You're way ahead of me. :)
I was working on this chart before being interrupted by a Kentucky Derby get together.
I wanted to see when there was low precipitation and high lake levels, and when there was high precipitation and low lake levels. In other words, does the occurrence and size of the green area correlate with precipitation or with raised lake elevation.
Aside from a few spikes in precipitation, between April 2011 and November 2014 there was persistently high lake levels and relatively low precipitation. This is particularly true between January 2013 and January 2014 when there was a drought and high lake levels.
It would be very interesting to examine the status of the green area during this period.
Hi Ray76, There may be an odd plot discrepancy on the linear X axis reservoir levels in your graph - OR - the DSOD reference data is somehow off. I'm using CA Division of Safety of Dams (DSOD) report data. They read the reservoir levels personally at station gauges for DSOD report purposes. Since they are using fractions of a foot, it infers they have access to a precision gauge.
I've been only able to reference two points so far. The first point -in 2015- seems to be shifted by 14 to 15 days in order to match your plots with the DSOD reservoir level to intersect equal elevations. The second point -in 2016- is pretty much in agreement.
Using DSOD data the reservoir was at 723.0 ft on 2/3/2015. Your Plot has it at/near 748 ft. (delta near 25 ft).
Second reference point, DSOD data, the reservoir was at 778.8 ft on 8/22/2016. Your Plot is pretty much accurate at that date (estimated at 775 ft on your plot slope).
I'll try to get other DSOD data to compare against (you have to dig to find these tidbits in reports).