Total streamflow across the Mattole River was last observed at 5,680 cfs, and is expected to yield approximately 11,266 acre-ft of water today; about 142% of normal. River levels are high. Average streamflow for this time of year is 3,990 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 4,060 cfs. This is also the highest stage along the Mattole River, with a gauge stage of 15.17 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.