash rack accumulation events was on average 1.8 cm/hr, which is 30% faster than the deposition rate. A minimum cumulative degree minutes of supercooling of 4.5 °C.min was required for the start of a trash rack ice accumulation event.