“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
A recent NASA satellite image shows low water levels in Lake Powell in Spring 2013. Click here to visit the NASA page. The last decade has been rough for a key reservoir in the intricate water storage system that sustains much of the American Southwest. Lake Powell, a meandering network of flooded canyons in southern Utah, has seen inflow rates from its key tributaries dwindle due to severe drought. Inflow between 2000 and 2012 has been the lowest 13-year period on record since the lake was created in 1963. A welcome surge of water arrived in 2011, but 2012 was a near-record dry year. And 2013 isn’t looking much better. Meteorologists expect another dry year, and hydrologists are forecasting that the combined inflow of 2012 and 2013 will be the second lowest on record (trailing only 2001-2002). In early May 2013, the lake was 47 percent full. That is not a record low—the reservoir dipped to 33 percent of capacity in 2005—but U.S. Bureau of Reclamation forecasters expect Lake Powell to drop to 42 percent of capacity by September, the end of the water year.
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.
Filed under: climate and weather, Colorado, Drought, global warming, rivers, water | Tagged: Colorado River, Colorado River Basin, drought, Lake Powell, United States Bureau of Reclamation, water | Leave a comment »