Hog's Back Falls
Encyclopedia
Waterfall
A waterfall is a place where flowing water rapidly drops in elevation as it flows over a steep region or a cliff.-Formation:Waterfalls are commonly formed when a river is young. At these times the channel is often narrow and deep. When the river courses over resistant bedrock, erosion happens...
s on the Rideau River
Rideau River
thumb|Rapids on the Rideau River opposite [[Carleton University]].The Rideau River is a Southern Ontario river which flows north from Upper Rideau Lake and empties into the Ottawa River at Rideau Falls in Ottawa, Ontario. Its length is 146 km...
in Ottawa
Ottawa
Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. The falls are located just north of Mooney's Bay and the point where the Rideau Canal
Rideau Canal
The Rideau Canal , also known as the Rideau Waterway, connects the city of Ottawa, Ontario, Canada on the Ottawa River to the city of Kingston, Ontario on Lake Ontario. The canal was opened in 1832 as a precaution in case of war with the United States and is still in use today, with most of its...
splits from the Rideau River.
Prior to the construction of the Rideau Canal, these were a gentle set of rapids originally known as Three Rock Rapids. The name Hog's Back came into use shortly before canal construction. Civil Engineer John MacTaggart, in 1827, described them as “a noted ridge of rocks, called the Hog’s Back, from the circumstances of raftsmen with their wares [timber rafts] sticking on it in coming down the stream.” These rapids were about 600 metres (2 000 feet) in length with a drop of about 1.8 metres (6 feet). They were navigable by canoe, no portage was required.
As part of his concept for a slackwater navigation system, Lt. Colonel John By's design for the Rideau Canal called for a large dam to be raised in this location. It would divert water from the Rideau River
Rideau River
thumb|Rapids on the Rideau River opposite [[Carleton University]].The Rideau River is a Southern Ontario river which flows north from Upper Rideau Lake and empties into the Ottawa River at Rideau Falls in Ottawa, Ontario. Its length is 146 km...
into the artificially-created section of the canal leading to the Ottawa locks. It would also flood the Three Island Rapids located upstream (the head of present day Mooney's Bay marks the foot of these rapids).
The building of this dam provided one of the greatest construction challenges (it collapsed 3 times during construction) of the Rideau Canal, but when completed in 1831 it flooded the Rideau River at that point by 12.5 metres (41 feet). To accommodate the natural flow of the Rideau River and to prevent damage from spring flooding, a large waste water weir was constructed. The water from this flows though a channel that was excavated in the eastern bank of the Rideau River. This created the Hogs Back Falls that we see today.
This location marks where the route of the Rideau Canal leaves the Rideau River and enters a man made canal leading to the Ottawa locks. A series of locks lowers boats from this location to the Ottawa River
Ottawa River
The Ottawa River is a river in the Canadian provinces of Ontario and Quebec. For most of its length, it now defines the border between these two provinces.-Geography:...
.