Clearest lake

[mcmahon2005]

In your opinion, what lake do u think has the greatest visibilty. The clearest i hav seen would probably Lost Lake near snoqualmie pass. One day in fall the water was maybe 45-50 feet in visibility.

[Anonymous]

Upper Rivord.

[bob pfeifer]

The standard measure in the limnological community is the depth at which a Secchi disk can be seen when lowered from a boat under more or less standardized conditions. Believe it or not, good ol’ Lake Serene on Mount Index has one of the deepest readings I can recall, something like 90 feet.

A Secchi disk is an 8″ or 10″ (I forget which) metal disk with two opposing quarters painted gloss back, the other two pure white. The disk is lowered straight down until it can no longer be seen by the viewer. Particles or bugs in the water scatter light reducing the transparency. Wing Lake has a LOT of soil particles in the water, and its transparency was an inch or two for me a few weeks back. Many of our granite-basin lakes have very little nutrients and sediment input or plankton/algae production, so their water is very clear.

An interesting side note – the deep blue color seen in lakes like Crater Lake in Oregon (Mount Mazama) is caused by absorption of all but the blue range of the light spectrum – this effect is magnified with increasing transparency. Take a look at Boulder Lake in the Sultan Basin to have your socks blown completely off.

OKAY I looked up some data in one of my Excel files. Here are the Secchi depths for a series of lakes to give you some idea of the higher values:

Big Heart 82 ft; Malachite 85; Serene 92; Boulder (Sultan) 62; Angeline 92; Rachel 80; Summit (Pierce Co) 70; Upper Klonaqua 59. The overall mean reading for 246 lakes scattered around the state’s mountains was 18.8 feet, so 80-90 feet is darned clear, relatively speaking. Although Boulder was “only” 62, that lake has a remarkable color, to say the least.

[Vlad Karpinsky]

Bob,

I wonder if you have clarity data on Caroline and Big Granite? Those are two clearest lakes I’ve seen.

[bob pfeifer]

Vlad –

Not sure which Big Granite you mean. Skagit County? The single USGS reading I have from the two larger Granites are around 10 feet – not very clear.

Caroline’s reading was 85 feet. I thought about that lake when I first posted this stuff yesterday – one of my all-time favorite lakes. Not just because it is gorgeous, but because I had some wonderful trips to it.

[attachment=2]1712203L_LakeHigh_1_091784.jpg[/attachment] This shot taken in 1984 from near the top of Preacher Mtn shows the intense blue.

[attachment=1]1712203L_LakeLow_3_091684.jpg[/attachment] This Fall shot shows Gerry Erickson in the lake’s SE corner. His wife Juel soaks up the sun on the rocks by the lake’s edge. A very quick clue to a lake being damned clear – note how the lake edge in the shallow water looks blue even in 5-8 feet of water.

[attachment=0]1712203L_LakeLow_5_080997.jpg[/attachment] In August of 1997 I took my son Eric to the lake and more or less re-created the Gerry photo. You will see that blue edge in many of the super-clear lakes. Big Snow comes to mind….

[Vlad Karpinsky]

@bob pfeifer wrote:

Vlad –

Not sure which Big Granite you mean. Skagit County? The single USGS reading I have from the two larger Granites are around 10 feet – not very clear.

Yes, Big Granite in Skagit County. I’m very surprised it scored only 10 feet, it seems very clear. Here are a few pictures from last year. The second one is taken with waterproof camera while rafting on the lake – I put camera underwater. It is hard to feel scale, but the visibility here is more the 60 feet. Those are some good size trees and boulders on the bottom.

Thanks for the info, Bob.

[bob pfeifer]

Vlad –

Yes, that 10-ft value looked suspicious to me, too. I think they were reporting from one or two of the other Granites in the group. Disregard it.

[Mark Harris]

This is an interesting thread. By any chance do you have a measurement for Lake Elsey above the White River in the Glacier Peak Wilderness? It seemed so very clear and deep to me. I would throw a lure out and let it sink for a very, very long time and then real it up as fast as I could to watch fish swim straight up from the deep.

Mark

[bob pfeifer]

Sorry Mark, I don’t. Most of the Secchi readings I have were gathered by the US Geological Survey, mostly in the 1970s prior to large scale wilderness designations when they could set down on the larger lakes with a helicopter with pontoons and gather data in a hurry. They tended to skip the smaller lakes.

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