Heat-trapping greenhouse gases may dessicate Colorado River Basin
It’s very likely the southwestern U.S. will be hit by droughts unlike any seen since the region was settled by Europeans. Global warming has driven the odds of a 10-year drought to at least 50 percent, and the chances of a 35-year megadrought range from 20 to 50 percent during the next century, according to a new study led by researchers with Cornell, the University of Arizona and the U.S. Geological Survey.
Near critical shortages in California prompt action
By Summit Voice
FRISCO — With Colorado River water supplies disappearing at a dizzying rate, and with a thirsty — and politically mighty — California parched by drought, the biggest water users at the table said this week they’ll invest $11 million to try and conserve significant amounts of water across all sectors, including including agricultural, municipal and industrial uses.
The Central Arizona Project, Denver Water, The Metropolitan Water District of Southern California and Southern Nevada Water Authority all signed on to what is being presented as a landmark water conservation agreement aimed at demonstrating “the viability of cooperative, voluntary compensated measures,” according to a press release from Denver Water. Continue reading “Major Colorado River players announce conservation push”→
Satellite data suggests more than 75 percent of water loss in drought-stricken basin is from groundwater pumping
By Summit Voice
FRISCO — Groundwater pumping is a huge factor in the Colorado River Basin water equation, California-based researchers said this week, announcing the results of satellite study that for the first time quantifies how groundwater contributes to the water needs of western states.
Along with surface diversions and pipelines, water users in the basin are also unsustainably depleting underground aquifers. For example, mountain resort towns in Colorado tap underground water from headwaters streams like Tenmile Creek and the Blue River for municipal use.
2013 brought record levels of dust to Colorado’s mountains
By Bob Berwyn
FRISCO — Dust storms that darken the Rocky Mountain snowpack and speed snowmelt are becoming more extreme, according to new research. Particularly heavy dust-on-snow events can speed the melt-out of the snowpack by a full six weeks, all other factors being equal, said Jeffrey Deems, a researcher with the Western Water Assessment and the National Snow and Ice Data Center.
“In 2006 we were impressed at how much dust there was. Then 2009 turned up, and 2010, and 2013 was the dustiest year we’ve recorded in the San Juans,” Deems said, explaining that the latest study, put together by researchers with NOAA’sCooperative Institute for Research in Environmental Sciences was aimed at updating previous work with data from those heavy dust years.
FRISCO — Projections of future flows in the Colorado River have been all over the map, ranging from a 6 percent reduction in flows all the way up to a 45 percent drop.
Getting a better handle on that number is critical for water managers from Colorado to California, but fine-tuning models to address global warming impacts on the scale of a single river basin is a big challenge.
“Slight improvement in the Colorado basin water supply is like expecting a road-killed jackrabbit to feed a whole pack of hungry coyotes. It’s not nearly enough to go around. ~USDA hydrologist Randall Julander
By Bob Berwyn
FRISCO — With May inflow into Lake Powell less than half the long-term average, the U.S. Bureau of Reclamation is projecting that total reservoir storage in the Colorado River Basin will dip to about 29.3 million acre feet. That’s just 49 percent of storage capacity and the lowest level since the peak of the early 2000s drought, when the 2005 water year started with storage at 29.8 million acre feet (50 percent of capacity). More Lake Powell water info here: http://lakepowell.water-data.com/.
May’s inflow into Lake Powell was 1,121 thousand acre-feet, about 48 percent of average — a stark reminder that winter and spring precipitation was well below average in large parts of the Colorado River Basin, despite a surge of late-season moisture in the headwaters region of north-central Colorado. But at least the May inflow was an improvement from April, when inflow was only about a third of average.
After releasing about 602,000 acre-feet downstream, Lake Powell’s elevation at the end of May was at about 3,599 feet, which is about 100 feet below full. According to BuRec, the reservoir elevation is expected to remain within several feet of the current elevation throughout spring and summer as inflow from runoff roughly matches reservoir releases. In late summer, the reservoir elevation will begin to decline again.
For the April to July runoff season, water managers are now projecint that total inflow will be about 3 million acre feet, which is about 42 percent of the average inflow for the 1981 to 2010 period, with the overall water supply outlook remaining significantly below average. Lake Powell will probably end the current water year at just 44 percent of capacity.
The past decade has seen significant variability in precipitation totals, with near record runoff in 2011, followed by two of the driest years on record.