Streamwood Enhancement

Large wood from fallen trees, logs, root wads, and large branches provides essential habitat for Steelhead and Coho salmon and helps maintain natural stream function. Lack of wood has been identified as a critical threat to the health of our local waterways and fisheries. The wood also increases the overall complexity of the stream channel and provides a host of other benefits such as:  

• More spawning gravels. Slowing the flow of water, especially during high flows, thereby providing pockets of refuge for adult fish to move upstream and for juveniles to rear. This slower water also lets larger sediment like gravel fall out, providing important spawning substrate.
• Formation of pools. During winter storms, wood helps form and maintain pools, which provide cold places for fish to hide from predators during periods of low flow. Endangered Coho salmon are found mostly in pool habitats with lots of large wood.
• Lower water temperature. Helps decrease water temperature by providing shaded areas along streams and creating pockets of cooler water for cold-water loving species.
• Food for fish. Traps organic material like leaves and twigs that provide nutrients for insects and invertebrates (critters without spines), which in turn provide food for fish.
• Reduced erosion. Helps streambanks by preventing erosion of soil along banks.
• Diversity of species. Wildlife such as the red-legged frog and western pond turtle prefer habitats with large wood
• Groundwater recharge. When in the right place, can also improve connectivity to adjacent floodplains, which are important habitats and help recharge local shallow groundwater

There are a lot of misconceptions about wood in streams, with some seeing it as a threat or liability, or even passage barriers for fish. In most cases, large wood in a stream can and should be left alone because of the benefits that it provides to both fish and properties. There are times when stream wood needs to be managed to minimize risks to downstream bridges or culverts. Most fish can swim through, under, or around wood and logjams. Our hope is for the community to understand and appreciate that wood is playing an important role in the health of our streams and provides our communities with important social and ecological benefits.

Unless it’s causing flooding or erosion that threatens life or property, streamwood should be left in place. Steelhead and Coho salmon and their habitat are protected under the Federal Endangered Species Act and State and local laws. To cut up or remove large streamwood requires permission from the California Department of Fish and Wildlife (CDFW). If you are concerned about stream wood on your property and feel modification is necessary, the County of Santa Cruz provides no-cost assessments. Contact Public Works Drainage Division at (831) 477-3999 for assistance. 

The RCD helps to educate the community about the benefits of leaving wood in place. We also work with landowners to design, engineer and construct projects that strategically place and anchor large trees in place, that over time will improve critical stream habit, stabilize streambanks and aggrade over deep channels.

By actively adding wood to streams, we are trying to mimic a process that historically would have happened naturally, when downed trees from mature forests alongside the creek would have occasionally fallen into the stream, creating a more complex habitat. But because there is so much less wood in our streams then there used to be, we are trying to accelerate wood recruitment to provide these benefits and natural processes sooner. 

We have worked with diverse partners to place wood and logjams in numerous streams in the county including Zayante Creek, Soquel Creek, San Vicente and Scotts Creek, and are continually working on identifying future project on both private and public lands.