Phat,When I was down in NZ, crossing rivers was par for the course and it did take some attention. The water was often glacier melt and just above freezing. This was before I had trekking poles and one time I did fall over, straight forward onto my hands and knees. Fortunately, the water wasn't very deep and I was able to stand back up without being hurt.

One thing I learned-never take your boots off. After crossing, just wring out the water in your socks (wool or Capilene in my case), pour it out of your boots, put them all back on and keep walking. After a short while, the socks would be dry.

Also, undo the waistband on your pack and loosen the straps a bit- a precaution if you go over and have to ditch your pack. Don't forget to undo the chest strap if you have one.