MATTOLE RIVER

Last Updated: December 20, 2025

Get the latest River Levels, Streamflow, and Hydrology for in River flows across 2 streamgages of the Mattole River


Summary

Total streamflow across the Mattole River was last observed at 3,015 cfs, and is expected to yield approximately 5,980 acre-ft of water today; about 94% of normal. Average streamflow for this time of year is 3,222 cfs, with recent peaks last observed on 2023-03-14 when daily discharge volume was observed at 38,900 cfs.

Maximum discharge along the river is currently at the Mattole R Nr Petrolia Ca reporting a streamflow rate of 9,660 cfs. This is also the highest stage along the Mattole River, with a gauge stage of 18.27 ft at this location. This river is monitored from 2 different streamgauging stations along the Mattole River, the highest being situated at an altitude of 599 ft, the Mattole R Nr Ettersburg Ca.

River Details

Last Updated 2025-12-19
Discharge Volume 5,980 ACRE-FT
Streamflow 3,015.0 cfs
-1835.0 cfs (-37.84%)
Percent of Normal 93.59%
Maximum 38,900.0 cfs
2023-03-14
Seasonal Avg cfs
       
River Streamflow Levels
Streamgauge Streamflow Gauge Stage 24hr Change (%) % Normal Minimum (cfs) Maximum (cfs) Air Temp Elevation
Mattole R Nr Ettersburg Ca
USGS 11468900
3380 cfs 16.1 ft -37.59
Mattole R Nr Petrolia Ca
USGS 11469000
9660 cfs 18.27 ft -37.94
Seasonal Discharge Comparison
Maximum Streamflow Discharge
Streamflow Elevation Profile

Historically, the Mattole Valley was home to the indigenous Mattole people who lived along the river for thousands of years. The river is unique in that it is one of the few undammed rivers left in California, allowing for a relatively natural flow regime. The Mattole River watershed provides critical habitat for threatened and endangered species, including coho and Chinook salmon, steelhead trout, and the Pacific lamprey. There are no major reservoirs or dams on the river, and the water is primarily used for agriculture and recreational purposes such as fishing, swimming, and river rafting.