LWD and the Health of the Stream

Every healthy stream in salmon country, especially small ones, are shaped by large logs and branches that fall in the stream. This "large woody debris (LWD)" as it is called, slows down the water, and create pools, riffles, and bends in the course of the stream. Not only are they a source of nutrients, but they create new habitats for the residents of the stream - thereby promoting biodiversity. Lastly, they help slow down the flow of water, which reduces erosion - a story for another day. Today's image shows some of this LWD in my creek - notice the pool that forms downstream compared to the riffles upstream. You can also see a lot of LWD in the video from the previous post.