Long Term American River Flow Scenarios

[STEELIES/26c3]

These are PROJECTED scenarios based on two POTENTIAL inflow outcomes... from the ARG group which works closely with DWR, BOR and other public and private environmental agencies

ASSUMING AN INFLOW BASED ON 90% OF HISTORICAL AVERAGE:

APR 7,000cfs
MAY 8,500cfs
JUN 6,500cfs
JUL 4,000cfs
AUG 4,000cfs
SEPT 3,300cfs


ASSUMING AN INFLOW BASED ON 50% OF HISTORICAL AVERAGE:

APR 9,500cfs
MAY 8,500cfs
JUN 9,500cfs
JUL 5,000cfs
AUG 5,000cfs
SEPT 4,000cfs

[Sheepdog8404]

Thanks for posting that, Steelies! I'm a little confused on the different blocks though. Both are based on 90% of historical average?

[STEELIES/26c3]

Sorry, I did a cut/paste and forgot to change 90% to 50% for lower table. It has since been corrected.

[Sheepdog8404]

That makes more sense now!

So here's my question, since our snow pack is about 200% of historical average, should we see flows almost twice that of the first block?

[STEELIES/26c3]

To be honest, I don't get how they arrived at those scenarios. The numbers seem reversed to me...
If there is a higher percentage of historical flow (90% vs 50%) shouldn't the numbers (flows by month) be reversed?
The data above suggests that a greater inflow based on percentage of historical average would result in a lower monthly flow in the river.
Often, I find my intuition makes more sense than some science, go figure.

[Jeff C.]

I was thinking the same thing Mark! Things looked like they're reversed. Anyway it looks like you can double the projections Gary. We'll have to wait and see how the flows are actually managed.

[STEELIES/26c3]

It's fairly easy to project week to week once weather patterns stabilize.

The problem in doing so up until now is that we have had runoff in to Folsom based on snow, rain, rain/snow, sun...

Now that the snow looks to be done falling in the Sierras, we will see how the flows in to Folsom Lake fluctuate over a week long period and that should remain fairly uniform. At that point, there will either be a trend upward (my guess) or downward and we will have an idea what flows out of Folsom and on the Lower AR will be.

Right now, the trend is stable to slightly downward as water is coming in to Folsom at 14,223 cfs, going out to Natoma at 15,359 cfs and going out to the American River at Nimbus at 14,911 cfs

The other and more important trend I look at is the level of Lake Folsom over a span of a week to 2 weeks. Folsom Lake's level peaked at 763010 cfs on April 21 and is currently 737414 cfs on April 28 so it is trending downward significantly.

In this upcoming week of uninterupted, constant sunny weather, it will be much easier to determine future trends based on flows and lake level as shown above. And simply going off of general snow melt patterns throughout history... we already know flows will greatly increase as we move in to summer.

Regardless, it is GREAT to have this much water and the fishing will be epic for those who can abandon their old ideas about where and how they like to fish the AR...