Whenever the natural flow at Dotsero gets below about 1200 or so and the Eagle is done for the season. Then the XCEL energy power plant (formerly Public Service) call will kick in and the Bureau of Reclamation will start releasing out of Green Mountain Res. to meet the water right at Shoshone Power Plant. It's what makes the Upper C floatable during the late part of the season.
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse