Quebec Built a Dam. It Turned a Crater's Centre Into an Island.

Quebec built a dam. It turned a crater's centre into an island. Before the Daniel-Johnson Dam raised the Manicouagan Reservoir, two crescent lakes curved around opposite sides of a Triassic impact structure and the land between them was mainland. When the water joined at both ends, the centre became René-Levasseur Island, more than 2,000 square kilometres of forest that logging trucks now reach by barge. The dam, Manic-5, stands about 50 kilometres south of the ring, outside most satellite pictures. This is the documented story of ground changed twice: an impact more than 200 million years ago that left the ring, and a hydroelectric project after 1959 whose rising water closed the last land connections and named the island after the engineer who did not live to see the dam inaugurated. In this video: More than 200 million years ago: the impact; about a kilometre of rock eroded since; Mount Babel the central uplift; glacial grooves to the south-southeast 1664: the Jesuit Henri Nouvel records 64 Papinachois trading at the lake; his name for it, Saint Barnabas, is on Father Laure's map of 1731, then fades Manicouagan and Mouchalagane: two lakes, one drainage 1964: a declassified American reconnaissance photograph of the two lakes, with the dam under construction Nine drill holes, more than a kilometre of impact melt rock (O'Connell-Cooper and Spray, 2011) 1959: the Manicouagan-Outardes project begins; river deposits removed to more than 50 metres; 13 arches on 14 buttresses; 214 metres high, 1.3 kilometres long, 2.2 million cubic metres of concrete, nearly 13,000 workers; concrete six months a year, between 7 and 15 degrees René Levasseur: Hydro-Québec in 1960, Manic-5 in 1962, chief engineer 1964, director 1965; the site broadcast live at Expo 67; Georges Dor's La Manic, 1966 November 29th, 1965: Premier Jean Lesage inaugurates the world's first 735 kilovolt line; 1,400 towers and ten tower models between Manicouagan and Boucherville May 1966: the name Manicouagan Reservoir approved; September 1968: Levasseur dies four days before Daniel Johnson, who dies at the site the night before the ceremony; the inauguration held a year later 1968 to 1977: the dam completed; eight Francis units in service in 1970 and 1971; Landsat shows the ring in 1972; filling complete in 1977, the year the island's name is approved 1980 to 1990: a second, underground station for winter peaks The shore: a rapid drawdown in the 1980s and pioneer plants; the Louis-Babel ecological reserve, 1991, with the Pessamit band council; stands undisturbed for more than two centuries 1998 to 2009: four access options, a 4.7 kilometre barge crossing, hearings in 2002, a report and a decree in 2003, both ramps built by 2009 Key figures: more than 200 million years; 2,000 square kilometres; 214 metres; 1.3 kilometres; 2.2 million cubic metres; 13,000 workers; 735 kilovolts; 1,400 towers; 4.7 kilometres. Timeline: 1664, 1731, 1959, 1964, 1965, 1966, 1968, 1969, 1970, 1971, 1972, 1977, 1980, 1990, 1991, 1998, 2002, 2003, 2009, 2011, 2015. Watch next:    • Sudbury's Crater Is Hard to See. Its Mines...   Sudbury's Crater Is Hard to See: the crater that is hard to see, and the mines whose positions give it away    • Lake Superior's Rift Is Over a Billion Yea...   Lake Superior's Rift Is Over a Billion Years Old: the rift that is over a billion years old, and the much younger lake above it Chapters: 0:00 Trucks by barge 2:09 Two lakes, one river 2:54 The inhabited country 4:07 The 1964 photograph 4:51 Reading the crater 5:59 Nine drill holes 7:03 Where the dam went 7:47 Manic-5, 1959 9:22 214 metres 10:11 René Levasseur 11:17 735 kilovolts 13:09 Names before water 13:51 Four days 14:35 Completion, in stages 15:56 The water closes 17:20 An island by name, 1977 18:25 The second station 19:06 The shore and the reserve 21:01 Timber and the crossing 22:08 Hearings and ramps 24:22 What the dam changed 26:10 The ledger Every claim in this video is drawn from the documented record: NASA Earth Observatory, 2003 and 2022; USGS EROS, the 1964 Argon image; the Commission de toponymie du Québec; Hydro-Québec's history pages, tour page, 2019 release and stations table; O'Connell-Cooper and Spray, 2011; Quirion, 2015; Décret 515-2003; BAPE report 171; the Québec environment ministry's 2003 reserve study, 2009 Météorite plan and Louis-Babel page. The dam is downstream of the ring, not across it. The 1966 and 1977 dates are name approvals, not the day the water closed. The impact age is carried as more than 200 million years where NASA's pages give 212, 214 and 215.5. Living persons are described by their published work only. Subscribe and turn on notifications. Tell us in the comments: is there a dated map, photograph or family record showing this area before the reservoir filled? Say what it shows and where it can be checked. #Canada #Quebec #Geography #Manicouagan #ManicouaganReservoir #ImpactCrater #HydroQuebec #DanielJohnsonDam #Triassic #Innu