Dow's Lake

Dow's Lake
Dows Lake Pavilion
Location	Ottawa
Coordinates	45°23′40″N 75°42′06″W / 45.394412°N 75.701551°W / 45.394412; -75.701551Coordinates: 45°23′40″N 75°42′06″W / 45.394412°N 75.701551°W / 45.394412; -75.701551
Lake type	Artificial lake
Primary inflows	Rideau Canal
Primary outflows	Rideau Canal
Basin countries	Canada

Dow's Lake in Ottawa, Ontario, Canada is a small man-made lake on the Rideau Canal, situated two kilometres north of Hog's Back Falls in the middle of Ottawa. It is at the south end of Preston Street, just south of Carling Avenue, and just to the west of Bronson Avenue. At the south end of the lake is Carleton University, and to the west is the Dominion Arboretum, at the edge of the Central Experimental Farm.

The lake is named after Abram Dow, an American-born settler who came to Ontario in the early 19th Century and who owned land in this area in 1816. Before the construction of the Canal, this area was known as Dow's Great Swamp. The lake was created when a dam was constructed along the north shore (Queen Elizabeth Driveway is now atop the dam) to allow flooding for the canal. Originally, the Rideau Canal was to run north from Dow's Lake, but land speculation and Colonel By's reluctance to reward such speculation resulted in the current location of the canal.

In past years, the parkland to the north and east was rail yards until the 1940s and the area was mostly industrial. Situated next to the pavilion on the western shore is Canadian Forces Reserve Barrack Dow's Lake. This installation, opened in 1943, is home to HMCS Carleton a unit of the Canadian Naval Reserve.

A rail tunnel, which was formerly owned and operated by Canadian Pacific, passes under the lake. This tunnel replaced a rail line that once crossed the lake on the surface. The OC Transpo introduced the O-Train (today's Trillium Line) in 2001, a light-rail transit system, which remains the primary user of the tunnel.