Identification: Is This Water Hemlock or Other Toxic Plant?

Can you identify this plant? It's early spring (mid-February near Duck Lake, Powell River area) so only the roots and a single early shoot is visible. I found many of these plants in a small creek and in the marshy edges of the creek. The white, reddish- brown, and ridged roots are very long, ropey, and deep (the ends are cut off in the photos). They may be 1-2 feet long or more and range from very thin to about 1/4-3/8 inches wide. They spread deeply and widely into the muck and into the running water.

One of the attached photos is a collection of root pieces that floated downstream. When cut vertically, the stem base (maybe root top) is not chambered, but seems solid and pulpy. I have not smelled the plant. I filter water from this creek and am concerned the roots I cut may be leaking toxins into my water source. I do not plan to eat the plant.
Someone thought it was skunk cabbage.

 

It definitely resembles skunk cabbage (swamp lantern) : Celebrating Skunk Cabbage

Water hemlock should be more carrot-like, and have air chambers within it: Poison hemlock and Western waterhemlock: deadly plants that may be growing in your pasture

 

Thank you, Daniel! You have confirmed what I believed true but was nervous to trust my own swamp cabbage inexperience.