Total streamflow across the Mattole River was last observed at 1,925 cfs, and is expected to yield approximately 3,818 acre-ft of water today; about 185% of normal. River levels are high. Average streamflow for this time of year is 1,041 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 1,350 cfs. This is also the highest stage along the Mattole River, with a gauge stage of 14.01 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.