Tuesday, July 5, 2022

Possible Record Low Great Salt Lake

The Great Salt Lake is expected to set a new historical low elevation at the Saltair Boat Harbor this year and provisional data from the USGS suggests it is pretty close to that level right now.

Below is yesterday's MODIS image from NASA's Aqua satellite showing the large area of exposed playa the northern and southern arms of the lake, including the former Farmington Bay immediately adjacent to Antelope Island and the Salt Lake Valley.  

Observations from the USGS at the Saltair Boat Harbor show that the highest lake elevations since 2007 were achieved in 2013 when the lake was near 4199 feet.  Last year, we bottomed out at 4190.4 feet, which is the record low at this site.  The recovery this spring was limited.  


The latest provisional data since June 1 shows the general downward trend with measurements since July 2 near or below 4190.4 feet, the current record. 


Lake-elevation observations are tricky, so the USGS will need to weigh in on whether or not we are "officially" at the record low, but it appears we are close.  With a few months of decline likely to come, we will easily beat that record by the end of fall and may drop down to near 4189 feet.  

A lot of people ask me about the future of the lake.  In the short term, a best-case scenario would be a return to snowier winters that we have generally seen over the past two decades.  Some temporary recovery would be possible if that occurred. On the other hand, shrinkage will continue if we see the drought persist.  Efforts to increase natural flows to the lake will help slow the shrinkage, but in the long term, I suspect aridification due to climate change will make "saving" the Great Salt Lake as we know it very difficult without importing water.  

8 comments:

  1. I recall driving out to Saltair after skiing Snowbird Memorial Day 1985. It was abandoned and partly submerged. I see that the max elevation of 4,211.85 feet was attained in 1986. I also recall that an expensive flood diversion channel was built to prevent the lake from encroaching upon the city. Those were the days!

    As for the current dry period starting in 2011-12, Utah has fared the worst of the 8 ski regions I track, at 83% of long term (~50 years) average. California is at 85%. During those 11 years California has 7 under 80% seasons while Utah has 6. The California drought seasons are generally more severe, but the 12-year average in California is higher because the the two big seasons in 2017 and 2019 were 161% and 143% in California but only 123% and 117% in Utah.

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  2. Does the drop in lake level have anything to do with poor snow years?

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    1. There are several contributors. The lake naturally fluctuates due in large part to year-to-year variations in snowfall, but diversions for human water consumption has reduced lake levels by about 11 feet. Climate change is also exacerbating things by affecting the efficiency of runoff and evaporation from the lake.

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    2. Useful info. The 11 feet is half the decrease from 1986 record high. The same factors (more people, agriculture and evaporation) in California mean more moderate droughts cause as least as much water supply crunch as a sever drought 30 years ago.

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  3. I keep hearing the 11 ft number, but it was calculated several years ago. Is it possible it should now be 12 feet or more?

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    1. I'm not aware of an update. I don't know if it was a one-and-done study or something that can be updated.

      Having a better handle on the water balance of the lake and inflows would be a critical step in any effort to manage lake level.

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  4. Extended GFS MOS paints a rather horrifying picture for the next week, spitting out a high of 106 on Saturday and 110 next Wednesday. Taking that with a grain of salt as usual, but I'm somewhat surprised NWS doesn't have a heat advisory up for at least the northern valleys starting tomorrow.

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  5. Utah state record of 117F was officially tied last year on July 10, per NOAA NCEI https://twitter.com/NOAANCEI/status/1545458786369953792

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