|Don River (Ne cheng qua kekonk)|
The river as it runs beneath the Bloor Viaduct
|Major cities||Toronto, Markham, Vaughan, Richmond Hill|
|Length||38 km (24 mi)|
|Watershed||360 km² (139 sq mi)|
|Discharge at||Keating Channel in the Toronto Harbour|
|- average||4 m³/s (141 cu ft/s)|
|Source||Oak Ridges Moraine|
|- elevation||75 m (246 ft)|
|- left||Castle Frank Brook, Taylor-Massey Creek|
|- right||German Mills Creek|
The Don River is one of two rivers bounding the original settled area of Toronto, Canada along the shore of Lake Ontario, the other being the Humber River to the west. Toronto (təˈrɒntoʊ colloquially pronounced or) is the largest city in Canada and is the provincial capital of Ontario Lake Ontario is one of the five Great Lakes of North America. This article is about the river in Toronto Ontario Canada Links to other rivers of the same name can be found here. The Don is formed from two rivers, the East and West Branches, that meet about 7 kilometres (4 mi) north of Lake Ontario while flowing southward into the lake. The kilometre ( American spelling: kilometer) symbol km is a unit of Length in the Metric system, equal to one thousand A mile is a unit of Length, usually used to measure Distance, in a number of different systems including Imperial units United States Lake Ontario is one of the five Great Lakes of North America. The area below the confluence is known as the lower Don, and the areas above as the upper Don. The Don is also joined at the confluence by a third major branch, Taylor-Massey Creek. Taylor-Massey Creek is a tributary of the Don River in Toronto Ontario. The Toronto and Region Conservation Authority (TRCA) is responsible for managing the river and its surrounding watershed. Toronto and Region Conservation Authority ( TRCA) or Office de protection de la nature de Toronto et de la région is one of 36 conservation authorities
Humans first arrived in the Don approximately 12,500 years BP most likely as nomadic hunters. Before Present (BP years are a time scale used in Archaeology, Geology, and other scientific disciplines to specify when events in the past occurred  While there is little archaeological evidence in the Don valley itself, regional finds in the Great Lakes St. Lawrence area have revealed that permanent settlements started to occur about 6000 BP.  The most significant recorded find is known as the Withrow Site. It was discovered in 1886 during road building just east of Riverdale Park. Riverdale Park may refer to Riverdale Park California, a community in the United States Riverdale Park Maryland, a town in the United It contained human remains and other artifacts dating back to about 5000 years BP. 
It is unclear whether the Don River had a native Canadian name. In 1788, Alexander Aitkin, an English surveyor who worked in southern Ontario, referred to the Don River as Ne cheng qua kekonk. Sir Alexander Aitkin was deputy surveyor general and later the first surveyor general of Upper Canada. . Elizabeth Simcoe, wife of Lieutenant Governor John Graves Simcoe, reported in her diary that another named used was Wonscotanach. Elizabeth Simcoe (c 1762 - 1850 was an artist and diarist in Colonial Canada Lieutenant-General John Graves Simcoe ( February 25, 1752 &ndash October 26, 1806) was the first Lieutenant governor of Upper  This is an Anishnaabe phrase meaning black burnt grounds which could refer to an earlier forest fire. The Don River was named by J. G. Simcoe because the wide valley reminded him of the River Don in Yorkshire. This article is about the river in South Yorkshire England For other rivers with the same name see Don River (disambiguation.
After the founding of York in 1793, several mills were constructed along the lower Don. York ( is an historic Walled city sited at the confluence of the rivers Ouse and Foss in North Yorkshire, England. One of the first was at Todmorden Mills. Todmorden Mills was a small settlement located in the Don River valley in Toronto Ontario. These mills initially turned out lumber, flour and paper products. By the 1850s, the Lower Don was becoming an industrial setting. Petroleum storage facilities, poultry and pork processing plants were constructed along the banks of the Don. William Davies Company was a pork processing and packing company in Toronto, Canada. In 1879, the Don Valley Brick Works opened.  Polluted effluent from these factories and the growing city nearby was turning the Don and its marshy mouth into a polluted hazard.
