As expected, the AR will begin dropping.
It was hard to predict exactly what DWR would be doing with flows this year in light of the decent snow-pack and near-capacity reservoirs both in low-lying and high-altitude areas...
I extrapolated from the Data Center website and saw that Folsom Lake had a median capacity of 65% in July, going back as far as the 1970's. Yet, with the new spillway and its ability to release more water quickly, there was the potential to keep the lake fuller.
When I saw the snow all melted in mid to late July, I wondered how the lake was still receiving incoming flows of 3000cfs at times. I had forgotten to account for all of the reservoirs which, when full, contribute a significant amount to the level of Folsom Lake. Folsom Lake has been decreasing in volume by 1% every 3rd day or so.
The flows out of Folsom increased to its peak and current exit rate of 5,000 cfs which DWR has maintained throughout the entire month of July. Folsom Lake dropped from 94% to 62% in a matter of 9 weeks.
On May 23, 2018 Folsom Lake level peaked.
05/23/2018 05:00 463.93 ft 953,939 af 610 cfs in 3,372 cfs out
Its current numbers are as follows:
08/01/2018 08:00 431.67 ft 628,669 af 6,615 cfs in 1,237 cfs out
I figured 60% capacity was likely the target 'magic number' for August 1 and DWR just released its tapering flow schedule to support that.
The flows are coming down 500cfs and this should be the beginning of an approach to a maintained flow of 3000cfs-2500cfs on our American River by September if not sooner.
Here's the projected flow
DATE / TIME REL SCH
08/02/2018 21:00 4900 cfs
08/02/2018 22:00 4800 cfs
08/02/2018 23:00 4700 cfs
08/03/2018 00:00 4600 cfs
08/03/2018 01:00 4500 cfs
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