Grand Canyon Flow  Spring 2004

(By  Louis Strous)

The preceding plot shows river flow versus time of day, measured at Lee's Ferry during one week near the beginning of March 2004. The average flow during the week is 13,110 cfs or 371 m³/s. The average flow per day is 1.13 million cubic feet or 32 million m³.

The above plot shows the approximate date in March 2004 versus distance along the river. Some fixed dates and locations are marked. Our average speed between Lee's Ferry and Nankoweap Canyon should be about 11.6 miles or 18.6 km per day. The next stretch to Phantom Ranch should be done at about 10.3 miles or 16.6 km per day. The final stretch to Diamond Creek should be done at about 15.2 miles or 24.5 km per day.

The above plot shows the accumulated Rapids Points versus distance along the river. The number of Rapids Points of a given rapid is equal to the average of the class (scale 0 - 10) of the rapid at low water and at high water.

The last plot shows river elevation versus distance along the river. The average elevation drop is about 7.9 feet per mile or 1.5 m per km.

The following table provides information for 95 named rapids between Lee's Ferry and the Diamond Creek take-out. The information is: the ordinal number, the mile marker, the kilometer marker, the estimated elevation in feet and meters, the class of the rapid at low water and at high water, the cumulative rapids points including the current rapid, the delay (hours:minutes) of river tides relative to Lee's Ferry, the approximate beginning and end times of high water (>14,000 cfs) and the name of the rapid. If the name is followed by a * then a viewing point is defined for the rapid. The lowest tide is about three to four hours before the time listed for the beginning of the high tide. The average speed of the tide is about 4.7 mph or 7.6 km/h.

Plots generated and data calculated by Louis Strous, based on information from "The Colorado River in Grand Canyon: A Guide" by Larry Stevens and from the USGS.