Elbow River Historical Detention and Diversion Sites (Watersmart)
Total Page:16
File Type:pdf, Size:1020Kb
Elbow River Historical Detention and Diversion Sites January 2014 Submitted by: Submitted to: P. Kim Sturgess, P.Eng., FCAE Andre Corbould CEO Chief Assistant Deputy Minister WaterSMART Solutions Ltd. Alberta Flood Recovery Task Force #200, 3512 - 33 Street NW Government of Alberta Calgary, Alberta T2L 2A6 205 J.G. O’Donoghue Building 7000 – 113 Street Edmonton Alberta T6H 5T6 Contents Introduction ........................................................................................................................ 4 1. Historical Review .......................................................................................................... 4 1.1 Calgary Irrigation Company ............................................................................................5 1.1.1 Pirmez Diversion ................................................................................................................. 5 1.2 Department of Interior ...................................................................................................6 1.2.1 Department of Interior Storage Sites on the Elbow River .................................................. 7 1.2.2 Department of Interior Storage Sites on Fish Creek .......................................................... 8 1.2.3 Priddis Creek Diversion ....................................................................................................... 8 1.3 The 1979 Elbow River Flood Study ...............................................................................11 1.4 The 1986 Elbow River Floodplain Management Study ................................................11 2. Potential Detention and Diversion Volume ................................................................. 12 3. Summary of Findings .................................................................................................. 14 4. Recommendations ..................................................................................................... 16 5. Conclusion ................................................................................................................. 17 6. References ................................................................................................................. 18 Figures Figure 1: The Pirmez Canal ......................................................................................................................................... 6 Figure 2: Reservoir Site H South Branch of Fish Creek (Department of Interior, 1897 pVI). ..................................... 8 Figure 3: Proposed Method of Diverting Water from the Elbow River to North Fish Creek (Department of Interior, 1900). ................................................................................................................................................................ 9 Figure 4: 1986 Cost Estimate of the Priddis Creek Diversion (WER et al. 1986p5-17) ............................................. 10 Tables Table 1: Historical Detention and Diversion Volume ............................................................................................... 13 Table 2 : Markin Panel Proposed Projects on the Elbow Detention and Diversion Volumes .................................. 14 Table 3: Concepts with Greater Potential for Mitigation ......................................................................................... 15 Table 4: Concepts with Limited Potential for Flood Mitigation ............................................................................... 16 2 Executive Summary The purpose of this study is to review historical records to identify previously proposed detention and diversion sites on the Elbow River, and determine if these historical sites have any merit for further investigation and consideration by the Government of Alberta (GoA) as an alternative to the mitigation options currently being reviewed by the Flood Recovery Task Force. An initial historical review of potential detention and diversion sites on the Elbow River provided twelve possible options that could be implemented to mitigate for both flood and drought. Of the twelve identified historical detention and diversion sites it is recommended that the Priddis Creek diversion be seriously considered as an option for flood and drought mitigation. The Priddis Creek diversion is designed to mitigate for flooding upstream of Bragg Creek and the City of Calgary using the natural creek bed and low lying topographical areas for channeling the water flows. By using natural topography the Priddis Creek diversion has a greater potential to slow down the water; subsequently reducing peak flows. It is also recommended that the historical resevoir sites identifed by the Department of Interior in the 1890s, along with the McLean Site, should be further investigated for feasibility. These storage sites are recommended due to their use of natural topography and their ability to mitigate for flooding upstream of Bragg Creek and the City of Calgary. In order to ensure that all the flood mitigation options are considered for all watersheds throughout Alberta, Alberta WaterSMART recommends further investigation into all mitigation options by continuing to undertake this type of historical analysis for all watersheds throughout Alberta. 3 Introduction Alberta was devastated by the Great Flood of June 2013. Countless families, homes, businesses, properties, infrastructures and shared lands were affected. Following the immediate and necessary response and recovery efforts undertaken, the GoA is carefully identifying, considering and assessing the appropriate actions to mitigate, manage and help control future flooding events. Numerous ideas, proposals, and mitigation strategies are currently being assessed for feasibility and will be subject to final approval by the GoA. Within the Elbow River watershed, there are historical maps, reports and investigations that contain information with respect to detention and diversion sites that were proposed for use in flood and drought mitigation strategies. Some of these sites were studied to the point where engineering schematics were completed. For a variety of reasons, these proposed mitigation strategies were never carried through to implementation. The purpose of this study is to review historical records to identify previously proposed detention and diversion sites, and determine if these historical sites have any merit for further investigation and consideration by the GoA as an alternative and or complement to other mitigation options currently being reviewed. Note that detailed historical records exist for all of Alberta, but for the purposes of this study, the historical review will be limited to the Elbow River watershed upstream of the City of Calgary and Bragg Creek. Upon reviewing the past 100 to 110 years of historical documentation WaterSMART Solutions Ltd. (WaterSMART) uncovered a number of possible options that could be implemented as a part of a comprehensive plan for both flood and drought mitigation. In 2008, the GoA conducted a study on potential diversion and detention sites throughout all watersheds within Alberta. This study was entitled the 2008 Water for Life Assessment of Potential Water Storage and Diversion Scenarios (GoA, 2008). In this report all historical diversion and detention sites identified on the Elbow River during this review were compared to the 2008 Report to determine if they have previously been considered for feasibility. 1. Historical Review The chronological timeline of proposed historical detention and diversion sites located on the Elbow River is described below. It should be noted that while some concepts were originally identified for drought mitigation, and others were identified for flood mitigation, the various proposals offer the potential to address both drought and flood mitigation when considered as part of a comprehensive plan. 4 The Department of the Interior reservoir sites and the Calgary Irrigation Company canal/Pirmez diversion were originally developed for drought mitigation during the late 1890s. Over the past 50 years, these ideas have continued to be mentioned in flood mitigation reports developed on the Elbow. The Priddis Creek diversion, along with the Ford, Mitchell, Sarcee and McLean detention sites were all projects put forward over the last 100 to 110 years for flood mitigation on the Elbow River. 1.1 Calgary Irrigation Company The Calgary Irrigation Company was established by William Pearce who was a strong advocate of irrigation as a solution to the periodic droughts that affected the prairie west. The Company intended to provide water to the Town of Calgary and irrigation water to its immediate surroundings (Gilpin, 2010) (see Figure 1). 1.1.1 Pirmez Diversion This diversion was first conceptualized by the Calgary Irrigation Company in the 1890s (Figure 1). It was subsequently constructed before the turn of the century and is still operable today. The beginning of the Pirmez diversion is located on the Elbow River approximately two kilometres (kms) upstream of the Highway 22 and Highway 8 intersection (Map 1, attached). The diversion flows east approximately 21 kms, intersects and joins Six Mile Coulee, and then divides into two separate legs; one leg flows northeast for approximately 27 km where it terminates in the Bow River, and the other legs flows approximately 42 km southeast terminating in the Highwood River. The total route, including both legs, is approximately 90 kms (Map 1 attached). It is important to note