Канаданың Альберта провинциясының Боу өзені

River in Alberta, Canada

The Bow River is a river in Alberta, Canada. It begins within the Canadian Rocky Mountains and winds through the Alberta foothills onto the prairies, where it meets the Oldman River, the two then forming the South Saskatchewan River. These waters ultimately flow through the Nelson River into Hudson Bay. The Bow River runs through the city of Calgary, taking in the Elbow River at the historic site of Fort Calgary near downtown. The Bow River pathway, developed along the river's banks, is considered a part of Calgary's self image.

The fur trader James Gaddy and the Hudson's Bay Company explorer David Thompson are traditionally considered to be the first people of European origin to see the Bow River. They camped along the Bow with a group of Piikani during the 1787–88 winter. First Nations used the river's valleys for the buffalo hunt, in which herds of buffalo were driven over cliffs or into valleys where they could be killed more easily with bows and arrows. Of all the First Nations groups that lived in the Bow River area, only the Nakoda fished the river regularly. While other groups likely caught fish during harder times, they primarily hunted buffalo during the summer season when fishing would have been most plentiful. The river's water naturally attracted game, which the First Nations men also hunted, while women gathered the roots, nuts and berries and processed them for food. The river's game, its local sources for firewood, and its valleys' shelter made the river a common camp location for First Nations during the prairie winters. The danger of crossing the river meant it was a natural boundary for First Nations. The two main fords of the lower Bow River, Blackfoot Crossing and a ford near the Bow's confluence with the Elbow River (where today's central Calgary developed), became important gathering points for First Nations to exchange goods and celebrate festivities. Blackfoot Crossing was used by the Siksika as a winter campsite and is today a part of their reserve. In order to proceed with railway construction through present day Alberta and an orderly settlement of the Bow region, the government sought to extinguish title of First Nations to specific lands, and negotiated to do so through treaties. With bison numbers declining and white settlers becoming increasingly common in the region, the Nakoda, Tsuu Tʼina, Kainai, Piikanai, and Siksika met with representatives of the Canadian government at Blackfoot Crossing on the Bow River and signed Treaty 7 on 22 September 1877, ceding lands in exchange for defined reserves. Calgary Power had problems before this dam was completed in 1911. The Bow River originates from a northern mountain, and its flow varies considerably depending upon the amount and location of winter snowfalls. A storage reservoir was also created within Banff National Park in 1912 at Lake Minnewanka. Despite this additional reservoir and both plants, Calgary Power still struggled to fulfill its power contracts during winter months. In the 1920s, the company began planning new projects to control the Bow River. In this light, rivers could be seen as a series of interdependent parts, and engineering all of them could give technicians control over the system as a whole for the benefit of society. In this process, Calgary Power ultimately fulfilled conservationist ideology as it increasingly brought the Bow River's interdependent sectors, and thus it as a whole, under control, while failing to embody conservationist ideals of rationally developing the Bow initially. Also in line with conservationism, bureaucrats allowing the construction of the Minnewanka reservoir espoused that the nation's development as a whole superseded the need to protect a small part of Banff National Park's nature. Between 1910 and 1960, the Bow River was radically changed as it was systematically engineered to control its water flow and provide hydroelectric power. The seasonal summer flooding in Calgary was an issue of the past. Among the plan's critics was the Local Council of Women, reminding the city of its 1955 promise for a river park. After an Alberta Environment official discovered a toxic "blob" in the Bow in October 1989, human needs again were given priority. Originating from an abandoned wood preserving plant on the Bow River's bank, the "blob" in the river had released a carcinogenic plume that stretched more than downstream.

The Eastern Irrigation District (EID), headquartered in Brooks, Alberta, was originally part of land that the federal government granted to the Canadian Pacific Railway in lieu of a portion of the payment for the construction of the railway. In 1929 the CPR split the property into two parts and divested itself of both sections. In 1935 a delegation of irrigation farmers took control of the eastern section and established the EID. The EID, diverting its water at the Bassano and Newell dams, is the largest private land owner in Alberta. Recently the EID began promoting the recreational possibilities that have developed alongside the district's irrigation development. The EID currently owns and operates the Rolling Hills Reservoir Campground. In 1951, the Province of Alberta also established Kinbrook Island Provincial Park on the eastern bank of the Newell reservoir, which has been stocked with native species of fish.

The Western Irrigation District (WID), headquartered in Strathmore, Alberta, was the second half of the land divested by the CPR. The WID was established in 1944. The water of the WID, diverted at the Calgary Weir, is instrumental to southern Alberta agriculture and, unlike the other two districts, supports the urban needs city of Calgary. It is able to supply both agricultural and urban needs since the WID has higher levels of rainfall than the other two districts, and it receives much of Calgary's storm water.