In the 1880s the lower part of the Don south of the former Winchester St. bridge was straightened (east of the original mouth) and placed in a channel to create additional harbour space and industrial dock space for boats. Known as Don Improvement Project, the straightened river was also supposed to divert the polluted waters into the Ashbridges Bay marsh. This proved unsuccessful so the mouth was turned 90 degrees west where it empties into the inner harbour. This short extension of the harbour is known as the Keating Channel. The Keating Channel is a short waterway in the inner Harbour of Toronto Ontario on Lake Ontario. The channel north of Lake Shore Blvd. East ceased being navigable when the Gardiner Expressway was constructed in the 1950s. The Frederick G Gardiner Expressway, known locally as " the Gardiner " is an expressway connecting downtown Toronto, Ontario, Boats may still enter the Keating Channel by going underneath a lift bridge at Cherry St.
During the early part of the 20th century the river and the valley continued to be neglected. 31 separate sewage treatment facilities were built along the river.  Over 20 places in the valley and adjacent ravines were used as landfills for garbage and industrial refuse.  In 1917, the Don Destructor was built beside the Don just north of Dundas Ave. East. It was used as a garbage incinerator for 52 years burning about 50,000 tonnes per year. 
After World War II, rapid urban expansion occurred in the northern reaches of the watershed. In 1954, Hurricane Hazel struck the Toronto area. Hurricane Hazel was the worst Hurricane of the 1954 Atlantic hurricane season and one of the worst hurricanes of the 20th century Intensive flooding affected the lower reaches. Flood waters affected downtown Toronto as far east as Leslie Street and as far west as Bay Street. While no loss of life occurred in the Don Watershed the result of this storm was that the TRCA was given a mandate to construct flood control features as well as acquire property in the Don Valley as well as along its major tributaries. Large tracts of industrial land adjacent to the river were added to the regulatory floodplain. This meant that the TRCA had a veto on any developments that were not floodproofed.
In the early 1960s, the Don Valley Parkway was constructed through the Lower Don to serve the growing commuter traffic. The Don Valley Parkway (generally referred to as the DVP) is a controlled-access six-lane Freeway in Toronto, Ontario, Canada, so The increasing development reduced the natural areas of the watershed. This impacted the Don with increased pollution, heavy flooding, and turbid sediment laden waters. The combined result meant that by the 1960s the river was a neglected, polluted mess. In 1969, Pollution Probe held a much celebrated “Funeral for the Don” to highlight the plight of the river. 
Efforts to restore the Don gathered steam in 1989 with a public forum at the Ontario Science Centre which was attended by about 500 people.  The result was the formation of the Task Force to Bring Back the Don, a citizen’s advisory body to Toronto City Council. The Task Force to Bring Back the Don is a citizen advisory Committee that advises Toronto city council on issues concerning the Don River and Their mandate and vision was to make the Don “clean, green, and accessible”. Since then they have hosted garbage cleanups, tree plantings, and help to create or restore eight wetlands in the lower reaches of the valley, including Chester Springs Marsh, a 3 ha site south of the Bloor Viaduct.  Other groups also became active including Friends of the Don East. Friends of the Don East (FODE is an Canadian Non-governmental organization based in Toronto Ontario. The TRCA created the Don Watershed Regeneration Council to coordinate restoration efforts throughout the watershed.
In 1991 Bring Back the Don released a document called “Bringing Back the Don” which laid out plans for restoration, including a renaturalized mouth of the Don. In 1998 a plan to revive Toronto’s waterfront was initiated. One of the four projects mentioned was a natural mouth for the Don River. In 2001 an environmental assessment was started to look into a natural mouth of the Don. The project was also coupled with a plan to handle a major flood modelled on the expected output from a Hurricane Hazel size storm. In 2007, the Toronto Waterfront Development Corporation (now WaterfrontToronto) held a design competition that looked at four different configurations for the mouth of the Don. The winning bid was made by Michael Van Valkenburgh Associates. Michael R Van Valkenburgh is an American Landscape Architect and educator who currently resides in the West Village of New York City  The environmental assessment is expected to be complete in 2008 and construction is scheduled to begin in 2010. 
