June 21, 2017

Colorado’s runoff has peaked

Lake Powell 65 percent full, but much of it going to Mead

Lake Powell

By Gary Harmon
The Daily Sentinel

The runoff of 2017 is over and officials expect Lake Powell to rise to 65 percent full, but that relatively high level won’t last long as the inflow into the reservoir will be sent downstream to Lake Mead and Mexico.

In all, Lake Powell is to release just under 9 million acre-feet of water downstream this year, or 7.5 million acre-feet to meet the terms of the 1922 Colorado River compact, and 750,000 acre-feet for Mexico under a 1944 treaty.

Lake Powell functions as a savings account for the Upper Colorado River Basin states, which are required under the compact to release 7.5 million acre-feet per year, based on a rolling 10-year average, from Powell.

Lake Powell can contain just over 24 million acre-feet of water.

The high-runoff year ultimately won’t buy much insurance for the upper basin states, said Chris Treese, spokesman for the Colorado River Water Conservation District.

“It won’t make things worse,” Treese said. “We will continue to bump along about the 50 percent level” in Lake Powell.

While 9 million acre-feet amounts to a third of the capacity of Lake Powell, water continues to flow into the reservoir throughout the year, though well short of runoff levels.

The Bureau of Reclamation operates Lake Powell so as to keep enough pressure to generate electricity at Glen Canyon Dam. The dam’s eight turbines can produce up to 1,320 megawatts of electricity and the dam supplies power to 5.8 million customers.

The spring’s high runoff isn’t operationally significant, James Eklund, the former director of the Colorado Water Conservation Board who headed development of the Colorado water plan, said in an email.

From a strategic perspective, however, “it underscores that even in what seemed like a banner water year, we’re still a long way from recovery from the last 16-year dry spell” and highlights the need to keep enough water in Powell high enough to generate electricity, Eklund said.

Even though the runoff has peaked, people looking to enjoy the water should take care, said Andy Martsolf, emergency services director for Mesa County.

“The water in the Colorado is moving fast and it is cold,” Martsolf said. “People recreating on the river should always use a personal flotation device, multichamber inflatables, and tell someone who is not in their party where they are going and when to expect their return.”