WS 5/29/2011 at 0001 hr is 1.15 ft above DOT WP9 S9571 or 263.21 ft while the Colville Stage was 58.23
Elev of WP9 S9571 is 262.06 ft (orthometric height in ft Geoid 06) 

Colville peaked on 5/29 at 2045 hr at 59.05 ft about  .8 ft higher which would calculate a 
maximum peak of 264.0 ft at WP9 S9571

Correction from USGS River stage to true elevation is +207.03 ft


5/29            0001 hr       2045 hr Peak
DOT WP9 S9571   263.21        264.00 ft
USGS GAGE        58.23         59.05 stage
USGS GAGE       265.26        266.08 ft

flow passes by gage and begins flowing over landfill is  53.5 stage or 260.0 ft elev

There will be approximately 1 ft of water over landfill for each ft of river stage over 53.5 ft (or 260 ft elev)

from USGS rating No.3 (should verify with USGS)

stage  discharge
(ft)   (cfs)
58.5 270,000 
57.5 180,000 
56.5 140,000 
55.5 110,000 
54.5  90,000
53.5  75,000 begin flow over landfill