Total streamflow across the Umatilla River was last observed at 520 cfs, and is expected to yield approximately 1,031 acre-ft of water today; about 91% of normal. Average streamflow for this time of year is 569 cfs, with recent peaks last observed on 2019-04-10 when daily discharge volume was observed at 23,710 cfs.

Maximum discharge along the river is currently at the Umatilla River Near Umatilla reporting a streamflow rate of 222 cfs. However, the streamgauge with the highest stage along the river is the Umatilla R At W Reservation Bndy Nr Pendleton with a gauge stage of 3.64 ft. This river is monitored from 3 different streamgauging stations along the Umatilla River, the highest being situated at an altitude of 1,871 ft, the Umatilla River Above Meacham Creek.

The Umatilla River is a tributary of the Columbia River, located in northeastern Oregon. The river was historically home to the Umatilla Native American tribe, who fished and hunted along the river. The river runs for 89 miles, beginning in the Blue Mountains and flowing through the Umatilla National Forest. The river's hydrology has been impacted by the construction of several dams, including the McKay and Wildhorse Reservoirs. These dams provide irrigation water for agriculture and hydroelectric power. The river is also used for recreational activities such as fishing, boating, and camping. The Umatilla River supports populations of Chinook salmon, steelhead, and other fish species. Agricultural uses include the growing of wheat, hay, and fruit trees.