The Don Valley is notable because of its deep wide valley in the lower reaches. At the Bloor Street Viaduct, the valley is about 400 m wide while the river is only about 15 m wide.  This is due to its glacial origins. The Don River and its deep valley were formed about 12,000 years ago at the end of the Wisconsinan Glaciation. "Last glacial" redirects here For the period of maximum glacier extent during this time see Last Glacial Maximum The last glacial period During that glaciation which lasted for 35,000 years, all of Ontario was covered in ice. As the climate warmed the glaciers began to melt. As the ice front retreated in southern Ontario, several rivers were formed that drained into Lake Iroquois, a glacier lake which was the precursor to Lake Ontario. Glacial Lake Iroquois was a prehistoric Proglacial lake that existed at the end of the last Ice age approximately 13000 years ago The Don River is now small in comparison to the deep and wide valley that resulted from its glacial origin. The Don River is now classified as an underfit river. A misfit stream (or underfit stream) is a Stream that is far too small to have eroded the Valley which the stream occupies
The landscape at that time was loose glacial till so the large amounts of glacier melt water eroded deep valleys over thousands of years. As time progressed, isostatic uplift caused the earth's plate to rise and tilt. This caused Lake Iroquois to drain towards the south. A remnant of its shoreline can be seen on the north side of Davenport Road in Toronto. In the Don Valley, the old shoreline is evident just north of Eglinton Avenue. Eglinton Avenue is an east-west thoroughfare in Toronto, Ontario, Canada, and in Mississauga to the west  Today the source of the Don River is the Oak Ridges Moraine, another legacy of the Wisconsin glaciation. The Oak Ridges Moraine is an ecologically sensitive geological landform in the Mixedwood Plains of south central Ontario, Canada.
The location of the old shoreline is important when considering soils in the Don watershed. Soils north of the old shoreline are mostly luvisolic Halton Till while south of the shoreline they are still sandy glaciolacustrine deposits.
The Don Valley contains one of the most interesting locations for studying the regional geological history. The Don Valley Brick Works was an old brick making factory with a quarry where they extracted shale. The Don Valley Brick Works is a former quarry and industrial site located in the Don River valley in Toronto Ontario. At the rear wall, local geologists discovered a record of the past three glaciations. There are nine distinct layers visible dating back 120,000 years. 
Due to the urbanized nature of the watershed, the Don River experiences low base flows interspersed with high volume floods. The water level can rise very quickly following a moderate to heavy rainfall, up to 1-2 metres inside of three hours. The average base flow for the Don River is about 4 m3/s.  Peak flows occur in late February and late September which corresponds to seasonal variation in the Toronto region. Maximum flows, based on a Hurricane Hazel style flood have been estimated at nearly 1700 m3/s. Hurricane Hazel was the worst Hurricane of the 1954 Atlantic hurricane season and one of the worst hurricanes of the 20th century  On August 19, 2005, an unusually strong summer storm caused short term flooding in the Don Valley. Events 43 BC - Octavian, later known as Augustus compels the Roman Senate to elect him Consul. Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. Peak flow rates for that event were measured at 55. 3 m3/s. Since high flow rates occur during storm events, the resulting floods tend to scour the bottom of the river which reduces fish habitat. In addition, the flood waters carry a large amount of sediment washed into the river from surrounding tablelands. The sediment collects in the Keating Channel just past the mouth of the river. The Keating Channel is a short waterway in the inner Harbour of Toronto Ontario on Lake Ontario. The TRCA which is responsible for the dredging estimates that the amount of sediment dredged is 35,000 m3/year weighing nearly 60,000 tonnes. 
