They’re apparently dredging the entire reach of the canal. This came from one of the workers who I ran onto last summer around Swains Lock. Not sure about water levels around Carderock, but everything I’ve seen from Chain Bridge up to Swains has been super low. You can find pockets here and there if you’re willing to walk, but it’s really low.
Interestingly, this hasn’t translated (at least for me) into better carping conditions. I spent a few hours a couple of weeks ago around Chain Bridge and I didn’t see a single fish. Weird, considering the excellent sight fishing conditions.