BC Hydro has opened the Mica Dam spillway for the first time since 1997, sending up to 1,133 cubic meters of water per second down the three-pronged spillway, culminating in a violent and beautiful explosion of water at the dam base.
The water drops 150 metres as it races along the 585-metre spillway – the highest drop of any BC Hydro dam.
BC Hydro spokesperson Jennifer Walker-Larsen explained the planned, 24-hour water release on July 26–27 was a test of the dam spillway, “in anticipation of possible releases that may be needed to pass record high reservoir inflows this year.”
Although the 1,133-cubic-meter (40,000-cubic-feet) per second rate created a roaring torrent of water that dwarfs heavy construction vehicles parked nearby, Walker-Larsen said it was only a fraction of the dam’s maximum. The Mica Dam spillway was constructed to handle 3,171 cubic meters (112,000 cubic feet) per second.
The spilling follows very high water inflows into the Columbia River system in B.C.’s Southern Interior this season. The Mica Dam holds back the Kinbasket Reservoir, which is forecast to receive more inflow than any other year on record in 40 years since the dam was competed in 1973. BC Hydro experts expect the Kinbasket Reservoir to get 20.3 cubic kilometres of inflow from February to September this year – nearly five cubic kilometres more than normal.
The Mica Dam is located about 135 kilometres north of Revelstoke along Highway 23 North. It is currently undergoing extensive upgrades.
Here are three videos of the July 26–27 test taken by BC Hydro:
The spillway usually looks like this when closed:
PHOTO by Aaron Orlando/Revelstoke Times Review