Thursday, 9 February 2017

Ogoki Diversion and Nipigon River Dams


"Through a 1940 agreement with the United States, approval was given to Canada " to utilize immediately for the increase in power output at Niagara for war purposes, an additional flow of water equivalent to that which will be added to the Great Lakes as a result of diverting water from portions of the Albany Watershed..."  (HEPC, 1941). This led to the construction of the Ogoki River Diversion which sent water south into Lake Nipigon. In 1942, the Hydro Electric Power Commission promised the diversion "will increase the power resources of Southern Ontario and Quebec and improve levels of the Great Lakes for the benefit of Canada and the United States."

"The diversion increased flows into the Little Jackfish River by 113 cubic metres per second and this minor stream turned into an excavated soft, wide channel. It is estimated that 30 million cubic yards of sediment were released from the Little Jackfish River between 1943 and 1972. This resulted in 9 metres of sediment being deposited near the river mouth in Ombabika Bay, (Holmes, 1976)."

"The completion of the Pine Portage Dam in 1950 raised the water level on the Nipigon River by 31 metres, (100 feet) and flooded out almost 16 km of white water, rapids and waterfalls, including: the White Chutes, Victoria, Canal, Devil, Rabbit and Miner's Rapids. Lake Emma and Hannah were both flooded out and the whole area renamed Forgan Lake. The Pine Portage Dam raised Lake Nipigon water level by 12 cm, flooding over the Virgin Falls Dam."

"Until 1990, the dams on the river were operated by Ontario Hydro for the sole purpose of generating electricity, restricted by only their legal flooding rights. In 1990, when it was demonstrated that fluctuating water levels on the Nipigon River and excessive drawdown was killing developing Brook Trout in the spawning beds, an interim flow agreement was reached."

"In May 1991, in response to an April 1990 landslide on the Nipigon River, Ontario Hydro put further restrictions on their rate of flow reductions ensuring that flows were reduced in stages to reduce scouring of the river banks, (Atria, 1993)"

"By 1994, a long-term Nipigon River Water Management Strategy was developed. From this strategy, an Operating Plan to guide the day to day dam operations was released to the public in 2001."

Taken from: Water Resources, Limnology and Power Generation on the Lake Nipigon Basin, The Nipigon River and the Black Sturgeon River System, R. Swainson, 2001 (in preparation) OMNR

Used by The Lake Nipigon Signature Site  background document June 2001.

In 1920 Cameron Falls Dam raised 23 metres of water to eliminate the Narrows, Lake Jesse was backed up over  Lake Maria and Split Rapids and created a pond 19 km long up to White Chutes.

Alexander Dam in 1930 raised the river 18.5 metres and eliminated 2.5 km of waterfalls and rapids up to Cameron Falls.

So, when the HEPC made a statement in 1927 to"... enable the total flow of the Nipigon River to be utilized for power development as the land requires it." ...they were quite prophetic.

Total fall of river = 77 m

Total fall developed = 72.5 m

Total fall not developed = 4.5 m

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