Appendix A Flood Damages in 2013

Transcription

1 Appendix A Flood Damages in 2013 RPT App_A_Highwood_River_Flood_Damage_In_2013.Docx

2 Table of Contents page Sign-Off 1. Flood Damage in Background Town of High River Summary of Flood Damage Costs in River Basin... 2 List of Figures Figure 1-1: Depth of flooding in Town of High River in June (From Figure 15 in "2013 Flood Mitigation Master Plan - Town of High River, Alberta" by WorleyParsons Canada for Town of High River, 1 October 2013)... 3 List of Tables Table 1-1: Provincial Disaster Recovery Program Claims... 1 Table 1-2: Municipal DRP and Erosion Control Grants... 2 RPT App_A_Highwood_River_Flood_Damage_In_2013.Docx

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4 1. Flood Damage in Background The Town of High River is the largest community in the Highwood River basin, with a population of 12,920 (2011 census). Large floods occurred in 1894, 1899, 1902, 1908, 1912, 1923, 1929, 1932, 1942, 1995 and The June 2013 flood caused the most costly damages to date in the Town of High River and also caused significant erosion along the entire river. The magnitude of the damage in 2013 is directly related to extent and location of the development of the town compared to earlier years. During the 2013 flood, significant erosion and sediment deposition occurred along the Highwood River. However, river channel erosion and deposition is a natural evolutionary process of rivers and should be allowed to progress as far as practical. 1.2 Town of High River The June 2013 flood covered a very large part of the town and forced the evacuation of the entire town. Three people drowned in the Highwood River during the flood. The Town of High River suffered extensive damages during the June 2013 flood. Under the Provincial Disaster Recovery Program, the following number of claims had been submitted by the end of 2013: Table 1-1: Provincial Disaster Recovery Program Claims Claim Type Number of Claims Small Businesses 362 Condominiums 21 Homes 2,739 Institutions 27 Landlords 305 Tenants 1,106 During the flood, the Highwood River channel eroded significantly and caused lateral shifts along the river channel. The river bed was re-shaped by scour and deposition and by August 2013, scalping of the depositions were in progress at several locations to remove more than 60,000 m 3 of gravel and cobbles from the river channel. Highway 2A crosses the Highwood River in the middle of the town and an abandoned CP railway crosses the river parallel to and immediately upstream (west) of the highway bridge. During the flood, the railway bridge caused a constriction and the south approach to the bridge was partly washed out, thereby threatening the highway. Immediately downstream of the highway bridge is the off-take structure for the Little Bow River diversion. This diversion diverts up to 8 m 3 /s into the Little Bow Canal system for irrigation purposes. During the 2013 flood, the flood waters overtopping the right river bank washed out parts of the dykes along the Little Bow Canal. RPT App_A_Highwood_River_Flood_Damage_In_2013.Docx 1

5 1.3 Summary of Flood Damage Costs in River Basin The Alberta Government assists communities in their re-construction through their Municipal Disaster Recovery Program (DRP) and Erosion Control Grant program. The DRP covers repairs and restoration of existing infrastructure to a pre-disaster state. Table 1-2: Municipal DRP and Erosion Control Grants Type Location Amount (million) Municipal DRP Submissions Town of High River Various locations within MD of Foothills $79.7 $1.5 Erosion Control Grant Applications Town of High River Various locations within MD of Foothills $10.4 $2.6 All combined Highwood River basin $94.2 It should be noted that the above costs are those available to AECOM at the time of preparation of this report. The cost for MD of Foothills is specific to the Highwood River basin and was estimated from a summary report for the MD provided by the Flood Recovery Task Force. At the time of preparation of this report, the costs incurred by individuals and businesses were unavailable to AECOM. RPT App_A_Highwood_River_Flood_Damage_In_2013.Docx 2

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