The east branch of the Don, also called the Little Don River, rises at the south edge of the Oak Ridges Moraine just to the west of Yonge Street, flowing south-eastward through ravine forests in Richmond Hill, Thornhill, east of Willowdale and Don Mills. Yonge Street (pronounced "young" is a major arterial street in Toronto, Ontario, Canada, and its northern Suburbs It was formerly Richmond Hill ( 2006 population 162704 2007 Estimate 177587 The act expanded Richmond Hill's borders annexing parts of Whitchurch Township, Markham Thornhill ( 2006 population 106394 is an upscale community in the Greater Toronto Area in southern Ontario, Canada, located on the northern Canada 2008 Willowdalejpg|thumb|250px|Driving down Yonge Street toward Churchill Avenue in Willowdale in 2008]] Willowdale is an established community in the former City of North Don Mills is a residential neighbourhood in Toronto, Canada, and claims to be the first " New town " planned and fully integrated post-war A second branch of the eastern Don, known as German Mills Creek, parallels the main eastern branch and joins it at Steeles Avenue, the northern boundary of Toronto. German Mills Creek is a tributary of the Don River. It originates in Richmond Hill (near Yonge Street and 16th Avenue flows south through Markham and empties South of Lawrence Avenue the river passes through the Charles Sauriol Conservation Reserve. This area is mostly undeveloped parkland. The reserve occupies the valley south to the forks of the Don. It was at one time home of a Maple sugar shack and tapline, which was visited yearly by students from across East York. Maple sugar is what remains after the sap of the Sugar maple is boiled for longer than is needed to create Maple syrup or Maple taffy. East York was formerly a semi-autonomous Borough within the overall municipality of Metropolitan Toronto before East Charles Sauriol was a historic protector of the Don. Charles Joseph Sauriol, CM, ( May 3, 1904 – December 16, 1995) was a Canadian naturalist who was responsible
The western branch starts near Maple, Ontario, flowing south-east through the suburban industrial belt of Concord (Vaughan), and the G. Maple (ˈmeɪpəl (Estimated 2006 population 49388 is a high-growth suburban community northwest of Toronto, Ontario, Canada, part of the Concord is a Suburban community in the City of Vaughan in York Region, located north of Toronto, Ontario, Canada. Ross Lord Reservoir. A reservoir is most broadly a place or hollow vessel where Fluid is kept in Reserve, for later use It crosses Yonge Street as it flows through Hoggs Hollow, past York University's Glendon ("valley of the Don") campus, and then flows on to Leaside before joining the eastern half. Hoggs Hollow is an affluent neighbourhood in Toronto, Ontario, Canada, located in the Don River Valley and centred on the intersection of York University (Université York is a public Research university located in Toronto, Ontario. Glendon College (French Collège universitaire Glendon) is one of the two campuses of York University, Canada 's third-largest university in Toronto Leaside is a neighbourhood in Toronto, Ontario, Canada. The area takes its name from William Lea and the Lea family who settled there in the
Downstream from the forks, the river flows through a wooded area known as Crothers' Woods which is designated as an Environmentally Sensitive Area due to the high quality beech-maple forest that grows on the ravine slopes. Crothers' Woods is an area of the Don River valley in Toronto, Ontario, Canada. South of Pottery Road it enters a more degraded section and ends up in a straightened section that includes cement and steel dock wall, a remnant from an earlier industrial era. The river flows unceremoniously into the Keating Channel at Lake Shore Boulevard East which is at the north east corner of the Toronto Harbour. The Keating Channel is a short waterway in the inner Harbour of Toronto Ontario on Lake Ontario. Lake Shore Boulevard is an east-west route running along most of Toronto 's waterfront Toronto Harbour is a bay on the north shore of Lake Ontario, in Toronto, Ontario, Canada.
The western section of Taylor-Massey Creek and the southern portion of the western branch are surrounded by parkland (see also: Toronto ravine system). The Toronto ravine system is one of the most distinctive features of the geography of Toronto, Ontario, Canada. In more recent years the retreat of the industrial plants and rail infrastructure has freed up room which is now being turned into bicycling trails, which now extend from the shore of Lake Ontario northward in several directions to provide some 30km of off-road paved trails. Cycling is the use of Bicycles or - less commonly - Unicycles Tricycles Quadricycles and other similar wheeled Human powered vehicles While Toronto is fairly flat in general, local cyclists have developed a number of technically challenging singletrack trails throughout the area, following the main trails. XCRacerjpg|thumb|A cross-country rider on singletrack during a race]] Single track or singletrack is narrow Mountain biking trail that is approximately