Montreal is on alert and ready to help people prepare for flooding as water levels upriver begin to rise. The city activated its alert mode as part of its special flood response plan on Sunday and city workers erected temporary dikes along the shoreline in some areas where the river was already swelling above its banks. Neighbourhoods bordering Rivière-des-Prairies, Lake of Two Mountains and Lac St-Louis are particularly at risk of spring flooding, with water levels expected to increase over the next two days.