I guess that headline could be taken two ways. Drinking water is always good for a water-based organism. But the water I'm referring to here is the kind that you move through: in a swimming pool, lake or ocean.
I'm thinking about water therapy because my wife (who has a bad knee and has put on some weight) just joined a gym. I get my workout on a bike trainer in the basement; she will now go to the pool.
This was her first day. As she was preparing to leave, I shared my usual warning, "Be careful not to overdo it," while feeling quite certain that she would. She got back and said she felt some discomfort in her knee. I'm pretty sure she did overdo it, but I've got my fingers crossed that she didn't go way overboard.
Tomorrow will tell.
Still, I think returning to the water (she likes to swim) will be a good thing for her, and her knee. I tried to get her to ride a spare exercise bike in the basement. She never took much pleasure from that, and I think it was a bit irritating for her knee joint, even though I told her to keep the tension low.
She's definitely more excited about swimming.
I think water activities are great for bad knees, though you still have to be careful. Originally, I thought water would play a much bigger role in my recovery than it did. Probably it didn't because (1) I'm not really a water guy; I never learned how to swim and tend to stand around shivering in the pool (2) The water activities that I could do without aggravating my knees weren't that interesting to me.
In the end, I went the walking route, and as I say in the book, many weeks later I climbed out of the knee pain hole.
But anyone with access to a pool who has knee pain, and who enjoys water, should definitely try a program of water exercises. Linda Huey has some in the book she co-authored, Heal Your Knees, which is available on Amazon.
The buoyancy of water is like having a magic immersion machine that unloads your joints in space. If you're in the water up to your chest, no matter which way you turn, bend, step, jump, you're getting the benefits.
If you prefer to swim, consider wearing floats on your ankles (those same floats that are designed to be worn on the arms), until you're sure that the kicking motion doesn't worsen your knee pain. I used them myself with some success.
Make a splash! Good luck!