November 06, 2024

Update on Reservoir Levels

As we start the winter wet season, it is a good idea to check the reservoir levels in the western U.S.  How is our water supply doing before the big precipitation events?

In California, which has enormous water needs for a huge population and massive agriculture, the reservoirs are now in good shape, with water levels generally at or above normal. The substantial precipitation and great snowpack of last winter deserve the credit.

What about here in Seattle?  The statistics on November 4 indicate near-normal water storage and typical water consumption.  Recent rains have helped a lot.  Seattle has no water issues.

But all is not rosy in water land.    The Yakima reservoir system east of the central WA Cascades is very low, as it was last year (see below).  The key reason for the low water levels is probably the back-to-back El Nino years, which generally result in poor Cascade snowpack...an essential for feeding the eastside reservoirs.

With La Nina this year, we will probably see enhanced snowpack and far better reservoir levels next summer.   

Furthermore, the forecast total precipitation for the next ten days is very large, with substantial rain east of the Cascade crest.


Ff you really want to be impressed, check out the forecast snow totals for the same period.  Several feet in the Cascades and even more for the mountains of southwest BC.


I suspect talk of drought, low streamflow, and reservoirs needing refilling will be ending during the next month.




4 comments:

  1. I am a gardener in the lower Puget sound and was wondering when we could expect our first hard freeze of the year. Thanks.

    ReplyDelete
    Replies
    1. My guess--no frost on the pumpkin, means hardly any snow this winter...but maybe more rain than usual.

      Delete
  2. When did we have back to back El NiƱo years?

    ReplyDelete
  3. https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php

    ReplyDelete

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