At moderate to high flows, many North Coast rivers – the Noyo, Mattole, Eel, Tri

Question

At moderate to high flows, many North Coast rivers – the Noyo, Mattole, Eel, Trinity, Mad and especially the Klamath – carry vast quantities of clay (making the water look "muddy"), whereas the Smith River is usually very clear.

Why?  Learning goal: To be able to describe both the human-induced component (from upstream agriculture, dams, etc.) and also the natural component (i.e., natural clay production by hydrolysis of feldspars)

Footnote: A picture is worth a thousand words... Here's a photo of the upper Smith River, at moderately high flow, during a driving sleet storm (you can see the sleet coming down) on Mar. 5, 2017 after a VERY wet winter; yet note the clarity of the water:

Explanation / Answer

Before knowing why many north coast rivers carry vast quantities of clay, we have to first learn about the DYNAMICS OF MUD transport. Mud is a mixture of fine grained sediments like clay, silt and sand. Generally clay particles in aquatic environment tend to stick together, thus size, structure and density of mud particles vary dynamically. Accumulation of mud particles on the bottom do generate an open-spaced soil and slowly forms mud-bed. Then the resulting fluid mud can deform under wave action and if there is no barrier, the flow can be driven by gravity.

Now in the case of North coast rivers consider Klamath, at moderate to high flow carry caly particles because of the mud bed at the bottom. But we cannot observe any muddy water in case of low flow. This is very different from Smith river, which is considered as one of the most endangered river in the United States. There are no accumulation of large mud particles at the bottom like as in other rivers. It's free flowing nature and without even a single dam along its entire length makes smith river a jewel. Variety of fish survive in these water conditions. Even though fishing conditions aren't that great and impossibly low, still many enthusiasts fish along smith river. One more interesting fact about smith river is its ability to comeback into shape even after a storm.

But unfortunately some people are trying to perform mining activities and develop nickel mine near smith river(within a national forest). This is not acceptable and not at all fair for a private corporation to harm California's last river. The Smith river is California's Bristol bay.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.