The 2009 flood event in the Red River Basin: Causes, assessment and damages

Abstract

The Red River once again experienced significant flooding in spring 2009 due to high antecedent soil moisture from the previous fall and a deep snowpack and deep frost penetration. The peak stage at Fargo, North Dakota, broke the previous record set in 1897, and the peak stage at Grand Forks, ND, was the third largest in its 126 years of record. The computed natural river crest in Winnipeg, Manitoba, was the second largest experienced since official records began in 1912, and the unregulated flow volume at Selkirk, Manitoba, was the highest on record since 1852. Beyond its statistical significance, the 2009 Red River flood was unique due to the magnitude and frequency of ice-related issues throughout the duration of the flood. Ice jams developed within Winnipeg and near the community of Lockport, and went through phases of formation and release that made it difficult to forecast water levels. The presence of ice also affected operation of the Floodway Inlet Control Structure, and a small ice jam even developed within the Floodway itself. Despite the magnitude of the flood event and the challenges associated with the ice conditions, the extensive level of flood protection along the Red River generally reduced the level of inconvenience and flood damage. The exception was the area downstream of the City of Selkirk that underwent flooding of a magnitude that had not been experienced for a century and a half. A large number of homes along this reach of the river were damaged beyond repair and were subject to a government buyout after the flood.