Running water vs magic

I came to my senses in complete darkness, under a stream of freezing water. My head hurt enough to make the wound on my leg feel pleasant by comparison. My wrists and shoulders hurt even more. My neck felt stiff, and it took me a second to realize that I was vertical, my hands bound together over my head. My feet were tied too. My muscles started jumping and twitching under the cold water and I tried to get out from under it. The ropes prevented me. The cold started cutting into me. It hurt a lot.
I tried to get loose, working my limbs methodically, testing the ropes, trying to free my hands. I couldn't tell if I was making any progress. Thanks to the cold, I couldn't even feel my wrists, and it was too dark to see.
I got more scared by the moment. If I couldn't work my hands free, I might have to risk using magic to scorch the ropes. Hell, I was cold enough that the thought of burning myself had a certain appeal. But when I started trying to reach out for the power to manage it, it slithered away from me. Then I understood. Running water. Running water grounds magical energies, and every time I tried to get something together the water washed it away.

Death Masks Chapter 21, Page 194