What exactly is a watershed? When I asked map maker extraordinaire Morgan Hite to make a map of Driftwood Creek’s watershed, he did indeed make a beautiful one. But he first had a few words to say about the concept itself:

Sometimes I like the theoretical abstraction of the watershed, but other times it troubles me. The theoretical bit is this: If you hike up into the mountains, sit down on a convenient rock, and pull out your water bottle, and then you empty that water bottle onto the ground (because you’ve just, perhaps, found a spring of better-tasting water), where will that water go? And the theoretical answer is that it will run downhill, into the nearest creek, and thence down to a river and on to the ocean. It’s kind of like Paddle to the Sea, where the tiny canoe goes from the Ontario uplands to the Atlantic. Everywhere From Which Downhill Leads To Here: that’s a watershed.

The troubling bit is that in reality the water you pour out onto the ground will not run to the nearest creek. It sinks into the soil and disappears. Or, if you are on something impermeable, like solid rock or pavement, it runs out until it is spread thin, and then evaporates. Either way it does not reach the nearest creek. You can try this.

So given that water’s actual behaviour is to mix with buried groundwater, or join the vaporous air, is a watershed even a real thing? If we tried to map it, would we have to include all that underground and all that atmosphere? If the concept is irreproducable by experiment, is it still a valuable idea?

I’m still pondering that. It didn’t prevent me from mapping the watershed though. The theoretical watershed.

(It’s a large file – if you click on it, you’ll see the detail more clearly.)

This is how Morgan went about making the map:

With Driftwood Creek I wanted to make a map that presents the watershed embedded in the larger landscape. It should be apparent that you can drive or walk into and out of the watershed, whether you use trails or roads.

From a 1988 map that Marvin George and Neil Sterritt prepared, called the “Territory of WAH KAH KEG’HT,” I was able to draw a few Wet’suwet’en place names. Spellings have changed in the 29 years since then; Wah Kah Keg’ht, for example, is now usually written Ut’akhgit (a chief of the Likhsilyu/Small Frog clan, a name currently held by Henry Alfred). C’ede’i Kwe (Driftwood Creek) is now written C’ide’ Yïkwah. For consistency, I stuck to the old spellings.

I was surprised to learn that, although Driftwood Creek seems to be simply across the river and up the hill from Smithers, it is in fact farther north. If you went due east from Lake Kathlyn and the airport, you would hit Glenwood Hall, the southernmost point in Driftwood Creek’s watershed.

The width of creeks is exaggerated on the map, because water is the main theme. I show Driftwood Creek as 55 metres across. It’s really only about ten.

I wanted to fade the area outside the watershed, but not to fade as much the roads, trails, contours and creeks. So I used two partially transparent masks: one that fades everything equally, and a second that acts only on the basemap of shaded relief and forest type.

The shaded relief, which gives the map its 3D look, is based on measurements made from the Space Shuttle. One of its missions was to use radar to measure the height and shape of every mountain, ridge, valley and depression it flew over. Bright areas and shadows are based on a (hypothetical) sun in the north-northwest.

Unexpectedly, the Driftwood Creek watershed turns out to look like a puffin. Silverking Lake is the eye, and the place where Driftwood Creek flows into the Bulkley is the tail.

Morgan also created a 3D version of the map that gives a visual sense of not only the distance, but the altitude gained if you were to walk or bike from the Snake Road Bridge crossing into Silverking Basin. Thanks for both of these, Morgan.