COLUMBIA − BLO ROCK ISLAND DAM
(
RISW1
)
State:
Washington
County:
Douglas
Latitude:
47 19' 57" North
Longitude:
120 4' 48" West
Elevation:
609 ft
Supporting NWS Forecast Office:
WFO Spokane
Click for NWS Official River Forecasts for RISW1
Daily Historical Statistics for March 19, 2026
Mean Flow:
98600 cfs
Max Flow:
221000 cfs (1983)
Min Flow:
40800 cfs (1989)
Statistics based on water years:
1962-2025
* statistics estimated based on current rating
The 4-10 Day Trend Forecast is based on model guidance and uncertainty during this period is greater.
Data Used In Plot
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Data Used In Plot
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Data Used In Plot
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Data Used In Plot
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RISW1
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