The Bow River Irrigation District (BRID), headquartered in Vauxhall, Alberta, was created in 1968, making it the most recent district to be supplied by the Bow. The BRID diverts the Bow at the Carseland weir and also uses the McGregor, Travers, and Little Bow dams. Each has a reservoir that is also used for recreational purposes. In March 2012, the citizens of the BRID voted in favour of expanding the area of the district by An expansion of passed in 2004 as well. This means that, for the second time in eight years, the BRID will increase its demand on the Bow River by roughly 10 percent.

Of the 45 crops that are grown in the Bow River basin, only 10 could be produced without irrigation. Because of the dependence of the region on Bow River irrigation water, in the early 21st century all three irrigation districts began to make major changes in order to continue to serve their large mandated areas. In 2006, as a part of the "Water for Life Initiative", the Alberta government placed a moratorium on any new licenses for water use from the Bow, Oldman, and South Saskatchewan River basins. The government also requested that the three irrigation districts increase their efficiency by 30 percent. The irrigation districts are improving their irrigation system by changing most canals to pipelines in order to decrease contamination, spillage, and loss of water to evaporation. A drawback of this change is that trees must be cleared in order to prevent roots from damaging the pipeline, changing the habitat. in 1987 the EID in association with the Alberta Fish and Wildlife Division and Ducks Unlimited Canada established a partnership to create additional wildlife habitat within the Eastern Irrigation District's boundaries. This demonstrated the EID's goal of encouraging wildlife in order to contribute to the growth of its tourist sector. Hunting and fishing are now promoted on the EID's website.

The Bow River provides habitat for wildlife and many opportunities for recreation such as fishing and boating. Both fly fishermen and spinner fishermen share the river in all four seasons of the year. Serious anglers from all over the world visit the Bow River for its thriving population of brown trout and rainbow trout. The Bow River holds a resident population of rainbow and brown trout that has one of the best growth rates to be found on any river system in the world today. A trout that is 4 to 5 years old will be around long, and the Bow River holds many fish that are this size or larger. Mainly the river is fished south of the city of Calgary, past where the water treatment sites dump into the river. The volume of nutrients and number of fish are higher there. Outdoor adventurers use primarily three types of boats to enjoy the river, the inflatable boat, the Jon boat and the canoe. There are several spots located on the river to launch watercraft, including Graves Landing, Highway 22X Bridge, Policeman's Flats and McKinnon Flats. The Bow River pathway, is developed on both banks of the river throughout the city of Calgary and is used for cycling, hiking, jogging, as well as rollerblading and skateboarding. Along the Bow River pathway, many people partake in canoeing, kayaking, rafting, paddle boarding, and other activities on the water. Dog owners and families often use the river banks and beaches for outdoor recreation.

The recreation and tourism sector of the Bow developed closely alongside the river's water irrigation projects. Similarity, after a three year refurbishing project ending in 1987, the town of Bassano, about northeast of the dam, began advertising the Bassano dam as a tourist attraction for the town. At this point the Bassano dam now also started offering group tours, fishing and picnic areas, and a scenic viewpoint. Communities have also recently begun to appear around Ghost Dam as well.

In 1904 the Bow River Weir was constructed close to Calgary's downtown core in order to divert water into the Western Irrigation District. Since its construction a side effect of the weir had been that it created a circulating wave, with a lethal and powerful undertow, immediately downstream of it. Because rafting, canoeing, and kayaking down the Bow River are such popular summer activities, there had been many fatalities. Furthermore, because fish were not able to pass through the structure, they too became trapped in the circulating wave and a dense, unnatural concentration of pelicans congregated immediately following the weir. In order to combat the circulating wave and undertow, in August 2007 the Province of Alberta through the Alberta Lottery fund, in conjunction with the Calgary Foundation and the City of Calgary, began construction of the Bow River Weir paddle around, named the Harvie Passage. The passage allowed for the wave to be dispersed over a set of several smaller rapids while still supplying water to its irrigation district. Altogether, the paddle around cost $18 million and was completed in the spring of 2012. In June 2013, just a year after the project was completed, Calgary was hit with an epic 100 year flood, and all of the Harvie Passage work was destroyed. After that flood, the passage was closed to the public and a safety boom ahead of the rapids was re installed. It was estimated that rebuilding the Harvie Passage to the original intent of the project (completed in 2012) would cost $23.4 million. By 2021, construction on the Harvie Passage was complete. The passage was redesigned to withstand a flood similar to the one that damaged the previous structures.

An invasive species known as Didymosphenia geminata, a type of algae commonly called "rock snot", is threatening the stocked exotic invasive brown trout stocks.