By Cindy Tanaka:
Lagunitas Creek is a home for many species of salmon and for a rare species of shrimp. In the past, the morphology of the creek was changed due to agriculture to increase the farmland area. Not only was the morphology changed but there was a dam installed further upstream that controls the velocity of the water flow. When a large storm brings an abundance of water, the flow of the stream has a high velocity since the river is straight and lacks debris. The young salmon living in the shallows of the stream stand no chance against rushing water – young fish are swept down the river and do not survive. The dam also prevented a build up of sediment from settling at the bottom of the river. This area was in need of help from people who had tempered with Mother Nature upstream. People who would contribute to helping the creek include the Department of Fish and Wildlife, and Trout Unlimited.
The restoration project we visited worked to increase habitat in the stream by placing logs into the stream. The logs – native redwood trees from around the area – decrease the water flow and provide aquatic species a place to rest or hide. Most importantly the logs prevent young salmon from being washed away in a storm. The logs also provided the lakebed with nutrients by creating flood plains when there is an abundance of water. To prevent the logs from being carried away by the river, rods and boulders anchored them to the lakebed. While installing the debris, the restoration workers were careful to not harm the species they were trying to help.
They also made new channels in retired farming fields where the river used to flow. The goal of the restoration project was to increase the amount of flood plains in the area, and to do this, they planted native vegetation such as willows in the new channels. The cost of the project was only $40,000 across 8 sites, however there was also a lot of time and effort that went into the project, including the work involved in filing paperwork and applying for permits.
Overall, the restoration project in Lagunitas Creek seems to be successful and in the hands of smart, capable people.
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