Lewis River River Levels

Last Updated: December 4, 2025

The Lewis River is located in southwestern Washington state and stretches 95 miles, originating from the western slopes of Mount Adams.


Summary

Total streamflow across the Lewis River was last observed at 7,318 cfs, and is expected to yield approximately 14,515 acre-ft of water today; about 80% of normal. Average streamflow for this time of year is 9,188 cfs, with recent peaks last observed on 2023-12-06 when daily discharge volume was observed at 40,500 cfs.

Maximum discharge along the river is currently at the Lewis River At Ariel reporting a streamflow rate of 6,460 cfs. This is also the highest stage along the Lewis River, with a gauge stage of 4.71 ft at this location. This river is monitored from 2 different streamgauging stations along the Lewis River, the highest being situated at an altitude of 1,085 ft, the Lewis River Above Muddy River Near Cougar.

River Details

Last Updated 2025-12-04
Discharge Volume 14,515 ACRE-FT
Streamflow 7,318.0 cfs
+2188.0 cfs (+42.65%)
Percent of Normal 79.65%
Maximum 40,500.0 cfs
2023-12-06
Seasonal Avg 9,188 cfs
       
River Streamflow Levels
Streamgauge Streamflow Gauge Stage 24hr Change (%) % Normal Minimum (cfs) Maximum (cfs) Air Temp Elevation
Lewis River Above Muddy River Near Cougar
USGS 14216000
858 cfs 2.24 ft -10.63
Lewis River At Ariel
USGS 14220500
6460 cfs 4.71 ft 54.92
Seasonal Discharge Comparison
Maximum Streamflow Discharge
Streamflow Elevation Profile

The Lewis River is the name of two separate rivers in the South Island of New Zealand. The valley of the better known of these forms the southeastern approach to the Lewis Pass. It is a tributary of the Boyle River.