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Hydrologic Conditions: Colorado River Basin, April-May 2016

Current Conditions

Mead currrent conditions (05-2016)_WEB

Lake Mead: Lake Mead’s current elevation is now 1.89 feet below the elevation of Lake Mead in May 2015 and 89.14 feet below the historical May elevation of Lake Mead.


Powell currrent conditions (05-2016)_WEB

Lake Powell: Lake Powell’s current elevation is now 1.15 feet below the elevation of Lake Powell in May 2015 and 27.32 feet below the historical May elevation of Lake Powell.


24-Month Study

Mead 24-Month (May-16)_WEB

Lake Mead: The May 2016 24-Month Study projects that Lake Mead’s January 2017 elevation will be 1,079.60 feet, or 4.6 feet above the trigger elevation for a declaration of a shortage condition for 2017. The April 2016 24-Month Study projected an elevation of 1,079.84 feet. The May 2016 forecasts for Lake Mead elevations through December 2016 are slightly above the levels forecasted in April. Then they generally fall slightly below the April forecasts.

Actual Lake Mead elevations in 2013 through early 2014 followed projections from the January 2013 study, when actual elevations plummeted generally in tandem with the projections from the August 2013 study. The August 2014 study projected a slight increase in Lake Mead elevations which was slightly below actual elevations. With a recent rebound in inflows, the forecasts prepared last summer are above the August 2014 forecast.

The August 2015 study forecasts that Lake Mead elevations will fall below the trigger for shortages in late spring 2016 but rebound towards the trigger for January 2017. The May 2016 projections are slightly above the August 2015 projections. Right now, the prospect for a shortage declaration in 2017 for the Colorado River Basin sits on a “knife edge.”

The continuing trend of progressively lower “highs” in successive winter elevations and lower “lows” in successive summer elevations belies a continuing downward trend in Lake Mead elevations. 2017 is looking like the first time shortages may be triggered in the Lower Basin.

Powell 24-Month (May-16)_WEB

Lake Powell: The May 2016 24-Month Study continues with a projected upward trend in Lake Powell elevations, although the projected elevation is below the projections from the April 2016 24-Month Study. Actual Lake Powell elevations in 2013 were generally running below forecasted levels in January 2013, but above the levels projected in the August 2013 study. Actual elevations have generally tracked the projections in the August 2014 study. The August 2015 study projected elevations above the August 2014 study.  The May 2016 projected elevations are running slightly below the August 2015 study projections.

The trend of progressively higher “highs” in successive June elevations and higher “lows” in successive March elevations continues. When will Powell elevations reach their peak?

Monthly Elevations

  Mead history (05-2016)_WEB

Lake Mead: Monthly elevations in 2016 are lower than in 2015 and have dropped from about 80 feet below historical average monthly elevations to nearly 90 feet below historical average monthly elevations.


Powell history (05-2016)_WEB

Lake Powell: Monthly elevations, which were higher in 2016 than 2015 from January through April, have fallen below the 2015 levels, but remain about 30 feet below historical monthly average elevations.