Great Salt Lake Water Watch 2009
Day One - October 1st, 2008
Summary of the 2007 - 2007 Great Salt Lake Water Year
Well, here we are. The beginning of a new water year. Hopefully this new year brings bountiful results compared to the dismal tumbleweed infested desert season that ended the 2008 water year.
Great Salt Lake did not have a good water year. We ended out the year with only 81% of normal. Most of that moisture came in the fall and early winter of 2007/2008. Because we really dried up after that. Since January 1st of this year we have only had 62% normal precipitation to Great Salt Lake. Every monsoonal storm that hit Utah this summer went right around us. Sitting here in my office, watching the radar, it was an amazing thing to watch. Less than a handfull of monsoonal storms actually put any moisture back into the lake.
What is a Water Year
Utah Hydrologists start the new water year at October 1st. and end it September 30th. October 1st is when we begin storing water in the mountains and evaporation becomes a small factor in depleting our storage basin. This is true for Great Salt Lake also. Our evaporation has all but stopped. We are loosing very little water now. Yet the mountains will start retaining our next year runoff in the form of snow.
So lets forget this last water year. It is no longer worth our consideration. Throw it out like the bad trash it is. Good riddance. We can now look forward hopefully to plentiful direct precipitation and a bountiful snowpack.
What Are We Looking For in a Water Year for Great Salt Lake
Great Salt Lake depends on two big factors regarding water: Direct precipitation and Snowpack supply for the river runoffs.
We depend on both equally. Great Salt Lake gets 50% of its water from direct precipitation into the lake. the other 50% comes from the three major rivers; Bear River, Weber/Ogden River and Jordan River. We will be watching both direct precipitation into Great Salt Lake and snowpack for the three drainage basins that feed Great Salt Lake.
A third factor that is critical to Great Salt Lake is evaporation. This is associated with air temperatures above normal and the dryness of the surrounding air. This is a number that has little significance at this point in the year. We will look at this factor more closely starting around May.
So Where Are We Now?
Since today is the beginning of the water year and it is sunny with a lack of rain today, we are basically at zero on all our numbers:
But there is good news to the beginning of this season. We appear to have a juicy Pacific storm barreling down on us right now. The front should be here Saturday evening. And the forecast is not only calling for rain in the valleys, but it is also talking about snow levels dropping down to the 6500 foot level. This would be upper bench level. A good beginning to our water year.
And Now The Numbers - The Report
Lake Level: 4194.1
Trend: Steadying out with little water loss expected for the rest of the season
Current Direct Precipitation: 0
Departure From Normal: 0
Percentage of Normal: 100%
Current Snowpack (GSL Drainage): 0
Departure From Normal 0
Percentage of Normal 100%
Obviously not good nor bad news yet.
And The Forecast
Temperatures: Temperatures are forecasted to be somewhat above normal through December
Precipitation: Precipitation is forecasted to have an equal chance of drier than normal or wetter than normal. Great Salt Lake seems to be well north of the area that is forecasted to be drier than normal. This area is focused around Arizona and New Mexico.
Drought Forecast: The drought that still exists in the upper Bear River Drainage area is expected to persist or intensify through December: All other GSL Drainage areas are out of the drought and there is no development expected.
So right now we are forecasted to have a typical average fall.
My Take On All This
It is now very obvious that the valley floor and ground water reservoirs were very dry after several years of drought. Water coming down from a nearly record snowpack soaked up into the ground and began filling these ground reservoirs. From what I am seeing and have heard, these ground reservoirs are still low. They did not fill up this year. It will take one more year of good to normal runoff before these ground reservoirs begin reaching normal levels. Upper level water storage is in good shape. If we have a normal year, we are still likely to have some problem with full runoff reaching Great Salt Lake. This is normal. Historically it seems Great Salt Lake is about two years behind the mountains. Once the mountains have a really good snowpack we start seeing significant water increases in Great Salt Lake two years later.
And the Bear River is in a world of hurt still. There is no Bear River Bay right now. It is gone. The Bear River is the most significant contributor to Great Salt Lake runoff. It will take at least one good water year to repair this drainage basin.
This means we really need a lot of direct precipitation in the lake to make up for a runoff that still won't be at normal levels next year.
Or we could have a great snowpack and then a really hot March. This will get the water down here fast before the ground thaws out and allows it to be soaked up. This is exactly what happened the two previous years and why we came up those years. We got the water before the upper elevations and valleys could soak it up.
This is my take . . . . . But, then again, what do I know. I'm just winging it.
Dave Shearer
Harbormaster
Great Salt Lake Marina
Have you checked your docklines lately?
