TUALATIN − NEAR DILLEY (DLLO3)
   State:  Oregon
   County:  Washington
   Latitude:  45 28' 30" North
   Longitude:  123 7' 23" West
   Elevation:  147 ft

   Supporting NWS Forecast Office: WFO Portland

   
Click for NWS Official River Forecasts for DLLO3
   


   Action Stage:  
16 ft
   Flood Stage:  
17.5 ft
   Moderate Flood Stage:  
18.5 ft
   Major Flood Stage:  
19.5 ft
Daily Historical Statistics for May 31, 2026
Mean Stage: 10.44 ft  Mean Flow: 124 cfs
Max Stage: 12.45 ft  Max Flow: 302 cfs (1960)
Min Stage:  9.31 ft   Min Flow: 55 cfs (1966)

Statistics based on water years: 1940-2024
* statistics estimated based on current rating

Record Stage: 
19.34 ft
Record Flow: 
17100 cfs
Date of Record: 
December 22, 1964

The 4-10 Day Trend Forecast is based on model guidance and uncertainty during this period is greater.

Hydrograph plot for DLLO3

Data Used In Plot   "label   USACE Observations   USACE Map   


Hydrograph plot for DLLO3

Data Used In Plot   "label   ---