Dowd is a much narrower channel than the rest of the Eagle below. It basically is the idea where 1000cfs in the Grand Canyon is nothing, but run 1000cfs down a little creek and it is a lot of water. I haven't done it at the current level, I was driving by the other day thinking that you could probably run it if you wanted. I was also driving by the tail end of the edwards mile thinking it looked like a cobblestone driveway. I think people also don't run the upper and lower Eagle below Dowd at super low levels because there are other rivers nearby running at much better levels.
If you do lots of class III and IV around here, you will run the Eagle while it is good, then maybe start boating in Glenwood after it comes down. Some persistent boaters hit up Dowd even when it is low so they can get a quick run in without driving somewhere else after work. If you are visiting Vail Valley this time of year, and want to go boating, I'd say go check out Shoshone down in Glenwood.