Streamflow conditions in the far west remained in the above-normal range during August, with well above average flows reported from southern Washington south through California and as far east as central Colorado. In sharp contrast to the far west, extreme low-flow conditions persisted in parts of the Great Plains states, and the below-average flows that were reported only in scattered areas of the Southeast in July extended throughout the mid-Atlantic and southeast during August, according to the U.S. Geological Survey (USGS) (see map, courtesy of USGS).
USGS hydrologists said that the combined flow of the nation's three largest rivers—the Mississippi, St. Lawrence, and Columbia—reflected the contrast in the water picture, with the unusually high flows of the west balanced by the many low flows in the east. During August, the combined flow was 2237 billion liters per day (bid) (492 billion gallons a day), only 5 percent above the average and down 33 percent from July's combined flow. These three major rivers drain more than half of the coterminous United States and serve as a useful guide to the status of the nation's water resources.