Prairie Dams: An Overview

R. A. (Bob) Halliday for

Partners FOR the Saskatchewan River Basin

October 2, 2018

Slide 2

Outline

History Nation Building Environmental Effects

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A Short History

1867 – Confederation 1870 – Rupert’s Land Sale 1871-1877 – Seven Treaties 1871-1883ff – Dominion Land Survey

Dominion Land Survey

Slide 4

Slide 5

A Short History

1867 – Confederation 1870 – Rupert’s Land Sale 1871-1877 – Seven Treaties 1871-1883ff – Dominion Land Survey The CPR – 1882-1883 1894 – North-west Irrigation Act 1905 – Alberta and Saskatchewan 1930 – Resource Transfer Act 1935 – Prairie Farm Rehabilitation Act

North-west Irrigation Act 1894

First irrigation project 1880 – Fish Creek First water diversion permit 1889 – St.

Mary River Early 1890s – A significant drought June 25, 1894 – First documented

streamflow measurement entirely in Canada

The Act declared all water belongs to the Crown

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Nation Building

Dams for water supply and irrigation Dams for hydro power

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Water Supply and Irrigation

St Mary Canal - 1900 Other diversions Alberta Irrigation Districts Act 1915 Eastend Dam 1904 -1918 – PFRA 1936 St. Mary Dam 1951 – PFRA Gardiner Dam 1967 - PFRA Oldman River Dam 1991

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Hydro Power - Alberta

Prince’s Island 1893 Power Surveys Bow River Basin 1907 Horseshoe Falls 1911 – 14 MW Kananaskis Falls 1913 – 19 MW Brazeau River 1963 – 355 MW

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Horseshoe Falls 1911

Slide 10 Courtesy TransAlta

Brazeau River 1963

Slide 11 Courtesy TransAlta

Hydro Power - Saskatchewan

Power Surveys – 1907-1910 – Saskatoon and Prince Albert – La Colle Falls – 1909-1913

Island Falls GS 1930 – CRPC E.B. Campbell Dam - 1963

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Hydro Power - Manitoba

Hydro power for Brandon 1900 Pinawa Dam 1906 – 22 MW Power Surveys

– 1906-1911 Winnipeg River – 1913 – Churchill & Nelson rivers

Winnipeg River Dams – 1920s-1950s Kelsey Dam 1961 – Nelson River

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Minnedosa River Station 1900

Slide 14 Courtesy Manitoba Hydro

Pinawa Generating Station 1906

Slide 15 Courtesy Manitoba Hydro

Limestone GS 1992

Slide 16 Courtesy Manitoba Hydro

Things Change

Opposition to hydropower in BNP – 1920s

W.A.C. Bennett Dam – 1960s Grand Rapids – 1960s Churchill River Diversion MB – 1970s Churchill River SK – 1970s Rafferty/Alameda – 1980s Oldman Dam – 1980s

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Effects of Dams

Flow Regime – Riverine to lacustrine – Ecosystem fragmentation – River regulation

»quantity and timing of peak flows – Enables water withdrawals – Storage or run-of-the-river – In-stream flows or conservation flows

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Water Quantity - Hydro

Slide 19 Courtesy PFSRB

Water Quantity - Irrigation

Slide 20 Courtesy PFSRB

Effects of Dams

Sediment and nutrient transport – Nutrients, sediments, and

contaminants bound to sediments are deposited in reservoir

– Decrease in downstream turbidity »effects on biota »channel degradation

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Effects of Dams

Fisheries – Blockage of sediments, nutrients – Reregulation, reduced flood regime – Fish migration, spawning, stranding – Productive reservoir fishery – Productive tailwater fishery

»temperature effects

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Effects of Dams

Ice Processes – Reduced ice jam frequency – Consequences for floodplain

ecosystems

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Effects of Dams

Courtesy Stewart Rood Slide 24

Floodplain Ecosystems

Conclusions

Dams have been key to economic and social development in prairie Canada

Generally non-controversial until the 1960s-1980s

Environmental consequences are now recognized

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