Figure 2. Regulated (Obs) and Unregulated Flows for the Middle Fork Willamette River at Jasper, Oregon. There are three major reservoirs upstream of this location. Note the reduced peaks to limit downstream flooding, increased flows in the spring and summer to meet downstream flow targets, and the seasonal capture (spring) and release of volume (fall) as the pools are brought up from and drawn down to winter levels, respectively. Data prepared by Portland District, USACE.