You could get away with that if you were above the mouth or around cross park. At the mouth you should start with at least a 6 to 8 ounce weight. With the river level right now you will see some guys using 10-16 ounces in that dirty water by Meldrum. Get away from that dirty water and focus on the mouth of the clack and higher. Go bright and use some scent or make sure you tie some sand shrimp on with wonder thread or magic thread. You can do the same with a spin n glo w/yarn and some scent if you find the mouth is busy then try Clackamette between the mouth and the boat ramp, not many snags in there or Cross park. It is just a rocky/sand flat through most of it and that is why I suggest a bobber, just drift on through and move often. Sometimes the fish will push up only to move below where you are fishing.
Your offering should be about 16"-24" above your weight (plunking) with the river depth right now. If you switch to steel fishing, go bobber and start at 3' and work down from there. Just stay close to the bank, fish don't always like that deeper/stronger water in the middle.