Rating curve used to calculate discharge is a two part function:
where
Equation 1 is a rating curve developed at the cross section from 2003-2006.
Equation 2 is a historical rating curve developed at the cross section from 1978-79 using the closed vortex/staff gauge by Pete Klingeman.
The Oregon Coast Range and the Oak Creek watershed in particular experience cool, wet winters and warm, dry summers. Mean annual precipitation is approximately 1400 mm falling mainly between October and May. Snow falls at the higher elevations in the watershed.