St' Mary Dam

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St. Mary Dam Irrigation in Southern Alberta

• Taylor Schmidt

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• July 17th, 1951 Newspaper article
• The article describes how the opening of the dam
  attracted 10,000 people.
• Turning point in Alberta for the rehabilitation
  of the semi-arid area of Southern Alberta into
  rich, fertile farmland.
• Southern Alberta naturally inhabitable until
  Irrigation to 524,000 acres creating prosperous
  community
• 25 miles Southwest of Lethbridge

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St. Mary Irrigation Project History

• The Canadian Northwest Irrigation Company
  conceived the idea of the St. Mary River
  irrigation project in 1892. Later called the
  Alberta Railway and Irrigation company, they
  combined mining, irrigation, and railway
  business owned by the British Galt family. This
  family owned land in the Magrath, Raymond,
  Lethbridge, and Coaldale districts that were
  granted to them as subsidies by the Canadian
  Government for building railways in the area.
• In 1912 the Canadian Pacific Railway bought out
  the Alberta Railway and Irrigation Company.

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St. Mary Irrigation Project under CPR

• The Canadian Pacific Railway put forth minimal
  effort in increasing the capacity of the project.
  
• CPR kept ownership until 1945 when they
  transferred control to the Alberta government.
• Transfer of ownership spurred construction of the
  dam through legislation.

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St. Mary Dam Statistics

• The St. Mary dam was the largest dam in Canada at
  that time
• It stands sixty-two meters tall, 773 meters in
  length, and has a 27 kilometre long reservoir
  that is able to hold 357 million cubic meters of
  usable storage.
• The dam was originally planned to irrigate only
  300,000 acres using flood irrigation but the
  invention of sprinkler irrigation enabled
  provision of water to 465,000 acres between the
  dam and land as far east as Medicine Hat.
• Water is moved through 1500 miles of canals and
  pipelines and three hydroelectric power plants.
  The total estimated replacement cost of the St.
  Mary Project is 923 million.
• The dam cost the government seven million but has
  provided the agriculture industry sustainability
  for many years.
• The reservoir today is a popular recreational
  site involving activities such as camping,
  fishing and hiking.
• Fountain located in Henderson Lake, Lethbridge
  as a symbol that the St. Mary Irrigation project
  is a fountain of life for Lethbridge and Southern
  Alberta.

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Estimated Economics of Irrigation in Southern
Alberta

• Brings stability to agriculture and increases
  productivity of the land by 300.
• Without the irrigation project the population of
  Southern Alberta would be about 65-75 percent of
  what it is today.
• Excess of 5 Billion benefits from irrigation in
  agriculture and 13,000 full time jobs.
• Irrigation in Alberta represents for two-thirds
  of all irrigation development in Canada.

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Irrigation Water Allocations
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Water Shortages

• The St. Mary Irrigation district was forced to
  implement a policy in 1974 due to more requests
  to have land irrigated than water that was
  available.
• The policy is called the moratorium policy which
  provides fair and equal distribution of any water
  that becomes available.
• Selections are based on soil testing and land
  size.
• Project is subject to Montanas water
  consumption, if they were to hold back an
  additional 50,000 acre-feet of water, 40,000
  acres of irrigated land would be lost
• Acre-foot Unit of Volume commonly used in the
  states that is the equivalent of one acre of
  surface area at a depth of one foot.
• Implications for agriculture as well as over
  forty other industries.

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Irrigation Water Efficiency Over Time

• As you can see the efficiency in irrigation
  techniques has become 38 more water efficient,
  some reasons for this are the advent of sprinkler
  system irrigation vs. the past flood techniques
  as well as better efficiency in the canal and
  pipeline systems.

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St. Mary Dam

• As you can see the St. Mary Dam was the biggest
  addition to the St. Mary Project as well as
  irrigation in Canada.
• It was the turning point for industry in Southern
  Alberta and in encouraging immigrants to inhabit
  this area of Canada.