Use whatever gauge you want to use.

The headworks section right now is using the gauge of the outflow from Howard Hanson, that number is skewed because water is diverted out for city water supply. Right now around 600 cfs is diverted.

484 is the gauge at purification plant which is where most people put in for the headworks, technically that is the number that reflects most of the headworks portion although you can get a pass and put in higher where that 1070 number reflects. Not sure if you can run above the diversion though, I doubt it.

The yo yo is the gauge in auburn 1070. From Kanaskat Palmer, to Auburn you have side tribs, and creeks that come in, Icey, Soos, etc.. Those add 586 cfs right now. Just the creek at Paradise that makes that nice little water fall is probably close to 20 -50 cfs more at high times and then you have plenty of other side creeks and streams along the way. Soos Creek and ICy are the biggest though. Soos is below the yoyo stretch but a better indicator then the upper gorge gauge.

Here is a table of data that might help you make more sense of it.

Green/Duwamish River Basin
12105900	GREEN RIVER BELOW HOWARD A HANSON DAM, WA	---	1,120	6.41	12/03 22:00 PST
12106700	GREEN RIVER AT PURIFICATION PLANT NEAR PALMER, WA	793	484	5.02	01/03 10:00 PST
12108500	NEWAUKUM CREEK NEAR BLACK DIAMOND, WA	72.0	23	1.83	10/15 16:00 PDT
12112600	BIG SOOS CREEK ABOVE HATCHERY NEAR AUBURN, WA	188	210	3.77	01/03 10:15 PST
12113000	GREEN RIVER NEAR AUBURN, WA	1,370	1,070	54.60	01/03 09:45 PST
12113344	GREEN RIVER AT 200TH STREET AT KENT, WA	---	1,190	14.32	01/03 10:00 PST
12113346	SPRINGBROOK CREEK AT ORILLIA, WA	14.0	5.4	13.94	01/03 09:45 PST
12113347	MILL CREEK AT EARTHWORKS PARK AT KENT, WA	5.80	2.2	43.00	01/03 09:45 PST
12113349	MILL CREEK NEAR MOUTH AT ORILLIA, WA	19.0	4.4	15.28	01/03 09:45 PST
12113350	GREEN RIVER AT TUKWILA, WA	---	--	7.14	01/03 10:15 PST

Also worth keeping an eye on the dates of the listed gauge readings...  Note that the 1120cfs you're seeing as the reading from below HHD is not current, and is therefore pretty useless info (unless you're interested in what was being released from HHD back on December 3rd, 2012...)  I've always found the Purification Plant reading the best indicator for gorge and yo yo levels, as that gauge is below the Tacoma diversion and above those creeks that James mentions (of which both Newaukum and Soos are pretty sizable - especially during periods of good rain).  And the Auburn gauge is below those creeks...     

Edited by jalmquist - 04 Jan 2013 at 4:51pm

Wouldn't the purification chart be the best starting point to gauge the gorge at all? If the biggest (metered) inflows are below the Yo-Yo, would it not be safe to make a few educated guesses based on the Auburn minus creek inflow in comparison to post Tacoma withdrawal? Overall, it will only increase in flow as one progresses down the gorge, as is the nature of things. Is my reasoning correct?