They graze very close to the waters edge so it important that the dogs do not come at them to hard or they could spook and fall in the canal. Which as John explains can happen now and again. But the herder is always there to pull them out.
A good herder always keeps an eye on the sheep.
When the dog got to the side as you can see he began to shake and drench his hero's.
Also if you look, just behind the dog shaking is the camera my husband was holding for me. Obviously it got a bit wet, but I was thankful he thought to lay it down before going after the dog or I would have been out one expensive camera. I am glad it survived the incident.