Creating a New Streambed

The “new” Doan Creek was carefully planned and constructed. Fish biologists and engineers included factors such as natural riparian vegetation, the grade and shape of the channel, and the right conditions for fish in their design.

The restored creek has specifically-placed meanders (bends), pools, vegetation, and riffles to simulate natural stream conditions and create an ideal home for fish, in particular threatened/endangered steelhead and salmon.

Fish and other species need a diversity of habitats in order to find food, shelter, and reproduce. A riffle, which is a section of fast moving water in a shallow portion of the stream, is important for adding air to the water. Riffles are primary locations where aquatic insects congregate and where fish choose to spawn and feed. Pools, sections of deeper, slower-moving water, are important “resting areas” for fish, as they are cooler and more shaded. Pools and riffles must be placed a specific distance apart for optimal function. The meanders and shallow slope of the creek help disperse the energy of the flowing water.

 

This map shows the places where there will be riffles and pools, and where woody debris will be placed. Woody debris provides hiding places for fish, bank stability, shade, and channel diversity. Riffles provide food and channel diversity. Pools provide cover and a resting area.

NPS photo

 

Click here to see a larger version of this map and other maps of the proposed new Doan Creek channel.