Do you mean 100 ft a day per stem, or in total? I know of a few spp that can, under ideal conditions put about a foot a day on some of their growing tips.

If it is either of these two,
himalayan Balsam
japanese knotweed.
you have work to do right now. The links indentify them, and tell you how to deal with them. Follow their advice to the letter. If it says use herbicides, then do so. Do not worry about any potential damage to the ecosystem from the hebicides. Unless you get rid of these highly invasive species, there won't be an ecosystem left. They're introduced spp, and so nothing in europe or america really uses them for food or habitat, and as they have no controls, they out-compete native plants, and spread, and carry on spreading. This is bad news.