The Walker is normally running at 152 cfs on this date, and today it is at 39 cfs. Here is the link to current flow rate on the Walker:
I was up there two weeks ago or so when it was running about 60 cfs, and it was already getting pretty low. I don't think you will have much trouble crossing.
The bridge I know about is a couple hundred yards downstream from the Leavitt Meadows trailhead/parking lot. There may be additional bridges upstream, but others will have to chime in for that info.
Have a good trip!