Commonwealth Lake Park is your typical urban duck pond nestled in the Portland suburb of Beaverton. Such parks are certainly not the places to go if you seek a wilderness experience, but they can be excellent places to study waterfowl up close. They also serve as a quick and easy birding fix when “life” prevents you from getting out in the field as much as you should.
Species that are normally rather shy, like this Pied-billed Grebe, will often allow a close approach is parks such as this.
American Coots, common and often dismissed by birders, are quite lovely when you get close enough.
Gadwall
male Common Merganser, with what I think is a Yellow Bullhead
female Common Merganser
Greater White-fronted Geese are common migrants over the Portland area, but uncommon winter residents. Four have been spending the winter at Commonwealth.
Since the remodeling of Portland’s Westmoreland Park a couple of years ago, there really hasn’t been a good spot to easily study gulls in the Portland area. This adult Ring-billed Gull was a cooperative model.
This Ring-billed Gull is in his second plumage cycle.
So while I would much rather walk for several miles in a natural setting to find birds, I am grateful for little urban parks like Commonwealth.
Ethical Birder 
I don’t know how you did it, but you did make that coot look “lovely.” I found a new (to me) gull spot near my house! It would be far for you but I had Western, Thayer’s, Ring-billed, Glaucous-winged, and Herring all in the mix. Unfortunately it’s going to be developed into a real park/urban plaza thing soon. If you’re out in NE Portland check it out, a block south of NE 106th and Halsey.