Posted on | October 1, 2010 | No Comments
Seventy five years ago, President Franklin Delano Roosevelt dedicated Hoover Dam. The concrete is looking good. The thing showing its age is the Colorado River water impounded behind it. The elevation of Lake Mead, the storage reservoir serving California, Arizona, Nevada and the Republic of Mexico, dropped last night to 1,083.83 feet, the lowest closing elevation for September since 1937. That year, the world’s then largest reservoir was still filling. Now its over-allocated water is steadily disappearing. Elsewhere in the Bad News Department, the river serving it is unlikely to be flush this coming winter according to a new study comparing drought stress evident from tree rings and ocean currents. Rather, in Long-Term Relationships Between Ocean Variability and Water Resources in Northeastern Utah, RAND Corp researcher Abbie Tingstad and UCLA geographer Glen MacDonald suggest that a strengthening La Nina combined with the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation could mean that the Pacific is cooking drought soup for the Colorado River watershed. Their study is in the October issue of the Journal of the American Water Resources Association. To let numbers tell the story, click here for month-on-month and year-on-year Lake Mead elevations going back to 1935.