Water Supply at the Autumnal Equinox

King’s River at Sheep Creek, Autumnal Equinox 2012

Like our ancestors, we like to note key celestial events such as the Autumnal Equinox — the official first day of Fall.  This year we were away from the office, so we couldn’t post anything.  Instead, we were engaged in some serious, first-hand evaluation of the water supply situation here in California.  And we have the photos to prove it!

First, let’s look at the Department of Water Resources graphical summary of reservoir storage:

http://cdec.water.ca.gov/cdecapp/resapp/getResGraphsMain.action

King’s River at Sheep Creek, May 2011

It has been deteriorating for the past year because this has been a particularly dry year.  Overall, the numbers are not terrific, but they are not well below normal levels.  This is due to the spectacular precipitation we had the previous year.

But reservoir storage is only part of the story.  Water is also stored in the form of snow pack and groundwater.  These latter forms are also the sources of flow for surface streams like the South Fork of the King’s River, pictured twice today.

At approximately the same location on this river, contrast the May 2011 levels versus those of this past Autumnal Equinox.  (In case you’re not a Druid, that was last Friday.)  The difference is quite striking; there is far less water present now than a year and a half ago.  That provides us with a good look at the rest of the water supply picture.  And, in short, pray for rain!

2 Responses to Water Supply at the Autumnal Equinox

  1. avatar Cassie says:

    Actually, in the Herndon/Reston area (and probably all of Loudoun County), September 26th is the day when the dyliaght and night time hours are of exactly the same length (6:59 a.m. sunrise, 6:59 p.m. sunset). Sept 22nd is the astronomical equinox, when the sun crosses the equator, but the length of the day depends on where you live on Earth.

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