Blue Mesa Reservoir’s decline has slowed down thanks to rain
It may be Blue Mesa Reservoir has weathered the worst of the Drought of 2012.
According to the Bureau of Reclamation, the 29-mile long impoundment west of Gunnison continues to drop, but the decline has slowed thanks to higher-than-average precipitation last month in the upper Gunnison Basin.
It comes as news to the drought-lovers among us, but in July the basin received more than 150 percent of its average long-term precipitation, according to records from the National Weather Service.
This year rightfully has been compared to 2002, the last time similar drought-like conditions were seen and the year when Blue Mesa plummeted to an elevation of 7,435 feet, more than 84 feet below full.
This summer, after a dry winter and equally dry spring (June precipitation in the Gunnison Basin was less than 50 percent of average), Blue Mesa was dropping at close to a foot every four days, a rate that has slowed thanks to July moisture.
“The rains saved us this year,” said Eric Knight, a hydrologist with the Bureau of Reclamation in Grand Junction. “The better question, though, is whether we can keep that going through the end of the year.”
Blue Mesa finished July about 50 feet down (7,469.5 feet), a little more than midway between full (7,519.4 feet) and 2002.
Friday the reservoir was down another two feet to 7,467.6, about nine feet higher than the same date in 2002. That two feet may not sound like much, but it represents a significant amount of water given the expansive reservoir basin.
Downstream water users, federally protected water rights, endangered fish, hydropower and the requisite to prevent icing upstream of the reservoir are factored into whether water is kept in the reservoir or released into the Gunnison River.
During Thursday’s Aspinall Unit Operations meeting at Elk Creek Marina near (but not quite as near as earlier this year) Blue Mesa, it was announced by the Bureau of Reclamation that Blue Mesa is forecast to reach 7,449 feet by December 31.
That’s about 14 feet above the 2002 low and well below the 7,490-feet level that has to be reached by year’s end to prevent ice floes from backing up the river above the Lake City Bridge.
“We’ve been below that level most of the year,” Knight said. “But we’ll be keeping it above where we were in 2002.”
In many wet years, when nature provides the moisture and demand for stored water goes down, the BuRec has to crank up Blue Mesa late-summer releases to meet that Dec. 31 icing level.
That obviously won’t be needed this year. Instead, the Bureau and water users are holding back releases now to ensure enough water stays in the reservoir to keep river flows up longer in the summer.
Plus, the Uncompahgre Valley Water Users Association, which already has reduced the water available to individual users, has cut back its demand for Gunnison River water and instead is taking advantage of water in Ridgway Reservoir.
The Gunnison River below the East Portal of the Gunnison Tunnel was at 613 cubic feet per second Friday, a level forecast to drop to around 350 cfs later this summer.
It’s forecast that level will continue through the end of the year.
“In 2002 we allowed the river through the Black Canyon to get below 300 cfs, but that won’t happen this year,” said Knight, with the caveat that the rains continue through the summer. “If the rains hold out, I think everything will balance out.”
One casualty of the dry year is Paonia Reservoir, which as of Friday was virtually empty at 2 percent capacity. The dam backs up the waters of Muddy Creek for Fire Mountain Canal and Leroux Creek water users.
Data Friday from the state Division of Water Resources indicated no water being stored in the reservoir, with Muddy Creek flowing unheeded through the dam to its confluence with Anthracite Creek.