River Beat: Up to Driest 11 years on the Colorado

This observation from the first draft of next year’s U.S. Bureau of Reclamation Colorado River Annual Operating Plan should come as no surprise:

Inflow to Lake Powell has been below average in nine of the past eleven years (2000-2010). Although slightly above average inflows occurred in 2005 and 2008, drought conditions in the Colorado River Basin persist. Provisional calculations of the natural flow for the Colorado River at Lees Ferry, Arizona, show that the average natural flow since calendar year 2000 (2000-2010 inclusively) is 12.0 maf (14,800 mcm). This is the lowest eleven-year average in over 100 years of record keeping on the Colorado River.

(Draft AOP – pdf)