Colorado River Basin Storage: Lake Mead and Lake Powell

Some of my first comments on WUWT were in regards to Lake Powell water levels. Even then I understood that to correctly document water levels on the Colorado River Basin, you had to look, as a minimum, at both Mead and Powell. There was a new river operations approach begun in 2005, formalized in 2007, which has had the net effect of slowly increasing the water levels in Lake Powell, but at the expense of Lake Mead. Indeed, there was little change in the river system as a whole from 2005-2010, with combined water storage for the two reservoirs bouncing around 50%. This winter was the first year in the last eight or so with a sustained improvement in storage – although whether that can be maintained is still in question with forecasts of widespread low water flows.

http://www.wcc.nrcs.usda.gov/cgibin/sssf.pl

Pulling together the water volume data for the two reservoirs was slightly tricky. For some reason, I cannot lay my hands on Lake Mead volume data. But I did find an elevation-volume conversion table in a pdf file: Lake Mead Area and Capacity Tables An abbreviated form of table is available as a text file here. Source for the above chart here.

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Note: Lake Mead falls into the Lower Colorado basin from a Bureau of Reclamation management perspective. My mistake in conflating the two basins and have updated portions of this post to reflect that.

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I am watching the most wild, beautiful cloudscape I think I have ever seen. A bank of soft, round cumulus mammatus packed together like melted marshmallows contrasted against the dark green of the Front Range. Floating freely are more normal cumulus cumulonimbus, but so sharply delineated in the light towards the end of the day as to appear other-worldly. A backdrop of strongly blue skies with some intermittent high bands of opaque, streaked cirrus clouds. A wild play of grays and whites, including sharp, well-defined unnatural-appearing linear shadows traced onto the clouds from other clouds further west. And among this varied, evolving geometry of clouds at several distinctly different heights, there is the changing light of sunset – from whites and grays and blues of late afternoon to the oranges and reds of dusk. Wild clouds. Wild colors. Wild winds. Thunder rumbling over the ridge. Lightning flashing in the cloudscape to the east, over the plains.